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Sample records for fan stage part

  1. Results of an Advanced Fan Stage Operating Over a Wide Range of Speed and Bypass Ratio. Part 1; Fan Stage Design and Experimental Results

    Science.gov (United States)

    Suder, Kenneth L.; Prahst, Patricia S.; Thorp, Scott A.

    2011-01-01

    NASA s Fundamental Aeronautics Program is investigating turbine-based combined cycle (TBCC) propulsion systems for access to space because it provides the potential for aircraft-like, space-launch operations that may significantly reduce launch costs and improve safety. To this end, National Aeronautics and Space Administration (NASA) and General Electric (GE) teamed to design a Mach 4 variable cycle turbofan/ramjet engine for access to space. To enable the wide operating range of a Mach 4+ variable cycle turbofan ramjet required the development of a unique fan stage design capable of multi-point operation to accommodate variations in bypass ratio (10 ), fan speed (7 ), inlet mass flow (3.5 ), inlet pressure (8 ), and inlet temperature (3 ). In this paper, NASA has set out to characterize a TBCC engine fan stage aerodynamic performance and stability limits over a wide operating range including power-on and hypersonic-unique "windmill" operation. Herein, we will present the fan stage design, and the experimental test results of the fan stage operating from 15 to 100 percent corrected design speed. Whereas, in the companion paper, we will provide an assessment of NASA s APNASA code s ability to predict the fan stage performance and operability over a wide range of speed and bypass ratio.

  2. High-Tip-Speed, Low-Loading Transonic Fan Stage. Part 1: Aerodynamic and Mechanical Design

    Science.gov (United States)

    Wright, L. C.; Vitale, N. G.; Ware, T. C.; Erwin, J. R.

    1973-01-01

    A high-tip-speed, low-loading transonic fan stage was designed to deliver an overall pressure ratio of 1.5 with an adiabatic efficiency of 86 percent. The design flow per unit annulus area is 42.0 pounds per square foot. The fan features a hub/tip ratio of 0.46, a tip diameter of 28.74 in. and operates at a design tip speed of 1600 fps. For these design conditions, the rotor blade tip region operates with supersonic inlet and supersonic discharge relative velocities. A sophisticated quasi-three-dimensional characteristic section design procedure was used for the all-supersonic sections and the inlet of the midspan transonic sections. For regions where the relative outlet velocities are supersonic, the blade operates with weak oblique shocks only.

  3. Results of an Advanced Fan Stage Operating Over a Wide Range of Speed and Bypass Ratio. Part 2; Comparison of CFD and Experimental Results

    Science.gov (United States)

    Celestina, Mark L.; Suder, Kenneth L.; Kulkarni, Sameer

    2010-01-01

    NASA and GE teamed to design and build a 57 percent engine scaled fan stage for a Mach 4 variable cycle turbofan/ramjet engine for access to space with multipoint operations. This fan stage was tested in NASA's transonic compressor facility. The objectives of this test were to assess the aerodynamic and aero mechanic performance and operability characteristics of the fan stage over the entire range of engine operation including: 1) sea level static take-off; 2) transition over large swings in fan bypass ratio; 3) transition from turbofan to ramjet; and 4) fan wind-milling operation at high Mach flight conditions. This paper will focus on an assessment of APNASA, a multistage turbomachinery analysis code developed by NASA, to predict the fan stage performance and operability over a wide range of speeds (37 to 100 percent) and bypass ratios.

  4. Design of a Low Speed Fan Stage for Noise Suppression

    Science.gov (United States)

    Dalton, W. N.; Elliot, D. B.; Nickols, K. L.

    1999-01-01

    This report describes the design of a low tip speed, moderate pressure rise fan stage for demonstration of noise reduction concepts. The fan rotor is a fixed-pitch configuration delivering a design pressure ratio of 1.378 at a specific flow of 43.1 lbm/sec/sq ft. Four exit stator configurations were provided to demonstrate the effectiveness of circumferential and axial sweep in reducing rotor-stator interaction tone noise. The fan stage design was combined with an axisymmetric inlet, conical convergent nozzle, and nacelle to form a powered fan-nacelle subscale model. This model has a 22-inch cylindrical flow path and employs a rotor with a 0.30 hub-to-tip radius ratio. The design is fully compatible with an existing NASA force balance and rig drive system. The stage aerodynamic and structural design is described in detail. Three-dimensional (3-D) computational fluid dynamics (CFD) tools were used to define optimum airfoil sections for both the rotor and stators. A fan noise predictive system developed by Pratt & Whitney under contract to NASA was used to determine the acoustic characteristics of the various stator configurations. Parameters varied included rotor-to-stator spacing and vane leading edge sweep. The structural analysis of the rotor and stator are described herein. An integral blade and disk configuration was selected for the rotor. Analysis confirmed adequate low cycle fatigue life, vibratory endurance strength, and aeroelastic suitability. A unique load carrying stator arrangement was selected to minimize generation of tonal noise due to sources other than rotor-stator interaction. Analysis of all static structural components demonstrated adequate strength, fatigue life, and vibratory characteristics.

  5. Experimental Investigation of a High Pressure Ratio Aspirated Fan Stage

    Science.gov (United States)

    Merchant, Ali; Kerrebrock, Jack L.; Adamczyk, John J.; Braunscheidel, Edward

    2004-01-01

    The experimental investigation of an aspirated fan stage designed to achieve a pressure ratio of 3.4:1 at 1500 ft/sec is presented in this paper. The low-energy viscous flow is aspirated from diffusion-limiting locations on the blades and flowpath surfaces of the stage, enabling a very high pressure ratio to be achieved in a single stage. The fan stage performance was mapped at various operating speeds from choke to stall in a compressor facility at fully simulated engine conditions. The experimentally determined stage performance, in terms of pressure ratio and corresponding inlet mass flow rate, was found to be in good agreement with the three-dimensional viscous computational prediction, and in turn close to the design intent. Stage pressure ratios exceeding 3:1 were achieved at design speed, with an aspiration flow fraction of 3.5 percent of the stage inlet mass flow. The experimental performance of the stage at various operating conditions, including detailed flowfield measurements, are presented and discussed in the context of the computational analyses. The sensitivity of the stage performance and operability to reduced aspiration flow rates at design and off design conditions are also discussed.

  6. Two-Stage Fan I: Aerodynamic and Mechanical Design

    Science.gov (United States)

    Messenger, H. E.; Kennedy, E. E.

    1972-01-01

    A two-stage, highly-loaded fan was designed to deliver an overall pressure ratio of 2.8 with an adiabatic efficiency of 83.9 percent. At the first rotor inlet, design flow per unit annulus area is 42 lbm/sec/sq ft (205 kg/sec/sq m), hub/tip ratio is 0.4 with a tip diameter of 31 inches (0.787 m), and design tip speed is 1450 ft/sec (441.96 m/sec). Other features include use of multiple-circular-arc airfoils, resettable stators, and split casings over the rotor tip sections for casing treatment tests.

  7. Hot Runner Mold Design of Fan Diverter Parts

    Science.gov (United States)

    Juan, D. J.; Cheng, Y. L.

    2017-09-01

    In this study, we discuss the case of plastic parts for the production of fan steering gear shaft parts injection molding, and use POM plastic steel to produce plastic parts from traditional cold runners. Because of the parts have a hole, which need side slide. The runner produce more waste after plastic parts injection make the runner waste account for the cost is relatively high, the cost of stock preparation is relatively increased when the product quantity demanded is great. After the crushing treatment of the waste, the backfill will affect the quality, and in the crushing process, the volume generated will make the operator to withstand up to 130 dB of noise. The actual test results show that the production cycle reduce 6.25%, while the production yield increase by about 5% and material costs reduced by 2% . It can be recovered within a year, not to mention the increase of the quality and reduction the noise on the staff of the benefit is impossible to estimate.

  8. Investigation of modification design of the fan stage in axial compressor

    Science.gov (United States)

    Zhou, Xun; Yan, Peigang; Han, Wanjin

    2010-04-01

    The S2 flow path design method of the transonic compressor is used to design the one stage fan in order to replace the original designed blade cascade which has two-stage transonic fan rotors. In the modification design, the camber line is parameterized by a quartic polynomial curve and the thickness distribution of the blade profile is controlled by the double-thrice polynomial. Therefore, the inlet flow has been pre-compressed and the location and intensity of the shock wave at supersonic area have been controlled in order to let the new blade profiles have better aerodynamic performance. The computational results show that the new single stage fan rotor increases the efficiency by two percent at the design condition and the total pressure ratio is slightly higher than that of the original design. At the same time, it also meets the mass flow rate and the geometrical size requirements for the modification design.

  9. Application of a Two-dimensional Unsteady Viscous Analysis Code to a Supersonic Throughflow Fan Stage

    Science.gov (United States)

    Steinke, Ronald J.

    1989-01-01

    The Rai ROTOR1 code for two-dimensional, unsteady viscous flow analysis was applied to a supersonic throughflow fan stage design. The axial Mach number for this fan design increases from 2.0 at the inlet to 2.9 at the outlet. The Rai code uses overlapped O- and H-grids that are appropriately packed. The Rai code was run on a Cray XMP computer; then data postprocessing and graphics were performed to obtain detailed insight into the stage flow. The large rotor wakes uniformly traversed the rotor-stator interface and dispersed as they passed through the stator passage. Only weak blade shock losses were computerd, which supports the design goals. High viscous effects caused large blade wakes and a low fan efficiency. Rai code flow predictions were essentially steady for the rotor, and they compared well with Chima rotor viscous code predictions based on a C-grid of similar density.

  10. Application of high-turning bowed compressor stator to redesign of highly loaded fan stage

    Institute of Scientific and Technical Information of China (English)

    Shaobin LI; Jiexian SU; Zhongqi WANG

    2008-01-01

    A redesign of a highly loaded fan stage by using high-turning bowed compressor stator was conducted. The original tandem stator was replaced by the highly loaded bowed stator which was applicable to highly sub-sonic flow conditions. 3D contouring technique and local modification of blade were applied to the design of the bowed blade in order to improve the aerodynamic per-formance and the matching of the rotor and stator blade rows. Performance curves at different rotating speeds and performances at different operating points for both the original fan stage and redesigned fan stage were obtained by numerical simulations. The results show that the highly loaded bowed stator can be used not only to improve the structure and the aerodynamic performances at various operating points of the compressor stage but also to pro-vide high performances at off-design conditions. It is believed that the highly loaded bowed stator can advance the design of high-performance compressor.

  11. Performance of a low-pressure fan stage with reverse flow

    Science.gov (United States)

    Moore, R. D.; Lewis, G. W., Jr.; Tysl, E. R.

    1976-01-01

    The reverse flow aerodynamic performance of a 51-centimeter-diameter fan stage is presented. The stage was tested with the variable pitch rotor blades set through feather at -75 deg, -80 deg, and -85 deg from design setting angle. Of the three tested the stage with the rotor blades set at -75 deg exhibited the highest pressure ratio and highest flow. For all three configurations, there was little or no flow in the inner third of the exit passage due to the rotor blade being almost perpendicular to the axial direction in the hub region.

  12. LES Investigation of Wake Development in a Transonic Fan Stage for Aeroacoustic Analysis

    Science.gov (United States)

    Hah, Chunill; Romeo, Michael

    2017-01-01

    Detailed development of the rotor wake and its interaction with the stator are investigated with a large eddy simulation (LES). Typical steady and unsteady Navier-Stokes approaches (RANS and URANS) do not calculate wake development accurately and do not provide all the necessary information for an aeroacoustic analysis. It is generally believed that higher fidelity analysis tools are required for an aeroacoustic investigation of transonic fan stages.

  13. Performance of a highly loaded two stage axial-flow fan

    Science.gov (United States)

    Ruggeri, R. S.; Benser, W. A.

    1974-01-01

    A two-stage axial-flow fan with a tip speed of 1450 ft/sec (442 m/sec) and an overall pressure ratio of 2.8 was designed, built, and tested. At design speed and pressure ratio, the measured flow matched the design value of 184.2 lbm/sec (83.55kg/sec). The adiabatic efficiency at the design operating point was 85.7 percent. The stall margin at design speed was 10 percent. A first-bending-mode flutter of the second-stage rotor blades was encountered near stall at speeds between 77 and 93 percent of design, and also at high pressure ratios at speeds above 105 percent of design. A 5 deg closed reset of the first-stage stator eliminated second-stage flutter for all but a narrow speed range near 90 percent of design.

  14. End-wall boundary layer measurements in a two-stage fan

    Science.gov (United States)

    Ball, C. L.; Reid, L.; Schmidt, J. F.

    1983-01-01

    Detailed flow measurements made in the casing boundary layer of a two-stage transonic fan are summarized. These measurements were taken at stations upstream of the fan, between all blade rows, and downstream of the last blade row. At the design tip speed of 429 m/sec the fan achieved a peak efficiency of 0.846 at a pressure ratio of 2.471. The boundary layer data were obtained at three weight flows at the design speed: one near choke flow, one near peak efficiency, and one near stall. Conventional boundary layer parameters were calculated from the data measured at each measuring station for each of the three flows. A classical two dimensional casing boundary layer was measured at the fan inlet and extended inward to approximately 15 percent of span. A highly three dimensional boundary layer was measured at the exit of each blade row and extended inward to approximately 10 percent of span. The steep radial gradient of axial velocity noted at the exit of the rotors was reduced substantially as the flow passed through the stators. This reduced gradient is attributed to flow mixing. The amount of flow mixing was reflected in the radial redistribution of total temperature as the flow passed through the stators. The data also show overturning of the tip flow at the stator exits that is consistent with the expected effect of the secondary flow field. The blockage factors calculated from the measured data show an increase in blockage across the rotors and a decrease across the stators.

  15. Investigations on an Axial Flow Fan Stage subjected to Circumferential Inlet Flow Distortion and Swirl

    Institute of Scientific and Technical Information of China (English)

    M.Govardhan; K.Viswanath

    1997-01-01

    The combined effects of swirl and circumferential inlet flow distortion on the flow field of an axial flow fan stage are reported in this paper,The study involves measurements at the inlet of the rotor and exit of the rotor and stator atdesign and off design flow conditions.The study indicated that at the design flow condition,swirl had caused deterioration of the performance in addition to that caused by distortion.Pressure rise imparted in the distortion zone is hogher than in the free zone.The attenuation of distortion is high in the presence of swirl.

  16. Aerodynamic and acoustic effects of eliminating core swirl from a full scale 1.6 stage pressure ratio fan (QF-5A)

    Science.gov (United States)

    Woodward, R. P.; Acker, L. W.; Stakolich, E. G.

    1978-01-01

    Fan QF-5A was a modification of fan QF-5 which had an additional core stator and adjusted support struts to turn the core exit flow from a 30 deg swirl to the axial direction. This modification was necessary to eliminate the impingement of the swirling core flow on the axial support pylon of the NASA-Lewis Quiet Fan Facility that caused aerodynamic, acoustic and structural problems with the original fan stage at fan speeds greater than 85 percent of design. The redesigned fan QF-5A did obtain the design bypass ratio with an increased core airflow suggesting that the flow problem was resolved. Acoustically, the redesigned stage showed a low frequency broadband noise reduction compared to the results for fan QF-5 at similar operating conditions.

  17. Rotor tip clearance effects on overall and blade-element performance of axial-flow transonic fan stage

    Science.gov (United States)

    Moore, R. D.

    1982-01-01

    The effects of tip clearance on the overall and blade-element performance of an axial-flow transonic fan stage are presented. The 50-centimeter-diameter fan was tested at four tip clearances (nonrotating) from 0.061 to 0.178 centimeter. The calculated radial growth of the blades was 0.040 centimeter at design conditions. The decrease in overall stage performance with increasing clearance is attributed to the loss in rotor performance. For the rotor the effects of clearance on performance parameters extended to about 70 percent of blade span from the tip. The stage still margin based on an assumed operating line decreased from 15.3 to 0 percent as the clearance increased from 0.061 to 0.178 centimeter.

  18. Composite fan stator assembly

    Energy Technology Data Exchange (ETDEWEB)

    Donges, G.L.

    1993-07-13

    A composite fan stator assembly is described for a gas turbine engine having at least two fan rotor stages, the composite stator assembly comprising: an annular composite fan case assembly including an access port, the fan case assembly circumferentially disposed around first and second fan rotor stage locations, a composite fan stator stage supported by and extending radially inward of the fan case assembly and axially disposed between the two fan rotor stage locations, the fan stator stage includes at least one removable vane segment accessible for removal through the access port for assembly and reassembly, the composite fan case assembly including a separable composite forward fan case assembly and a separable composite aft fan case assembly spaced axially aft of the forward fan case assembly, the forward fan case assembly being bolted to the aft fan case assembly, wherein the composite fan stator stage is axially and radially trapped and supported by the forward and aft fan case assemblies. A composite stator vane assembly comprising: a composite inner shroud, a composite outer shroud disposed radially outward of the inner shroud, a plurality of vanes disposed between the shrouds, the vanes including a suction side and a pressure side and radially inner and outer roots, the roots extending through platforms of corresponding ones of the inner and outer shrouds, four box-type attachment elements corresponding to curved suction and pressure sides of the inner and outer roots, the box-type attachment elements having two connected legs angled with respect to each other, a first one of the legs extending along, conforming to the curve of, and bonded to a corresponding one of the airfoil root sides, and a second one of the legs extending along and bonded to a composite shroud surface.

  19. Inlet flow distortion in turbomachinery. I - Comparison of theory and experiment in a transonic fan stage. II - A parameter study

    Science.gov (United States)

    Seidel, B. S.; Matwey, M. D.; Adamczyk, J. J.

    1980-01-01

    In the present paper, a semi-actuator-disk theory is reviewed that was developed previously for the distorted inflow to a single-stage axial-flow compressor. Flow distortion occurs far upstream; it may be a distortion in stagnation temperature, stagnation pressure, or both. Losses, quasi-steady deviation angles, and reference incidence correlations are included in the analysis, and both subsonic and transonic relative Mach numbers are considered. The theory is compared with measurements made in a transonic fan stage, and a parameter study is carried out to determine the influence of solidity on the attenuation of distortions in stagnation pressure and stagnation temperature.

  20. Preliminary design study of a quiet, high flow fan (QHF) stage. [turbofans - quiet engine program

    Science.gov (United States)

    Walker, C. L.; Kisner, L. S.; Delaney, R. A.; Beguhn, A. A.; Frye, D. E.

    1974-01-01

    Concepts selected to reduce fan generated noise in a turbofan are presented. Near-sonic flow at the fan inlet to reduce upstream propagated noise and the use of long-chord vanes to reduce downstream noise is discussed. The near-sonic condition at the rotor inlet plane was achieved by designing for high specific mass flow and by maintaining the high flow at reduced power by variable stators and variable fan exhaust nozzle. The long-chord vanes reduce response to unsteady flow. The acoustic design showed that long-chord stators would significantly reduce turbofan source noise and that other stator design parameters have no appreciable effect on noise for the spacing and chord length of the turbofan design. Four rig flow paths studied in the aerodynamic preliminary design are discussed. Noise prediction results indicate that a turbofan powered aircraft would be under federal air regulations levels without any acoustic treatment.

  1. Fan Noise Source Diagnostic Test: Rotor Alone Aerodynamic Performance Results

    Science.gov (United States)

    Hughes, Christopher E.; Jeracki, Robert J.; Woodward, Richard P.; Miller, Christopher J.

    2005-01-01

    The aerodynamic performance of an isolated fan or rotor alone model was measured in the NASA Glenn Research Center 9- by 15- Foot Low Speed Wind Tunnel as part of the Fan Broadband Source Diagnostic Test conducted at NASA Glenn. The Source Diagnostic Test was conducted to identify the noise sources within a wind tunnel scale model of a turbofan engine and quantify their contribution to the overall system noise level. The fan was part of a 1/5th scale model representation of the bypass stage of a current technology turbofan engine. For the rotor alone testing, the fan and nacelle, including the inlet, external cowl, and fixed area fan exit nozzle, were modeled in the test hardware; the internal outlet guide vanes located behind the fan were removed. Without the outlet guide vanes, the velocity at the nozzle exit changes significantly, thereby affecting the fan performance. As part of the investigation, variations in the fan nozzle area were tested in order to match as closely as possible the rotor alone performance with the fan performance obtained with the outlet guide vanes installed. The fan operating performance was determined using fixed pressure/temperature combination rakes and the corrected weight flow. The performance results indicate that a suitable nozzle exit was achieved to be able to closely match the rotor alone and fan/outlet guide vane configuration performance on the sea level operating line. A small shift in the slope of the sea level operating line was measured, which resulted in a slightly higher rotor alone fan pressure ratio at take-off conditions, matched fan performance at cutback conditions, and a slightly lower rotor alone fan pressure ratio at approach conditions. However, the small differences in fan performance at all fan conditions were considered too small to affect the fan acoustic performance.

  2. Overall and blade element performance of a 1.20 pressure ratio fan stage with rotor blades reset -7 deg

    Science.gov (United States)

    Lewis, G. W., Jr.; Kovich, G.

    1976-01-01

    A 51-cm-diam model of a fan stage for short haul aircraft was tested in a single stage compressor research facility. The rotor blades were set 7 deg toward the axial direction (opened) from the design setting angle. Surveys of the air flow conditions ahead of the rotor, between the rotor and stator, and behind the stator were made over the stable operating range of the stage. At the design speed and a weight flow of 30.9 kg/sec, the stage pressure ratio and efficiency were 1.205 and 0.85, respectively. The design speed rotor peak efficiency of 0.90 occurred at a flow rate of 32.5 kg/sec.

  3. High-loading, 1800 ft/sec tip speed transonic compressor fan stage. 1: Aerodynamic and mechanical design

    Science.gov (United States)

    Morris, A. L.; Halle, J. E.; Kennedy, E. E.

    1972-01-01

    A single stage fan with a tip speed of 1800 ft/sec (548.6m/sec) and hub/tip ratio of 0.5 was designed to produce a pressure ratio of 2.285:1 with an adiabatic efficiency of 84.0%. The design flow per inlet annulus area is 38.7 lbm/sq ft-sec (188.9KG/sqm-sec). Rotor blades have modified multiple-circular-arc and precompression airfoil sections. The stator vanes have multiple-circular-arc airfoil sections.

  4. Unsteady flows in a single-stage transonic axial-flow fan stator row

    Science.gov (United States)

    Hathaway, Michael Dale

    Detailed measurements of the unsteady velocity field within the stator flow of a transonic axial-flow fan were acquired using a laser anemometer. They were obtained on axisymmetric surfaces located at 10 and 50 percent span from the shroud, with the fan operating at maximum efficiency at design speed. The ensemble-average and variance of the measured velocities are used to identify rotor-wake-generated (deterministic) unsteadiness and turbulence, respectively. Correlations of both deterministic and turbulent velocity fluctuations provide information on the characteristics of unsteady interactions within the stator row. These correlations are derived from the Navier-Stokes equation in a manner similar to deriving the Reynolds stress terms, whereby various averaging operators are used to average the aperiodic, deterministic, and turbulent velocity fluctuations known to be present in multistage turbomachines. The correlations of deterministic and turbulent velocity fluctuations throughout the axial fan stator row are presented. In particular, amplification and attenuation of both types of unsteadiness are shown to occur within the stator blade passage.

  5. Rotor-rotor interaction for counter-rotating fans. Part 1: Three-dimensional flowfield measurements

    Science.gov (United States)

    Shin, Hyoun-Woo; Whitfield, Charlotte E.; Wisler, David C.

    1994-11-01

    The rotor wake/vortex flowfield generated in a scale model simulator of General Electric's counter-rotating unducted fan (UDF) engine was investigated using three-dimensional hot-wire anemometry. The purpose was to obtain a set of benchmark experimental aerodynamic data defining the rotor wake and vortex structure, particularly in the tip region, and to relate this observed flow structure to its acoustic signature. The tests were conducted in a large, freejet anechoic chamber. Measurements of the three components of velocity were made at axial stations upstream and downstream of each rotor for conditions that simulate takeoff, cutback, and approach power. Two different forward blade designs were evaluated. The tip vortices, the axial velocity defect in the vortex core, and differences in the interaction of the wakes and vortices generated by the forward and aft rotor are used to explain differences in noise generated by the two different rotor designs. Part 1 presents the three-dimensional flowfield measurements. Part 2 (aeroacoustic prediction and analysis), which will be presented later, will give an acoustic prediction using the measured data.

  6. Foreign Object Damage to Fan Rotor Blades of Aeroengine Part Ⅰ: Experimental Study of Bird Impact

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The conditions of experiment for bird impact to blades have been improved. The experiment of bird impact to the fan rotor blades of an aeroengine is carried out. Through analyzing the transient state response of blades impacted by bird and the change of blade profile before and after the impact, the anti-bird impact performance of blades in the first fan rotor is verified. The basis of anti-foreign object damage design for the fan rotor blades of an aeroengine is provided.

  7. Ultra high tip speed (670.6 m/sec) fan stage with composite rotor: Aerodynamic and mechanical design

    Science.gov (United States)

    Halle, J. E.; Burger, G. D.; Dundas, R. E.

    1977-01-01

    A highly loaded, single-stage compressor having a tip speed of 670.6 m/sec was designed for the purpose of investigating very high tip speeds and high aerodynamic loadings to obtain high stage pressure ratios at acceptable levels of efficiency. The design pressure ratio is 2.8 at an adiabatic efficiency of 84.4%. Corrected design flow is 83.4 kg/sec; corrected design speed is 15,200 rpm; and rotor inlet tip diameter is 0.853 m. The rotor uses multiple-circular-arc airfoils from 0 to 15% span, precompression airfoils assuming single, strong oblique shocks from 21 to 43% span, and precompression airfoils assuming multiple oblique shocks from 52% span to the tip. Because of the high tip speeds, the rotor blades are designed to be fabricated of composite materials. Two composite materials were investigated: Courtaulds HTS graphite fiber in a Kerimid 601 polyimide matrix and the same fibers in a PMR polyimide matrix. In addition to providing a description of the aerodynamic and mechanical design of the 670.0 m/sec fan, discussion is presented of the results of structural tests of blades fabricated with both types of matrices.

  8. Foreign Object Damage to Fan Rotor Blades of Aeroengine Part Ⅱ: Numerical Simulation of Bird Impact

    Institute of Scientific and Technical Information of China (English)

    Guan Yupu; Zhao Zhenhua; Chen Wei; Gao Deping

    2008-01-01

    Bird impact is one of the most dangerous threats to flight safety. The consequences of bird impact can be severe and, therefore, the aircraft components have to be certified for a proven level of bird impact resistance before being put into service. The fan rotor blades of aeroengine are the components being easily impacted by birds. It is necessary to ensure that the fan rotor blades should have adequate resistance against the bird impact, to reduce the flying accidents caused by bird impacts. Using the contacting-impacting algorithm, the numerical simulation is carried out to simulate bird impact. A three-blade computational model is set up for the fan rotor blade having shrouds. The transient response curves of the points corresponding to measured points in experiments, displacements and equivalent stresses on the blades are obtained during the simulation. From the comparison of the transient response curves obtained from numerical simulation with that obtained from experiments, it can be found that the variations in measured points and the corresponding points of simulation are basically the same. The deforming process, the maximum displacements and the maximum equivalent stresses on blades are analyzed. The numerical simulation verifies and complements the experiment results.

  9. Overall and blade element performance of a 1.20-pressure-ratio fan stage with rotor blades reset -5 deg

    Science.gov (United States)

    Lewis, G. W., Jr.; Osborn, W. M.; Moore, R. D.

    1976-01-01

    A 51-cm-diam model of a fan stage for a short haul aircraft was tested in a single stage-compressor research facility. The rotor blades were set 5 deg toward the axial direction (opened) from design setting angle. Surveys of the air flow conditions ahead of the rotor, between the rotor and stator, and behind the stator were made over the stable operating range of the stage. At the design speed of 213.3 m/sec and a weight flow of 31.5 kg/sec, the stage pressure ratio and efficiency were 1.195 and 0.88, respectively. The design speed rotor peak efficiency of 0.91 occurred at the same flow rate.

  10. An Assessment of NASA Glenn's Aeroacoustic Experimental and Predictive Capabilities for Installed Cooling Fans. Part 1; Aerodynamic Performance

    Science.gov (United States)

    VanZante, Dale E.; Koch, L. Danielle; Wernet, Mark P.; Podboy, Gary G.

    2006-01-01

    Driven by the need for low production costs, electronics cooling fans have evolved differently than the bladed components of gas turbine engines which incorporate multiple technologies to enhance performance and durability while reducing noise emissions. Drawing upon NASA Glenn's experience in the measurement and prediction of gas turbine engine aeroacoustic performance, tests have been conducted to determine if these tools and techniques can be extended for application to the aerodynamics and acoustics of electronics cooling fans. An automated fan plenum installed in NASA Glenn's Acoustical Testing Laboratory was used to map the overall aerodynamic and acoustic performance of a spaceflight qualified 80 mm diameter axial cooling fan. In order to more accurately identify noise sources, diagnose performance limiting aerodynamic deficiencies, and validate noise prediction codes, additional aerodynamic measurements were recorded for two operating points: free delivery and a mild stall condition. Non-uniformities in the fan s inlet and exhaust regions captured by Particle Image Velocimetry measurements, and rotor blade wakes characterized by hot wire anemometry measurements provide some assessment of the fan aerodynamic performance. The data can be used to identify fan installation/design changes which could enlarge the stable operating region for the fan and improve its aerodynamic performance and reduce noise emissions.

  11. 14 CFR 29.908 - Cooling fans.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Cooling fans. 29.908 Section 29.908... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant General § 29.908 Cooling fans. For cooling fans that are a part of a powerplant installation the following apply: (a) Category A. For cooling fans...

  12. Aerodynamic performance of axial-flow fan stage operated at nine inlet guide vane angles. [to be used on vertical lift aircraft

    Science.gov (United States)

    Moore, R. D.; Reid, L.

    1979-01-01

    The overall performance of a fan stage with nine inlet guide vane angle settings is presented. These data were obtained over the stable flow range at speeds from 60 to 120 percent of design for vane setting angles from -25 to 42.5 degrees. At design speed and design inlet guide vane angle, the stage has a peak efficiency of 0.892 at a pressure ratio of 1.322 and a flow of 25.31 kg/s. The stall margin based on peak efficiency and stall was 20 percent. Based on an operating line passing through the peak efficiency point at the design setting angle, the useful operating range of the stage at design speed is limited by stall at the positive setting angles and by choke at the negative angles. At design the calculated static thrust along the operating line varied from 68 to 114 percent of that obtained at design setting angle.

  13. Redesigned rotor for a highly loaded, 1800 ft/sec tip speed compressor fan stage 1: Aerodynamic and mechanical design

    Science.gov (United States)

    Halle, J. E.; Ruschak, J. T.

    1975-01-01

    A highly loaded, high tip-speed fan rotor was designed with multiple-circular-arc airfoil sections as a replacement for a marginally successful rotor which had precompression airfoil sections. The substitution of airfoil sections was the only aerodynamic change. Structural design of the redesigned rotor blade was guided by successful experience with the original blade. Calculated stress levels and stability parameters for the redesigned rotor are within limits demonstrated in tests of the original rotor.

  14. Toward Improved Rotor-Only Axial Fans - Part I: A Numerically Efficient Aerodynamic Model for Arbitrary Vortex Flow

    DEFF Research Database (Denmark)

    Sørensen, Dan Nørtoft; Sørensen, Jens Nørkær

    2000-01-01

    A numerically efficient mathematical model for the aerodynamics of rotor-only axial fans has been developed. The model is based on a blade-elementprinciple whereby the rotor is divided into a number of annular streamtubes. For each of these streamtubes relations for velocity, pressure, and radial......A numerically efficient mathematical model for the aerodynamics of rotor-only axial fans has been developed. The model is based on a blade-elementprinciple whereby the rotor is divided into a number of annular streamtubes. For each of these streamtubes relations for velocity, pressure......, and radialposition are derived from the incompressible conservation laws for mass, tangential momentum, and energy. The resulting system of equations isnonlinear and, due to mass conservation and pressure equilibrium far downstream of the rotor, strongly coupled. The equations are solved using the...

  15. Depositional Characteristics of Lake-Floor Fan of Cretaceous Lower Yaojia Formation in Western Part of Central Depression Region,Songliao Basin

    Institute of Scientific and Technical Information of China (English)

    Xin Renchen; Li Guifan; Feng Zhiqiang; Liang Jiangping; Lin Changsong

    2009-01-01

    Based on the integrated subsurface data,including those of over 600 m drilled cores,more than 30 drilled wells and 600 km2 three-dimensional (3D) seismic-reflection data of the study area, the characteristics of the lake-floor fan of lower Yaojia(姚家) Formation have been clarified.An evident lacustrine slope break and a steep slope belt developed in the west of Songliao(松辽)basin during depositional period of Qingshankou(青山口)-Yaojia formations(K2).The slope gradient was about 15 m/km.During the depositional period of lower Yaojia Formation,the lake shrank and the shore line of the western Songliao basin shifted to the lacustrine slope-break.The wedge-shaped sediment body,which is interpreted as the lowstand system tract of SQy1 (LSTy1),developed in the area below the slope-break.The LSTyl is pinched out in the west of the study area.As to the thickness of LSTyl,ft is thicker in the east with SO m in its thickness than in the west The LSTyl,rich in sandstone,can be divided into lower part LSTylL and upper part LSTy1u based on two onlap seismic reflection phases,and core and logging data clearly.The various sediments' gravity flow deposits developed and the complex of lake-floor fan formed in the LSTyl under the slope-break in the western part of the central depression region.The lake-floor fan consists of various sediments' gravity flow deposits,including: (1) turbidity deposits with characteristics of Bouma sequences; (2) sand-bearing muddy debrite dominated by mud and mixed by sand; (3) mud-bearing sandy debrites characterized by dominated sand and mixed by mud; (4) sandy debris laminar flow deposits with massive or inclined bedding,and (5) sandy slump deposits developed as deforma tional sedimentary structure.During the lower lake-level period (LSTy1L),the western clinoform region was erosion or sediment pass-by area; the terrigenous clastic was directly transported to deep-water area,converted to channelized sandy debris flow,and combined with slump

  16. Acoustic and aerodynamic performance of a 1.5-pressure-ratio, 1.83-meter (6 ft) diameter fan stage for turbofan engines (QF-2)

    Science.gov (United States)

    Woodward, R. P.; Lucas, J. G.; Balombin, J. R.

    1977-01-01

    The fan was externally driven by an electric motor. Design features for low-noise generation included the elimination of inlet guide vanes, long axial spacing between the rotor and stator blade rows, and the selection of blade-vane numbers to achieve duct-mode cutoff. The fan QF-2 results were compared with those of another full-scale fan having essentially identical aerodynamic design except for nozzle geometry and the direction of rotation. The fan QF-2 aerodynamic results were also compared with those obtained from a 50.8 cm rotor-tip-diameter model of the reverse rotation fan QF-2 design. Differences in nozzle geometry other than exit area significantly affected the comparison of the results of the full-scale fans.

  17. Two-Stage Part-Based Pedestrian Detection

    DEFF Research Database (Denmark)

    Møgelmose, Andreas; Prioletti, Antonio; Trivedi, Mohan M.

    2012-01-01

    Detecting pedestrians is still a challenging task for automotive vision system due the extreme variability of targets, lighting conditions, occlusions, and high speed vehicle motion. A lot of research has been focused on this problem in the last 10 years and detectors based on classifiers has...... gained a special place among the different approaches presented. This work presents a state-of-the-art pedestrian detection system based on a two stages classifier. Candidates are extracted with a Haar cascade classifier trained with the DaimlerDB dataset and then validated through part-based HOG...... of several metrics, such as detection rate, false positives per hour, and frame rate. The novelty of this system rely in the combination of HOG part-based approach, tracking based on specific optimized feature and porting on a real prototype....

  18. Effects of supplemental recombinant bovine somatotropin and mist-fan cooling on the renal tubular handling of sodium in different stages of lactation in crossbred Holstein cattle.

    Science.gov (United States)

    Boonsanit, Dolrudee; Chanpongsang, Somchai; Chaiyabutr, Narongsak

    2012-08-01

    The effect of supplementary administration of recombinant bovine somatotrophin (rbST) on the renal tubular handling of sodium in crossbred 87.5% Holstein cattle housed in normal shade (NS) or mist-fan cooled (MF) barns was evaluated. The cows were injected with 500 mg rbST at three different stages of lactation. The MF barn housed cows showed a slightly decreased ambient temperature and temperature humidity index, but an increased relative humidity. Rectal temperature and respiration rates were significantly lower in cooled cows. The rbST treated cows, housed in NS or MF barns, showed markedly increased milk yields, total body water, extracellular fluid and plasma volume levels, along with a reduced rate of urine flow and urinary excretion of sodium, potassium and chloride ions and osmolar clearance, in all three stages of lactation. Renal tubular sodium and water reabsorption were increased after rbST administration without any alteration in the renal hemodynamics. Lithium clearance data suggested that the site of response is in the proximal nephron segment, which may be mediated via increases in the plasma levels of aldosterone and IGF-1, but not vasopressin, during rbST administration.

  19. Analysis on Stall of Double Stage Adjustable-blade AXial Flow Induced Draft Fan in High-load Operation%双级动叶可调式轴流引风机高负荷失速分析

    Institute of Scientific and Technical Information of China (English)

    王军民

    2016-01-01

    Through the elaboration on the mechanism of axial flow fan stall and in combination with double stage adjustable-blade axial flow induced draft fan stall in actual production of a power plant, the paper ana-lyzes the deep-seated causes of the stall and thus puts forward the principle of stall handling of induced draft fan in high load and effective measures for install prevention.%通过阐述轴流通风机失速的机理,结合某发电厂实际生产中双级动叶可调式轴流引风机失速的现象,分析发生失速的深层次原因,提出机组高负荷下处理引风机失速异常的原则以及防止失速的有效措施。

  20. Highly Loaded Fan by Using Tandem Cascade Rotor Blade

    Science.gov (United States)

    Hasegawa, Hiroaki; Suga, Shinya; Matsuoka, Akinori

    For axial flow compressors and fans in the aircraft engines higher pressure ratio is required in order to attain the high thrust engines. In this study, the fan with the tandem cascades was introduced to increase the fan pressure ratio. The use of tandem cascades in the fan allows savings in length and weight and therefore a compact fan could be built. The design of fan with tandem cascades and the fan testing were carried out to develop the high pressure ratio fan for the Air Turbo Ramjet (ATR) propulsion system. The ATR is a combined cycle engine which performs like a turbojet engine at subsonic speeds and a ramjet at supersonic speeds. In particular, high fan pressure ratio contributes to increase the engine thrust during subsonic flight at which the engine does not make use of ram effect. The results of the fan testing indicate that the pressure ratio of 2.2 is achieved in single stage fan.

  1. Turbofan gas turbine engine with variable fan outlet guide vanes

    Science.gov (United States)

    Wood, Peter John (Inventor); Zenon, Ruby Lasandra (Inventor); LaChapelle, Donald George (Inventor); Mielke, Mark Joseph (Inventor); Grant, Carl (Inventor)

    2010-01-01

    A turbofan gas turbine engine includes a forward fan section with a row of fan rotor blades, a core engine, and a fan bypass duct downstream of the forward fan section and radially outwardly of the core engine. The forward fan section has only a single stage of variable fan guide vanes which are variable fan outlet guide vanes downstream of the forward fan rotor blades. An exemplary embodiment of the engine includes an afterburner downstream of the fan bypass duct between the core engine and an exhaust nozzle. The variable fan outlet guide vanes are operable to pivot from a nominal OGV position at take-off to an open OGV position at a high flight Mach Number which may be in a range of between about 2.5-4+. Struts extend radially across a radially inwardly curved portion of a flowpath of the engine between the forward fan section and the core engine.

  2. Aerodynamic performance of 0.5 meter-diameter, 337 meter-per-second tip speed, 1.5 pressure-ratio, single-stage fan designed for low noise aircraft engines

    Science.gov (United States)

    Gelder, T. F.; Lewis, G. W., Jr.

    1974-01-01

    Overall and blade-element aerodynamic performance of a 0.271-scale model of QF-1 are presented, examined, and then compared and evaluated with that from similar low noise fan stage designs. The tests cover a wide range of speeds and weight flows along with variations in stator setting angle and stator axial spacing from the rotor. At design speed with stator at design setting angle and a fixed distance between stage measuring stations, there were no significant effects of increasing the axial spacing between rotor stator from 1.0 to 3.5 rotor chords on stage overall pressure ratio, efficiency or stall margin.

  3. Implementation of a model for the reduction of latent capacity of an air-conditioner at part-load conditions with continuous fan operation

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, K.H.; Blake, J. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Energy Technology Centre

    2004-07-01

    The performance of air-conditioners and their moisture removal effectiveness is degraded when the indoor circulation fan is in continuous mode and the compressor is off. Early experiments have shown that when the compressor is off, the cooling coil acts as an evaporative cooler and vapour condensates on its surface. This vapour goes back into the air stream and back to the conditioned space, resulting in higher humidity levels. A model has been developed by previous examiners to predict the degradation of the performance of the air-conditioner. The model accounts for the conditions of the air entering the coil, thermostat cycling rate, air-conditioner transient performance, and the moisture-retaining characteristics of the cooling coil. However, this model has not been used within a building energy simulation program. This paper demonstrates how the model can be used as part of an air-conditioning model in the ESP-r/HOT3000 building energy analysis program. Within ESP-r/HOT3000, the model can determine the effect of moisture evaporation from the coil, during compressor off-cycle within continuous fan operation. It can also examine the effect on temperature and relative humidity inside a residential building during the cooling season. The model can also determine the effect of equipment latent capacity degradation on electricity use by air conditioners. The study identifies the problems associated with an over-sized air conditioner. 5 refs., 3 tabs., 7 figs.

  4. Ky Fan inequalities

    CERN Document Server

    Moslehian, Mohammad Sal

    2011-01-01

    There are several inequalities in the literature carrying the name of Ky Fan. We survey these well-known Ky Fan inequalities and some other significant inequalities generalized by Ky Fan and review some of their recent developments.

  5. The aerodynamic design and performance of the General Electric/NASA EEE fan. [Energy Efficient Engine

    Science.gov (United States)

    Sullivan, T. J.; Hager, R. D.

    1983-01-01

    The aerodynamic design and test results of the fan and quarter-stage component for the GE/NASA Energy Efficient Engine (EEE) are presented. The fan is a high bypass ratio, single-stage design having 32 part-span shrouded rotor blades, coupled with a unique quarter-stage arrangement that provides additional core-stream pressure ratio and particle separation. The fan produces a bypass pressure ratio of 1.65 at the exit of the low aspect ratio vane/frame and a core-stream pressure ratio of 1.67 at the entrance to the core frame struts. The full-scale fan vehicle was instrumented, assembled and tested as a component in November 1981. Performance mapping was conducted over a range of speeds and bypass ratios using individually-controlled bypass and core-stream discharge valves. The fan bypass and core-stream test data showed excellent results, with the fan exceeding all performance goals at the important engine operating conditions.

  6. Structure and climate controls on the evolution of a Mid-Late Jurassic alluvial fan-delta system in the western part of Yanshan fold-and-thrust belt

    Science.gov (United States)

    Lin, Chengfa; Liu, Shaofeng; Yao, Xiang; Ma, Pengfei

    2016-04-01

    The Yanshan fold-thrust belt experienced several significant tectonic events during Mesozoic time and developed thrust fault-bounded intramontane sedimentary basins. However, elaborate works of sedimentology is inadequate in the Yanshan belt, particularly in its western segment, leading to a failure in comprehensively understanding how bounding-faults and climate change influence the basin filling processes. Our detailed sedimentological study of the Middle Jurassic Xiahuayuan Formation and Upper Jurassic-Lower Cretaceous Jiulongshan Formation in the Xiahuayuan basin of northern Hebei province, indicates a genetic relationship between the evolution of an alluvial fan-delta system and the tectonic and climate setting. The Xiahuayuan Formation was assigned to a debris flow-dominated Gilbert-type fan-delta composed of topset conglomerates, foreset massive siltstone-fine grained sandstone interbedded with lenticular conglomerate units and bottomset/lake bottom fine-grained deposits, spatially restricted to the northern part of the basin. While the lower Jiulongshan Formation was considered as a relatively small debris flow- and turbidity currents-dominated fan-delta with a single-ramp portrait, prograding into the middle part of the basin. And the upper part of Jiulongshan Formation contributed to the lake bottom component of the delta system during the forming of the Jiulongshan Formation. Our results reveal a transformation of a fan-delta from Gilbert-type to single-ramp type and the basinward migration of this fan-delta during Mid-Late Jurassic in the Xiahuayuan basin. And it is assumed that the activity of a thrust fault along the northern basin margin and the rapid switch of climate conditions from warm and humid to hot and dry triggered the transformation and migration of this fan-delta system.

  7. The Effect of Bypass Nozzle Exit Area on Fan Aerodynamic Performance and Noise in a Model Turbofan Simulator

    Science.gov (United States)

    Hughes, Christopher E.; Podboy, Gary, G.; Woodward, Richard P.; Jeracki, Robert, J.

    2013-01-01

    The design of effective new technologies to reduce aircraft propulsion noise is dependent on identifying and understanding the noise sources and noise generation mechanisms in the modern turbofan engine, as well as determining their contribution to the overall aircraft noise signature. Therefore, a comprehensive aeroacoustic wind tunnel test program was conducted called the Fan Broadband Source Diagnostic Test as part of the NASA Quiet Aircraft Technology program. The test was performed in the anechoic NASA Glenn 9- by 15-Foot Low Speed Wind Tunnel using a 1/5 scale model turbofan simulator which represented a current generation, medium pressure ratio, high bypass turbofan aircraft engine. The investigation focused on simulating in model scale only the bypass section of the turbofan engine. The test objectives were to: identify the noise sources within the model and determine their noise level; investigate several component design technologies by determining their impact on the aerodynamic and acoustic performance of the fan stage; and conduct detailed flow diagnostics within the fan flow field to characterize the physics of the noise generation mechanisms in a turbofan model. This report discusses results obtained for one aspect of the Source Diagnostic Test that investigated the effect of the bypass or fan nozzle exit area on the bypass stage aerodynamic performance, specifically the fan and outlet guide vanes or stators, as well as the farfield acoustic noise level. The aerodynamic performance, farfield acoustics, and Laser Doppler Velocimeter flow diagnostic results are presented for the fan and four different fixed-area bypass nozzle configurations. The nozzles simulated fixed engine operating lines and encompassed the fan stage operating envelope from near stall to cruise. One nozzle was selected as a baseline reference, representing the nozzle area which would achieve the design point operating conditions and fan stage performance. The total area change from

  8. Quaternary alluvial fans of Ciudad Juárez, Chihuahua, northern México: OSL ages and implications for climatic history of the region

    Science.gov (United States)

    Zúñiga de León, David; Kershaw, Stephen; Mahan, Shannon

    2016-01-01

    Alluvial fans formed from sediments derived from erosion of the Juárez Mountains in northernmost México have a significant flood impact on the Ciudad Juárez, which is built on the fan system. The northern part of Ciudad Juárez is the most active; further south, older parts of the fan, upon which the rest of the city is built, were largely eroded by natural processes prior to human habitation and subsequently modified only recently by human construction. Three aeolian sand samples, collected from the uppermost (youngest) parts of the fan system in the city area, in places where human intervention has not disturbed the sediment, and constrain the latest dates of fan building. Depositional ages of the Quaternary alluvial fans were measured using Optically Stimulated Luminescence (OSL) on aeolian sands that have inter-fingered with alluvial fan material. These dates are: a) sample P1, 31 ka; b) sample P2, 41 ka; c) sample P3, 74 ka, between Oxygen Isotope Stages (OIS) 3 to 5. They demonstrate that fan development, in the area now occupied by the city, terminated in the Late Pleistocene, immediately after what we interpret to have been an extended period of erosion without further deposition, lasting from the Late Pleistocene to Holocene. The three dates broadly correspond to global glacial periods, implying that the cool, dry periods may reflect periods of aeolian transport in northern México in between phases that were wetter to form the alluvial fans. Alluvial fan margins inter-finger with fluvial terrace sediments derived from the Río Bravo, indicating an additional component of fan dissection by Río Bravo lateral erosion, presumed to be active during earlier times than our OSL ages, but these are not yet dated. Further dating is required to ascertain the controls on the fan and fluvial system.

  9. Unsteady Flows in a Single-Stage Transonic Axial-Flow Fan Stator Row. Ph.D. Thesis - Iowa State Univ.

    Science.gov (United States)

    Hathaway, Michael D.

    1986-01-01

    Measurements of the unsteady velocity field within the stator row of a transonic axial-flow fan were acquired using a laser anemometer. Measurements were obtained on axisymmetric surfaces located at 10 and 50 percent span from the shroud, with the fan operating at maximum efficiency at design speed. The ensemble-average and variance of the measured velocities are used to identify rotor-wake-generated (deterministic) unsteadiness and turbulence, respectively. Correlations of both deterministic and turbulent velocity fluctuations provide information on the characteristics of unsteady interactions within the stator row. These correlations are derived from the Navier-Stokes equation in a manner similar to deriving the Reynolds stress terms, whereby various averaging operators are used to average the aperiodic, deterministic, and turbulent velocity fluctuations which are known to be present in multistage turbomachines. The correlations of deterministic and turbulent velocity fluctuations throughout the axial fan stator row are presented. In particular, amplification and attenuation of both types of unsteadiness are shown to occur within the stator blade passage.

  10. PICNIC - FANS, ULTRAS AND HOOLIGANS - INTERNAL DIFFERENTIATE OF SUBCULTURE GROUP FOOTBALL FANS IN POLAND

    Directory of Open Access Journals (Sweden)

    Maciej Solinski

    2006-01-01

    Full Text Available This article is a main part of "Internal differentiate of subculture group of football fans in Poland" project. Author has tried to show how the subculture of football fans can be differentiate. Author ha presented three different subgroups of Polish fans. It is very important to divide this subculture, because each subgroup has different mentality and style. That is why I have paid the most attention on this element.

  11. Reliability analysis of forty-five strain-gage systems mounted on the first fan stage of a YF-100 engine

    Science.gov (United States)

    Holanda, R.; Frause, L. M.

    1977-01-01

    The reliability of 45 state-of-the-art strain gage systems under full scale engine testing was investigated. The flame spray process was used to install 23 systems on the first fan rotor of a YF-100 engine; the others were epoxy cemented. A total of 56 percent of the systems failed in 11 hours of engine operation. Flame spray system failures were primarily due to high gage resistance, probably caused by high stress levels. Epoxy system failures were principally erosion failures, but only on the concave side of the blade. Lead-wire failures between the blade-to-disk jump and the control room could not be analyzed.

  12. How to do things with fan subs: Media engagement as subcultural capital in anime fan subbing

    Directory of Open Access Journals (Sweden)

    Douglas Schules

    2014-09-01

    Full Text Available Anime fandom has been a fairly constant subject in fan scholarship, although only recently have conversations about fan subbing begun to circulate. As useful as those conversations are, none have directly dealt either with the mechanisms of fan subbing, particularly the use of linear notes, as a practice or with how these subs intersect with the flows of subcultural capital. Fan subbing, both as a productive and a consumptive practice, plays a small but influential part in subcultural capital. Engagement with media is a compositional element of such capital in this community.

  13. High pressure axial flow fans for modern coal power stations

    Energy Technology Data Exchange (ETDEWEB)

    Cyrus, Vaclav [AHT Energetika s.r.o., Praha (Czech Republic); Koci, Petr [ZVVZ Milevsko a.s. (Czech Republic)

    2008-07-01

    Brown coal fired power stations, located in Northern Bohemia, have mostly older boiler blocks with an output of 110 and 200 MWe. Flue gases are cleaned by the desulphurization plants installed between 1993 and 1997. Usually, each boiler block has two air fans and one to three flue gas fans. Flue gas fans operate in severe conditions; fan blades should be resistant to the flue gases containing sulphur and acid drops with the operating temperature at 170 C to 190 C. Additionally, flue gas also often contains ash particles. Currently, some boiler blocks are gradually being refurbished. New blocks with an electrical power output of 600 to 700 MWe are at the design stage. Submitted paper shows our design study of one stage axial flow fan for the new blocks. Results from the new aerodynamic research of the axial flow stages were used in the fan design. (orig.)

  14. Improving Best Air Conditioner Efficiency by 20-30% through a High Efficiency Fan and Diffuser Stage Coupled with an Evaporative Condenser Pre-Cooler

    Energy Technology Data Exchange (ETDEWEB)

    Parker, Danny S; Sherwin, John R; Raustad, Richard

    2014-04-10

    The Florida Solar Energy Center (FSEC) conducted a research project to improve the best residential air conditioner condenser technology currently available on the market by retrofitting a commercially-available unit with both a high efficiency fan system and an evaporative pre-cooler. The objective was to integrate these two concepts to achieve an ultra-efficient residential air conditioner design. The project produced a working prototype that was 30% more efficient compared to the best currently-available technologies; the peak the energy efficiency ratio (EER) was improved by 41%. Efficiency at the Air-Conditioning and Refrigeration Institute (ARI) standard B-condition which is used to estimate seasonal energy efficiency ratio (SEER), was raised from a nominal 21 Btu/Wh to 32 Btu/Wh.

  15. Aerodynamic modelling and optimization of axial fans

    Energy Technology Data Exchange (ETDEWEB)

    Noertoft Soerensen, Dan

    1998-01-01

    A numerically efficient mathematical model for the aerodynamics of low speed axial fans of the arbitrary vortex flow type has been developed. The model is based on a blade-element principle, whereby the rotor is divided into a number of annular stream tubes. For each of these stream tubes relations for velocity, pressure and radial position are derived from the conservation laws for mass, tangential momentum and energy. The equations are solved using the Newton-Raphson methods, and solutions converged to machine accuracy are found at small computing costs. The model has been validated against published measurements on various fan configurations, comprising two rotor-only fan stages, a counter-rotating fan unit and a stator-rotor stator stage. Comparisons of local and integrated properties show that the computed results agree well with the measurements. Optimizations have been performed to maximize the mean value of fan efficiency in a design interval of flow rates, thus designing a fan which operates well over a range of different flow conditions. The optimization scheme was used to investigate the dependence of maximum efficiency on 1: the number of blades, 2: the width of the design interval and 3: the hub radius. The degree of freedom in the choice of design variable and constraints, combined with the design interval concept, provides a valuable design-tool for axial fans. To further investigate the use of design optimization, a model for the vortex shedding noise from the trailing edge of the blades has been incorporated into the optimization scheme. The noise emission from the blades was minimized in a flow rate design point. Optimizations were performed to investigate the dependence of the noise on 1: the number of blades, 2: a constraint imposed on efficiency and 3: the hub radius. The investigations showed, that a significant reduction of noise could be achieved, at the expense of a small reduction in fan efficiency. (EG) 66 refs.

  16. Performance of transonic fan stage with weight flow per unit annulus area of 208 kilograms per second per square meter (42.6 (lb/sec)/sq ft)

    Science.gov (United States)

    Urasek, D. C.; Kovich, G.; Moore, R. D.

    1973-01-01

    Performance was obtained for a 50-cm-diameter compressor designed for a high weight flow per unit annulus area of 208 (kg/sec)/sq m. Peak efficiency values of 0.83 and 0.79 were obtained for the rotor and stage, respectively. The stall margin for the stage was 23 percent, based on equivalent weight flow and total-pressure ratio at peak efficiency and stall.

  17. The Connemara Fan: a major glacial grounding line fan west of Ireland

    Science.gov (United States)

    McCarron, Stephen; Praeg, Daniel; Monteys, Xavier; Scott, Gill

    2014-05-01

    Glacigenic topography on the mid-shelf (~130-350 m water depth) west of Galway, Ireland appears to have the morphological form, internal architecture and sediments associated with a large glacial grounding-line fan. Seismic data collected in 2009 and 2012 (during the GLAMAR and GATEWAYS 1 campaigns) reveal that the broad, arcuate ridges of the 'Olex moraine' form the landward part of a fan system which prograded beyond the mid-shelf break (defining the outer margin of the 'Clare Platform') westwards into the Porcupine Seabight. The topography is comparable to larger shelf-edge trough-mouth fans found further north along the same margin, however no discernible 'trough' has been identified on the Clare Platform. The ridge and fan topographic assemblage is renamed the 'Connemara Fan' in its entirety, based on its genetic relations and geographic location due west of Connemara, western Ireland. A macrofossil recovered from within a debris flow on the outer fan slope comprised of remobilised plumites dates to ~ 20 ka Cal B.P., indicating sediment reworking downslope following deglacial sediment input to at least that time. The Connemara Fan is the most southerly glacigenic fan identified along the north-east Atlantic margin. Its identification also adds to our knowledge of possibly multiple generations of ice sheets feeding onto the Irish shelf from west-central Ireland and the occurrence of ice sheet geometries and dynamics that evacuated ice, melt-water and sediment (ice streams?) westwards across the Clare Platform during past glaciations.

  18. Diagenetic evolution and its effect on reservoir-quality of fan delta sandstones during progressive burial:Evidence from the upper part of the fourth member of Shahejie formation, Bonan sag, Jiyang depression

    Institute of Scientific and Technical Information of China (English)

    马奔奔; 张少敏; 操应长; 贾艳聪; 王艳忠

    2015-01-01

    Petrographic analysis combined with various techniques, such as thin section identification, fluid inclusions, isotopic data, petro-physical property testing and oil testing results, was used to study diagenetic evolution and its effect on reservoir-quality of fan delta reservoirs of Es4s in the Bonan sag. The diagenesis is principally characterized by strong compaction, undercompaction, multi-phase of dissolution and cementation. Compaction played a more important role than cementation in destroying the primary porosity of the sandstones. The reservoirs have experienced complicated diagenetic environment evolution of “weak alkaline− acid−alkalinity−acid−weak alkalinity” and two-stage of hydrocarbon filling. The diagenetic sequences are summarized as “early compaction/early pyrite/gypsum/calcite/dolomite cementation→feldspar dissolution/the first stage of quartz overgrowth→ early hydrocarbon filling→quartz dissolution/anhydrite/Fe-carbonate cementation→Fe-carbonate dissolution/feldspar dissolution/ the second stage of quartz overgrowth→later hydrocarbon filling→later pyrite cementation. In the same diagenetic context, the diagenetic evolution processes that occurred in different sub/micro-facies during progressive burial have resulted in heterogeneous reservoir properties and oiliness. The braided channel reservoirs in fan delta plain are poorly sorted with high matrix contents. The physical properties decrease continually due to the principally strong compaction and weak dissolution. The present properties of braided channel reservoirs are extremely poor, which is evidenced by few oil layers developed in relatively shallow strata while dry layers entirely in deep. The reservoirs both in the underwater distributary channels and mouth bars are well sorted and have a strong ability to resist compaction. Abundant pores are developed in medium-deep strata because of modifications by two-stage of acidic dissolution and hydrocarbon filling. The

  19. How End-Stage Renal Disease Patients Manage the Medicare Part D Coverage Gap

    Science.gov (United States)

    Kovacs, Pamela J.; Perkins, Nathan; Nuschke, Elizabeth; Carroll, Norman

    2012-01-01

    Medicare Part D was enacted to help elderly and disabled individuals pay for prescription drugs, but it was structured with a gap providing no coverage in 2010 between $2,830 and $6,440. Patients with end-stage renal disease (ESRD) are especially likely to be affected due to high costs of dialysis-related drugs and the importance of adherence for…

  20. Performance of transonic fan stage with weight flow per unit annulus area of 178 kilograms per second per square meter (6.5(lb/sec)/(sq ft))

    Science.gov (United States)

    Moore, R. D.; Urasek, D. C.; Kovich, G.

    1973-01-01

    The overall and blade-element performances are presented over the stable flow operating range from 50 to 100 percent of design speed. Stage peak efficiency of 0.834 was obtained at a weight flow of 26.4 kg/sec (58.3 lb/sec) and a pressure ratio of 1.581. The stall margin for the stage was 7.5 percent based on weight flow and pressure ratio at stall and peak efficiency conditions. The rotor minimum losses were approximately equal to design except in the blade vibration damper region. Stator minimum losses were less than design except in the tip and damper regions.

  1. Solar powered headwear fan

    Energy Technology Data Exchange (ETDEWEB)

    Hirsh, G.B.; Volk, S.; Cirrito, W.; Brann, D.

    1987-07-21

    A fan assembly is described. A housing is adapted for resting on an exterior surface of headwear. A fan mounted in the housing at one end of the housing is adapted for forcing air through an opening defined in a forward protuberance of the headwear. Solar cell means are mounted on the housing at another end of the housing opposite to and remote from the one end for powering the fan means and adapted for resting on a crown of the headwear. Vent means are defined by the housing for allowing air to be sucked into the housing and forced out of the housing when the power means drive the fan means. Mounting means are defined by the housing, including hinge means for removably mounting the modular fan assembly on an exterior surface of the headwear. A portion of the housing occupies a substantial distance between the fan means and the solar cell means. Display means are defined by the portion of the housing between the power means and the fan means for displaying of decorative graphic material.

  2. 浦东拟黑麻蝇三龄幼虫记述(双翅目:麻蝇科)%DESCRIPTION OF THE THIRD STAGE LARVA OF BEZIELLA PUDONGENSIS FAN, CHEN ET LU (IN PRESS) (DIPTERA:SARCOPHAGIDAE)

    Institute of Scientific and Technical Information of China (English)

    卢兆荣; 邓耀华; 陈之梓

    2003-01-01

    调查中在上海浦东芦苇荡里的死螃蜞体内发现三龄幼虫,经饲养羽化出浦东拟黑麻蝇Beziella pudongensis Fan,Chen et Lu,sp.n.(武夷科学,待发表)雄、雌成虫.本新种三令幼虫记述,亦是拟黑麻蝇属中的幼虫首次报道. 本新种与黑尾黑麻蝇Helicophagella melanura(Meigen)的雄虫虽貌似而不近缘,本文从它们三龄幼虫的体壁、口咽器、前气门、后气门、后突起群的突形等都有很大差异,而生态习性也显然不同,黑尾黑麻蝇幼虫常在人、畜粪中发现,是住区常见蝇种之一,而浦东拟黑麻蝇幼虫仅在大片芦苇荡地表的死螃蜞体内发现.两者绝非近缘属、种.%The third stage larva here described were collected from a dead body of amphibious crab in a reedy marsh at Pudong, Shanghai, China. After rearing them, both sexes of Beziella pudongensis Fan, Chen et Lu (as new species in press, the paper will be published in the journal"Wuyi Science" ) were identified.The third stage larva of the genus Beziella Enderlein is described for the first time.Present species in male is superficially similar to that of Helicophagella melanura (Meigen),but not closely related. According to present study, the characteristics including cephalopharyngeal sclerites, anterior and posterior spiracles, perispiracular tubercles etc. between them are well different. They also differ in bionomics that H. melanura is well known as a common synanthropic fly breeding mainly in human and animal excrement, whereas the larvae of present species being found from a dead amphibious crab on ground in a broad reedy marsh near sea wall. Evidently, they are not close relatives.

  3. Simulation of fan topography and soil profile using a coupled soilscape-landscape evolution model

    Science.gov (United States)

    Welivitiya, Dimuth; Willgoose, Garry; Hancock, Greg

    2017-04-01

    In this study the evolution of a fluvial fan, its topography and soil profile grading under erosion and deposition and soil profile weathering was simulated using SSPAM coupled soil-landscape evolution model. A constant rainfall was simulated on a synthetic landform and a fluvial fan depositional structure was allowed to form at the latter part of the landform. At each time step the geomorphological and particle size distribution information of the fan was recorded. Using this recorded information, the evolutionary characteristics of the fan as well as the surface and subsurface sediment characteristics was examined and compared with experimental and field observation data. Different fan profile sections were also derived from the recorded data and analysed. The simulation produced a fluvial fan semicircular in shape, with concave up long profiles and convex up cross profiles. The surface sediment sizes of the simulated fan were coarsest near the fan apex and fines toward the fan toe with coarse grained sediment filaments extending radially from the fan apex. These geomorphological features and surface sediment distribution agrees well with field observations of natural fans. The results of the simulation also show that the fan develops as a result of the channel bringing sediments in to the fan and periodically changing its path due to steepening of channel gradient by sediment deposition. The position of the channel is fixed at the fan apex and the channel path constantly changes along any radial direction form the fan apex. This process is remarkably similar to the process of "Fan head trenching" described in literature which is the dominant process in fluvial fan development in the field. Finally, the analysis of fan cross-sections revealed complex sediment layering patterns in the fan profile. The simulation results of the SSSPAM coupled soilscape-landscape evolution model provide qualitatively correct geomorphological and sedimentary characterization of the

  4. Performance of transonic fan stage with weight flow per unit annulus area of 198 kilograms per second per square meter (40.6(lb/sec)/sq ft)

    Science.gov (United States)

    Kovich, G.; Moore, R. D.; Urasek, D. C.

    1973-01-01

    The overall and blade-element performance are presented for an air compressor stage designed to study the effect of weight flow per unit annulus area on efficiency and flow range. At the design speed of 424.8 m/sec the peak efficiency of 0.81 occurred at the design weight flow and a total pressure ratio of 1.56. Design pressure ratio and weight flow were 1.57 and 29.5 kg/sec (65.0 lb/sec), respectively. Stall margin at design speed was 19 percent based on the weight flow and pressure ratio at peak efficiency and at stall.

  5. "I'm Buffy, and you're history": Putting fan studies into history [editorial

    Directory of Open Access Journals (Sweden)

    Nancy Reagin

    2011-03-01

    Full Text Available This essay kicks off the special historical issue of Transformative Works and Cultures by offering an overview of the ways in which fan communities have been studied by academic historians, and how fan studies has written the history of fan communities. The essay discusses historical work done by amateur fan historians throughout the 20th century; what academic historians can offer fan communities; why academic historians could benefit from studying fandoms as part of the history of popular culture; and what fan studies as a discipline might gain from a broader historical analysis of fandoms.

  6. Towards a three-component model of fan loyalty: a case study of Chinese youth.

    Science.gov (United States)

    Zhang, Xiao-xiao; Liu, Li; Zhao, Xian; Zheng, Jian; Yang, Meng; Zhang, Ji-qi

    2015-01-01

    The term "fan loyalty" refers to the loyalty felt and expressed by a fan towards the object of his/her fanaticism in both everyday and academic discourses. However, much of the literature on fan loyalty has paid little attention to the topic from the perspective of youth pop culture. The present study explored the meaning of fan loyalty in the context of China. Data were collected by the method of in-depth interviews with 16 young Chinese people aged between 19 and 25 years who currently or once were pop fans. The results indicated that fan loyalty entails three components: involvement, satisfaction, and affiliation. These three components regulate the process of fan loyalty development, which can be divided into four stages: inception, upgrade, zenith, and decline. This model provides a conceptual explanation of why and how young Chinese fans are loyal to their favorite stars. The implications of the findings are discussed.

  7. Towards a three-component model of fan loyalty: a case study of Chinese youth.

    Directory of Open Access Journals (Sweden)

    Xiao-xiao Zhang

    Full Text Available The term "fan loyalty" refers to the loyalty felt and expressed by a fan towards the object of his/her fanaticism in both everyday and academic discourses. However, much of the literature on fan loyalty has paid little attention to the topic from the perspective of youth pop culture. The present study explored the meaning of fan loyalty in the context of China. Data were collected by the method of in-depth interviews with 16 young Chinese people aged between 19 and 25 years who currently or once were pop fans. The results indicated that fan loyalty entails three components: involvement, satisfaction, and affiliation. These three components regulate the process of fan loyalty development, which can be divided into four stages: inception, upgrade, zenith, and decline. This model provides a conceptual explanation of why and how young Chinese fans are loyal to their favorite stars. The implications of the findings are discussed.

  8. Characterizing subsurface hydraulic heterogeneity of alluvial fan using riverstage fluctuations

    Science.gov (United States)

    Wang, Yu-Li; Yeh, Tian-Chyi Jim; Wen, Jet-Chau; Huang, Shao-Yang; Zha, Yuanyuan; Tsai, Jui-Pin; Hao, Yonghong; Liang, Yue

    2017-04-01

    The objective of this study is to demonstrate the ability of riverstage tomography to estimate 2-D spatial distribution of hydraulic diffusivity (D) of Zhuoshui River alluvial fan, Taiwan, using groundwater level data from 65 wells and stream stage data from 5 gauging stations. In order to accomplish this objective, wavelet analysis is first conducted to investigate the temporal characteristics of groundwater level, precipitation, and stream stage. The results of the analysis show that variations of groundwater level and stream stage are highly correlated over seasonal and annual periods while that between precipitation is less significant. Subsequently, spatial cross-correlation between seasonal variations of groundwater level and riverstage data is analyzed. It is found that the correlation contour map reflects the pattern of sediment distribution of the fan. This finding is further substantiated by the cross-correlation analysis using both noisy and noise-free groundwater and riverstage data of a synthetic aquifer, where aquifer heterogeneity is known exactly. The ability of riverstage tomography is then tested with these synthetic data sets to estimate D distribution. Finally, the riverstage tomography is applied to the alluvial fan. The results of the application reveal that the apex and southeast of the alluvial fan are regions with relatively high D and the D values gradually decrease toward the shoreline of the fan. In addition, D at northern alluvial fan is slightly larger than that at southern. These findings are consistent with the geologic evolution of this alluvial fan.

  9. Measurements of the unsteady flow field within the stator row of a transonic axial-flow fan. Part 2: Results and discussion

    Science.gov (United States)

    Hathaway, M. D.; Suder, K. L.; Okiishi, T. H.; Strazisar, A. J.; Adamczyk, J. J.

    1987-01-01

    Unsteady velocity field measurements made within the stator row of a transonic axial-flow fan are presented. Measurements were obtained at midspan for two different stator blade rows using a laser anemometer. The first stator row consists of double circular-arc airfoils with a solidity of 1.68. The second features controlled-diffusion airfoils with a solidity of 0.85. Both were tested at design-speed peak efficiency conditions. In addition, the controlled-diffusion stator was also tested at near stall conditions. The procedures developed here are used to identify the rotor wake generated and unresolved unsteadiness from the velocity measurements (rotor wake generated unsteadiness refers to the unsteadiness generated by the rotor wake velocity deficit and unresolved unsteadiness refers to all remaining unsteadiness which contributes to the spread in the distribution of velocities such as vortex shedding, turbulence, etc.). Auto and cross correlations of these unsteady velocity fluctuations are presented to show their relative magnitude and spatial distributions. Amplification and attenuation of both rotor wake generated and unresolved unsteadiness are shown to occur within the stator blade passage.

  10. Debris-flow dominance of alluvial fans masked by runoff reworking and weathering

    NARCIS (Netherlands)

    de Haas, Tjalling; Ventra, Dario; Carbonneau, Patrice E.; Kleinhans, Maarten G.

    2014-01-01

    Arid alluvial fan aggradation is highly episodic and fans often comprise active and inactive sectors. Hence the morphology and texture of fan surfaces are partly determined by secondary processes of weathering and erosion in addition to primary processes of aggradation. This introduces considerable

  11. Debris-flow dominance of alluvial fans masked by runoff reworking and weathering.

    OpenAIRE

    Haas, T.; Ventra, D.; Carbonneau, P. E.; Kleinhans, M. G.

    2014-01-01

    Arid alluvial fan aggradation is highly episodic and fans often comprise active and inactive sectors. Hence the morphology and texture of fan surfaces are partly determined by secondary processes of weathering and erosion in addition to primary processes of aggradation. This introduces considerable uncertainty in the identification of formative processes of terrestrial and Martian fans from aerial and satellite imagery. The objectives of this study are (i) to develop a model to describe the s...

  12. Air Distribution in Rooms with a Fan-Driven Convector

    DEFF Research Database (Denmark)

    Larsen, Tine Steen; Bindels, Rob H.W.; Michalak, Lukasz

    2007-01-01

    Experiments with a fan-driven convector used for both heating and cooling are de.scribed in this paper. Only the cooling situation is considered. The convector is positioned in the upper corner ofthe room, and from there the cold air is let out through the device along the ceiling. The airflow...... coming from the dijfuser is partly controlled by the momentum flow and partly from gravity forces, where the thermal load in the room and the temperature difference between room air and supply air affect the airflow from the convector. The convector system was tested in the same test room in which many...... regular ventilation systems were tested earlier to be ahle to compare airflow from the convector .system with regular ventilation ,systems at a later stage of this research. The heat load in the room consists of a thermal manikin sitting at a desk, a computer, and a desk lamp producing a total heat load...

  13. Early diagenesis in the sediments of the Congo deep-sea fan dominated by massive terrigenous deposits: Part III - Sulfate- and methane- based microbial processes

    Science.gov (United States)

    Pastor, L.; Toffin, L.; Decker, C.; Olu, K.; Cathalot, C.; Lesongeur, F.; Caprais, J.-C.; Bessette, S.; Brandily, C.; Taillefert, M.; Rabouille, C.

    2017-08-01

    Geochemical profiles (SO42-, H2S, CH4, δ13CH4) and phylogenetic diversity of Archaea and Bacteria from two oceanographic cruises dedicated to the lobes sediments of the Congo deep-sea fan are presented in this paper. In this area, organic-rich turbidites reach 5000 m and allow the establishment of patchy cold-seep-like habitats including microbial mats, reduced sediments, and vesicomyid bivalves assemblages. These bivalves live in endosymbiosis with sulfur-oxidizing bacteria and use sulfides to perform chemosynthesis. In these habitats, unlike classical abyssal sediments, anoxic processes are dominant. Total oxygen uptake fluxes and methane fluxes measured with benthic chambers are in the same range as those of active cold-seep environments, and oxygen is mainly used for reoxidation of reduced compounds, especially in bacterial mats and reduced sediments. High concentrations of methane and sulfate co-exist in the upper 20 cm of sediments, and evidence indicates that sulfate-reducing microorganisms and methanogens co-occur in the shallow layers of these sediments. Simultaneously, anaerobic oxidation of methane (AOM) with sulfate as the electron acceptor is evidenced by the presence of ANMEs (ANaerobic MEthanotroph). Dissolved sulfide produced through the reduction of sulfate is reoxidized through several pathways depending on the habitat. These pathways include vesicomyid bivalves uptake (adults or juveniles in the bacterial mats habitats), reoxidation by oxygen or iron phases within the reduced sediment, or reoxidation by microbial mats. Sulfide uptake rates by vesicomyids measured in sulfide-rich sea water (90±18 mmol S m-2 d-1) were similar to sulfide production rates obtained by modelling the sulfate profile with different bioirrigation constants, highlighting the major control of vesicomyids on sulfur cycle in their habitats.

  14. Fan Noise Source Diagnostic Test: Tone Modal Structure Results

    Science.gov (United States)

    Heidelberg, Laurence J.

    2002-01-01

    This investigation is part of a test series that was extremely comprehensive and included aerodynamic and acoustic testing of a fan stage using two different fan rotors and three different stator designs. The test series is known as the Source Diagnostic Test (SDT) and was conducted by NASA Glenn as part of the Advanced Subsonic Technology (AST) Noise Reduction Program. Tone mode measurements of one of the rotors with three different stators were made. The stator designs involve changes in vane count and sweep at constant solidity. The results of both inlet and exhaust tone mode measurements are presented in terms of mode power for both circumferential and radial mode orders. The results show benefits of vane sweep to be large, up to 13 dB in total tone power. At many conditions, the increase in power due to cutting on the rotor/stator interaction is more than offset by vane sweep. The rotor locked mode is shown as an important contributor to tone power when the blade tip speed is near and above Mach one. This is most evident in the inlet when the direct rotor field starts to cut on.

  15. Fans af Bruce

    DEFF Research Database (Denmark)

    Vaaben, Nana Katrine

    2007-01-01

    Analysen viser, hvordan det samme ritual under en koncert forener og opdeler de fans, der orienterer sig mod Bruce Springsteen. På den ene side forener ritualet hele publikum i en stor fælles "Intimitet for mange" og på den anden side splitter det dem, fordi det bliver tydeligt, hvem der er de ri...

  16. What a Football Fan

    Institute of Scientific and Technical Information of China (English)

    王保安; 孙鹏

    2004-01-01

    While the football fan was thrilled to be at the Super Bowl, he was disappointed with the location of his seat. Peering across the stadium through his binoculars, he spied an empty seat on the 50-yard line and made his way there.

  17. The Conceptual Design of High Pressure Reversible Axial Tunnel Ventilation Fans

    Directory of Open Access Journals (Sweden)

    A. G. Sheard

    2012-01-01

    Full Text Available Tunnel ventilation fans, classically, must have the ability to both supply and extract air from a tunnel system, with the operator's choice dependent on the tunnel ventilation system's operating mode most appropriate at any given point in time. Consequently, tunnel ventilation fans must incorporate a reversible aerodynamic design which limits the maximum fan pressure rise. This paper presents three high pressure reversible fan concepts. These comprise a two-stage counter rotating fan, a single-stage high speed fan, and a two-stage fan with a single motor and impeller on each end of the motor shaft. The authors consider the relative merits of each concept. The third concept offers the most compact fan, transform, silencer, and damper package size. The authors discuss the mechanical design challenges that occur with a two-stage fan with a single motor and impeller on each end of the motor shaft. They present and consider a selected motor bearing arrangement and casing design for maintainability. Finally, the authors present both prototype fan and full-scale package aerodynamic and acoustic performance, before discussing the challenges presented by high temperature certification in accordance with the requirements of EN 12101-3: 2012.

  18. Effects of perforation number of blade on aerodynamic performance of dual-rotor small axial flow fans

    Science.gov (United States)

    Hu, Yongjun; Wang, Yanping; Li, Guoqi; Jin, Yingzi; Setoguchi, Toshiaki; Kim, Heuy Dong

    2015-04-01

    Compared with single rotor small axial flow fans, dual-rotor small axial flow fans is better regarding the static characteristics. But the aerodynamic noise of dual-rotor small axial flow fans is worse than that of single rotor small axial flow fans. In order to improve aerodynamic noise of dual-rotor small axial flow fans, the pre-stage blades with different perforation numbers are designed in this research. The RANS equations and the standard k-ɛ turbulence model as well as the FW-H noise model are used to simulate the flow field within the fan. Then, the aerodynamic performance of the fans with different perforation number is compared and analyzed. The results show that: (1) Compared to the prototype fan, the noise of fans with perforation blades is reduced. Additionally, the noise of the fans decreases with the increase of the number of perforations. (2) The vorticity value in the trailing edge of the pre-stage blades of perforated fans is reduced. It is found that the vorticity value in the trailing edge of the pre-stage blades decreases with the increase of the number of perforations. (3) Compared to the prototype fan, the total pressure rising and efficiency of the fans with perforation blades drop slightly.

  19. Why do fans attend world Wrestling Entertainment? | Kruger | South ...

    African Journals Online (AJOL)

    South African Journal for Research in Sport, Physical Education and Recreation ... at a live Smackdown event in July 2011, which was part of the WWE's world tour. ... Therefore, marketing campaigns directed at these fans should be designed ...

  20. Acoustic Measurements of an Uninstalled Spacecraft Cabin Ventilation Fan Prototype

    Science.gov (United States)

    Koch, L. Danielle; Brown, Clifford A.; Shook, Tony D.; Winkel, James; Kolacz, John S.; Podboy, Devin M.; Loew, Raymond A.; Mirecki, Julius H.

    2012-01-01

    Sound pressure measurements were recorded for a prototype of a spacecraft cabin ventilation fan in a test in the NASA Glenn Acoustical Testing Laboratory. The axial fan is approximately 0.089 m (3.50 in.) in diameter and 0.223 m (9.00 in.) long and has nine rotor blades and eleven stator vanes. At design point of 12,000 rpm, the fan was predicted to produce a flow rate of 0.709 cu m/s (150 cfm) and a total pressure rise of 925 Pa (3.72 in. of water) at 12,000 rpm. While the fan was designed to be part of a ducted atmospheric revitalization system, no attempt was made to throttle the flow or simulate the installed configuration during this test. The fan was operated at six speeds from 6,000 to 13,500 rpm. A 13-microphone traversing array was used to collect sound pressure measurements along two horizontal planes parallel to the flow direction, two vertical planes upstream of the fan inlet and two vertical planes downstream of the fan exhaust. Measurements indicate that sound at blade passing frequency harmonics contribute significantly to the overall audible noise produced by the fan at free delivery conditions.

  1. Wikipedia and participatory culture: Why fans edit [symposium

    Directory of Open Access Journals (Sweden)

    Paul Thomas

    2016-09-01

    Full Text Available Online, fans of popular culture media partake in participatory culture in various ways, such as writing fan fiction and scrutinizing media on message boards. Another way they do so is by editing relevant articles in the online encyclopedia Wikipedia. In fact, research has shown that Wikipedia articles skew heavily toward pop culture, suggesting that fans of pop culture are among the most enthusiastic of Wikipedia's editors. Of course, the question emerges: Why are pop culture fans in particular so interested in editing Wikipedia? Building on previous research, I argue that fans want to take part in the production of the media that they enjoy, that Wikipedia allows editors to create their own paratext (i.e., the Wikipedia article in relation to a main text (e.g., a movie, a television show, a book series, and that this paratext may be heavily used by the general public. Such usage is a form of implicit approval that affirms the editors' knowledge and encourages them to make more edits. Thus, Wikipedia validates the fan editor's work in a way that other outlets for participatory culture (e.g., fan fiction, fan art, songwriting cannot.

  2. Fan Stall Flutter Flow Mechanism Studied

    Science.gov (United States)

    Lepicovsky, Jan

    2002-01-01

    Modern turbofan engines employ a highly loaded fan stage with transonic or low-supersonic velocities in the blade-tip region. The fan blades are often prone to flutter at off-design conditions. Flutter is a highly undesirable and dangerous self-excited mode of blade oscillations that can result in high-cycle fatigue blade failure. The origins of blade flutter are not fully understood yet. Experimental data that can be used to clarify the origins of blade flutter in modern transonic fan designs are very limited. The Transonic Flutter Cascade Facility at the NASA Glenn Research Center was developed to experimentally study the details of flow mechanisms associated with fan flutter. The cascade airfoils are instrumented to measure high-frequency unsteady flow variations in addition to the steady flow data normally recorded in cascade tests. The test program measures the variation in surface pressure in response to the oscillation of one or more of the cascade airfoils. However, during the initial phases of the program when all airfoils were in fixed positions, conditions were found where significant time variations in the pressures near the airfoil leading edges could be observed.

  3. Transplantation in end-stage pulmonary hypertension (Third International Right Heart Failure Summit, part 3).

    Science.gov (United States)

    Lala, Anuradha

    2014-12-01

    The Third International Right Heart Summit was organized for the purpose of bringing an interdisciplinary group of expert physician-scientists together to promote dialogue involving emerging concepts in the unique pathophysiology, clinical manifestation, and therapies of pulmonary vascular disease (PVD) and right heart failure (RHF). This review summarizes key ideas addressed in the section of the seminar entitled "Transplantation in End-Stage Pulmonary Hypertension." The first segment focused on paradigms of recovery for the failing right ventricle (RV) within the context of lung-alone versus dual-organ heart-lung transplantation. The subsequent 2-part section was devoted to emerging concepts in RV salvage therapy. A presentation of evolving cell-based therapy for the reparation of diseased tissue was followed by a contemporary perspective on the role of mechanical circulatory support in the setting of RV failure. The final talk highlighted cutting-edge research models utilizing stem cell biology to repair diseased tissue in end-stage lung disease-a conceptual framework within which new therapies for PVD have potential to evolve. Together, these provocative talks provided a novel outlook on how the treatment of PVD and RHF can be approached.

  4. Observational Analysis of Coronal Fans

    Science.gov (United States)

    Talpeanu, D.-C.; Rachmeler, L; Mierla, Marilena

    2017-01-01

    Coronal fans (see Figure 1) are bright observational structures that extend to large distances above the solar surface and can easily be seen in EUV (174 angstrom) above the limb. They have a very long lifetime and can live up to several Carrington rotations (CR), remaining relatively stationary for many months. Note that they are not off-limb manifestation of similarly-named active region fans. The solar conditions required to create coronal fans are not well understood. The goal of this research was to find as many associations as possible of coronal fans with other solar features and to gain a better understanding of these structures. Therefore, we analyzed many fans and created an overview of their properties. We present the results of this statistical analysis and also a case study on the longest living fan.

  5. A Two-Stage Layered Mixture Experiment Design for a Nuclear Waste Glass Application-Part 2

    Energy Technology Data Exchange (ETDEWEB)

    Cooley, Scott K.; Piepel, Gregory F.; Gan, Hao; Kot, Wing; Pegg, Ian L.

    2003-12-01

    Part 1 (Cooley and Piepel, 2003a) describes the first stage of a two-stage experimental design to support property-composition modeling for high-level waste (HLW) glass to be produced at the Hanford Site in Washington state. Each stage used a layered design having an outer layer, an inner layer, a center point, and some replicates. However, the design variables and constraints defining the layers of the experimental glass composition region (EGCR) were defined differently for the second stage than for the first. The first-stage initial design involved 15 components, all treated as mixture variables. The second-stage augmentation design involved 19 components, with 14 treated as mixture variables and 5 treated as non-mixture variables. For each second-stage layer, vertices were generated and optimal design software was used to select alternative subsets of vertices for the design and calculate design optimality measures. A model containing 29 partial quadratic mixture terms plus 5 linear terms for the non-mixture variables was the basis for the optimal design calculations. Predicted property values were plotted for the alternative subsets of second-stage vertices and the first-stage design points. Based on the optimality measures and the predicted property distributions, a ''best'' subset of vertices was selected for each layer of the second-stage to augment the first-stage design.

  6. Fan Cart: The Next Generation

    Science.gov (United States)

    Lamore, Brian

    2016-10-01

    For years the fan cart has provided physics students with an excellent resource for exploring fundamental mechanics concepts such as acceleration, Newton's laws, impulse, momentum, work-energy, and energy conversions. The Physics Teacher has even seen some excellent do-it-yourself (DIY) fan carts and activities. If you are interested in developing the `E' portion of your and your students' STEM (science, technology, engineering, and math) skills, one way to accomplish this is to revisit the DIY fan cart. In this article I share a design of a new edition of the DIY fan cart and some ideas for incorporating the engineering design process into your high school curriculum.

  7. Numerical Study of Transition of an Annular Lift Fan Aircraft

    Directory of Open Access Journals (Sweden)

    Yun Jiang

    2016-09-01

    Full Text Available The present study aimed at studying the transition of annular lift fan aircraft through computational fluid dynamics (CFD simulations. The oscillations of lift and drag, the optimization for the figure of merit, and the characteristics of drag, yawing, rolling and pitching moments in transition are studied. The results show that a two-stage upper and lower fan lift system can generate oscillations of lift and drag in transition, while a single-stage inner and outer fan lift system can eliminate the oscillations. The characteristics of momentum drag of the single-stage fans in transition are similar to that of the two-stage fans, but with the peak of drag lowered from 0.63 to 0.4 of the aircraft weight. The strategy to start transition from a negative angle of attack −21° further reduces the peak of drag to 0.29 of the weight. The strategy also reduces the peak of pitching torque, which needs upward extra thrusts of 0.39 of the weight to eliminate. The peak of rolling moment in transition needs differential upward thrusts of 0.04 of the weight to eliminate. The requirements for extra thrusts in transition lead to a total thrust–weight ratio of 0.7, which makes the aircraft more efficient for high speed cruise flight (higher than 0.7 Ma.

  8. Experimental Methods Applied in a Study of Stall Flutter in an Axial Flow Fan

    Directory of Open Access Journals (Sweden)

    John D. Gill

    2004-01-01

    Full Text Available Flutter testing is an integral part of aircraft gas turbine engine development. In typical flutter testing blade mounted sensors in the form of strain gages and casing mounted sensors in the form of light probes (NSMS are used. Casing mounted sensors have the advantage of being non-intrusive and can detect the vibratory response of each rotating blade. Other types of casing mounted sensors can also be used to detect flutter of rotating blades. In this investigation casing mounted high frequency response pressure transducers are used to characterize the part-speed stall flutter response of a single stage unshrouded axial-flow fan. These dynamic pressure transducers are evenly spaced around the circumference at a constant axial location upstream of the fan blade leading edge plane. The pre-recorded experimental data at 70% corrected speed is analyzed for the case where the fan is back-pressured into the stall flutter zone. The experimental data is analyzed using two probe and multi-probe techniques. The analysis techniques for each method are presented. Results from these two analysis methods indicate that flutter occurred at a frequency of 411 Hz with a dominant nodal diameter of 2. The multi-probe analysis technique is a valuable method that can be used to investigate the initiation of flutter in turbomachines.

  9. River path selection in response to uplift and interaction with alluvial fans

    Science.gov (United States)

    Grimaud, J. L.; Paola, C.; Voller, V. R.

    2015-12-01

    River systems construct stratigraphic successions and build land by depositing and redistributing sediments as they migrate across the entire basin. This mobility arises from the intrinsic variability of a river system but can also be forced by external changes. It is particularly observable in tectonically active basins where the basement can be partly uplifted and where sediments can come from multiple sources. Theoretically, the ability of these perturbations to steer channels depends on their capacity to create lateral topographic gradients at a faster rate than the aggradation. Following these lines, we present an experimental study on the impacts of lateral tilting by tectonics and lateral alluvial fans on rivers path. The experiment was conducted in the eXperimental Earth Scape facility, also known as the Jurassic tank, where the basement tilting rate can be monitored by controlling individually gravel subsidence through 108 hexagonal cells. The basin was relatively uplifted on one side of the tank according to an anticline-shape and sediments were input through two sources: a main, axial one and a lateral, secondary one. We analyzed the differences in the topographic signature and flow occupation of rivers in response to the uplift or the lateral sediment source as well as the competition of these forcing in the late stages of the experiments. We found that both tectonic tilting and fan activity tend to decrease the basin-wide channel mobility. Indeed, the area at the convergence of the two interacting fans is a long-lasting topographic low that tends to channelize the flow while areas away from it are less visited. The position of this boundary is correlated with the relative flow contribution from both fans. This highlights the self-healing capacity of fans that are able to rapidly restore a graded shape. As opposed to fans, an uplifted area will not heal but force rivers to carve long-lasting valleys and increase the relief. When eroded, these uplifted

  10. Development of a new free wake model considering a blade vane interaction for a low noise axial fan planform optimization

    Science.gov (United States)

    Shin, Hyungki; Sun, Hyosung; Lee, Soogab

    2006-03-01

    Multidisciplinary Design Optimization (MDO) is an essential part for low noise axial fan design since various parameters, such as flow rate, efficiency, noise etc., should be considered. For this reason, Response Surface Method (RSM) design technique is adopted as an axial fan design method. RSM has an advantage of choosing objective functions and constraint conditions unrestrictedly on a design space. However, RSM needs a lot of independent variables to construct a proper response surface. Thus an efficient and accurate flow analysis tool is indispensable for optimization. In an axial fan, the discrete (commonly called Blade-Passage-Frequency) components are usually dominant in the noise spectrum. Especially the blade-guide vane interaction is one of most important noise sources. In order to predict this noise component efficiently at the design stage, a new free wake model named Finite Vortex Element (FVE) is devised to simulate this blade-guide vane interaction, which is very difficult to analyze numerically in a conventional free wake model. In this new free wake model, the blade-wake-guide vane interaction is described by cutting a vortex filament when the filament collides with a guide vane. This FVE model is compared with a conventional curved vortex methodology and verified by a comparison with measured data to show its effectiveness and validity. Then FVE model is coupled with RSM to implement a low noise axial fan blade optimization. Using this method, a reduction of 8 dB(A) at 2 m from fan hub in the overall noise level is achieved while the flow rate and the efficiency are maintained as the values of the baseline blade, which implies that FVE wake model coupled with RSM is very effective methodology for MDO problems such as a low noise axial fan design.

  11. Dynamic and Implications of Football Fans' Club and Fans ...

    African Journals Online (AJOL)

    DrNneka

    Dross (2009) identified football games as one event that has proved potent ... have potential of drawing human attention to participate either as a player or as a ... However, beyond what football fans wears, the fans are sometimes ready to ...

  12. Terrestrial Cosmogenic-Nuclide Dating of Alluvial Fans in Death Valley, California

    Science.gov (United States)

    Machette, Michael N.; Slate, Janet L.; Phillips, Fred M.

    2008-01-01

    We have used terrestrial cosmogenic nuclides (TCN) to establish the age of some of the most extensive Quaternary alluvial fans in Death Valley, California. These intermediate-age alluvial fans are most extensive on the western side of the valley, where tectonic deformation is considerably less pronounced than on the eastern side of the valley. These fans are characterized by a relatively smooth, densely packed desert pavement formed by well-varnished (blackened) clasts. These surfaces have been mapped as the Q2 gravel by previous workers and as unit Qai (intermediate age) by us. However, the intermediate-age gravels probably contain multiple subunits, as evidenced by slight differences in morphologic expression, soil formation, and inset geomorphic relations. The TCN technique used herein sums the cosmogenic 36Cl in approximately 2.5-meter-deep profiles through soil and host alluvium, thus avoiding some of the problems associated with the more typical surface-exposure dating of boulders or smaller clasts. Our TCN 36Cl dating of 12 depth profiles indicates that these intermediate-age (Qai) alluvial fans range from about 100 to 40 kilo-annum (ka), with a mean age of about 70 ka. An alternative interpretation is that alluvial unit Qai was deposited in two discrete episodes from 90 to 80 ka and from 60 to 50 ka, before and after MIS (marine oxygen-isotope stage) 4 (respectively). Without an intermediate-age unit, such as MIS 4 lake deposits, we can neither disprove nor prove that Qai was deposited in two discrete intervals or over a longer range of time. Thus, in Death Valley, alluvial unit Qai largely brackets MIS 4, which is not associated with a deep phase of Lake Manly. These Qai fans extend to elevations of about -46 meters (150 feet below sea level) and have not been transgressed by Lake Manly, suggesting that MIS 4 or MIS 2 lakes were rather shallow in Death Valley, perhaps because they lacked inflow from surface runoff of the Sierra Nevada drainages through

  13. Fans of Columbine shooters Eric Harris and Dylan Klebold

    Directory of Open Access Journals (Sweden)

    Andrew Ryan Rico

    2015-09-01

    Full Text Available On April 20, 1999, Eric Harris and Dylan Klebold murdered 12 students and one teacher at Columbine High School in Littleton, Colorado, in what was then the deadliest school shooting in American history. Despite causing a national panic and serving as a flash point for larger narratives on bullying, gun control, and media violence, both boys have gained active online fans. These fandoms dedicated to the Columbine shooters are widely referred to as dark examples of Internet communities, while the fans are also frequently denigrated as unstable and violent outcasts. Such dark online fandoms are yet to permeate mainstream culture or to challenge the preexisting perception of these communities as breeding grounds for the next wave of school shooters. While studies have covered the types of fans and their myriad interests, the field remains focused on more conventional examples of fan communities. In an effort to challenge and expand the object of focus when we study fandom, this qualitative study examines Columbine fans and their activity in order to understand the dominant motives they appear to have for engaging with and around such controversial figures and then concludes by exploring how this community might help us reflect more broadly on our concept of fandom. Redeeming these fans as part of diverse and complex communities of social relevance can demonstrate how even a dark fandom such as that of these Columbine shooters provides valuable cultural insights and benefits the field of fan studies.

  14. Promoting fan engagement: An exploration of the fundamental motives for sport consumption amongst premier league football spectators

    NARCIS (Netherlands)

    Stander, Frederick W.; van Zyl, Llewellyn E.; Motaung, Kemiso

    2016-01-01

    The aim of this study was to examine whether fan engagement could be predicted by the motivational dimensions of sport consumption. A sample of 806 football sport fans (African = 85%, male = 67.4%, part of an organised supporters club = 57.6%) were participants. They completed the Fan Engagement

  15. Promoting fan engagement: An exploration of the fundamental motives for sport consumption amongst premier league football spectators

    NARCIS (Netherlands)

    Stander, Frederick W.; Zyl, van Llewellyn E.; Motaung, Kemiso

    2016-01-01

    The aim of this study was to examine whether fan engagement could be predicted by the motivational dimensions of sport consumption. A sample of 806 football sport fans (African = 85%, male = 67.4%, part of an organised supporters club = 57.6%) were participants. They completed the Fan Engagement Sca

  16. Skífan

    OpenAIRE

    Elín Ólafsdóttir

    2011-01-01

    Skífan er eina fyrirtækið hér á landi sem sérhæfir sig í sölu á tónlist, mynddiskum, tölvuleikjum og leikjatölvum. Sú atvinnugrein sem Skífan tilheyrir hefur fengið að finna töluvert fyrir þróun internetsins þar sem mögulegt er að hlaða þessu efni niður hvort sem er með löglegum eða ólöglegum hætti. Markmið verkefnisins var að skoða hver áhrif sviðsmynda væru á rekstrarlíkan Skífunnar. Höfundur fór í gegnum atvinnuvega- og samkeppnisgreiningu með aðstoð eiganda og rekstrarstjóra Skífunnar...

  17. Fan Cart: The Next Generation

    Science.gov (United States)

    Lamore, Brian

    2016-01-01

    For years the fan cart has provided physics students with an excellent resource for exploring fundamental mechanics concepts such as acceleration, Newton's laws, impulse, momentum, work-energy, and energy conversions. "The Physics Teacher" has even seen some excellent do-it-yourself (DIY) fan carts and activities. If you are interested…

  18. Optimisation of Fan Blade Angle

    Directory of Open Access Journals (Sweden)

    Swaroop M P

    2017-01-01

    Full Text Available This report represents the optimization of fan blade angle in accordance with the various room temperatures that can be in the tropical area like India. We took this work mainly because cooling is an important factor now a days in every area where construction and rooms are there and ceiling fans are the most common device that is commonly used. So it is of utmost importance to tweak the performance of this ceiling fan so that it can function in its most optimal condition. We have modeled the fan in a modeling software (SOLIDWORKS and imported that into an analyzing software (ANSYS and a result is generated on the various blade angles (0, 4, 8 and 12.5 degrees in accordance to room conditions. A trend line curve with the obtained data is expected as the result which can be crucial for designing of future fans

  19. A Two-Stage Layered Mixture Experiment Design for a Nuclear Waste Glass Application-Part 1

    Energy Technology Data Exchange (ETDEWEB)

    Cooley, Scott K.; Piepel, Gregory F.; Gan, Hao; Kot, Wing; Pegg, Ian L.

    2003-12-01

    A layered experimental design involving mixture variables was generated to support developing property-composition models for high-level waste (HLW) glasses. The design was generated in two stages, each having unique characteristics. Each stage used a layered design having an outer layer, an inner layer, a center point, and some replicates. The layers were defined by single- and multi-variable constraints. The first stage involved 15 glass components treated as mixture variables. For each layer, vertices were generated and optimal design software was used to select alternative subsets of vertices and calculate design optimality measures. Two partial quadratic mixture models, containing 25 terms for the outer layer and 30 terms for the inner layer, were the basis for the optimal design calculations. Distributions of predicted glass property values were plotted and evaluated for the alternative subsets of vertices. Based on the optimality measures and the predicted property distributions, a ''best'' subset of vertices was selected for each layer to form a layered design for the first stage. The design for the second stage was selected to augment the first-stage design. The discussion of the second-stage design begins in this Part 1 and is continued in Part 2 (Cooley and Piepel, 2003b).

  20. PLSS 2.5 Fan Design and Development

    Science.gov (United States)

    Quinn, Gregory; Carra, Michael; Converse, David; Chullen, Cinda

    2015-01-01

    NASA is building a high fidelity prototype of an advanced portable life support system (PLSS) as part of the Advanced Exploration Systems Program. This new PLSS, designated as PLSS 2.5, will advance component technologies and systems knowledge in order to inform a future flight program. The oxygen ventilation loop of its predecessor, PLSS 2.0, is driven by a centrifugal fan developed using specifications from the Constellation Program. PLSS technology and system parameters have matured to the point where the existing fan will not perform adequately for the new prototype. In addition, areas of potential improvement have been identified with the existing fan that could be addressed in a new design. As a result, a new fan was designed and tested for the PLSS 2.5.

  1. Damage-Tolerant Fan Casings for Jet Engines

    Science.gov (United States)

    2006-01-01

    All turbofan engines work on the same principle. A large fan at the front of the engine draws air in. A portion of the air enters the compressor, but a greater portion passes on the outside of the engine this is called bypass air. The air that enters the compressor then passes through several stages of rotating fan blades that compress the air more, and then it passes into the combustor. In the combustor, fuel is injected into the airstream, and the fuel-air mixture is ignited. The hot gasses produced expand rapidly to the rear, and the engine reacts by moving forward. If there is a flaw in the system, such as an unexpected obstruction, the fan blade can break, spin off, and harm other engine components. Fan casings, therefore, need to be strong enough to contain errant blades and damage-tolerant to withstand the punishment of a loose blade-turned-projectile. NASA has spearheaded research into improving jet engine fan casings, ultimately discovering a cost-effective approach to manufacturing damage-tolerant fan cases that also boast significant weight reduction. In an aircraft, weight reduction translates directly into fuel burn savings, increased payload, and greater aircraft range. This technology increases safety and structural integrity; is an attractive, viable option for engine manufacturers, because of the low-cost manufacturing; and it is a practical alternative for customers, as it has the added cost saving benefits of the weight reduction.

  2. River terraces and alluvial fans: The case for an integrated Quaternary fluvial archive

    Science.gov (United States)

    Mather, A. E.; Stokes, M.; Whitfield, E.

    2017-06-01

    The fluvial archive literature is dominated by research on river terraces with appropriate mention of adjacent environments such as lakes. Despite modern sedimentary basins comprising a significant (>88%) volume of distributive fluvial systems, of which alluvial fans (>1 km, archive community. Published literature is used to examine both thematic and geographical based benefits of alluvial fan research that can assist understanding of Quaternary fluvial archives. 3 regional case studies are presented that illustrate the interaction between alluvial fan and river terrace archives at Quaternary time-scales at 3 different stages of landscape evolution. These are i) continuous mountain front alluvial fans interacting with a non incising but laterally eroding axial fluvial system; ii) alluvial fans which transition into fluvial terraces as sedimentary basins shift from net aggradation to net incision and iii) tributary-junction alluvial fans that develop predominantly within incising river valley systems. A simple conceptual model is proposed to summarise the dynamic role of alluvial fans within this landscape context. The alluvial fans act as potential 'buffers' between hillslopes and river terrace records under 'top down' climate-driven high sediment supply and alluvial fan aggradation, and 'couplers' during periods of less sediment (in relation to water) discharge and alluvial fan incision. These dynamics will change with the addition of 'bottom up' controls such as main river incision, which will typically enhance the coupling effect of both systems.

  3. Review: Bettina Fritzsche (2003. Pop-Fans. Studie einer Mädchenkultur [Pop-Fans: Study of a Girl Culture

    Directory of Open Access Journals (Sweden)

    Lothar Mikos

    2006-05-01

    Full Text Available This study focuses on the "girl culture" created by fans of boy groups and girl groups. The central case study is used to examine fan practices as cultural practices using reconstructive and documentary methodologies, and to assess the normative demands placed on young people. The study centers on the question of gender socialization by mediated symbolic resources, and shows that fan culture is a self-determined space in which girls can negotiate normative demands and engage with questions of gender, sexuality and the body, testing conformity and obstinacy. Fan activities are presented as part of the self-empowerment of girls. The study makes an important contribution to the research of a specific girl culture. It shows in a brilliant way how media representations are used as symbolic material in everyday cultural practices. URN: urn:nbn:de:0114-fqs0603187

  4. A history of RPGs: Made by fans; played by fans

    Directory of Open Access Journals (Sweden)

    Paul Mason

    2012-09-01

    Full Text Available I explore some aspects of the early history of tabletop role-playing games (RPGs that are perhaps not well known among media scholars, and which offer an alternative take on the idea of fan activity.

  5. "The florals": Female fans over 50 in the Sherlock fandom

    Directory of Open Access Journals (Sweden)

    Line Nybro Petersen

    2017-03-01

    Full Text Available This article uses e-mail interviews with nine female fans to explore what it means to be a fan over the age of 50 of the popular BBC drama Sherlock (2010–. The research aims to better understand the role of fandom in later life, in particular how the participants in this study negotiate their perceptions of their subjective age in relation to being a fan in this part of their life course. This study combines theory on cultural gerontology with fan studies and mediatization theory in order to understand the dynamics and processes that guide fans' negotiations of subjective age as well as the role of fan practices and the affordances of social media in these processes. I argue that fandom, as a manifestation of a mediatized culture, augments the relevance of subjective age and informs the way in which participants in middle and later life perceive and negotiate their own subjective age specifically in relation to fandom as youth culture, women's passion, and creativity.

  6. Stranger than fiction: Fan identity in cosplay

    Directory of Open Access Journals (Sweden)

    Nicolle Lamerichs

    2011-09-01

    Full Text Available Academic accounts of fan cultures usually focus on creative practices such as fan fiction, fan videos, and fan art. Through these practices, fans, as an active audience, closely interpret existing texts and rework them with texts of their own. A practice scarcely examined is cosplay ("costume play", in which fans produce their own costumes inspired by fictional characters. Cosplay is a form of appropriation that transforms and actualizes an existing story in close connection to the fan community and the fan's own identity. I provide analytical insights into this fan practice, focusing on how it influences the subject. Cosplay is understood as a performative activity and analyzed through Judith Butler's concept of performativity. I specifically focus on boundaries between the body and dress, and on those between reality and fiction. I aim to show that cosplay emphasizes the personal enactment of a narrative, thereby offering new perspectives on fan identity.

  7. Football – Feminisation – Fans

    DEFF Research Database (Denmark)

    Mintert, Svenja-Maria

    the number of female fans in football has grown over the past years. A national sense of community, emotion and passion for the game is in particular reached during the international tournaments at live football spectacles and many female fans cheer and sing for ‘their’ team with the utmost conviction. Yet...... sociological theories. The objective is, first, to develop new knowledge and understanding about the impact of football on gendered identity construction and negotiation – in both the performance and the consumption of football – and how these female fans contribute to a European dialogue, the gender......-specific experience and acting out of fandom, and the intersection between gender and national/European identity. The second objective is to study the role of gender in football and fan cultures with regard to gender-specific patterns of cross-cultural communication and identification. The third objective...

  8. Human Location Detection System Using Micro-Electromechanical Sensor for Intelligent Fan

    Science.gov (United States)

    Parnin, S.; Rahman, M. M.

    2017-03-01

    This paper presented the development of sensory system for detection of both the presence and the location of human in a room spaces using MEMS Thermal sensor. The system is able to detect the surface temperature of occupants by a non-contact detection at the maximum of 6 meters far. It can be integrated to any swing type of electrical appliances such as standing fan or a similar devices. Differentiating human from other moving and or static object by heat variable is nearly impossible since human, animals and electrical appliances produce heat. The uncontrollable heat properties which can change and transfer will add to the detection issue. Integrating the low cost MEMS based thermal sensor can solve the first of human sensing problem by its ability to detect human in stationary. Further discrimination and analysis must therefore be made to the measured temperature data to distinguish human from other objects. In this project, the fan is properly designed and program in such a way that it can adapt to different events starting from the human sensing stage to its dynamic and mechanical moving parts. Up to this stage initial testing to the Omron D6T microelectromechanical thermal sensor is currently under several experimental stages. Experimental result of the sensor tested on stationary and motion state of human are behaviorally differentiable and successfully locate the human position by detecting the maximum temperature of each sensor reading.

  9. Tips for giving a memorable presentation Part V: stage fright and rehearsing a presentation.

    Science.gov (United States)

    Harolds, Jay A

    2012-11-01

    Previous articles in this series have included many tips on composing a memorable presentation. This article will focus on rehearsing the presentation and dealing with stage fright. There are additional comments on making sure everything is optimized in the lecture room in advance and other tips for the actual presentation.

  10. Submarine-fan facies associations of the Eocene Butano Sandstone, Santa Cruz mountains, California

    Science.gov (United States)

    Nilsen, Tor H.

    1984-06-01

    The Eocene Butano Sandstone was deposited as a submarine fan in a relatively small, partly restricted basin in a borderland setting. It is possibly as thick as 3000 m and was derived from erosion of nearly Mesozoic granitic and older metamorphic rocks located to the south. Deposition was at lower bathyal to abyssal water depths. The original fan may have been 120-to 160-km long and 80-km wide. Outcrops of submarine-canyon, innerfan, middle-fan, and outer-fan facies associations indicate that the depositional model of Mutti and Ricci Lucchi can be used to describe the Butano Sandstone.

  11. The Female Vikings, a women's fan group in Denmark

    DEFF Research Database (Denmark)

    Mintert, Svenja-Maria; Pfister, Gertrud Ursula

    2014-01-01

    Traditionally, football and fandom have been male domains and celebrations of masculinity. So far there has been some sociological and historical research on women's football; however, little is known about women's fandom, in particular about its formation and development. This article focuses...... on the historical development of a Danish women-only fan group called 'The Female Vikings', which support a professional football club, Lyngby Boldklub (BK), in a city north of Copenhagen. The article explores the backgrounds and motivations of female fans, as well as their ways of staging femininity in a man...

  12. The Reasonable Explanation of Annihilation (fanā in Mysticism

    Directory of Open Access Journals (Sweden)

    Abulfazel Kiashemshaki

    2012-06-01

    Full Text Available Abstrak : Para mistikus melampaui tahap-tahap (derajat kesempurnaan mistik dan maqam spiritual dalam perjalanan mereka menuju Allah yang sulit dimengerti oleh non-mistikus. Karena itu, sebagian besar kalangan reflektif berusaha mengandalkan prinsip-prinsip intelektual dan teoritis mereka untuk memperoleh penjelasan atas pengalaman mistis dan ekstasi. Namun, keberhasilan penjelasannya sepenuhnya berada di bawah kuasa dan kekuatan dari prinsip-prinsip tersebut. (Fanā atau kesirnaan adalah salah satu tahap mistis atau keadaan yang sulit dimengerti oleh non-mistikus sehingga memunculkan berbagai teori yang berbeda untuk menjelaskannya. Pencapaian prestasi ilmiah dan filosofis merupakan penjelasan yang tepat atas fanā. Bagaimanapun upaya yang dilakukan dalam artikel ini membuktikan bahwa satu-satunya penjelasan yang sukses adalah penjelasan yang didasarkan pada prinsip-prinsip teosofi transendental dan mistisisme teoritis.Kata kunci : Fanā, Mistisisme, Penjelasan rasional, Mistisisme teoretis, Filsafat transendentalAbstract : Mystics are passing through stages (degrees of mystic perfection and esoteric abodes (spiritual stations in their spiritual journey to Allah which is difficult for unmystics to understand. Because of this, most of the reflective people are trying to rely on their intellectual and theoretical principles to obtain an understandable explanation of mystical experiences and ecstasy. However the success of such explanation completely lies in the power and strength of the above mentioned principles. (Fanā or annihilation is one of the mystical stages or states which unmystics find very difficult to reasonably understand, hence various and different theories have been provided for its explanation. Various scientific and philosophical achievements are appropriate explanations of annihilation (fanā which is valuable in its place; however effort had been made in this article to prove that the only successful explanation is an

  13. Criticality analysis for weapon disassembly at the Pantex-Plant part II: Staging

    Energy Technology Data Exchange (ETDEWEB)

    Knief, R.A. [Ogden Environmental & Energy Services, Albuquerque, NM (United States)

    1997-06-01

    This paper very briefly describes criticality investigations for nuclear weapon dismantlement at the Pantex Plant. The investigations performed were for pit staging, and build on previous criticality calculations for single pits. The KENO and MCNP computer models were used for pit and container combinations. Scenarios were based on administrative limits and actual or potential physical conditions in the facilities. Essentially all of the pit configurations modeled were subcritical by a substantial amount. It was concluded that a critical configuration involving pit/container combinations is not credible.

  14. STRESS ANALYSIS OF INJECTION MOLDED PARTS IN POST-FILLING STAGE

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The linear isothermo-viscoelastic constitutive equation is established according to the principle of viscoelastic mechanics. Given the boundary conditions of the temperature field, the linear themo-viscoelastic constitutive equation is established acording to the analysis of the thermorheologically simple. The stress analysis model is constructed on the base of some reasonable hypotheses which consider the restraint conditions of mold and the characteristics of injection molding in the post-filling stage. The mathematical model is calculated by the finite difference method. The results can help to predict the warpage of plastic products.

  15. Part 2: Potencies and interactions of polybrominated aromatic hydrocarbons in rainbow trout early life stage mortality

    Energy Technology Data Exchange (ETDEWEB)

    Hornung, M.W.; Zabel, E.W.; Peterson, R.E. [Univ. of Wisconsin, Madison, WI (United States); Bergman, A. [Stockholm Univ. (Sweden); Safe, S. [Texas A and M Univ., College Station, TX (United States)

    1994-12-31

    Polybrominated biphenyls (PBBs), dibenzo-p-dioxins (PBDDs), dibenzofurans (PBDFs), and diphenylethers (PBDPES) in aquatic environments may pose a risk to fish early life stage survival. Following rainbow trout egg microinjection, the potencies of these polybrominated aromatic hydrocarbons were determined using fish specific toxic equivalency factors (TEFs). TEFs are defined as the ratio of TCDD LD{sub 50} to brominated congener LD{sub 50}. Sac fry stage specific TCDD like toxicity included yolk sac edema, pericardial edema, multifocal hemorrhages and craniofacial malformations. TEFs of active congeners were: 2,3,7,8-TBDF = 0.23; 2,3,4,7,8-PBDF = 0.069; 1,2,3,4,7,8-HxBDD = 0.009. No signs of toxicity with 2,2{prime},4,4{prime}-TBDPE, 2,2{prime},3,4,4{prime}-PBDPE, or 2,2{prime},4,4{prime},5-PBDPE occurred at egg concentrations up to 126,37 {mu}g/g. Since these congeners occur as complex mixtures, the potential for additive, antagonistic, or synergistic interactions must also be determined for accurate risk assessment. Graded doses of 2,3,7,8-TBDD or 1,2,3,7,8-PBDD alone, or graded doses of fixed ratios of the two congeners were injected into newly fertilized rainbow trout eggs. Separate dose response curves were determined for each ratio and each individual congener. Isobolographic analysis supports the hypothesis that these congeners act additively.

  16. Football fan aggression: the importance of low Basal cortisol and a fair referee.

    Directory of Open Access Journals (Sweden)

    Leander van der Meij

    Full Text Available Fan aggression in football (soccer is a societal problem that affects many countries worldwide. However, to date, most studies use an epidemiological or survey approach to explain football fan aggression. This study used a controlled laboratory study to advance a model of predictors for fan aggression. To do so, football fans (n = 74 saw a match summary in which their favorite team lost against their most important rival. Next, we measured levels of aggression with the hot sauce paradigm, in which fans were given the opportunity to administer a sample of hot sauce that a rival football supporter had to consume. To investigate if media exposure had the ability to reduce aggression, before the match fans saw a video in which fans of the rival team commented in a neutral, negative, or positive manner on their favorite team. Results showed that the media exposure did not affect aggression. However, participants displayed high levels of aggression and anger after having watched the match. Also, aggression was higher in fans with lower basal cortisol levels, which suggests that part of the aggression displayed was proactive and related to anti-social behavior. Furthermore, aggression was higher when the referee was blamed and aggression was lower when the performance of the participants' favorite team was blamed for the match result. These results indicate that aggression increased when the match result was perceived as unfair. Interventions that aim to reduce football fan aggression should give special attention to the perceived fairness of the match result.

  17. Football fan aggression: the importance of low Basal cortisol and a fair referee.

    Science.gov (United States)

    van der Meij, Leander; Klauke, Fabian; Moore, Hannah L; Ludwig, Yannick S; Almela, Mercedes; van Lange, Paul A M

    2015-01-01

    Fan aggression in football (soccer) is a societal problem that affects many countries worldwide. However, to date, most studies use an epidemiological or survey approach to explain football fan aggression. This study used a controlled laboratory study to advance a model of predictors for fan aggression. To do so, football fans (n = 74) saw a match summary in which their favorite team lost against their most important rival. Next, we measured levels of aggression with the hot sauce paradigm, in which fans were given the opportunity to administer a sample of hot sauce that a rival football supporter had to consume. To investigate if media exposure had the ability to reduce aggression, before the match fans saw a video in which fans of the rival team commented in a neutral, negative, or positive manner on their favorite team. Results showed that the media exposure did not affect aggression. However, participants displayed high levels of aggression and anger after having watched the match. Also, aggression was higher in fans with lower basal cortisol levels, which suggests that part of the aggression displayed was proactive and related to anti-social behavior. Furthermore, aggression was higher when the referee was blamed and aggression was lower when the performance of the participants' favorite team was blamed for the match result. These results indicate that aggression increased when the match result was perceived as unfair. Interventions that aim to reduce football fan aggression should give special attention to the perceived fairness of the match result.

  18. Integrating Environmental Decisions into the Product Development Process: Part 2 - The Later Stages

    DEFF Research Database (Denmark)

    Poole, S.; Simon, M; Sweatman, A.

    1999-01-01

    This paper reports on the results of a three year UK government research project entitle DEsign for the Environment Decision Support (DEEDS). As part of this project, a survey of the electronicis and electrical industry was carried out in order to understand the way in which industry in the UK, C...... change fundamentally if the environemtn is considered pre-specification. In this second paper, we are concerned with the implementation of environmental considerations post-specification....

  19. Integrating Environmental Decisions into the Product Development Process: Part 1 - The Early Stages

    DEFF Research Database (Denmark)

    Bhamra, T.; Evans, S.; McAloone, Timothy Charles;

    1999-01-01

    This paper will report on the results of a three year UK government funded research project entitled Design for the Environment Decision Support (DEEDS). As part of this project a survey of the Electronic and Electrical Industry was carried out in order to understand the way in which industry...... process prior to the specification being finalised. A second paper, considers the findings from the later phases of the product development process....

  20. SPECIALIZED MAPPING OF CRUSTAL FAULT ZONES. PART 2: MAIN STAGES AND PROSPECTS

    Directory of Open Access Journals (Sweden)

    K. Zh. Seminsky

    2015-09-01

    Full Text Available The article is to complete the description of the special mapping method which theoretical basis and principles were published in [Seminsky, 2014]. With reference to data on the Ulirba site located in Priolkhonie (Western Pribaikalie, the content of special mapping is reviewed in detail. The method is based on paragenetical analysis of abundant jointing which specific feature is the lack of any visible displacement indicators. There are three stages in the special mapping method (Fig. 3 as follows:Stage I: Preparation and analysis of previously published data on the regional fault structure (Fig. 1, А–Г, establishment of a networks of stations to conduct structural geological monitoring and mass measurements of joints, re­cord of rock data (Fig. 2, А, general state of the fault network (Fig. 1, Д–З, fracture density (Fig. 2, Б and, if any, structures of the above-jointing level (Fig. 1, Е, З; Fig. 2, А.Stage II is aimed at processing of field data and includes activities in four groups (II.1–II.4 as follows: Group II.1: construction of circle diagrams, specification of characteristics of joint systems and their typical scatters (Fig. 4, А, identification of simple (generally tipple paragenesises, and determination of dynamic settings of their formation (translocal rank (Table 1, evaluation of densities and complexity of the joint networks, analysis of their spacial patterns within the site under mapping, and identification of the most intensively destructed zones in the rock massif (Fig. 2, Б–В. Group II.2: comparison of jointing diagrams with reference ones showing joint poles (Fig. 4, Б–В; Е–З; Л–Н, and, in case of their satisfactory correlation, making a conclusion of potential formation of a specific joint pattern in the local zone of strike-slip, normal faulting or reverse faulting (Fig. 4,  Г–Д, И–К, О–П; Fig. 5; Fig. 7, Б, and determination of relative age relationships between such zones on

  1. Sediment velocities from sonobuoys: Bengal Fan, Sunda Trench, Andaman Basin, and Nicobar Fan

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, E.L.; Bachman, R.T.; Curray, J.R.; Moore, D.G.

    1977-07-10

    New measurements of interval compressional wave velocities were made in the first sediment layer using the sonobuoy technique during two expeditions in the Bay of Bengal, in the Andaman Sea, and over the Nicobar Fan and Sunda Trench. Sediment interval velocities from these areas were added to those previously reported, and revised diagrams and regression equations of instantaneous and mean velocity versus one-way travel time are furnished for four areas of the Bengal Fan, and for the Anadman Basin, Nicobar Fan, Sunda Trench. The velocity gradients directly below the sea floor were used to separate the Bengal Fan into four geoacoustic provinces. In the north and west the velocity gradients are 0.86 and 1.28 s/sup -1/, respectively, whereas in the central part of the fan the gradient is 1.87 s/sup -1/. These variations indicate lesser increases of velocity with depth in the sea floor in the north and west, and they are probably due to more rapid deposition, less consolidation, and less lithification near the riverine source areas of the sediments. The near-surface velocity gradients in the other areas are the Andaman Basin, 1.53 s/sup -1/, the Nicobar Fan 1.63 s/sup -1/, and the Sunda Trench, 1.41 s/sup -1/. The linear velocity gradients (from the sediment surface to a given travel time) in 17 areas of the Indian Ocean, Pacific area, Atlantic Ocean, and Gulf of Mexico were averaged at each 0.1 s from 0 to 0.5 s of one-way travel time. These averaged gradients ranged from 1.32 s/sup -1/ at t=0 to 0.76 s/sup -1/ at t=0.5 s. The regression equation for the velocity gradients a, in s/sup -1/, as a function of one-way travel time t, in seconds, is a=1.316-1.117t (for use from t=0 to 0.5 s). These average velocity gradients can be used with sediment surface velocities and one-way travel times (measured from reflection records) to compute sediment layer thickness in areas of turbidites lacking interval velocity measurements in the first sediment layer.

  2. [Changes in the monoamine content in different parts of hypothalamus depending on the stages of the estrous cycle].

    Science.gov (United States)

    Babichev, V N; Adamskaia, E I

    1976-01-01

    Fluorimetric determination of monoamines in various regions of the hypothalamus and at different stages of the estral cycle in rats showed that the serotonin, noradrenaline, and particularly dophamine content changed both in the course of the cycle and at different time (10, 15 and 18 hours) of the same stage of the cycle. Dophamine concentration in the arcuate area--the centre of the tonic activity--reached its maximum at 18 hours of the diestrus-2 (D2) and fell to the minimum at 10 hours of the proestrus (P). Noradrenaline level in the preoptic area increased at 18 hours of the D2 and fell at 10 hours of the P. It is supposed that in the hypothalamic regulation of the estral cycle at least two monoamines (dopamine and noradrenaline) took part; the trigger role belongs to noradrenaline of the preoptic area (the cyclic centre).

  3. On Some Generalized Ky Fan Minimax Inequalities

    Directory of Open Access Journals (Sweden)

    Luo Xianqiang

    2009-01-01

    Full Text Available Some generalized Ky Fan minimax inequalities for vector-valued mappings are established by applying the classical Browder fixed point theorem and the Kakutani-Fan-Glicksberg fixed point theorem.

  4. Fan Noise Source Diagnostic Test: Vane Unsteady Pressure Results

    Science.gov (United States)

    Envia, Edmane

    2002-01-01

    To investigate the nature of fan outlet guide vane pressure fluctuations and their link to rotor-stator interaction noise, time histories of vane fluctuating pressures were digitally acquired as part of the Fan Noise Source Diagnostic Test. Vane unsteady pressures were measured at seven fan tip speeds for both a radial and a swept vane configuration. Using time-domain averaging and spectral analysis, the blade passing frequency (BPF) harmonic and broadband contents of the vane pressures were individually analyzed. Significant Sound Pressure Level (SPL) reductions were observed for the swept vane relative to the radial vane for the BPF harmonics of vane pressure, but vane broadband reductions due to sweep turned out to be much smaller especially on an average basis. Cross-correlation analysis was used to establish the level of spatial coherence of broadband pressures between different locations on the vane and integral length scales of pressure fluctuations were estimated from these correlations. Two main results of this work are: (1) the average broadband level on the vane (in dB) increases linearly with the fan tip speed for both the radial and swept vanes, and (2) the broadband pressure distribution on the vane is nearly homogeneous and its integral length scale is a monotonically decreasing function of fan tip speed.

  5. Topological invariants of a fan associated to a toric variety

    CERN Document Server

    Ford, T J

    1995-01-01

    Associated to a toric variety X of dimension r over a field k is a fan \\Delta on \\Bbb R^r. The fan \\Delta is a finite set of cones which are in one-to-one correspondence with the orbits of the torus action on X. The fan \\Delta inherits the Zariski topology from X. In this article some cohomological invariants of X are studied in terms of whether or not they depend only on \\Delta and not k. Secondly some numerical invariants of X are studied in terms of whether or not they are topological invariants of the fan \\Delta. That is, whether or not they depend only on the finite topological space defined on \\Delta. The invariants with which we are mostly concerned are the class group of Weil divisors, the Picard group, the Brauer group and the dimensions of the torsion free part of the \\'etale cohomology groups with coefficients in the sheaf of units. The notion of an open neighborhood of a fan is introduced and examples are given for which the above invariants are sufficiently fine to give nontrivial stratifications...

  6. Advance Noise Control Fan II: Test Rig Fan Risk Management Study

    Science.gov (United States)

    Lucero, John

    2013-01-01

    Since 1995 the Advanced Noise Control Fan (ANCF) has significantly contributed to the advancement of the understanding of the physics of fan tonal noise generation. The 9'x15' WT has successfully tested multiple high speed fan designs over the last several decades. This advanced several tone noise reduction concepts to higher TRL and the validation of fan tone noise prediction codes.

  7. College Student Theater Fans

    Institute of Scientific and Technical Information of China (English)

    ZHOUCHAO; CHENZHUO

    2004-01-01

    CHINA has a long tradition of amateur performers called piaoyou or "ticket friends." Piaoyou perform highlights from favorite operas on stage to a rapt audience, but in contrast to conventional opera performances, both performers and viewers are vibrant folk opera aficionados. Piaoyou are generally middle-aged and senior citizens, but today young enthusiasts are to be found in China's universities. Wuhan University has such a group of students.

  8. Steady and Unsteady Casingwall Flow Phenomena in a Single-Stage Low-Speed Compressor at Part-Load Conditions

    Directory of Open Access Journals (Sweden)

    H. Saathoff

    2003-01-01

    Full Text Available This article describes an investigation of the casingwall flow phenomena in a single-stage, axial-flow, low-speed compressor at part-load conditions, utilizing an oil-flow technique to visualize the boundary layer development and highfrequency sensors to measure ensemble-averaged velocity and flow-angle distributions as well as unsteady total pressure distributions. Representative results are shown and discussed. The results enable different sources of endwall blockage to be identified and changes with flow rate to be determined.

  9. Exposure characterization for highway construction. Part I: Cut and cover and tunnel finish stages.

    Science.gov (United States)

    Blute, N A; Woskie, S R; Greenspan, C A

    1999-09-01

    The purpose of this study was to characterize respirable dust, crystalline silica, diesel, and noise exposures to construction workers on a large highway construction project in Boston, Massachusetts. The study primarily focused on operating engineers and laborers, and to a lesser extent on ironworkers and carpenters during the tunnel finish and cut and cover stages. Full and partial shift noise dosimeter measurements were collected. Eighty percent of the 40 noise measurements were at or above 85 dBA, with the operating engineers averaging 91 dBA. Sample collection for respirable dust, crystalline silica, and diesel particulates measured as elemental carbon was done using cyclones and personal cascade impactors. Exposure to respirable dust ranged from 0.06 to 21.77 mg/m3 for the 77 workers sampled, with the laborers having the highest mean concentration of 2.85 mg/m3. The respirable quartz measurements for the 32 samples collected ranged from the detection limit of 0.008 mg/m3 to 1.64 mg/m3, with the highest mean concentration of 0.31 mg/m3 attributed to the laborers. The use of drills, when compared to other machine types, produced the highest exposures to respirable quartz. The levels for elemental carbon ranged from 4 to 178 micrograms/m3 (mean of 41 micrograms/m3) inside enclosed work spaces, compared with 0.5 to 53 micrograms/m3 (mean of 10 micrograms/m3) for samples collected in unenclosed work sites. Statistical modeling of the factors influencing the elemental carbon exposures showed that machine type, worker distance from the diesel source, the number of other diesel sources in the work area, and site enclosure were all significant exposure determinants. The results indicate that high exposures to noise, respirable dust, and crystalline silica are common in the highway construction industry.

  10. Online Fan Fiction and Critical Media Literacy

    Science.gov (United States)

    Black, Rebecca W.

    2010-01-01

    This article explores English-language-learning (ELL) youths' engagement with popular media through composing and publicly posting stories in an online fan fiction writing space. Fan fiction is a genre that lends itself to critical engagement with media texts as fans repurpose popular media to design their own narratives. Analyses describe how…

  11. Surface processes on a mud-dominated Mars analogue alluvial fan, Atacama Desert, northern Chile

    Science.gov (United States)

    Hobley, D. E.; Howard, A. D.; Morgan, A. M.; Matsubara, Y.; Moore, J. M.; Parsons, R.; Williams, R. M.; Burr, D. M.; Hayes, A. G.; Dietrich, W.

    2012-12-01

    . The older, inactive parts of the Atacama fan surface develop partially inverted topography, leaving paleochannels in positive relief. Lack of direct rainfall onto the fan itself means the fan surface is not locally fluvially incised, and the dominant degradation process is aeolian stripping of overbank deposits. Low granular ripples with ~1 m spacing are common on the low surfaces, presumably moving by reptation, and part of a partially mobile desert pavement derived primarily from the channel deposits and channel-marginal overbank sediments. Both development of a coarse grain lag on paleochannel ridge crests and cementation of ridge flanks by halite produce the erodability contrast necessary for inversion.

  12. Rotor redesign for a highly loaded 1800 ft/sec tip speed fan. 1: Aerodynamic and mechanical design report

    Science.gov (United States)

    Norton, J. M.; Tari, U.; Weber, R. M.

    1979-01-01

    A quasi three dimensional design system and multiple-circular-arc airfoil sections were used to design a fan rotor. An axisymmetric intrablade flow field calculation modeled the shroud of an isolated splitter and radial distribution. The structural analysis indicates that the design is satisfactory for evaluation of aerodynamic performance of the fan stage in a test facility.

  13. Fan/Ram Duct Program

    Science.gov (United States)

    1973-10-01

    mwm^mmmt c INPUT I ] H—f TRANSIENT ROUTINE P"" CONTROL """I FAN ] COMPRESSOR MAIN BURNER I DUCT HZ HIGH TURBINE in— LOW TURBINE I...and pressure ratio. 6. Low Turbine Low turbine characteristics, identical In form to those of the high turbine, are shown in figures 27 and 28. 7

  14. School Athletics and Fan Aggression

    Science.gov (United States)

    Bryan, Clifford; Horton, Robert

    1976-01-01

    Several hypotheses are developed regarding fans and their behavior based upon a review of the literature. An exploratory study is then described, in which participant observers at a university sports arena observed cases of aggressive behavior among the spectators. Based upon the literature review and the findings of the study, four…

  15. Euler/Navier-Stokes Solvers Applied to Ducted Fan Configurations

    Science.gov (United States)

    Keith, Theo G., Jr.; Srivastava, Rakesh

    1997-01-01

    Due to noise considerations, ultra high bypass ducted fans have become a more viable design. These ducted fans typically consist of a rotor stage containing a wide chord fan and a stator stage. One of the concerns for this design is the classical flutter that keeps occurring in various unducted fan blade designs. These flutter are catastrophic and are to be avoided in the flight envelope of the engine. Some numerical investigations by Williams, Cho and Dalton, have suggested that a duct around a propeller makes it more unstable. This needs to be further investigated. In order to design an engine to safely perform a set of desired tasks, accurate information of the stresses on the blade during the entire cycle of blade motion is required. This requirement in turn demands that accurate knowledge of steady and unsteady blade loading be available. Aerodynamic solvers based on unsteady three-dimensional analysis will provide accurate and fast solutions and are best suited for aeroelastic analysis. The Euler solvers capture significant physics of the flowfield and are reasonably fast. An aerodynamic solver Ref. based on Euler equations had been developed under a separate grant from NASA Lewis in the past. Under the current grant, this solver has been modified to calculate the aeroelastic characteristics of unducted and ducted rotors. Even though, the aeroelastic solver based on three-dimensional Euler equations is computationally efficient, it is still very expensive to investigate the effects of multiple stages on the aeroelastic characteristics. In order to investigate the effects of multiple stages, a two-dimensional multi stage aeroelastic solver was also developed under this task, in collaboration with Dr. T. S. R. Reddy of the University of Toledo. Both of these solvers were applied to several test cases and validated against experimental data, where available.

  16. [Medroxyprogesterone Acetate as Part of Palliative Care for Terminal-Stage Breast Cancer Patients--A Report of Two Cases].

    Science.gov (United States)

    Okamoto, Akiko; Ueno, Hiroshi; Yamashiro, Akiko; Okada, Megumi; Nakasone, Arisa; Hatano, Takahiko; Harada, Akiho; Taniguchi, Ayano; Onishi, Keiko; Kwon, Chul; Fukazawa, Keita; Taguchi, Tetsuya; Amaya, Fumimasa; Hosokawa, Toyoshi

    2016-03-01

    Various effective strategies have recently been described in the treatment of breast cancer, including endocrine therapy, chemotherapy, and molecular-targeted therapy, providing long-term survival benefits even after cancer recurrence. However, terminal-stage patients experience side effects and worse quality of life (QOL), in addition to deterioration of their general condition caused by the progression of the disease itself. When providing the best supportive care, use of anti-cancer drugs is not taboo and can represent a good option as long as physical, social, psychological, and spiritual supports are provided to both the patients and their families. Medroxyprogesterone acetate (MPA) is an endocrine therapeutic drug. In Japan, MPA is used only as a late-line endocrine therapy for breast cancer recurrence because many other endocrine therapy drugs are much more effective and MPA increases the risk of thrombosis and obesity. Here, we report 2 patients with breast cancer who reached terminal stage more than 10 years after the first diagnosis. MPA was administered as the final-line treatment. During that time, their appetite and QOL improved and the patients became more active than when they had been undergoing aggressive anticancer treatment. Both patients spent quality time with their families until their death. MPA may be a good option as part of palliative care of breast cancer patients in terminal stage.

  17. Measurement of unsteady surface pressure on rotor blades of fans by pressure-sensitive paint

    Science.gov (United States)

    Yokoyama, Hiroshi; Miura, Kouhei; Iida, Akiyoshi

    2017-01-01

    To clarify the unsteady pressure distributions on the rotor blades of an axial fan, a pressure-sensitive paint (PSP) technique was used. To capture the image of the rotating fan as a static image, an optical derotator method with a dove prism was adopted. It was confirmed by preliminary experiments with a resonator and a speaker that the pressure fluctuations with 347 Hz can be measured by the present PSP. The measured mean pressure distributions were compared with the predicted results based on large-eddy simulations. The measured instantaneous surface pressure is instrumental to identify acoustic source of fan noise in the design stage.

  18. Controls on modern tributary-junction alluvial fan occurrence and morphology: High Atlas Mountains, Morocco

    Science.gov (United States)

    Stokes, Martin; Mather, Anne E.

    2015-11-01

    Modern tributary-junction alluvial fans (cone-shaped depositional landforms formed in confined valley settings) were analysed from a 20-km-long reach of the Dades River in the distal part of the fold-thrust belt region in the south-central High Atlas Mountains of Morocco. Here, a deeply dissected network of ephemeral tributary streams and a perennial trunk drainage characterised by an arid mountain desert climate are configured onto a folded and thrust faulted Mesozoic sedimentary sequence. Out of 186 tributary streams, only 29 (16%) generated alluvial fans at their tributary junctions. The fan-generating catchments possess higher relief, longer lengths, lower gradients, and larger areas than nonfan-generating catchments. Whilst geologically, fan-generating catchments are underlain by folded/steeply dipping weak bedrock conducive to high sediment yield. Tributary-junction fans are built from debris flow or fluvial processes into open or confined canyon trunk valley settings. The proximity of the perennial trunk drainage combined with the valley morphology produces lobate or foreshortened trimmed fan forms. Analysis of fan (area, gradient, process), catchment (area, relief, length, gradient), and tributary valley (width) variables reveals weak morphometric relationships, highlighted by residual plots that show dominance of smaller and lower gradient than expected fan forms. These morphometric relationships can be explained by interplay between the catchment and trunk drainage geology, morphology, climate, and flood regime that are combined into a conceptual 'build and reset' model. Ephemeral tributary-junction fans develop progressively during annual localised winter-spring storm events, attempting to build towards a morphological equilibrium. However, the fans never reach an equilibrium morphological form as they are reset by rare (> 10 year) large floods along the River Dades that are linked to regional incursions of Atlantic low pressure troughs. The model

  19. Portable Life Support System 2.5 Fan Design and Development

    Science.gov (United States)

    Quinn, Gregory; Carra, Michael; Converse, David; Chullen, Cinda

    2016-01-01

    NASA is building a high-fidelity prototype of an advanced Portable Life Support System (PLSS) as part of the Advanced Exploration Systems Program. This new PLSS, designated as PLSS 2.5, will advance component technologies and systems knowledge to inform a future flight program. The oxygen ventilation loop of its predecessor, PLSS 2.0, was driven by a centrifugal fan developed using specifications from the Constellation Program. PLSS technology and system parameters have matured to the point where the existing fan will not perform adequately for the new prototype. In addition, areas of potential improvement were identified with the PLSS 2.0 fan that could be addressed in a new design. As a result, a new fan was designed and tested for the PLSS 2.5. The PLSS 2.5 fan is a derivative of the one used in PLSS 2.0, and it uses the same nonmetallic, canned motor, with a larger volute and impeller to meet the higher pressure drop requirements of the PLSS 2.5 ventilation loop. The larger impeller allows it to operate at rotational speeds that are matched to rolling element bearings, and which create reasonably low impeller tip speeds consistent with prior, oxygen-rated fans. Development of the fan also considered a shrouded impeller design that could allow larger clearances for greater oxygen safety, assembly tolerances and particle ingestion. This paper discusses the design, manufacturing and performance testing of the new fans.

  20. Feeding stage, species, body part and sex-specific activity of glutathione S-transferase in mosquito.

    Science.gov (United States)

    Tripathy, A; Kar, S K

    2015-03-01

    In the present study, the feeding stage, body parts, development and sex specific activity of Glutathione S-transferases (GSTs) were observed in different mosquito species (Aedes aegypti, Culex quinquefasciatus, Anopheles stephensi, An. culicifacies, An. annularis, An. subpictus, An. vagus). GST activity was assayed spectrophotometrically at 23°C, using a UV Max microplate Reader, to measure the rate of conjugation of GSH to CDNB. A significant species-specific difference in the activity of GST was noticed, highest being in unfed Ae. aegypti (41.2 nmol/min/mg) followed by unfed Cx. quinquefasciatus (7.9 nmol/min/mg) and the least in unfed An. stephensi (5.8 nmol/min/mg). In all the species the GST activity was found to be significantly higher in fully fed and gravid stages compared with the unfed, while the enzyme activity was reduced after egg laying either to the level of unfed animals or well below its level in all the experimental species. The GST activity was found to be higher in the abdominal region of all the experimental species in comparison with the other body parts (head and thorax). The GST activity of An. stephensi increased gradually through the larval stages and reached the maximum level in the pupae and remained at that level in the newly emerged adults. However, its activity declined markedly (10 fold) with ageing from 5 to 40 days. A significant sex-related difference in the specific activity of GST was found in An. stephensi where approximately 3.5 fold lower activity was observed in males compared with its females, whereas no significant variation was noticed in Ae. aegypti and Cx. quinquefasciatus. The study corroborates the fact that GSTs are differentially regulated by multiple mechanisms in response to xenobiotics modulation in situation-specific manner such as species, sex, feeding and developmental stage. The knowledge of situation-specific modulation of GST will provide a better understanding of GST based insecticide resistance

  1. WHO ARE FANS OF FACEBOOK FAN PAGES? AN ELECTRONIC WORD-OF-MOUTH COMMUNICATION PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    Xiao Hu

    2014-12-01

    Full Text Available Given its great business value and popularity, Facebook fan pages have attracted more and more attention in both industry and academia. Fans of Facebook fan pages play an important role in electronic word-of-mouth (eWOM communication. This study focused on the population of fans on Facebook fan pages and examined the differences between fans and non-fans in terms of demographics, social network sites (SNS use, Internet use, and online shopping behaviors. The results indicated that fans used SNS more frequently than non-fans. Additionally, from the eWOM perspective, the researchers moderated product types in the model of people’s word-of-mouth (WOM preferences and found that people had different preferences for eWOM and traditional WOM for different products. Traditional WOM is still the most important source of information for people when shopping online.

  2. Outburst fan deposit from pyroclastic flows, Williamson River canyon, south-central Oregon

    Science.gov (United States)

    Cummings, M. L.; Eibert, D.

    2016-12-01

    Pyroclastic flows from the Holocene eruption of Mount Mazama in the Cascade volcanic arc of Oregon, blocked the narrow (210 to 225 m wide, 35 to 40 m deep), bedrock-lined canyon of the Williamson River. The estimated volume of the long, narrow blockage was 4.4 x 10^7 cubic meters. The blockage eventually failed releasing an impounded lake and depositing a debris fan at the mouth of the canyon. Remnants of the debris fan underlie a gently sloping surface dissected by various abandoned channels of the river. The modern Williamson River cut its channel across the upper part of the fan. Three bedrock units are present as boulders: hydrovolcanic tuff (Di = 2.75 m) derived from tuff cones in the lower reaches of the canyon, distinctly layered geochemically primitive olivine basalt (Di = 3.4 m) that crops out approximately 6 km upstream, and massive basaltic andesite that underlies the channel in the upper canyon and cliffs that define the right bank of the canyon near the mouth. Matrix between boulders and deposits that flank and overlie the boulder deposit are dominated by medium- to fine-grained sand (ASTM; 61-70 wt. % in matrix; 76-100 wt. % elsewhere). Sand grains are predominantly well-rounded phenocryst-bearing glass that vary from massive to moderately vesiculated and crystals of plagioclase and hornblende commonly with attached remnants of groundmass. Crystals are most abundant in the medium- and fine-grained size range (>20 and fragments (twigs and molds) are common in medium-sand and larger. Elongate bars of rounded pumice gravel provide local current directions during the waning stage of the outburst flood. The thickness of the boulder deposit near the mouth of the canyon is not known. Sand deposits are 1 to 1.5 m thick near the mouth of the canyon and thin to 70 cm at about 3.4 km from the mouth of the canyon.

  3. Football – Feminisation – Fans

    DEFF Research Database (Denmark)

    Mintert, Svenja-Maria

    Football has long time been considered as a genuine masculine domain. However, in the current football culture, the dualism of masculinity and femaleness is in progress. More and more women consume football which is in many countries considered the most popular sport, not only in Scandinavia where...... the number of female fans in football has grown over the past years. A national sense of community, emotion and passion for the game is in particular reached during the international tournaments at live football spectacles and many female fans cheer and sing for ‘their’ team with the utmost conviction. Yet......, the combination ‘women and football’ is still adhered to certain scepticism. Objective The overall objective of this Ph.D. thesis is to contribute to the body of knowledge associated with the distinct aspects of women’s football, female fandom and gender identities in European football drawing upon various...

  4. An Interview with Fan Wu

    Institute of Scientific and Technical Information of China (English)

    李娜

    2006-01-01

    Fan Wu grew up on a farm in South China, in the community to where her parents were exiled during the Cultural Revolution (1966-1976). Wu moved to the United States in 1997, to attend Stanford University, and she began writing in 2002. She now lives and works in northern California, the United State. February Flowers is her first novel. During her recent book tour in China, she took time to talk to Women of China. Women of China (WOC): What inspired

  5. Flow Stability Model for Fan/Compressors with Annular Duct and Novel Casing Treatment

    Institute of Scientific and Technical Information of China (English)

    LIU Xiaohua; SUN Dakun; SUN Xiaofeng; WANG Xiaoyu

    2012-01-01

    A three-dimensional compressible flow stability model is presented in this paper,which focuses on stall inception of multi-stage axial flow compressors with a finite large radius annular duct configuration for the first time.It is shown that under some assumptions,the stability equation can be obtained yielding from a group of homogeneous equations.The stability can be judged by the non-dimensional imaginary part of the resultant complex frequency eigenvalue.Further more,based on the analysis of the unsteady phenomenon caused by casing treatment,the function of casing treatment has been modeled by a wall impedance condition which is included in the stability model through the eigenvalues and the corresponding eigenfunctions of the system.Finally,some experimental investigation and two numerical evaluation cases are conducted to validate this model and emphasis is placed on numerically studying the sensitivity of the setup of different boundary conditions on the stall inception of axial flow fan/compressors.A novel casing treatment which consists ofa backchamber and a perforated plate is suggested,and it is noted that the open area ratio of the casing treatment is less than 10%,and is far smaller than conventional casing treatment with open area ratio of over 50%,which could result in stall margin improvement without obvious efficiency loss of fan/compressors.

  6. Low-pressure reversible axial fan with straight profile blades and relatively high efficiency

    Directory of Open Access Journals (Sweden)

    Spasić Živan T.

    2012-01-01

    Full Text Available The paper presents the design and operating characteristics of a model of reversible axial fan with only one impeller, whose reversibility is achieved by changing the direction of rotation. The fan is designed for the purpose of providing alternating air circulation in wood dryers in order to reduce the consumption of electricity for the fan and increase energy efficiency of the entire dryer. To satisfy the reversibility of flow, the shape of the blade profile is symmetrical along the longitudinal and transversal axes of the profile. The fan is designed with equal specific work of all elementary stages, using the method of lift forces. The impeller blades have straight mean line profiles. The shape of the blade profile was adopted after the numerical simulations were carried out and high efficiency was achieved. Based on the calculation and conducted numerical simulations, a physical model of the fan was created and tested on a standard test rig, with air loading at the suction side of the fan. The operating characteristics are shown for different blade angles. The obtained maximum efficiency was around 0.65, which represents a rather high value for axial fans with straight profile blades.

  7. Influence of seasons, different plant parts, and plant growth stages on saponin quantity and distribution in Bacopa monnieri

    Directory of Open Access Journals (Sweden)

    Watoo Phrompittayarat

    2011-04-01

    Full Text Available Brahmi or Bacopa monnieri (L. Wettst. is becoming popular as a food supplement due to its enhancing effect onmemory and intellect. Previous studies showed that a group of saponins are active compounds in this plant. However, untilnow little evidence has been obtained to indicate whether saponins are consistently present throughout the plant growthstages or the compounds are affected by the seasons. In order to answer those questions, we cultivated Brahmi under thenet house in three seasons. Influence of plant growth stages on saponin quantity and distribution was also investigated.In each season, treatments were plant ages with different plant parts having a factorial completely randomized design with 3replications. Five saponins, i.e. bacoside A3, bacopaside II, bacopaside X, bacopasaponin C and bacopaside I, were analyzedusing HPLC and reported as total saponins.The results showed that total saponin contents in Brahmi were the highest in rainy season while the weight yield ofBrahmi was the highest in summer. Ages of Brahmi (1-4 months slightly affected total saponin content. High level of totalsaponins (1.91±0.48% w/w was detected at the shoot of Brahmi. These findings indicate that the saponin quantity is affectedby seasons and the distribution of the saponins is different in each part of the plant. This information will be beneficial tothe production of Brahmi for both household and industry

  8. Stratigraphy, depositional rates, and other DSDP Leg 96 conclusions: Mississippi fan

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, J.M.; Bouma, A.H.

    1984-04-01

    The Quaternary Mississippi fan consists of at least seven seismically mappable fan lobes. Eight sites were drilled into the youngest fan lobe during DSDP Leg 96. The Holocene (Ericson Zone Z) is capped by a marly foraminiferal ooze. Assuming an age of 12,000 yr for the Holocene/Pleistocene boundary, a minimum accumulation rate of 3-30 cm/1000 yr (1-12 in/1000 yr) is computed for the Holocene. The youngest fan lobe was deposited during the upper part of Ericson Zone Y (late Wisconsin glacial, 12,000-85,000 y.B.P.). Deposition rates for the Y Zone are extremely high for the middle fan sites, averaging 12 m/1000 yr (39 ft/1000 yr). Lower fan accumulation rates are 7 m/1000 yr (23 ft/1000 yr) for the channel sites and 6 m/1000 yr (20 ft/1000 yr) for the channel-mouth depositional lobes. These rates are not corrected for compaction. Foraminifera are scarce; the occurrence of shallow-water benthic species indicates a displaced inner and middle neritic origin for the sediments. Drilling on the youngest fan lobe shows that most of the silts and sands were transported through the upper and middle fan channel onto the lower fan, producing a 6 to 10-km (4 to 6-mi) wide, 135-m (443-ft) thick aggradational channel deposit. Much of the fine-grained sediment spilled out of the channel onto the adjacent overbank areas, constructing broad marginal plain. The channels on the lower fans are smaller and shift position frequently. Channel-mount depositional lobes are constructed at the end of the active channels and are composed of more than 50% net sand.

  9. Acoustic Power Transmission Through a Ducted Fan

    Science.gov (United States)

    Envia, Ed

    2016-01-01

    For high-speed ducted fans, when the rotor flowfield is shock-free, the main contribution to the inlet radiated acoustic power comes from the portion of the rotor stator interaction sound field that is transmitted upstream through the rotor. As such, inclusion of the acoustic transmission is an essential ingredient in the prediction of the fan inlet noise when the fan tip relative speed is subsonic. This paper describes a linearized Euler based approach to computing the acoustic transmission of fan tones through the rotor. The approach is embodied in a code called LINFLUX was applied to a candidate subsonic fan called the Advanced Ducted Propulsor (ADP). The results from this study suggest that it is possible to make such prediction with sufficient fidelity to provide an indication of the acoustic transmission trends with the fan tip speed.

  10. Energy efficient engine shroudless, hollow fan blade technology report

    Science.gov (United States)

    Michael, C. J.

    1981-01-01

    The Shroudless, Hollow Fan Blade Technology program was structured to support the design, fabrication, and subsequent evaluation of advanced hollow and shroudless blades for the Energy Efficient Engine fan component. Rockwell International was initially selected to produce hollow airfoil specimens employing the superplastic forming/diffusion bonding (SPF/DB) fabrication technique. Rockwell demonstrated that a titanium hollow structure could be fabricated utilizing SPF/DB manufacturing methods. However, some problems such as sharp internal cavity radii and unsatisfactory secondary bonding of the edge and root details prevented production of the required quantity of fatigue test specimens. Subsequently, TRW was selected to (1) produce hollow airfoil test specimens utilizing a laminate-core/hot isostatic press/diffusion bond approach, and (2) manufacture full-size hollow prototype fan blades utilizing the technology that evolved from the specimen fabrication effort. TRW established elements of blade design and defined laminate-core/hot isostatic press/diffusion bonding fabrication techniques to produce test specimens. This fabrication technology was utilized to produce full size hollow fan blades in which the HIP'ed parts were cambered/twisted/isothermally forged, finish machined, and delivered to Pratt & Whitney Aircraft and NASA for further evaluation.

  11. Analysis and control of computer cooling fan noise

    Science.gov (United States)

    Wong, Kam

    This thesis is divided into three parts: the study of the source mechanisms and their separation, passive noise control, and active noise control. The mechanisms of noise radiated by a typical computer cooling fan is investigated both theoretically and experimentally focusing on the dominant rotor-stator interaction. The unsteady force generated by the aerodynamic interaction between the rotor blades and struts is phase locked with the blade rotation and radiates tonal noise. Experimentally, synchronous averaging with the rotation signal extracts the tones made by the deterministic part of the rotor-strut interaction mechanism. This averaged signal is called the rotary noise. The difference between the overall noise and rotary noise is defined as random noise which is broadband in the spectrum. The deterministic tonal peaks are certainly more annoying than the broadband, so the suppression of the tones is the focus of this study. Based on the theoretical study of point force formulation, methods are devised to separate the noise radiated by the two components of drag and thrust forces on blades and struts. The source separation is also extended to the leading and higher order modes of the spinning pressure pattern. By using the original fan rotor and installing it in various casings, the noise sources of the original fan are decomposed into elementary sources through directivity measurements. Details of the acoustical directivity for the original fan and its various modifications are interpreted. For the sample fan, two common features account for most of the tonal noise radiated. The two features are the inlet flow distortion caused by the square fan casing, and the large strut carrying the electric wires for the motor. When the inlet bellmouth is installed and the large strut is trimmed down to size, a significant reduction of 12 dB in tonal sound power is achieved. These structural corrections constitute the passive noise control. However, the end product still

  12. Computing Gröbner fans

    DEFF Research Database (Denmark)

    Fukuda, K.; Jensen, Anders Nedergaard; Thomas, R.R.

    2005-01-01

    This paper presents algorithms for computing the Gröbner fan of an arbitrary polynomial ideal. The computation involves enumeration of all reduced Gröbner bases of the ideal. Our algorithms are based on a uniform definition of the Gröbner fan that applies to both homogeneous and non...... are not always normal fans of polyhedra in which case reverse search applies automatically. Computational results using our implementation of these algorithms in the software package Gfan are included....

  13. REFINEMENTS OF THE FAN-TODD'S INEQUALITIES

    Institute of Scientific and Technical Information of China (English)

    庄国基

    2002-01-01

    Refinements to inequalities oninner product spaces are presented. In this respect, inequalities dealt with in this paper are: Cauchy's inequality, Bessel's inequality, Fan-Todd's inequality and Fan-Todd's determinantal inequality. In each case, a strictly increasing function is put forward, which lies between the smaller and the larger quantities of each inequality. As a result,an improved condition for equality of the Fan-Todd's determinantal inequality is deduced.

  14. The Challenges of Teaching Fan Studies

    DEFF Research Database (Denmark)

    Stephan, Matthias

    , has only gained in popularity. Yet, the nature of the course in question, an interdisciplinary open elective, has meant a class with a variety of backgrounds, preparation, and expectations from fan studies and its critical apparatus. In addition, due to the course being taught in English, it attracts...... a conversation about the best methods for teaching fan studies, and help to open up fan studies to be integrated into other courses and programs....

  15. Unsteady flowfield simulation of ducted prop-fan configurations

    Science.gov (United States)

    Janus, J. M.; Horstman, Howard Z.; Whitfield, David L.

    1992-01-01

    A technique for the simulation of unsteady flows in and around complex rotating machinery is presented. Additional domain decomposition mechanisms are introduced which extend the range of applicability of software developed for the time-accurate simulation of rotating machinery flowfields. The flow models uses the unsteady 3D Euler equations, discretized as a finite-volume method, utilizing a high-resolution approximate Riemann solver for cell interface flux definitions. Multiblock domain decomposition is used to partition the field radially, axially, as well as circumferentially into an ordered arrangement of blocks which exhibit varying degrees of similarity. A general high-order numerical scheme is applied to satisfy the geometric conservation law. Two configurations are presented - ducted single rotation prop-fan and a rotor-deswirl vane combination which form a single stage fan. Comparisons are made to other numerical solutions for these geometries and to available experimental data.

  16. Experimental investigation of unsteady fan flow interaction with downstream struts

    Science.gov (United States)

    Ng, W. F.; Obrien, W. F.; Olsen, T. L.

    1986-07-01

    In the present study of the unsteady pressure field produced on fan rotor blades by interaction with downstream struts, a single stage, low speed axial-flow fan was instrumented with blade-mounted high frequency pressure transducers. In addition, stationary pressure problems were used to map out the flowfield. Fluctuating pressure measurements are presented for blade midspan and 85-percent span on both the suction and pressure surfaces of the rotor blades at several positions of the downstream struts, and for two different flow coefficients. The strut is found to produce an effect on the unsteady pressure field on the rotor blades; this effect exceeds that due to the stator at design rotor-stator-strut spacing, but it rapidly declines as the struts are moved downstream.

  17. Modeling and Control of the Springback Effect in the Bottom Sheet Metal Part One-Stage Drawing Process

    Directory of Open Access Journals (Sweden)

    A. S. Chumadin

    2014-01-01

    Full Text Available The main objective of this study is to reduce a manufacturing complexity of bottom sheet metal parts by improving the accuracy of parts produced. This study is aimed at using the finite element analysis to prove assumptions that there is a transition frontier between the processes of forming and drawing, and there are capabilities to control springback effect by moving this frontier positions.The process, the stress-strain state of which in the dome corresponds to the process of forming parts, and in the flange area to the drawing process, was considered to be a formingdrawing process.Based on previous studies, techniques to reduce a springback have been proposed which enable us to use three calculation schemes for the process simulation:The frontier transition position control between the processes of forming and drawing by changing the contact pressure on the flange by varying the frictions coefficients on the die and binder surfaces;Springback manage through the additional tensile forces in the flange area of the blank;Springback manage through the technological insert at the first process stage.For ease of comparison with previous research results the same geometric parameters and material properties of the items are used in the simulation.The springback analysis used a finite element method in the AutoFormTM incremental module with automatically mashed and standard tolerance computation properties. The blank, binder, punch, and die were then imported to the module by CATIATM interface in .iges format.The calculation has shown that the optimal value for the least thinning and springback parts are available for the second scheme whereby ring punch makes additional tension in the flange area (from 1.09 to 0.35 mm with thinning from 0.80 to 0.73 mm. The use of flange retention of sheet blank at the expense of variable frictional forces showed the springback value reduction by 4 times (from 1.09 to 0.27 mm. However thinning was 16% (from 0.80 to

  18. Mesozoic and late tertiary submarine fan sequences and their tectonic significance, Sumba, Indonesia

    Science.gov (United States)

    Von Der Borch, C. C.; Grady, A. E.; Hardjoprawiro, S.; Prasetyo, H.; Hadiwisastra, S.

    1983-12-01

    The Indonesian island of Sumba occupies a critical zone which separates a "normal" subduction complex (Java Trench System) from a continent-island arc collision zone (Banda Arc). Sumba is considered by some authors to be a microcontinental fragment, although in this context its pre-fragmentation origin is uncertain. Detailed studies of the stratigraphy of Sumba, however, throw light on the origin and subsequent geological history of the island and surrounding areas. On available evidence, the oldest outcropping rocks are of Cretaceous age and locally contain a tropical Tethyan marine fauna. They comprise dark-coloured, sometimes carbonaceous and often volcanogenic mudstones, sandstones, gravels and diamictites, pervasively intruded by andesitic and dacitic dykes and locally intruded by granodiorite plutons. These sediments are siliclastic and appear to have had a continental provenance. The Cretaceous rocks in many areas compromise part of a major submarine fan complex which, at least in south-central Sumba, prograded towards the southwest and south. Shallow marine and non-marine Paleogene sediments and volcanic agglomerates lie unconformably above the uplifted, tilted and eroded Cretaceous strata. These are overlain in turn by the widely outcropping Miocene Sumba Formation, an oceanic sequence with island-arc affinities. Accessible outcrops of the Sumba Formation comprise platform carbonates with abundant reef developments in west Sumba, and a major submarine fan—pelagic chalk complex in east Sumba. The fan complex, which extends beneath the southern Savu Sea north of Sumba, is dominated by large-scale slumps, olistostromes and thin- and thick-bedded turbidites. Turbidite sands and gravels invariably are volcaniclastic, containing components derived from a typical inner (volcanic) arc complex. Paleocurrent indicators are difficult to find in the Sumba Formation, thus it is uncertain at this stage whether the volcaniclastic turbidites were derived from the

  19. Pseudohypericin and Hyperforin in Hypericum perforatum from Northern Turkey: Variation among Populations, Plant Parts and Phenological Stages

    Institute of Scientific and Technical Information of China (English)

    Cüneyt ?irak; Jolita Radusiene; Valdimaras Janulis; Liudas Ivanauskas

    2008-01-01

    Hypericum perforatum is a perennial medicinal plant known as "St. John's wort" in Western Europe and has been used in the treatment of several diseases for centuries. In the present study, morphologic, phenologic and population variability in pseudohypericin and hyperforin concentrations among H. perforatum populations from Northern Turkey was investigated for the first time. The aerial parts of H. perforatum plants representing a total of 30 individuals were collected at full flowering from 10 sites of Northern Turkey to search the regional variation in the secondary metabolits concentrations. For morphologic and phenologic sampling, plants from one site were gathered in five phenological stages: vegetative,floral budding, full flowering, fresh fruiting and mature fruiting. The plant materials were air-dried at room temperature and subsequently assayed for chemical concentrations by high performance liquid chromatography. Secondary metabolite concentrations ranged from traces to 2.94mg/g dry weight (DW) for pseudohypedcin and traces -6.29mg/g DW for hyperforin. The differences in the secondary metabolite concentrations among populations of H. perforatum were found to be significant. The populations varied greatly in hyperforin concentrations, whereas they produced a similar amount of pseudohypericin. Concentrations of both secondary metabolites in all tissues increased with advancing of plant development and higher accumulation levels were reached at flowering. Among different tissues, full opened flowers were found to be superior to stems, leaves and the other reproductive parts with regard to pseudohypericin and hyperforin accumulations. The present findings might be useful to optimize the processing methodology of wild-harvested plant material and obtain Increased concentrations of these secondary metabolites.

  20. Active Control of Fan Noise

    Institute of Scientific and Technical Information of China (English)

    Nobuhiko YAMASAKI; Hirotoshi TAJIMA

    2008-01-01

    In the wake-rotor interaction fan noise, a number of the interacting modes at the blade passing frequency (BPF)and its harmonics are generated which are prescribed by the number of stator and rotor blades etc. In the present study, the dominant mode is tried to be suppressed by the secondary sound from the loudspeaker actuators. One of the novel features of the present system is the adoption of the control board with the Field Programmable Gate Array (FPGA) hardware and the LabVIEW software to synchronize the circumferentially installed loudspeaker actuators with the relative location of rotational blades under arbitrary fan rotational speeds. The experiments were conducted under the conditions of three rotational speeds of 2004, 3150, and 4002 [rpm]. The reduction in the sound pressure level (SPL) was observed for all three rotational speeds. The sound pressure level at the BPF was reduced approximately 13 [dB] for 2004 [rpm] case, but not so large reduction was attained for other cases probably due to the inefficiency of the loudspeaker actuators at high frequencies

  1. Variable scale channel avulsion history using fan architecture and stratigraphy, and sediment provenance of Sutlej-Yamuna fans in northwest Gangetic plains during Late Quaternary

    Science.gov (United States)

    Singh, Ajit; Gupta, Sanjeev; Sinha, Rajiv; Densmore, Alexander; Buylaert, Jan-Pieter; Carter, Andrew; Van-Dijk, Wout M.; Joshi, Suneel; Nayak, Nibedita; Mason, Philippa J.; Kumar, Dewashish; Mondal, Setbandhu; Murray, Andrew; Rai, Shiv P.; Shekhar, Shashank

    2016-04-01

    Channel avulsion during fan development controls distribution and deposition of channel sandbodies and hence alluvial architecture of a fan system. Variable scale spatio-temporal information of fluvial responses to past climate changes is stored in these channel sandbodies. Further these channel sandbodies form fluvial aquifers in alluvial fans and therefore understanding of alluvial architecture and stratigraphy of a fan is crucial for development of groundwater management strategies. In this study we used multiple approaches to map subsurface fluvial aquifer architecture and alluvial stratigraphy, and to estimate sediment provenance using U-Pb dating of detrital zircon grains of Sutlej-Yamuna fan system in northwest India. Satellite imagery based geomorphic mapping shows two large fan system with interfan area. The fan surfaces show presence of major and minor paleochannels. 2D resistivity tomography along several transects across fan surfaces shows distinct layers with contrasting resistivity values. These geo-electric facies corresponds to presence of channel sandbodies beneath surface signature of paleochannels and finer floodplain deposits useful to demarcate lateral extent of subsurface channel sandbodies. A more detailed subsurface stratigraphy using ~50m deep sediment cores and their luminescence ages from across fan surface shows presence of multi-storey sandbodies (MSB) separated by floodplain fines. Within the MSB, individual channel deposits are identified by presence of channel scour surfaces located at coarse sand overlying fine sand layer. Depositional ages of MSB's ranges from ~81 ka (late MIS5) to ~15 ka (MIS2) with major depositional break during MIS3 in parts of the fans. Sediment aggradation rate varies laterally across fan surface as well as vertically down the depth with an average rate of 0.54 mm/year. Fluvial channel persistence for studied time interval (about last 81 ka BP) shows major depositional breaks (and possible incision) at ~41 ka

  2. Towards engagement: A comparison of fan groups in the context of a major South African football club

    Directory of Open Access Journals (Sweden)

    Frederick W. Stander

    2016-04-01

    Full Text Available Orientation: The commercial growth of sport clubs is often a direct consequence of the level of engagement of its fans. However, limited research has been done to understand how the engagement experience of these fans could be enhanced.Research purpose: The objective of this research was to evaluate whether differences exist amongst groups of sport fans in terms of their levels of engagement. This is conducted on the basis of customer engagement – relationship marketing – and market segmentation theories,and in an effort to inform practical strategies that could be used to leverage engagement. By establishing that differences do exist between segments of sport fans, practical strategies could be developed based on such differences.Research approach, design and method: A cross-sectional, quantitative design was utilised in this study. A convenience sample of 430 adult fans of one of South Africa’s largest and best supported professional football clubs participated in the study. Two fan groupings were compared, namely fans who belonged to a formal supporters’ branch of the club versus fans who did not, and fans who frequented the social media platforms of such club versus fans who did not. Multi group confirmatory factor analysis and latent variable modelling were implemented to compare groups of fans in terms of sport fan engagement. Measurement invariance was reviewed to compare the equivalence of measurement between the groups.Main findings: Statistical analysis revealed greater levels of fan engagement amongst fans that form part of formal supporters’ branches as well as amongst fans who regularly visit the sport club’s social media platforms.Practical/managerial implications: By making use of supporters’ branches and social media,practical engagement strategies are available to professional sport clubs that seek to enhance the engagement experience of their fans. These strategies could assist clubs in developing customised

  3. Influence of the effectiveness of raw materials on the reliability of thermoelectric cooling devices. Part I: single-stage TEDs

    Directory of Open Access Journals (Sweden)

    Zaikov V. P.

    2015-02-01

    Full Text Available Increase of the reliability of information systems depends on the reliability improvement of their component elements, including cooling devices, providing efficiency of thermally loaded components. Thermoelectric devices based on the Peltier effect have significant advantages compared with air and liquid systems for thermal modes of the radio-electronic equipment. This happens due to the absence of moving parts, which account for the failure rate. The article presents research results on how thermoelectric efficiency modules affect the failure rate and the probability of non-failure operation in the range of working temperature of thermoelectric coolers. The authors investigate a model of relative failure rate and the probability of failure-free operation single-stage thermoelectric devices depending on the main relevant parameters: the operating current flowing through the thermocouple and resistance, temperature changes, the magnitude of the heat load and the number of elements in the module. It is shown that the increase in the thermoelectric efficiency of the primary material for a variety of thermocouple temperature changes causes the following: maximum temperature difference increases by 18%; the number of elements in the module decreases; cooling coefficient increases; failure rate reduces and the probability of non-failure operation of thermoelectric cooling device increases. Material efficiency increase by 1% allows reducing failure rate by 2,6—4,3% in maximum refrigeration capacity mode and by 4,2—5,0% in minimal failure rate mode when temperature difference changes in the range of 40—60 K. Thus, the increase in the thermoelectric efficiency of initial materials of thermocouples can significantly reduce the failure rate and increase the probability of failure of thermoelectric coolers depending on the temperature difference and the current operating mode.

  4. Fan Atomized Burner design advances & commercial development progress

    Energy Technology Data Exchange (ETDEWEB)

    Kamath, B. [Heat-Wise, Inc., Ridge, NY (United States); Butcher, T.A. [Brookhaven National Lab., Upton, NY (United States)

    1996-07-01

    As a part of the Oil Heat Research and Development program, sponsored by the US Department of Energy, Brookhaven National Laboratory (BNL) has an on-going interest in advanced combustion technologies. This interest is aimed at: improving the initial efficiency of heating equipment, reducing long term fouling and efficiency degradation, reducing air pollutant emissions, and providing practical low-firing rate technologies which may lead to new, high efficiency oil-fired appliances. The Fan-Atomized Burner (FAB) technology is being developed at BNL as part of this general goal. The Fan-Atomized Burner uses a low pressure, air atomizing nozzle in place of the high pressure nozzle used in conventional burners. Because it is air-atomized the burner can operate at low firing rates without the small passages and reliability concerns of low input pressure nozzles. Because it uses a low pressure nozzle the burner can use a fan in place of the small compressor used in other air-atomized burner designs. High initial efficiency of heating equipment is achieved because the burner can operate at very low excess air levels. These low excess air levels also reduce the formation of sulfuric acid in flames. Sulfuric acid is responsible for scaling and fouling of heat exchanger surfaces.

  5. Bright Streaks and Dark Fans

    Science.gov (United States)

    2007-01-01

    The south polar region of Mars is covered every year by a layer of carbon dioxide ice. In a region called the 'cryptic terrain,' the ice is translucent and sunlight can penetrate through the ice to warm the surface below. The ice layer sublimates (evaporates) from the bottom. The dark fans of dust seen in this image come from the surface below the layer of ice, carried to the top by gas venting from below. The translucent ice is 'visible' by virtue of the effect it has on the tone of the surface below, which would otherwise have the same color and reflectivity as the fans. Bright streaks in this image are fresh frost. The CRISM team has identified the composition of these streaks to be carbon dioxide. Observation Geometry Image PSP_003113_0940 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on 26-Mar-2007. The complete image is centered at -85.8 degrees latitude, 106.0 degrees East longitude. The range to the target site was 244.9 km (153.0 miles). At this distance the image scale is 49.0 cm/pixel (with 2 x 2 binning) so objects 147 cm across are resolved. The image shown here has been map-projected to 50 cm/pixel . The image was taken at a local Mars time of 06:20 PM and the scene is illuminated from the west with a solar incidence angle of 79 degrees, thus the sun was about 11 degrees above the horizon. At a solar longitude of 207.6 degrees, the season on Mars is Northern Autumn.

  6. Radar facies and architecture of alluvial fans and related sediments in high-energy alpine environments, British Columbia

    Science.gov (United States)

    Ekes, Csaba

    2000-08-01

    It is widely recognized that the dominant depositional processes on alluvial fans include rock falls, rock slides, rock avalanches, debris flows, sheetfloods and incised-channel floods. A fundamental question addressed in this thesis is: Can ground penetrating radar (GPR) differentiate between the sediments associated with these processes? Do these individual deposits have characteristic radar reflection signatures? The dissertation is divided into two parts. In part one, a calibration exercise conducted in southern British Columbia, it was demonstrated that GPR was able to obtain good penetration and resolution in rock fall, rock slide, fluvial and alluvial fan sediments, and that a characteristic radar reflection pattern (or radar facies) can be assigned to these deposits. Bedrock reflection pattern is characterised by a discontinuous radar signal and by stacked diffractions. The radar facies for rock slide and rock avalanche sediments, where boulders constitute the predominant clast size, is characterized by discontinuous, high amplitude, macro-scale, hyperbolic reflections that are different from diffractions generated by bedrock. Alluvial fans dominated by debris flow processes produce a chaotic and discontinuous radar pattern; diffractions in these patterns are attributed to boulders. Alluvial fans dominated by sheetflood processes are likely to produce surface-parallel, gently dipping, more or less continuous radar patterns. Large-scale meandering-river radar-patterns are characterized by high amplitude, continuous, dipping clinoforms. Braided-river radar facies, based on data collected on the Kicking Horse braidplain, are characterized by predominantly horizontally continuous reflections with few identifiable features. Based solely on GPR data, it was possible to distinguish between sediments of meandering and braided rivers. Analysis of over 95 km GPR data suggests that alluvial fan radar-reflection patterns are distinctly different from those observed in

  7. Acoustic and aerodynamic performance of a 1.83-meter (6-ft) diameter 1.25-pressure-ratio fan (QF-8)

    Science.gov (United States)

    Woodward, R. P.; Lucas, J. G.

    1976-01-01

    A 1.25-pressure-ratio 1.83-meter (6-ft) tip diameter experimental fan stage with characteristics suitable for engine application on STOL aircraft was tested for acoustic and aerodynamic performance. The design incorporated proven features for low noise, including absence of inlet guide vanes, low rotor blade tip speed, low aerodynamic blade loading, and long axial spacing between the rotor and stator blade rows. The fan was operated with five exhaust nozzle areas. The stage noise levels generally increased with a decrease in nozzle area. Separation of the acoustic one-third octave results into broadband and pure-tone components showed the broadband noise to be greater than the corresponding pure-tone components. The sideline perceived noise was highest in the rear quadrants. The acoustic results of QF-8 were compared with those of two similar STOL application fans in the test series. The QF-8 had somewhat higher relative noise levels than those of the other two fans. The aerodynamic results of QF-8 and the other two fans were compared with corresponding results from 50.8-cm (20-in.) diam scale models of these fans and design values. Although the results for the full-scale and scale models of the other two fans were in reasonable agreement for each design, the full-scale fan QF-8 results showed poor performance compared with corresponding model results and design expectations. Facility effects of the full-scale fan QF-8 installation were considered in analyzing this discrepancy.

  8. Dynamic response of Hovercraft lift fans

    Science.gov (United States)

    Moran, D. D.

    1981-08-01

    Hovercraft lift fans are subjected to varying back pressure due to wave action and craft motions when these vehicles are operating in a seaway. The oscillatory back pressure causes the fans to perform dynamically, exhibiting a hysteresis type of response and a corresponding degradation in mean performance. Since Hovercraft motions are influenced by variations in lift fan pressure and discharge, it is important to understand completely the nature of the dynamic performance of lift fans in order to completely solve the Hovercraft seakeeping problem. The present study was performed to determine and classify the instabilities encountered in a centrifugal fan operating against time-varying back pressure. A model-scale experiment was developed in which the fan discharge was directed into a flow-measuring device, terminating in a rotating valve which produced an oscillatory back pressure superimposed upon a mean aerodynamic resistance. Pressure and local velocity were measured as functions of time at several locations in the fan volute. The measurements permitted the identification of rotating (or propagating) stall in the impeller. One cell and two cell configurations were classified and the transient condition connecting these two configurations was observed. The mechanisms which lead to rotating stall in a centrifugal compressor are presented and discussed with specific reference to Hovercraft applications.

  9. Fan-structure waves in shear ruptures

    Science.gov (United States)

    Tarasov, Boris

    2016-04-01

    This presentation introduces a recently identified shear rupture mechanism providing a paradoxical feature of hard rocks - the possibility of shear rupture propagation through the highly confined intact rock mass at shear stress levels significantly less than frictional strength. According to the fan-mechanism the shear rupture propagation is associated with consecutive creation of small slabs in the fracture tip which, due to rotation caused by shear displacement of the fracture interfaces, form a fan-structure representing the fracture head. The fan-head combines such unique features as: extremely low shear resistance (below the frictional strength), self-sustaining stress intensification in the rupture tip (providing easy formation of new slabs), and self-unbalancing conditions in the fan-head (making the failure process inevitably spontaneous and violent). An important feature of the fan-mechanism is the fact that for the initial formation of the fan-structure an enhanced local shear stress is required, however, after completion of the fan-structure it can propagate as a dynamic wave through intact rock mass at shear stresses below the frictional strength. Paradoxically low shear strength of pristine rocks provided by the fan-mechanism determines the correspondingly low transient strength of the lithosphere, which favours generation of new earthquake faults in the intact rock mass adjoining pre-existing faults in preference to frictional stick-slip instability along these faults. The new approach reveals an alternative role of pre-existing faults in earthquake activity: they represent local stress concentrates in pristine rock adjoining the fault where special conditions for the fan-mechanism nucleation are created, while further dynamic propagation of the new fault (earthquake) occurs at low field stresses even below the frictional strength.

  10. Disabled Woman Heads Beijing Fans Association

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    THE next time you go to a football match in Beijing, look around the edge of the field. You might see a young woman in a wheelchair cheering her favorite team. Wu Jinghong is more than a handicapped person, more than a woman football fan. She is the head of the Beijing Football Fans Association, a group more than 1,000 members strong. Wu alone started the association in 1988 and because she is a woman, encouraged other women fans to openly support their favorite teams.

  11. Sherlock (Holmes in Japanese (fan works [symposium

    Directory of Open Access Journals (Sweden)

    Lori Morimoto

    2017-03-01

    Full Text Available I explore the history of Japanese writing centered on Sherlock Holmes as a means of interrogating the 2014 BBC Sherlock pastiche John and Sherlock Casebook 1: Jon, zenchi renmei e iku (The stark naked league, written by Japanese Sherlockian Kitahara Naohiko for mainstream publication by the publishing house Hayakawa shobō. I argue that exploration of the Japanese (fan cultural contexts of Kitahara's book begins to reveal the limits of the Anglo-American-centered framework through which fan studies scholars explore fan/producer relationships.

  12. It’s me, Mario!: Movies, video games and pop culture in the realization of a fan made trailer

    Directory of Open Access Journals (Sweden)

    Camila Schäfer

    2013-09-01

    Full Text Available This article takes as its object the fan made trailer Mario: The movie, which brings the narrative of the video game Super Mario in the form of a movie trailer. Our analysis part of this appropriation, made by fans, language and aesthetics of the movie trailer and the narrative of a video game, to think about how certain elements of pop culture and movie universe are already part of the culturaland aesthetic references of many people.

  13. Heat transfer and performance characteristics of axial cooling fans with downstream guide vanes

    Science.gov (United States)

    Terzis, Alexandros; Stylianou, Ioannis; Kalfas, Anestis I.; Ott, Peter

    2012-04-01

    This study examines experimentally the effect of stators on the performance and heat transfer characteristics of small axial cooling fans. A single fan impeller, followed by nine stator blades in the case of a complete stage, was used for all the experimental configurations. Performance measurements were carried out in a constant speed stage performance test rig while the transient liquid crystal technique was used for the heat transfer measurements. Full surface heat transfer coefficient distributions were obtained by recording the temperature history of liquid crystals on a target plate. The experimental data indicated that the results are highly affected by the flow conditions at the fan outlet. Stators can be beneficial in terms of pressure drop and efficiency, and thus more economical operation, as well as, in the local heat transfer distribution at the wake of the stator blades if the fan is installed very close to the cooling object. However, as the separation distance increases, enhanced heat transfer rate in the order of 25% is observed in the case of the fan impeller.

  14. Readers Theatre, Brecht and Literature for Student, Classroom and Stage (Part 1: "Alienation" as a Tool of Communication).

    Science.gov (United States)

    Ratliff, Gerald Lee

    1980-01-01

    Describes the use of Bertolt Brecht's theories regarding literature and performance. Details the selected use of Reader's Theatre techniques in analyzing and staging literature in the secondary classroom environment. (JMF)

  15. 30 CFR 75.311 - Main mine fan operation.

    Science.gov (United States)

    2010-07-01

    ... back-up fan system— (1) Only persons necessary to evaluate the effect of the fan stoppage or restart... back-up fan system is used that does not provide the ventilating quantity provided by the main mine fan... fire or other products of combustion are approved in the ventilation plan. (g) If multiple mine...

  16. Knowing fans, knowing music : an exploration of fan interaction on Twitter

    OpenAIRE

    2011-01-01

    In this thesis, I examine what "knowing music" means to participants in online social musicking activities, along with the role Twitter plays in this process. I compare the way I came to "know" music through social networks with others' behaviors regarding music and social networking. Using Henry Jenkins's research framework as an aca-fan (a portmanteau word combining academic and fan), I study fan communities from the inside out. I begin by outlining my story of coming to know the music that...

  17. Numerical Analysis for the Air Flow of Cross Flow Fan

    Science.gov (United States)

    Sakai, Hirokazu; Tokushge, Satoshi; Ishikawa, Masatoshi; Ishihara, Takuya

    There are many factors for designing the cross flow fan. Therefore, the performance of cross flow fan is not clear yet. We can analyze the transient flow of a cross flow fan using sliding mesh approach. One of the tasks using Computational Fluid Dynamics (CFD) is a way of modeling for analysis heat exchangers with cross flow fan. These tasks are very important for design. The paper has a modeling of heat exchangers and meshing the fan blades. The next tasks, we focus the ability of cross flow fan when we change the geometry of fan blades.

  18. 78 FR 62494 - Energy Conservation Program: Energy Conservation Standards for Ceiling Fans

    Science.gov (United States)

    2013-10-22

    ... Part 430 RIN 1904-AC87 Energy Conservation Program: Energy Conservation Standards for Ceiling Fans... certain information to help inform its current rulemaking to consider setting energy conservation... INFORMATION: I. Introduction Title III, Part B \\1\\ of the Energy Policy and Conservation Act of 1975 (EPCA...

  19. Characteristics of tip-leakage flow in an axial fan

    Science.gov (United States)

    Park, Keuntae; Choi, Haecheon; Choi, Seokho; Sa, Yongcheol

    2014-11-01

    An axial fan with a shroud generates complicated vortical structures by the interaction of the axial flow with the fan blades and shroud near the blade tips. Large eddy simulation (LES) is performed for flow through a forward-swept axial fan, operating at the design condition of Re = 547,000 based on the radius of blade tip and the tip velocity. A dynamic global model (Lee et al. 2010) is used for a subgrid-scale model, and an immersed boundary method in a non-inertial reference frame (Kim & Choi 2006) is adopted for the present simulation. It is found that two vortical structures are formed near the blade tip: the main tip leakage vortex (TLV) and the auxiliary TLV. The main TLV is initiated near the leading edge, develops downstream, and impinges on the pressure surface of the next blade, where the pressure fluctuations and turbulence intensity become high. On the other hand, the auxiliary TLV is initiated at the aft part of the blade but is relatively weak such that it merges with the main TLV. Supported by the KISTI Supercomputing Center (KSC-2014-C2-014).

  20. Active Vibration Reduction of Titanium Alloy Fan Blades (FAN1) Using Piezoelectric Materials

    Science.gov (United States)

    Choi, Benjamin; Kauffman, Jeffrey; Duffy, Kirsten; Provenza, Andrew; Morrison, Carlos

    2010-01-01

    The NASA Glenn Research Center is developing smart adaptive structures to improve fan blade damping at resonances using piezoelectric (PE) transducers. In this paper, a digital resonant control technique emulating passive shunt circuits is used to demonstrate vibration reduction of FAN1 Ti real fan blade at the several target modes. Single-mode control and multi-mode control using one piezoelectric material are demonstrated. Also a conceptual study of how to implement this digital control system into the rotating fan blade is discussed.

  1. Magnetic anomalies in Central Bengal fan

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, T.C.S.; Lakshminarayana, S.; Sarma, K.V.L.N.S.

    Total magnetic field anomalies recorded over the Central Bengal Fan are analysed and the depths to the magnetic basement are computed using the analytical signal and the Werner deconvolution methods. To the west and east of 85 degrees E...

  2. Computing Gröbner fans

    DEFF Research Database (Denmark)

    Fukuda, K.; Jensen, Anders Nedergaard; Thomas, R.R.

    2005-01-01

    This paper presents algorithms for computing the Gröbner fan of an arbitrary polynomial ideal. The computation involves enumeration of all reduced Gröbner bases of the ideal. Our algorithms are based on a uniform definition of the Gröbner fan that applies to both homogeneous and non......-homogeneous ideals and a proof that this object is a polyhedral complex. We show that the cells of a Gröbner fan can easily be oriented acyclically and with a unique sink, allowing their enumeration by the memory-less reverse search procedure. The significance of this follows from the fact that Gröbner fans...

  3. Quiet, High-Efficiency Vaneaxial Fans Project

    Data.gov (United States)

    National Aeronautics and Space Administration — During this Phase I effort, CRG proposes to demonstrate the ability to significantly reduce the acoustic signature of vaneaxial fans by establishing quiet...

  4. Mexican Fan Palm - Orange Co. [ds350

    Data.gov (United States)

    California Department of Resources — This dataset provides the known distribution of Mexican fan palm (Washingtonia robusta) in southern Orange County. The surveys were conducted from May to June, 2007...

  5. Synchronous and Cogged Fan Belt Performance Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Cutler, D.; Dean, J.; Acosta, J.

    2014-02-01

    The GSA Regional GPG Team commissioned the National Renewable Energy Laboratory (NREL) to perform monitoring of cogged V-belts and synchronous belts on both a constant volume and a variable air volume fan at the Byron G. Rodgers Federal Building and U.S. Courthouse in Denver, Colorado. These motor/fan combinations were tested with their original, standard V-belts (appropriately tensioned by an operation and maintenance professional) to obtain a baseline for standard operation. They were then switched to the cogged V-belts, and finally to synchronous belts. The power consumption by the motor was normalized for both fan speed and air density changes. This was necessary to ensure that the power readings were not influenced by a change in rotational fan speed or by the power required to push denser air. Finally, energy savings and operation and maintenance savings were compiled into an economic life-cycle cost analysis of the different belt options.

  6. Study on the Social Intercourse of Fan Zuyu%范祖禹交游考述

    Institute of Scientific and Technical Information of China (English)

    高叶青

    2011-01-01

    The famous historian Fan Zuyu of the Song Dynasty had lost his parents when he was young.He was brong up by his great-uncle Fan Zhen and uncle Fan Bailu.Father-in-law Lv Gongzhu exerted a great influence to Fan Zuyu.Su Shi and Fan Zuyu were the townsman,they appreciated each other.There were also close relationship among Fan Zuyu、 Huang Tingjian and Qin Guan.It was the longest and most intensive time that Fan Zuyu and Sima Guang got along with each other.Furthermore,Fu Bi,Shao Young,Cheng Yi,Cheng Hao also had been played the important part in Fan Zuyu's life.%北宋著名史学家范祖禹早年失去双亲,在叔祖范镇及季父范百禄的教养下长大成人。岳父吕公著的品性对范祖禹产生了较大的影响。苏轼与范祖禹情属乡谊,相互赏识。范祖禹与黄庭坚、秦观之间的感情也非常深厚。居洛修书期间是范祖禹与司马光一生中相处时间最长、接触最密集的时期。此外,富弼、邵雍、程颐、程颢等人也在范祖禹的人生中扮演了重要的角色。

  7. Experimental and numerical analysis on noise reduction in a multi-blade centrifugal fan

    Science.gov (United States)

    Chen, X. J.; Y Cao, T.; Su, J.; Qin, G. L.

    2013-12-01

    In this work, analysis on noise source and reduction in a multi-blade centrifugal fan used for air-conditioners was carried out by experimental and numerical methods. Firstly, an experimental system using microphone mounted on volute surface for measuring surface pressure fluctuations of volute was designed and introduced, then surface pressure fluctuations of the whole volute for a multi-blade centrifugal fan were measured by this system, and the inlet noise for this fan was also obtained. And then, based on the experimental results, the aerodynamic noise source of the studied fan was analysed. The surface pressure fluctuations of the volute showed that there were largest surface pressure fluctuations near the volute tongue, and peaks appeared at the Blade Passing Frequency (BPF). The spectra of fan inlet noise showed that the peaks also appeared at BPF, and noise levels in a wide range of frequency were also larger. Secondly, the internal flow of the fan was simulated by commercial software under the same conditions with the experiment, and then the fluid flow and acoustic power field were obtained and discussed. The contours of acoustic power level showed that the larger noise was generated at the impeller area close to the outlet of scroll and at the volute tongue, which is same as that from experiment. Based on all of the results, we can find that the vortex noise is an important part of fan noise for the studied fan, and the rotation noise also cannot be neglected. Finally, several reduction methods that are thought to be effective based on experimental and numerical results were suggested.

  8. Dual Fan Separator within the Universal Waste Management System

    Science.gov (United States)

    Stapleton, Tom; Converse, Dave; Broyan, James Lee, Jr.

    2014-01-01

    Since NASA's new spacecraft in development for both LEO and Deep Space capability have considerable crew volume reduction in comparison to the Space Shuttle, the need became apparent for a smaller commode. In response the Universal Waste Management System (UWMS) was designed, resulting in an 80% volume reduction from the last US commode, while enhancing performance. The ISS WMS and previous shuttle commodes have a fan supplying air flow to capture feces and a separator to capture urine and separate air from the captured air/urine mixture. The UWMS combined both rotating equipment components into a single unit, referred to at the Dual Fan Separator (DFS). The combination of these components resulted in considerable packaging efficiency and weight reduction, removing inter-component plumbing, individual mounting configurations and required only a single motor and motor controller, in some of the intended UWMS platform applications the urine is pumped to the ISS Urine Processor Assembly (UPA) system. It requires the DFS to include less than 2.00% air inclusion, by volume, in the delivered urine. The rotational speed needs to be kept as low as possible in centrifugal urine separators to reduce air inclusion in the pumped fluid, while fans depend on rotational speed to develop delivered head. To satisfy these conflicting requirements, a gear reducer was included, allowing the fans to rotate at a much higher speed than the separator. This paper outlines the studies and analysis performed to develop the DFS configuration. The studies included a configuration trade study, dynamic stability analysis of the rotating bodies and a performance analysis of included labyrinth seals. NASA is considering a program to fly the UWMS aboard the ISS as a flight experiment. The goal of this activity is to advance the Technical Readiness Level (TRL) of the DFS and determine if the concept is ready to be included as part of the flight experiment deliverable.

  9. A method to assess fluvial fan channel networks, with a preliminary application to fans in coastal British Columbia

    Science.gov (United States)

    Millard, Thomas Hugh; Hogan, Dan L.; Wilford, David J.; Roberts, Brian

    2010-03-01

    The channel network on a fluvial fan distributes sediment across the fan surface and determines fan development. We present a method to characterize fan channel networks (FCNs) so that the effect of controls (e.g., sediment supply) on the FCN can be evaluated. We then do a preliminary test of the method using three fans in coastal British Columbia. The method uses a set of three measures: 1) the spatial extent of hydrogeomorphic activity, measured as the percentage of the contemporary fan surface area occupied by active channels; 2) the topologic structure, using node counts to measure channel network complexity; and 3) a sediment budget to indicate the proportion of sediment that is stored on the fan, loosely characterized by comparing the second-largest clast size of sediment at the fan apex or intersection point with the second-largest clast at the toe of the fan. These measures were applied to two fan deltas and one partial fan delta in northern Vancouver Island, British Columbia, using channel surveys conducted in 2006 and 2007. All three fans are located within 30 km of each other, have similar climatic, physiographic, and vegetation settings, and have natural channel networks. Each fan has perennial channel flow at the fan apex. Watershed areas range from 19.5 to 35.6 km 2, and contemporary fan areas range from 0.2 to 0.7 km 2. The Melton Relative Relief ratio ranges from 0.24 to 0.30 and none of the fans show evidence of debris floods or debris flows. In addition to testing the efficacy of the FCN measures, we use these fans to explore the question of whether fans in similar geomorphic settings and with similar controls develop similar FCNs. Results show the fans have between 4.7-8.5 % of the contemporary fan surface occupied by the active channel network. Topologic node counts indicate that the two fan deltas have a similar level of channel complexity, with 42-54 nodes in total. The partial fan delta channel network is approximately half as complex, with

  10. Wordplay, mindplay: Fan fiction and postclassical narratology

    Directory of Open Access Journals (Sweden)

    Veerle Van Steenhuyse

    2014-09-01

    Full Text Available Recent narrative theories on story worlds, or the worlds evoked by narratives, call attention to the process of fan reading and the role which the canon plays in that process. This paper posits that such theories can help us understand literary techniques that make a difference on the level of the reading experience that is implied by fan fiction texts. This is illustrated with a close reading of Naguabo's "The Mother of All Marriage Proposals," a Jane Austen fic.

  11. Integral Compressor/Generator/Fan Unitary Structure

    OpenAIRE

    Dreiman, Nelik

    2016-01-01

    INTEGRAL COMPRESSOR / GENERATOR / FAN UNITARY STRUCTURE.*) Dr. Nelik Dreiman Consultant, P.O.Box 144, Tipton, MI E-mail: An extremely compact, therefore space saving single compressor/generator/cooling fan structure of short axial length and light weight has been developed to provide generation of electrical power with simultaneous operation of the compressor when power is unavailable or function as a regular AC compressor powered by a power line. The generators and ai...

  12. Fan affinity laws from a collision model

    CERN Document Server

    Bhattacharjee, Shayak

    2012-01-01

    The performance of a fan is usually estimated from hydrodynamical considerations. The calculations are long and involved and the results are expressed in terms of three affinity laws. In this work we use kinetic theory to attack this problem. A hard sphere collision model is used, and subsequently a correction to account for the flow behaviour of air is incorporated. Our calculations prove the affinity laws and provide numerical estimates of the air delivery, thrust and drag on a rotating fan.

  13. Developmental toxicity of PAH mixtures in fish early life stages. Part II: adverse effects in Japanese medaka.

    Science.gov (United States)

    Le Bihanic, Florane; Clérandeau, Christelle; Le Menach, Karyn; Morin, Bénédicte; Budzinski, Hélène; Cousin, Xavier; Cachot, Jérôme

    2014-12-01

    In aquatic environments, polycyclic aromatic hydrocarbons (PAHs) mostly occur as complex mixtures, for which risk assessment remains problematic. To better understand the effects of PAH mixture toxicity on fish early life stages, this study compared the developmental toxicity of three PAH complex mixtures. These mixtures were extracted from a PAH-contaminated sediment (Seine estuary, France) and two oils (Arabian Light and Erika). For each fraction, artificial sediment was spiked at three different environmental concentrations roughly equivalent to 0.5, 4, and 10 μg total PAH g(-1) dw. Japanese medaka embryos were incubated on these PAH-spiked sediments throughout their development, right up until hatching. Several endpoints were recorded at different developmental stages, including acute endpoints, morphological abnormalities, larvae locomotion, and genotoxicity (comet and micronucleus assays). The three PAH fractions delayed hatching, induced developmental abnormalities, disrupted larvae swimming activity, and damaged DNA at environmental concentrations. Differences in toxicity levels, likely related to differences in PAH proportions, were highlighted between fractions. The Arabian Light and Erika petrogenic fractions, containing a high proportion of alkylated PAHs and low molecular weight PAHs, were more toxic to Japanese medaka early life stages than the pyrolytic fraction. This was not supported by the toxic equivalency approach, which appeared unsuitable for assessing the toxicity of the three PAH fractions to fish early life stages. This study highlights the potential risks posed by environmental mixtures of alkylated and low molecular weight PAHs to early stages of fish development.

  14. Radiated noise of ducted fans

    Science.gov (United States)

    Eversman, Walter

    The differences in the radiated acoustic fields of ducted and unducted propellers of the same thrust operating under similar conditions are investigated. An FEM model is created for the generation, propagation, and radiation of steady, rotor alone noise and exit guide vane interaction noise of a ducted fan. For a specified number of blades, angular mode harmonic, and rotor angular velocity, the acoustic field is described in a cylindrical coordinate system reduced to only the axial and radial directions. It is found that, contrary to the usual understanding of the Tyler and Sofrin (1962) result, supersonic tip speed rotor noise can be cut off if the tip Mach number is only slightly in excess of unity and if the number of blades is relatively small. If there are many blades, the fundamental angular mode number is large, and the Tyler and Sofrin result for thin annuli becomes more relevant. Shrouding of subsonic tip speed propellers is a very effective means of controlling rotor alone noise.

  15. Early Vocalization of Preterm Infants with Extremely Low Birth Weight (ELBW), Part I: From Birth to Expansion Stage

    Science.gov (United States)

    Torola, Helena; Lehtihalmes, Matti; Heikkinen, Hanna; Olsen, Paivi; Yliherva, Anneli

    2012-01-01

    The vocalization of preterm infants with extremely low birth weight (ELBW) up to the expansion stage was systematically described and compared with those of healthy full-term infants. The sample consisted of 18 preterm ELBW infants and the control group of 11 full-term infants. The follow-up was performed intensively using video-recordings. The…

  16. The Effects of Inlet Box Aerodynamics on the Mechanical Performance of a Variable Pitch in Motion Fan

    Directory of Open Access Journals (Sweden)

    A. G. Sheard

    2012-01-01

    Full Text Available This paper describes research involving an in-service failure of a “variable pitch in motion” fan’s blade bearing. Variable pitch in motion fans rotate at a constant speed, with the changing blade angle varying the load. A pitch-change mechanism facilitates the change in blade angle. A blade bearing supports each blade enabling it to rotate. The author observed that as the fan aerodynamic stage loading progressively increased, so did the rate of blade-bearing wear. The reported research addressed two separate, but linked, needs. First, the ongoing need to increase fan pressure development capability required an increase in fan loading. This increase was within the context of an erosive operating regime which systematically reduced fan pressure development capability. The second need was to identify the root cause of blade-bearing failures. The author addressed the linked needs using a computational analysis, improving the rotor inflow aerodynamic characteristics through an analysis of the inlet box and design of inlet guide vanes to control flow nonuniformities at the fan inlet. The results of the improvement facilitated both an increase in fan-pressure-developing capability and identification of the root cause of the blade-bearing failures.

  17. Depositional evolution of the Melville Bay trough-mouth fan, NW Greenland

    Science.gov (United States)

    Knutz, Paul; Gregersen, Ulrik

    2015-04-01

    The continental margin of NW Greenland bordering northern Baffin Bay is characterized by major sediment accumulations, known as Trough-Mouth Fans (TMF). The fan depocentres represent intense sediment dispersal at the terminus of ice streams that during cold climate periods provided major drainage routes of the northern Greenland Ice Sheet into Baffin Bay. The imprint of paleo-icestreams is seen by erosional troughs crossing a >250 km broad shelf region, which caps a series of sedimentary basins containing thick Mesozoic-Tertiary strata packages. This presentation provides an overview of the seismic stratigraphic division, depositional architecture and examples of seismic facies of the Melville Bay TMF using a 5-10 km grid of industry-quality 2D seismic data (TGS). The focus will primarily be on the inception and early stage of glacial fan development. Comparing the present-day topography with the regional geology shows that the paleo-icestreams exploited the Cenozoic infill of former rift basins that are more conducive to erosion than the adjoining ridges and structural highs. The TMF sequence is constructed by a series of progradational seismic units that represent successive steps in location of ice stream terminus and associated depocenters. The slope fronts of the prograding units show abundant signatures of sediment instability and mass-wasting but evidence of along-slope current-driven processes is also recognized presumably linked to interglacial sea level high-stands. The topset of each unit is characterized by planar erosion that merges landward into hummocky positive geometries with low internal reflectivity. These features are generally interpreted as subglacial landforms, e.g. terminal moraines and ice-contact deposits, associated with grounding zone wedges. Unlike the most recent TMF units deposited in front of the present trough, the oldest glacigenic units have built out from a Neogene sediment prism that forms the core of modern shallow-water banks

  18. Microscopic Invasions, Prognoses, and Recurrence Patterns of Stage I Adenocarcinomas Manifesting as Part-Solid Ground-Glass Nodules: Comparison With Adenocarcinomas Appearing as Solid Nodules After Matching Their Solid Parts' Size.

    Science.gov (United States)

    Hwang, Eui Jin; Park, Chang Min; Kim, Young Tae; Kim, Hyungjin; Goo, Jin Mo

    2016-04-01

    The purpose of the present study was to compare the frequency of microscopic invasions, disease-free-survival (DFS), and the frequency and pattern of disease recurrence between stage I pulmonary adenocarcinomas appearing as solid nodules and those appearing as part-solid ground-glass nodules (GGNs) after matching their solid parts' size (D(solid)) and patients' age. Among 501 patients who underwent curative surgery for stage I pulmonary adenocarcinomas between 2003 and 2011, 172 patients (86 with solid nodules [M: F = 36: 50; mean age, 62.8 years] and 86 with part-solid GGNs [M:F = 30:56; mean age, 63.0 years]) matched for D(solid) and patients' age were included. DFS, frequency of microscopic invasions, recurrence, and recurrence pattern were compared between the two groups. No significant difference was observed in the frequency of microscopic invasions between the two groups (visceral pleural invasion, 30.23% vs. 29.07%, P = 0.867; lymphatic invasion, 5.81% vs. 3.49%, P = 0.720; vascular invasion, 1.16% vs. 0%, P = 1.000; solid nodules vs. part-slid GGNs, respectively) and DFS (estimated 5-year DFS, 83.6% vs. 81.9%, P = 0.744; solid nodules vs. part-slid GGNs, respectively). As for recurrence and recurrence pattern, there were no significant differences between the solid nodule group (14/86), and part-solid GGN group (12/86) (P = 0.670). Lung parenchymal nodules were the most frequent pattern of disease recurrence in both groups, followed by pleural seeding. In conclusion, after matching D(solid) and patients' age, there was no significant difference in the frequency of microscopic invasions, DFS, and the frequency and pattern of recurrence between stage I pulmonary adenocarcinomas appearing as solid nodules and part-solid GGNs.

  19. Controls on morphometry and morphology of alluvial and colluvial fans in the high-Arctic setting, Petuniabukta, Svalbard.

    Science.gov (United States)

    Tomczyk, Aleksandra; Ewertowski, Marek

    2016-04-01

    The Petuniabukta (78o42' N, 16o32') is a bay in the northern part of Billefjorden in the central part of Spitsbergen Island, Svalbard. The bay is surrounded by six major, partly glaciated valleys. A numerous alluvial and colluvial fans have developed within valleys as well as along the fiord margins. Distribution and characterization of morphometric parameters of fans were investigated using time-series of orthophotos and digital elevation models (generated based on 1961, 1990, 2009 aerial photographs) and high resolution satellite imagery from 2013. In addition, a very detailed DEM and orthophoto (5 cm resolution) have been produced from unmanned aerial vehicle (UAV) imagery from 2014 and 2015, covering three fans characterised by different types of surface morphology. A 1:40,000 map showing the distribution of almost 300 alluvial and colluvial fans (ranging in area from 325 km2 to 451 275 km2), together with time-series of 1:5,000 geomorphological maps of sample fans enabled an assessment of the spatial and temporal evolution of processes responsible for delivery and erosion of sediments from the fans. The relationship between terrain parameters (e.g. slope, exposition) as well as geology was also investigated. Many of the studied alluvial fans were at least partly coupled and sediments were transferred from the upstream zone to the downstream zone, either due to debris-flow or channelized stream flow. In other cases, coarse sediments were stored within fans, and fines were transported downstream by sheet flows or sub-surface flows. In most of smaller colluvial fans and debris cones, sediments were delivered by mass movement processes (mainly rockfalls and snowfalls) and did not reach lower margin of landforms. Analysis of historical aerial photographs indicated recent increase in the activity of debris-flow modification of surface morphology of fans. Fans located outside limits of the Little Ice Age (LIA) glaciation are dominated by the secondary processes

  20. Koroška Bela alluvial fan – The result of the catastrophic slope events; (Karavanke Mountains, NW Slovenia

    Directory of Open Access Journals (Sweden)

    Jernej Jež

    2008-12-01

    Full Text Available The Koroška Bela alluvial fan deposits were investigated to determine the genesis of the fan and the source area of sediments. The alluvial fan is composed of a sequence of diamicton layers, and related subaeric sediments that were deposited by multiple mass flow events, in some cases certainly by debris flows. The predominant sources ofsediments are tectonically deformed clastic and partly carbonate Carbonifferous and Permian rocks. In diamictons also pebbles of other rocks from the hinterland are present. These were eroded from the channel of Bela during the mass flow events. We estimate the future debris flow hazard along Bela stream as high.

  1. Fan relationship management in football - going beyond traditional product offerings to win the hearts of fans

    DEFF Research Database (Denmark)

    Cortsen, Kenneth

    2015-01-01

    The management and control of fan relations should go beyond a football club’s traditional product and service offerings and touch the important experiential side of the football economy. This will create a stronger platform to optimize ROI, ROE and ROO relating to different fan segments....

  2. Novel Crosstalk Measurement Method for Multi-Core Fiber Fan-In/Fan-Out Devices

    DEFF Research Database (Denmark)

    Ye, Feihong; Ono, Hirotaka; Abe, Yoshiteru;

    2016-01-01

    We propose a new crosstalk measurement method for multi-core fiber fan-in/fan-out devices utilizing the Fresnel reflection. Compared with the traditional method using core-to-core coupling between a multi-core fiber and a single-mode fiber, the proposed method has the advantages of high reliabili...

  3. Neurogenic abnormalities in Alzheimer's disease differ between stages of neurogenesis and are partly related to cholinergic pathology.

    Science.gov (United States)

    Perry, Elaine K; Johnson, Mary; Ekonomou, Antigoni; Perry, Robert H; Ballard, Clive; Attems, Johannes

    2012-08-01

    Neurogenesis occurs in the subventricular zone and the sub-granular layer of the hippocampus and is thought to take place in 5 stages, including proliferation, differentiation, migration, targeting, and integration phases, respectively. In Alzheimer's disease (AD) both increased and decreased neurogenesis has been reported and cholinergic activity is assumed to be involved in neurogenesis. The aim of this study was to systematically assess different phases of neurogenesis and their relation to AD and cholinergic pathology. We investigated post-mortem brain tissue from 20 AD patients and 21 non-demented controls that was neuropathologically characterized according to standardized criteria. Hippocampal sections were stained with antibodies against neurogenic markers Musashi-1, nestin, PSA-NCAM, doublecortin, and β-III-tubulin as well as ChAT (choline-acetyltransferase). Using image analysis immunoreactivity was assessed in the subventricular zone, the sub-granular layer, and the granule cell layer by determining the integrated optical density. In the sub-granular layer and the granule cell layer Musashi-1 and ChAT immunoreactivities were significantly lower in AD and decreased with increasing Braak stages. Conversely, immunorreactivities of both nestin and PSA-NCAM were significantly higher in AD and increased with increasing Braak stages while no changes were seen for doublecortin and β-III-tubulin, except for significantly higher doublecortin levels in the granule cell layer of AD cases. Of note, Musashi-1 immunoreactivity significantly correlated with ChAT immuonoreactivity across different Braak stages. In the subventricular zone only nestin immunoreactivity was significantly higher in AD and significantly increased with increasing Braak stages, while no significant differences were seen for all other markers. Our finding of a reduction of ChAT and Musashi-1 levels in AD is compatible with the assumption that cholinergic pathology per se has a detrimental

  4. Detailed analysis of fan-shaped jets in three dimensional numerical simulation

    Institute of Scientific and Technical Information of China (English)

    Rong-Lin Jiang; K. Shibata; H. Isobe; Cheng Fang

    2011-01-01

    We performed three dimensional resistive magnetohydrodynamic simulations to study the magnetic reconnection using an initially shearing magnetic field configuration (force free field with a current sheet in the middle of the computational box). It is shown that there are two types of reconnection jets: the ordinary reconnection jets and fan-shaped jets, which are formed along the guide magnetic field. The fan-shaped jets are significantly different from the ordinary reconnection jets which are ejected by magnetic tension force. There are two driving forces for accelerating the fan-shaped jets. One is the Lorentz force which initially dominates the motion of fluid elements, and then the gas pressure gradient force accelerates the fluid elements in the later stage. The dependence on magnetic reconnection angle and resistivity value has also been studied. The formation and evolution of these jets provide a new understanding of dynamic magnetohydrodynamicjets.

  5. [Part I. End-stage chronic organ failures: a position paper on shared care planning. The Integrated Care Pathway].

    Science.gov (United States)

    Gristina, Giuseppe R; Orsi, Luciano; Carlucci, Annalisa; Causarano, Ignazio R; Formica, Marco; Romanò, Massimo

    2014-01-01

    In Italy the birth rate decrease together with the continuous improvement of living conditions on one hand, and the health care progress on the other hand, led in recent years to an increasing number of patients with chronic mono- or multi-organ failures and in an extension of their life expectancy. However, the natural history of chronic failures has not changed and the inescapable disease's worsening at the end makes more rare remissions, increasing hospital admissions rate and length of stay. Thus, when the "end-stage" get close clinicians have to engage the patient and his relatives in an advance care planning aimed to share a decision making process regarding all future treatments and related ethical choices such as patient's best interests, rights, values, and priorities. A right approach to the chronic organ failures end-stage patients consists therefore of a careful balance between the new powers of intervention provided by the biotechnology and pharmacology (intensive care), both with the quality of remaining life supplied by physicians to these patients (proportionality and beneficence) and the effective resources rationing and allocation (distributive justice). However, uncertainty still marks the criteria used by doctors to assess prognosis of these patients in order to make decisions concerning intensive or palliative care. The integrated care pathway suggested in this position paper shared by nine Italian medical societies, has to be intended as a guide focused to identify end-stage patients and choosing for them the best care option between intensive treatments and palliative care.

  6. Advanced LIGO Two-Stage Twelve-Axis Vibration Isolation and Positioning Platform. Part 1: Design and Production Overview

    CERN Document Server

    Matichard, Fabrice; Mason, Kenneth; Mittleman, Richard; Abbott, Benjamin; Abbott, Samuel; Allwine, Eric; Barnum, Samuel; Birch, Jeremy; Biscans, Sebastien; Clark, Daniel; Coyne, Dennis; DeBra, Dan; DeRosa, Ryan; Foley, Stephany; Fritschel, Peter; Giaime, Joseph A; Gray, Corey; Grabeel, Gregory; Hanson, Joe; Hillard, Michael; Kissel, Jeffrey; Kucharczyk, Christopher; Roux, Adrien Le; Lhuillier, Vincent; Macinnis, Myron; OReilly, Brian; Ottaway, David; Paris, Hugo; Puma, Michael; Radkins, Hugh; Ramet, Celine; Robinson, Mitchell; Ruet, Laurent; Sareen, Pradeep; Shoemaker, Daivid; Stein, Andy; Thomas, Jeremy; Vargas, Michael; Warner, Jimmy

    2014-01-01

    New generations of gravity wave detectors require unprecedented levels of vibration isolation. This paper presents the final design of the vibration isolation and positioning platform used in Advanced LIGO to support the interferometers core optics. This five-ton two-and-half-meter wide system operates in ultra-high vacuum. It features two stages of isolation mounted in series. The stages are imbricated to reduce the overall height. Each stage provides isolation in all directions of translation and rotation. The system is instrumented with a unique combination of low noise relative and inertial sensors. The active control provides isolation from 0.1 Hz to 30 Hz. It brings the platform motion down to 10^(-11) m/Hz^(0.5) at 1 Hz. Active and passive isolation combine to bring the platform motion below 10^(-12) m/Hz^(0.5) at 10 Hz. The passive isolation lowers the motion below 10^(-13) m/Hz^(0.5) at 100 Hz. The paper describes how the platform has been engineered not only to meet the isolation requirements, but a...

  7. Effectiveness of an inlet flow turbulence control device to simulate flight noise fan in an anechoic chamber

    Science.gov (United States)

    Woodward, R. P.; Wazyniak, J. A.; Shaw, L. M.; Mackinnon, M. J.

    1977-01-01

    A hemispherical inlet flow control device was tested on a 50.8 cm. (20-inch) diameter fan stage in the NASA-Lewis anechoic chamber. The control device used honeycomb and wire mesh to reduce turbulence intensities entering the fan. Far field acoustic power level results show about a 5 db reduction in blade passing tone and about 10 dB reduction in multiple pure tone sound power at 90% design fan speed with the inlet device in place. Hot film cross probes were inserted in the inlet to obtain data for two components of the turbulence at 65 and 90% design fan speed. Without the flow control device, the axial intensities were below 1.0%, while the circumferential intensities were almost twice this value. The inflow control device significantly reduced the circumferential turbulence intensities and also reduced the axial length scale.

  8. Effectiveness of an inlet flow turbulence control device to simulate flight fan noise in an anechoic chamber

    Science.gov (United States)

    Woodward, R. P.; Wazyniak, J. A.; Shaw, L. M.; Mackinnon, M. J.

    1977-01-01

    A hemispherical inlet flow control device was tested on a 50.8 cm. (20-inch) diameter fan stage in the NASA-Lewis Anechoic Chamber. The control device used honeycomb and wire mesh to reduce turbulence intensities entering the fan. Far field acoustic power level results showed about a 5 dB reduction in blade passing tone and about 10 dB reduction in multiple pure tone sound power at 90% design fan speed with the inlet device in place. Hot film cross probes were inserted in the inlet to obtain data for two components of the turbulence at 65 and 90% design fan speed. Without the flow control device the axial intensities were below 1.0%, while the circumferential intensities were almost twice this value. The inflow control device significantly reduced the circumferential turbulence intensities and also reduced the axial length scale.

  9. Design Guidelines for Quiet Fans and Pumps for Space Vehicles

    Science.gov (United States)

    Lovell, John S.; Magliozzi, Bernard

    2008-01-01

    This document presents guidelines for the design of quiet fans and pumps of the class used on space vehicles. A simple procedure is presented for the prediction of fan noise over the meaningful frequency spectrum. A section also presents general design criteria for axial flow fans, squirrel cage fans, centrifugal fans, and centrifugal pumps. The basis for this report is an experimental program conducted by Hamilton Standard under NASA Contract NAS 9-12457. The derivations of the noise predicting methods used in this document are explained in Hamilton Standard Report SVHSER 6183, "Fan and Pump Noise Control," dated May 1973 (6).

  10. Numerical Aerodynamic Evaluation and Noise Investigation of a Bladeless Fan

    OpenAIRE

    mohammad jafari; Hossein Afshin; Bijan Farhanieh; Hamidreza bozorgasareh

    2015-01-01

    Bladeless fan is a novel fan type that has no observable impeller, usually used for domestic applications. Numerical investigation of a Bladeless fan via Finite Volume Method was carried out in this study. The fan was placed in center of a 4×2×2m room and 473 Eppler airfoil profile was used as cross section of the fan. Performance and noise level of the fan by solving continuity and momentum equations as well as noise equations of Broadband Noise Source (BNS) and Ffowcs Williams a...

  11. Evolution of the alluvial fans of the Luo River in the Weihe Basin, central China, controlled by faulting and climate change - A reevaluation of the paleogeographical setting of Dali Man site

    Science.gov (United States)

    Rits, Daniël S.; van Balen, Ronald T.; Prins, Maarten A.; Zheng, Hongbo

    2017-06-01

    The Luo River is located in the southern part of the Chinese Loess Plateau and the northern part of the Weihe Basin, in Central China. In the basin it flows proximal to the site of the Luyang Wetland core, which is an important archive of climate change over the past 1 Myr in this region. In this paper, the contribution of the Luo River to the sedimentary record is analyzed by reconstructing the evolution of this river during the Middle to Late Pleistocene. It is argued that an alluvial fan of the Luo River has contributed to the sedimentary archive until approximately 200-240 ka. From this moment onwards, the fan became incised and terraces began to form. The formation of a new alluvial fan further downstream led to the disconnection of the Luo River from the Luyang Wetland core site. We propose that this series of events was caused by the displacement of an intra-basinal fault and the resultant faulting-forced folding, which caused increased relative subsidence, and thus increased sedimentation rates at the core site. Therefore, a complete sediment record in the 'Luyang Wetland' was preserved, despite the disconnection from the Luo River. The chronology of the fans and terraces was established using existing age control (U-series, ESR, OSL, pIRIR290 and magnetic susceptibility correlation), and through correlation of the loess-paleosol cover to marine isotope stages. Based on sedimentological characteristics of the fluvial sequence, we suggest that incision of the Luo River occurred in two steps. Small incisions took place at transitions to interglacials and the main incision phases occur at the transition from an interglacial to glacial climate. Due to the incision, basal parts of the oldest Luo River alluvial fan are exposed, and it is in one of these exposures that the famous Dali Man skull was retrieved. This study shows that the Dali Man did not live on a river terrace as previously thought, but on an aggrading alluvial fan, during wet, glacial conditions.

  12. Dynamic headspace-gas-chromatography-olfactometry analysis of different anatomical parts of lovage (Levisticum officinale Koch.) at eight growing stages

    NARCIS (Netherlands)

    Bylaite, E.; Roozen, J.P.; Legger, A.; Venskutonis, R.P.; Posthumus, M.A.

    2000-01-01

    Volatiles of five different parts of lovage (leaves, stems, flowers, seeds, and roots) were isolated by dynamic headspace (DHS) method and analyzed by GC-FID and GC-olfactometry (GC-O) techniques. In total, 98 compounds were identified in the samples, of which 41 are reported as lovage volatiles for

  13. Ergosterol profiles, fatty acid composition, and antioxidant activities of button mushrooms as affected by tissue part and developmental stage.

    Science.gov (United States)

    Shao, Suqin; Hernandez, Marta; Kramer, John K G; Rinker, Danny L; Tsao, Rong

    2010-11-24

    This article investigated the mycochemical profiles and the antioxidant activities of the lipophilic extracts of the white and brown button mushrooms. We found that only free ergosterols were present in both mushrooms at 2.04-4.82 mg/g dry matter (DM). Ergosterol concentration was higher in early growth stages but decreased as the mushrooms grew, and it distributed evenly between the caps and stems during early developmental stages but accumulated more in the caps after maturation. The photochemiluminescence (PCL) values of the two mushrooms were 5.49-10.48 nmol trolox equivalent/mg DM, and the EC50 values of 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay ranged 20.19-41.49 mg DM/μg DPPH. The ergosterol content positively correlated with the antioxidant activities (r2>0.89). The total fatty acid content was 8.7 mg/g DM in the white and 5.1 mg/g DM in the brown button mushroom and contained mainly linoleic, palmitic, and stearic acids. Our data provide guidance for optimized harvesting time of mushrooms and maximized health benefits.

  14. [Diagnostics and therapy of dysphonia suitable for the ages and developmental stages of children and adolescents (part 2)].

    Science.gov (United States)

    Fuchs, M

    2008-02-01

    The incidence of dysphonia among children and adolescents is evaluated internationally at 6 % to 25 %. Nonetheless, hoarseness as a leading symptom among children is often insufficiently recognized by their parents/attachment figures, by the young patients themselves, and even by physicians. In an overview, the hereditary and acquired organic and functional causes - including secondary organic lesions of the vocal folds - their pathomechanisms and the symptoms typical for this age group are presented. For diagnostics suitable for these age groups and developmental stages, modern methods of laryngoscopy (including stoboscopy and real-time laryngoscopy), of functional diagnostics of vocal capacity and quality as well as anamnestic and psychometric procedures for the investigation of possible psychosomatic genesis are available. Frequent therapeutic measures are vocal hygienic counseling and psycho- and family dynamic therapies. Vocal exercise treatments are particularly employed for the consequences of laryngeal surgery and with voice techniques unfavorable as a precondition for increased vocal activity. Operative measures in the sound-producing areas of the vocal apparatus and in the framework of plastic reconstruction concentrate on the optimizing of vocal capacity and quality. In clinical routine, symptoms of dysphonia in children and adolescents should be consciously registered, and any long-term hoarseness, in this age group as well, should be examined by specialized physicians using the methods suitable to the age group and the developmental stage. When the appropriate indications are present, all of the therapeutic options currently available should be discussed.

  15. "But this is my story and this is how I wanted to write it": Author's notes as a fannish claim to power in fan fiction writing

    Directory of Open Access Journals (Sweden)

    Alexandra Herzog

    2012-09-01

    Full Text Available Issues of power have always been an important factor in fan fiction writing. The publishers of the source texts were long regarded as a dominant force, with fans conventionally relegated to the status of an audience largely deprived of authority, even when they produced fan fiction and thus challenged the sovereignty of interpretation original authors often preferred to keep for themselves. This essay argues that author's notes as a part of fannish paratext are an essential means of supporting the fan authors' claim to power by providing these writers with an explicit space to make their voices heard. They allow fans to express their interpretation of different models of authorship and give them the opportunity to assume a variety of author roles. Thus negotiating between a belief in the significance of the individual author, Barthes's death of the author, and newer collaborative forms of writing, fans constitute themselves as an authoritative body in regard to rights of interpreting text or writing fan fiction. Focusing on their own identity as writers, on the fannish community, and on their text and its position in the larger archive of the fandom, fans reconceptualize themselves as powerful producers, whose agency becomes obvious in the vast body of their texts. Author's notes, I claim, are thus crucial in fans assuming and exerting control and authority.

  16. Optimism Bias in Fans and Sports Reporters.

    Directory of Open Access Journals (Sweden)

    Bradley C Love

    Full Text Available People are optimistic about their prospects relative to others. However, existing studies can be difficult to interpret because outcomes are not zero-sum. For example, one person avoiding cancer does not necessitate that another person develops cancer. Ideally, optimism bias would be evaluated within a closed formal system to establish with certainty the extent of the bias and the associated environmental factors, such that optimism bias is demonstrated when a population is internally inconsistent. Accordingly, we asked NFL fans to predict how many games teams they liked and disliked would win in the 2015 season. Fans, like ESPN reporters assigned to cover a team, were overly optimistic about their team's prospects. The opposite pattern was found for teams that fans disliked. Optimism may flourish because year-to-year team results are marked by auto-correlation and regression to the group mean (i.e., good teams stay good, but bad teams improve.

  17. Optimism Bias in Fans and Sports Reporters.

    Science.gov (United States)

    Love, Bradley C; Kopeć, Łukasz; Guest, Olivia

    2015-01-01

    People are optimistic about their prospects relative to others. However, existing studies can be difficult to interpret because outcomes are not zero-sum. For example, one person avoiding cancer does not necessitate that another person develops cancer. Ideally, optimism bias would be evaluated within a closed formal system to establish with certainty the extent of the bias and the associated environmental factors, such that optimism bias is demonstrated when a population is internally inconsistent. Accordingly, we asked NFL fans to predict how many games teams they liked and disliked would win in the 2015 season. Fans, like ESPN reporters assigned to cover a team, were overly optimistic about their team's prospects. The opposite pattern was found for teams that fans disliked. Optimism may flourish because year-to-year team results are marked by auto-correlation and regression to the group mean (i.e., good teams stay good, but bad teams improve).

  18. ANALYTICAL METHODS FOR CALCULATING FAN AERODYNAMICS

    Directory of Open Access Journals (Sweden)

    Jan Dostal

    2015-12-01

    Full Text Available This paper presents results obtained between 2010 and 2014 in the field of fan aerodynamics at the Department of Composite Technology at the VZLÚ aerospace research and experimental institute in Prague – Letnany. The need for rapid and accurate methods for the preliminary design of blade machinery led to the creation of a mathematical model based on the basic laws of turbomachine aerodynamics. The mathematical model, the derivation of which is briefly described below, has been encoded in a computer programme, which enables the theoretical characteristics of a fan of the designed geometry to be determined rapidly. The validity of the mathematical model is assessed continuously by measuring model fans in the measuring unit, which was developed and manufactured specifically for this purpose. The paper also presents a comparison between measured characteristics and characteristics determined by the mathematical model as the basis for a discussion on possible causes of measured deviations and calculation deviations.

  19. Miocene Current-Modified Submarine Fans

    Science.gov (United States)

    Arce Perez, L. E.; Snedden, J.; Fisher, W. L.

    2016-12-01

    In the southwestern Gulf of Mexico, new and newly reprocessed seismic data has revealed a series of large bedforms, with set thicknesses of 130 to 250 meters. These exhibit hummocky, oblique and shingled to parallel seismic clinoform reflections. This seismic package has a paleowater depth of 450 meters. Those shingled seismic reflections in offshore east Mexico are interpreted as contourite drift deposits. These Miocene-age contourites may be related to strong ocean bottom currents that modified submarine fans and transported sediment to the north. Those contourites were identified on older seismic data, but are better imaged and interpreted on this new data. Plans are to map out and investigate the origin and extent of fans and contourites that extends over a large area of the Gulf of Mexico. In the Early Miocene several submarine fans systems were formed by the sediment input related to orogenic activity in Mexico. Submarine fan development persisted into the Middle Miocene due to continued uplift and erosion of the Mexican landmass. Initial, contourites are small and close proximity to the deep-water fan. In the Late Miocene time, contourite drift field reached its maximum extent in the Mexican deepwater area, anchored on its southern end by a submarine mound. This mounded submarine fan is located in the offshore northeast Veracruz and can be linked to increased uplift and erosion of the Trans-Mexican volcanic belt. In the Miocene-Pliocene, the large contourite drift begins to diminish in size and scale and is moribund by the Pliocene, with establishment of oceanic circulation similar to the present day. This research is important to understand more about the Gulf of Mexico and also for the Miocene timeframe that is a key phase in the earth's history. The role of the change in bottom water flow during progressive closure of the equatorial seaway separating North and South America will also be investigated.

  20. Experimental alluvial fans: Advances in understanding of fan dynamics and processes

    Science.gov (United States)

    Clarke, Lucy E.

    2015-09-01

    Alluvial fans are depositional systems that develop because of a disparity between the upstream and downstream sediment transport capacity of a system, usually at the base of mountain fronts as rivers emerge from the constrained mountain area onto the plain. They are dynamic landforms that are prone to abrupt changes on a geomorphological (decades to centuries) time scale, while also being long-term deposition features that preserve sedimentary strata and are sensitive indictors of environmental change. The complexity of interactions between catchment characteristics, climate, tectonics, internal system feedbacks, and environmental processes on field alluvial fans means that it is difficult to isolate individual variables in a field setting; therefore, the controlled conditions afforded by experimental models has provided a novel technique to overcome some of these complexities. The use of experimental models of alluvial fans has a long history and these have been implemented over a range of different research areas utilising various experimental designs. Using this technique, important advances have been made in determining the primary factors influencing fan slope, understanding of avulsion dynamics, identifying autogenic processes driving change on fan systems independent of any change in external conditions, and the mechanics of flow and flood risk on alluvial fans, to name a few. However, experiments cannot be carried out in isolation. Thus, combining the findings from experimental alluvial fans with field research and numerical modelling is important and, likewise, using these techniques to inform experimental design. If this can be achieved, there is potential for future experimental developments to explore key alluvial fan issues such as stratigraphic preservation potential and simulating extra terrestrial fan systems.

  1. Homophobia, heteronormativity, and slash fan fiction

    Directory of Open Access Journals (Sweden)

    April S. Callis

    2016-09-01

    Full Text Available I analyze the relationship between homophobia/heteronormativity and slash fan fiction. Through reading and coding almost 6,000 pages of Kirk/Spock fan fiction written from 1978 to 2014, I illuminate shifts in how normative gender and sexuality are portrayed by K/S authors. Writers of K/S, while ostensibly writing about the 23rd century, consciously or unconsciously include cultural norms from the 20th and 21st centuries. Thus, slash becomes a lens through which readers can view a decrease in both homophobia and heteronormativity in US culture over the past several decades.

  2. Flow control in axial fan inlet guide vanes by synthetic jets

    OpenAIRE

    Wurst P.; Trávníček Z.; Cyrus V.; Kordík J.

    2013-01-01

    Tested high pressure axial flow fan with hub/tip ratio of 0.70 and external diameter of 600 mm consisted of inlet guide vanes (IGV), rotor and stator blade rows. Fan peripheral velocity was 47 m/s. Air volume flow rate was changed by turning of rear part of the inlet guide vanes. At turning of 20 deg the flow was separated on the IGV profiles. The synthetic jets were introduced through radial holes in machine casing in the location before flow separation origin. Synthetic jet actuator was des...

  3. Indonesian Fan Girls’ Perception towards Soft Masculinity as Represented By K-pop Male Idols

    Directory of Open Access Journals (Sweden)

    Paramita Ayuningtyas

    2017-05-01

    Full Text Available This article aimed to examine how fan girls perceive this new form of masculinity represented by K-pop male idols (termed as soft masculinity. This research used a mixed method in collecting the data from a questionnaire distributed via e-mail and Line to twenty fan girls from various fandoms in April 2016. The result shows that the respondents are aware that in the entertainment business, gender identity can be modified and presented as a part of marketing strategy. In addition, they only see the soft masculinity delivered by K-pop male idols as a form of performance.

  4. Transient analysis of energy Transfer Control (ECT) and compressor bleed concepts of remote lift fan control

    Science.gov (United States)

    Sellers, J. F.

    1973-01-01

    The transient performance of two concepts for control of vertical takeoff aircraft remote lift fans is analyzed and discussed. Both concepts employ flow transfer between pairs of lift fans located in separate parts of the aircraft in order to obtain attitude control moments for hover and low-speed flight. The results presented are from a digital computer, dynamic analysis of the YJ97/LF460 remote drive turbofan. The transient responses of the two systems are presented for step demands in lift and moment.

  5. Fan fiction metadata creation and utilization within fan fiction archives: Three primary models

    Directory of Open Access Journals (Sweden)

    Shannon Fay Johnson

    2014-09-01

    Full Text Available Issues related to searchability and ease of access have plagued fan fiction since its inception. This paper discusses the predominate forms of fan-mediated indexing and descriptive metadata, commonly referred to as folksonomy or tagging, and compares the benefits and disadvantages of each model. These models fall into three broad categories: free tagging, controlled vocabulary, and hybrid folksonomy. Each model has distinct advantages and shortcomings related to findability, results filtering, and creative empowerment. Examples for each are provided. Possible ramifications to fan fiction from improved metadata and access are also discussed.

  6. Experiencing fan activism: Understanding the power of fan activist organizations through members' narratives

    Directory of Open Access Journals (Sweden)

    Neta Kligler-Vilenchik

    2012-06-01

    Full Text Available Fan activism, forms of civic engagement and political participation growing out of experiences of fandom, is a powerful mode of mobilization, particularly for young people. Building on 40 interviews with members of two organizations representing different configurations of fan activism, this article discusses three emerging elements that are key to the experience of membership in such groups. We suggest that the strength of fan activist groups builds on successfully combining these elements: two that are common to fandom, shared media experiences and a sense of community, and one that is traditionally ascribed to volunteerism and activism, the wish to help.

  7. Alluvial Fan Study Submission for UMATILLA COUNTY, OREGON

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Alluvial fan study data as defined in FEMA Guidelines and Specifications, Appendix G: Guidance for Alluvial Fan Flooding Analyses and Mapping

  8. Improving Fan System Performance: A Sourcebook for Industry

    Energy Technology Data Exchange (ETDEWEB)

    None

    2003-04-01

    This is one of a series of sourcebooks on motor-driven equipment produced by the Industrial Technologies Program. It provides a reference for industrial fan systems users, outlining opportunities to improve fan system performance.

  9. LDA measurements on the turbulent flow characteristics of a small-sized axial fan

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jang Kweon [Kunsan National Univ., Kunsan (Korea, Republic of)

    2001-07-01

    The operating point of a small-sized axial fan for refrigerator is strongly dependent upon the system resistance. Therefore, the turbulent flow characteristics around a small-sized axial fan may change significantly according to the operating point. This study represents three-dimensional turbulent flow characteristics around a small-sized axial fan measured at the four operating points such as {phi}=0.1, 0.18, 0.25 and 0.32 by using fiber-optic type LDA system. This LDA system is composed of a 5 W Argon-ion laser, two optics in back-scatter mode, three BSA's, a PC, and a three-dimensional automatic traversing system. A kind of paraffin fluid is utilized for supplying particles by means of fog generator. Mean velocity profiles downstream of a small--sized axial fan along the radial distance show that both the streamwise and the tangential components exist predominantly in downstream except {phi}=0.1 and have a maximum value at the radial distance ratio of about 0.8, but the radial component, which its velocity is relatively small, is acting role that only turns flow direction to the outside or the central part of axial fan. Moreover, all of the velocity components downstream at {phi}=0.1 show much smaller than those upstream due to the static pressure rise at the low-flowrate region.

  10. Fan Noise Source Diagnostic Test: LDV Measured Flow Field Results

    Science.gov (United States)

    Podboy, Gary C.; Krupar, Martin J.; Hughes, Christopher E.; Woodward, Richard P.

    2003-01-01

    Results are presented of an experiment conducted to investigate potential sources of noise in the flow developed by two 22-in. diameter turbofan models. The R4 and M5 rotors that were tested were designed to operate at nominal take-off speeds of 12,657 and 14,064 RPMC, respectively. Both fans were tested with a common set of swept stators installed downstream of the rotors. Detailed measurements of the flows generated by the two were made using a laser Doppler velocimeter system. The wake flows generated by the two rotors are illustrated through a series of contour plots. These show that the two wake flows are quite different, especially in the tip region. These data are used to explain some of the differences in the rotor/stator interaction noise generated by the two fan stages. In addition to these wake data, measurements were also made in the R4 rotor blade passages. These results illustrate the tip flow development within the blade passages, its migration downstream, and (at high rotor speeds) its merging with the blade wake of the adjacent (following) blade. Data also depict the variation of this tip flow with tip clearance. Data obtained within the rotor blade passages at high rotational speeds illustrate the variation of the mean shock position across the different blade passages.

  11. Geomorphic characterization of the Fortymile Wash alluvial fan, Nye County, Nevada, in support of the Yucca Mountain Project

    Science.gov (United States)

    Cline, M.; Delong, S.; Pelletier, J.

    2005-12-01

    In the event of an unlikely volcanic eruption through the proposed high-level radioactive waste repository at Yucca Mountain, contaminated ash may be deposited in portions of the Fortymile Wash drainage basin and subsequently redistributed to the Fortymile Wash alluvial fan by fluvial processes. Characterization of the Fortymile Wash alluvial fan has been undertaken as part of an effort to quantify the transport of contaminated ash throughout the fluvial system, especially to define the spatial distribution of fluvial activity over time scales of repository operation, and the rates of radionuclide migration into different soils on the fan. The Fortymile Wash alluvial fan consists of extremely low relief terraces as old as 70 ka. By conducting soils-geomorphic mapping and correlating relative surface ages with available geochronology from the Fortymile Wash fan and adjacent piedmonts, we identified 4 distinct surfaces on the fan. Surface ages are used to predict the relative stability of different areas of the fan to fluvial activity. Pleistocene-aged surfaces are assumed to be fluvially inactive over the 10 kyr time scale, for example. Our mapping and correlation provides a map of the depozone for contaminated ash that takes into account long-term channel migration for the time scales of repository operation, and it provides a geomorphic framework for predicting radionuclide dispersion rates into different soils across the fan. The standard model for vertical migration of radionuclides in soil is diffusion; therefore we used diffusion profiles derived from 137Cs fallout to determine radionuclide infiltration rates on the various geomorphic surfaces. The results show a strong inverse correlation of the geomorphic surface age and diffusivity values inferred from the 137Cs profiles collected on the different surfaces of the fan.

  12. Fan action and political participation on "The Colbert Report"

    Directory of Open Access Journals (Sweden)

    Marcus Schulzke

    2012-06-01

    Full Text Available The Colbert Report merges the increasingly popular political satire genre with fan activism. The result is that the fan community helps to construct Colbert's malleable character and demonstrates symbolic power through its willingness to act. The fans are usually a nonpartisan force, acting to produce entertainment rather than substantive political change. However, this can be politically meaningful, as the fans' projects promote collective action, parallel political activities like voting and protesting, and encourage critical thinking about political information.

  13. Advanced LIGO Two-Stage Twelve-Axis Vibration Isolation and Positioning Platform. Part 2: Experimental Investigation and Tests Results

    CERN Document Server

    Matichard, Fabrice; Mason, Kenneth; Mittleman, Richard; Abbott, Benjamin; Abbott, Samuel; Allwine, Eric; Barnum, Samuel; Birch, Jeremy; Biscans, Sebastien; Clark, Daniel; Coyne, Dennis; DeBra, Dan; DeRosa, Ryan; Foley, Stephany; Fritschel, Peter; Giaime, Joseph A; Gray, Corey; Grabeel, Gregory; Hanson, Joe; Hillard, Michael; Kissel, Jeffrey; Kucharczyk, Christopher; Roux, Adrien Le; Lhuillier, Vincent; Macinnis, Myron; OReilly, Brian; Ottaway, David; Paris, Hugo; Puma, Michael; Radkins, Hugh; Ramet, Celine; Robinson, Mitchell; Ruet, Laurent; Sareen, Pradeep; Shoemaker, Daivid; Stein, Andy; Thomas, Jeremy; Vargas, Michael; Warner, Jimmy

    2014-01-01

    This paper presents the results of the past seven years of experimental investigation and testing done on the two-stage twelve-axis vibration isolation platform for Advanced LIGO gravity waves observatories. This five-ton two-and-half-meter wide system supports more than a 1000 kg of very sensitive equipment. It provides positioning capability and seismic isolation in all directions of translation and rotation. To meet the very stringent requirements of Advanced LIGO, the system must provide more than three orders of magnitude of isolation over a very large bandwidth. It must bring the motion below 10^(-11) m/(Hz)^0.5 at 1 Hz and 10^(-12) m/(Hz)^0.5 at 10 Hz. A prototype of this system has been built in 2006. It has been extensively tested and analyzed during the following two years. This paper shows how the experimental results obtained with the prototype were used to engineer the final design. It highlights how the engineering solutions implemented not only improved the isolation performance but also greatl...

  14. Dead links, vaporcuts, and creativity in fan edit replication

    Directory of Open Access Journals (Sweden)

    Joshua Wille

    2015-09-01

    Full Text Available In my examination of a Star Wars prequel trilogy fan edit reportedly made by Topher Grace, I introduce the term vaporcut to describe fan edits with reputations that may generate critical discourse but that are not publicly released. I explore the ways some fan editors attempt to recreate intangible projects but inevitably produce variant works that reflect their own creative perspectives.

  15. Star Trek Rerun, Reread, Rewritten: Fan Writing as Textual Poaching.

    Science.gov (United States)

    Jenkins III, Henry

    1988-01-01

    Discusses women who write fiction and fan literature based on the "Star Trek" universe, outlining how Star Trek fans force the primary text to accommodate alternate interests. Also considers the issue of literary property in light of the moral economy of the fan community that shapes the range of permissible retellings of the program…

  16. Enduring legacy of a toxic fan via episodic redistribution of California gold mining debris.

    Science.gov (United States)

    Singer, Michael Bliss; Aalto, Rolf; James, L Allan; Kilham, Nina E; Higson, John L; Ghoshal, Subhajit

    2013-11-12

    The interrelationships between hydrologically driven evolution of legacy landscapes downstream of major mining districts and the contamination of lowland ecosystems are poorly understood over centennial time scales. Here, we demonstrate within piedmont valleys of California's Sierra Nevada, through new and historical data supported by modeling, that anthropogenic fans produced by 19th century gold mining comprise an episodically persistent source of sediment-adsorbed Hg to lowlands. Within the enormous, iconic Yuba Fan, we highlight (i) an apparent shift in the relative processes of fan evolution from gradual vertical channel entrenchment to punctuated lateral erosion of fan terraces, thus enabling entrainment of large volumes of Hg-laden sediment during individual floods, and (ii) systematic intrafan redistribution and downstream progradation of fan sediment into the Central Valley, triggered by terrace erosion during increasingly long, 10-y flood events. Each major flood apparently erodes stored sediment and delivers to sensitive lowlands the equivalent of ~10-30% of the entire postmining Sierran Hg mass so far conveyed to the San Francisco Bay-Delta (SFBD). This process of protracted but episodic erosion of legacy sediment and associated Hg is likely to persist for >10(4) y. It creates, within an immense swath of river corridor well upstream of the SFBD, new contaminated floodplain surfaces primed for Hg methylation and augments/replenishes potential Hg sources to the SFBD. Anticipation, prediction, and management of toxic sediment delivery, and corresponding risks to lowland ecology and human society globally, depend on the morphodynamic stage of anthropogenic fan evolution, synergistically coupled to changing frequency of and duration extreme floods.

  17. Acoustic analysis of a computer cooling fan

    Science.gov (United States)

    Huang, Lixi; Wang, Jian

    2005-10-01

    Noise radiated by a typical computer cooling fan is investigated experimentally and analyzed within the framework of rotor-stator interaction noise using point source formulation. The fan is 9 cm in rotor casing diameter and its design speed is 3000 rpm. The main noise sources are found and quantified; they are (a) the inlet flow distortion caused by the sharp edges of the incomplete bellmouth due to the square outer framework, (b) the interaction of rotor blades with the downstream struts which hold the motor, and (c) the extra size of one strut carrying electrical wiring. Methods are devised to extract the rotor-strut interaction noise, (b) and (c), radiated by the component forces of drag and thrust at the leading and higher order spinning pressure modes, as well as the leading edge noise generated by (a). By re-installing the original fan rotor in various casings, the noises radiated by the three features of the original fan are separated, and details of the directivity are interpreted. It is found that the inlet flow distortion and the unequal set of four struts make about the same amount of noise. Their corrections show a potential of around 10-dB sound power reduction.

  18. Generalized sorting profile of alluvial fans

    Science.gov (United States)

    Miller, Kimberly Litwin; Reitz, Meredith D.; Jerolmack, Douglas J.

    2014-10-01

    Alluvial rivers often exhibit self-similar gravel size distributions and abrupt gravel-sand transitions. Experiments suggest that these sorting patterns are established rapidly, but how—and how fast—this convergence occurs in the field is unknown. We examine the establishment of downstream sorting patterns in a kilometer-scale alluvial fan. The sharp transition from canyon to unconfined, channelized fan provides a well-defined boundary condition. The channel changes from deep and entrenched at the fan apex to shallow and depositional over a short distance, exhibiting nonequilibrium behavior. The resulting gravel-fining profile is not self-similar; the particle size distribution narrows until approximate equal mobility is achieved. Downfan, the gravel-sand transition appears to exhibit a self-similar form; field and laboratory data collapse when downstream distance is normalized by the location of the transition. Results suggest a generalized sorting profile for alluvial fans as a consequence of the threshold of motion and nonequilibrium channels.

  19. Fan Affinity Laws from a Collision Model

    Science.gov (United States)

    Bhattacharjee, Shayak

    2012-01-01

    The performance of a fan is usually estimated using hydrodynamical considerations. The calculations are long and involved and the results are expressed in terms of three affinity laws. In this paper we use kinetic theory to attack this problem. A hard sphere collision model is used, and subsequently a correction to account for the flow behaviour…

  20. Test particle acceleration in torsional fan reconnection

    Science.gov (United States)

    Hosseinpour, M.

    2014-12-01

    Magnetic reconnection is understood to be a potential mechanism for particle acceleration in astrophysical and space plasmas, especially in solar flares. Torsional fan reconnection is one of the proposed mechanisms for steady-state three-dimensional (3D) magnetic reconnection. By using the magnetic and electric fields for `torsional fan reconnection', the features of test particle acceleration with input parameters for the solar corona are investigated numerically. We show that torsional fan reconnection is potentially an efficient particle accelerator and a proton can gain up to tens of MeV of kinetic energy within only a few milliseconds. Although the final kinetic energy of the accelerated particle depends on the injection position but there exists only one scenario for the particle's trajectory with different initial positions in which the particle is accelerated on the fan plane. Moreover, adopting either spatially uniform or non-uniform localized plasma resistivity does not much influence the features of trajectory. These results are compared with those of torsional spine reconnection.

  1. Fan Affinity Laws from a Collision Model

    Science.gov (United States)

    Bhattacharjee, Shayak

    2012-01-01

    The performance of a fan is usually estimated using hydrodynamical considerations. The calculations are long and involved and the results are expressed in terms of three affinity laws. In this paper we use kinetic theory to attack this problem. A hard sphere collision model is used, and subsequently a correction to account for the flow behaviour…

  2. Technical and economic working domains of industrial heat pumps: Part 1 - single stage vapour compression heat pumps

    DEFF Research Database (Denmark)

    Ommen, Torben Schmidt; Jensen, Jonas Kjær; Markussen, Wiebke Brix;

    2015-01-01

    A large amount of operational and economic constraints limit the applicability of heat pumps operated with natural working fluids. The limitations are highly dependent on the integration of heat source and sink streams. An evaluation of feasible operating conditions was carried out considering...... the constraints of available refrigeration equipment and a requirement of a positive net present value of the investment. Six heat pump systems were considered, corresponding to an upper limit of the sink temperature of 120 °C. For each set of heat sink and source temperatures the best available technology...... was determined. The results showed that four different heat pump systems propose the best available technology at different parts of the complete domain. Ammonia systems presented the best available technology at low sink outlet temperature. At high temperature difference between sink in- and outlet...

  3. Fan Ky不等式的一个新改进%A New Improvement of Fan Ky's Inequality

    Institute of Scientific and Technical Information of China (English)

    黄政; 高明哲; 徐景实

    2010-01-01

    利用Gram矩阵的正定性和可变单位向量建立了Fan Ky不等式的一个新的改进,并且建立了反向Fan Ky不等式.对于非奇异矩阵,得到了Fan Ky不等式以及反向Fan Ky不等式的推广.

  4. Regenerative Blower for EVA Suit Ventilation Fan

    Science.gov (United States)

    Izenson, Michael G.; Chen, Weibo; Paul, Heather L.

    2010-01-01

    Portable life support systems in future space suits will include a ventilation subsystem driven by a dedicated fan. This ventilation fan must meet challenging requirements for pressure rise, flow rate, efficiency, size, safety, and reliability. This paper describes research and development that showed the feasibility of a regenerative blower that is uniquely suited to meet these requirements. We proved feasibility through component tests, blower tests, and design analysis. Based on the requirements for the Constellation Space Suit Element (CSSE) Portable Life Support System (PLSS) ventilation fan, we designed the critical elements of the blower. We measured the effects of key design parameters on blower performance using separate effects tests, and used the results of these tests to design a regenerative blower that will meet the ventilation fan requirements. We assembled a proof-of-concept blower and measured its performance at sub-atmospheric pressures that simulate a PLSS ventilation loop environment. Head/flow performance and maximum efficiency point data were used to specify the design and operating conditions for the ventilation fan. We identified materials for the blower that will enhance safety for operation in a lunar environment, and produced a solid model that illustrates the final design. The proof-of-concept blower produced the flow rate and pressure rise needed for the CSSE ventilation subsystem while running at 5400 rpm, consuming only 9 W of electric power using a non-optimized, commercial motor and controller and inefficient bearings. Scaling the test results to a complete design shows that a lightweight, compact, reliable, and low power regenerative blower can meet the performance requirements for future space suit life support systems.

  5. Psychoacoustic study on contribution of fan noise to engine noise

    Science.gov (United States)

    Zhang, Junhong; Liu, Hai; Bi, Fengrong; Ni, Guangjian; Zhang, Guichang; Lin, Jiewei; Yu, Hanzhengnan

    2012-07-01

    There are more researches on engine fan noise control focusing on reducing fan noise level through optimizing fan structure, and a lot of research achievements have been obtained. However, researches on the effect of fan noise to engine noise quality are lacking. The influences of the effects of fan structure optimization on the engine noise quality are unclear. Thus, there will be a decline in fan noise level, but the deterioration of engine noise quality. Aiming at the above problems, in consideration of fan structure design and engine noise quality, an innovative method to analyze the contribution of fan noise to engine noise quality using psychoacoustic theory is proposed. The noises of diesel engine installing different cooling fans are measured by using the acoustic pressure method. The experiment results are regarded as analysis samples. The model of sensory pleasantness is used to analyze the sound quality of a diesel engine with different cooling fans. Results show that after installing 10-blade fan in medium diameter the sensory pleasantness at each test point is increased, and the increase is 13.53% on average, which indicate the improvement of the engine noise quality. In order to verify the psychoacoustical analysis, the subjective assessment is carried out. The test result shows the noise quality of engine installed 10-blade fan in medium diameter is most superior. 1/3 octave frequency spectrum analysis is used to study the reason of the improvement of engine noise quality. It is found that after installing proper cooling fan the sound pressure level below 400 Hz are obviously increased, the frequency assignment and spectral envelope are more reasonable and a proper cooling fan can optimize the spectrum structure of the engine noise. The psychoacoustic study is applied in the contribution of fan noise to engine noise, and the idea of engine sound quality improvement through the structure optimization is proposed.

  6. Introduction of a Cooling-Fan Efficiency Index

    DEFF Research Database (Denmark)

    Schiavon, S.; Melikov, Arsen Krikor

    2009-01-01

    In a warm environment, air movement with elevated velocity is a well-known cooling strategy. The local air movement is typically generated by cooling fans (e.g., ceiling fan, table fans, etc.). Appearance, power input, and price are the main parameters considered today when purchasing cooling fans......, while cooling capacity and efficiency of energy use are unknown. To address this knowledge gap, this paper introduces the cooling-fan efficiency (CFE) index, defined as the ratio between the cooling effect (measured with a thermal manikin) generated by the device and its power consumption. The index...

  7. Alluvial fan facies of the Yongchong Basin: Implications for tectonic and paleoclimatic changes during Late Cretaceous in SE China

    Science.gov (United States)

    Chen, Liuqin; Steel, Ronald J.; Guo, Fusheng; Olariu, Cornel; Gong, Chenglin

    2017-02-01

    Late Cretaceous continental redbeds, the Guifeng Group of the Yongchong Basin in SE China have been investigated to conduct detailed fan facies description and interpretation. Tectonic activities determined the alluvial fan development along the basin margin, but the alluvial facies was linked with paleoclimate changes. The Guifeng Group is divided into the Hekou, Tangbian and Lianhe formations in ascending order. The Hekou conglomerates are typically polymict, moderately sorted with erosional bases, cut-and-fill features, normal grading and sieve deposits, representing dominant stream-flows on alluvial fans during the initial opening stage of the basin infill. The Tangbian Formation, however, is characterized by structureless fine-grained sediments with dispersed coarse clasts, and couplets of conglomerate and sandstone or siltstone and mudstone, recording a change to a playa and ephemeral lake environments with occasional stream flooding, thus indicating a basin expanding stage. The hallmark of the Lianhe Formation is disorganized, poorly sorted conglomerates lack of erosional bases, and a wide particle-size range from clay to boulders together reflect mud-rich debris-flows accumulating on fans, likely related to reactivation of faulting along the northwestern mountain fronts during a post-rift stage. The depositional system changes from stream-flows up through playa with ephemeral streams to debris-flows during the accumulation of the three formations are thus attributed to different source rocks and climatic conditions. Therefore, the fluvial-dominated fans of the Hekou Formation recorded a subhumid paleoclimate (Coniacian-Santonian Age). The dominant semiarid climate during the Campanian Age produced abundant fine-grained sediments in the playa and ephemeral lake environments of the Tangbian Formation. A climatic change towards more humidity during the late stage of the Guifeng Group (Maastrichtian Age) probably yielded high deposition rate of coarse clasts in

  8. Tributary debris fans and the late Holocene alluvial chronology of the Colorado River, eastern Grand Canyon, Arizona

    Science.gov (United States)

    Hereford, R.; Thompson, K.S.; Burke, K.J.; Fairley, H.C.

    1996-01-01

    Bouldery debris fans and sandy alluvial terraces of the Colorado River developed contemporaneously during the late Holocene at the mouths of nine major tributaries in eastern Grand Canyon. The age of the debris fans and alluvial terraces contributes to understanding river hydraulics and to the history of human activity along the river, which has been concentrated on these surfaces for at least two to three millennia. Poorly sorted, coarse-grained debris-flow deposits of several ages are interbedded with, overlie, or are overlapped by three terrace-forming alluviums. The alluvial deposits are of three age groups: the striped alluvium, deposited from before 770 B.C. to about A.D. 300; the alluvium of Pueblo II age deposited from about A.D. 700 to 1200; and the alluvium of the upper mesquite terrace, deposited from about A.D. 1400 to 1880. Two elements define the geomorphology of a typical debris fan: the large, inactive surface of the fan and a smaller, entrenched, active debris-flow channel and fan that is about one-sixth the area of the inactive fan. The inactive fan is segmented into at least three surfaces with distinctive weathering characteristics. These surfaces are conformable with underlying debris-flow deposits that date from before 770 B.C. to around A.D. 660, A.D. 660 to before A.D. 1200, and from A.D. 1200 to slightly before 1890, respectively, based on late-19th-century photographs, radiocarbon and archaeologic dating of the three stratigraphically related alluviums, and radiocarbon dating of fine-grained debris-flow deposits. These debris flows aggraded the fans in at least three stages beginning about 2.8 ka, if not earlier in the late Holocene. Several main-stem floods eroded the margin of the segmented fans, reducing fan symmetry. The entrenched, active debris-flow channels contain deposits debris fans at the mouth of the channel adjacent to the river. Early and middle Holocene debris-flow and alluvial deposits have not been recognized, as they were

  9. Fan-beam intensity modulated proton therapy

    Science.gov (United States)

    Hill, Patrick; Westerly, David; Mackie, Thomas

    2013-01-01

    Purpose: This paper presents a concept for a proton therapy system capable of delivering intensity modulated proton therapy using a fan beam of protons. This system would allow present and future gantry-based facilities to deliver state-of-the-art proton therapy with the greater normal tissue sparing made possible by intensity modulation techniques. Methods: A method for producing a divergent fan beam of protons using a pair of electromagnetic quadrupoles is described and particle transport through the quadrupole doublet is simulated using a commercially available software package. To manipulate the fan beam of protons, a modulation device is developed. This modulator inserts or retracts acrylic leaves of varying thickness from subsections of the fan beam. Each subsection, or beam channel, creates what effectively becomes a beam spot within the fan area. Each channel is able to provide 0–255 mm of range shift for its associated beam spot, or stop the beam and act as an intensity modulator. Results of particle transport simulations through the quadrupole system are incorporated into the MCNPX Monte Carlo transport code along with a model of the range and intensity modulation device. Several design parameters were investigated and optimized, culminating in the ability to create topotherapy treatment plans using distal-edge tracking on both phantom and patient datasets. Results: Beam transport calculations show that a pair of electromagnetic quadrupoles can be used to create a divergent fan beam of 200 MeV protons over a distance of 2.1 m. The quadrupole lengths were 30 and 48 cm, respectively, with transverse field gradients less than 20 T/m, which is within the range of water-cooled magnets for the quadrupole radii used. MCNPX simulations of topotherapy treatment plans suggest that, when using the distal edge tracking delivery method, many delivery angles are more important than insisting on narrow beam channel widths in order to obtain conformal target coverage

  10. Characterization of Composite Fan Case Resins

    Science.gov (United States)

    Dvoracek, Charlene M.

    2004-01-01

    The majority of commercial turbine engines that power today s aircraft use a large fan driven by the engine core to generate thrust which dramatically increases the engine s efficiency. However, if one of these fan blades fails during flight, it becomes high energy shrapnel, potentially impacting the engine or puncturing the aircraft itself and thus risking the lives of passengers. To solve this problem, the fan case must be capable of containing a fan blade should it break off during flight. Currently, all commercial fan cases are made of either just a thick metal barrier or a thinner metal wall surrounded by Kevlar-an ultra strong fiber that elastically catches the blade. My summer 2004 project was to characterize the resins for a composite fan case that will be lighter and more efficient than the current metal. The composite fan case is created by braiding carbon fibers and injecting a polymer resin into the braid. The resin holds the fibers together, so at first using the strongest polymer appears to logically lead to the strongest fan case. Unfortunately, the stronger polymers are too viscous when melted. This makes the manufacturing process more difficult because the polymer does not flow as freely through the braid, and the final product is less dense. With all of this in mind, it is important to remember that the strength of the polymer is still imperative; the case must still contain blades with high impact energy. The research identified which polymer had the right balance of properties, including ease of fabrication, toughness, and ability to transfer the load to the carbon fibers. Resin deformation was studied to better understand the composite response during high speed impact. My role in this research was the testing of polymers using dynamic mechanical analysis and tensile, compression, and torsion testing. Dynamic mechanical analysis examines the response of materials under cyclic loading. Two techniques were used for dynamic mechanical analysis

  11. Improvement in performance of main ventilation fan for mines

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, S.N. [Indian School of Mines, Dhanbad (India)

    2007-07-01

    This paper examined methods of improving the performance of main ventilation fans in mines. The basic principles of selecting and operating fans were reviewed, and methods of improving the energy efficiency of fans were evaluated. The study considered issues related to static efficiency, as well as curves and intersection points. Mine resistances were examined in relation to ventilation requirements at different phases of mine development. Flow losses and difficulties in producing accurate mathematical models of ventilation fans were also discussed. Fan operation set-points were reviewed. Details of tests conducted to determine the effects of the number of blades on fan performance were presented. The tests demonstrated the importance of incorporating cowl diffusers and guide vanes within the design of axial flow fans. The advantages of deblading were also discussed. 6 refs.

  12. Fluent-based numerical simulation of flow centrifugal fan

    Institute of Scientific and Technical Information of China (English)

    LI Xian-zhang

    2011-01-01

    Testing centrifugal fan flow field by physical laboratory is difficult because the testing system is complex and the workload is heavy, and the results observed by naked-eye deviates far from the actual value. To address this problem, the computational fluid dynamics software FLUENT was applied to establish three-dimensional model of the centrifugal fan. The numeral model was verified by comparing simulation data to experimental data. The pressure centrifugal fan and the speed changes in distribution in centrifugal fan was simulated by computational fluid dynamics software FLUENT. The simulation results show that the gas flow velocity in the impeller increases with impeller radius increase. Static pressure gradually increases when gas from the fan access is imported through fan impeller leaving fans.

  13. Numerical Aerodynamic Evaluation and Noise Investigation of a Bladeless Fan

    Directory of Open Access Journals (Sweden)

    mohammad jafari

    2015-01-01

    Full Text Available Bladeless fan is a novel fan type that has no observable impeller, usually used for domestic applications. Numerical investigation of a Bladeless fan via Finite Volume Method was carried out in this study. The fan was placed in center of a 4×2×2m room and 473 Eppler airfoil profile was used as cross section of the fan. Performance and noise level of the fan by solving continuity and momentum equations as well as noise equations of Broadband Noise Source (BNS and Ffowcs Williams and Hawkings (FW-H in both steady state and unsteady conditions were studied. Flow increase ratio of the fan was captured. Furthermore, BNS method could find outlet slit of the air as the main source of the noise generation. In order to validation of aeroacousticcode results, a simulation of noise for NACA 0012 airfoil via FW-H method was compared to experimental results and good agreement was obtained.

  14. Seismic architecture and evolution of the Disko Bay trough-mouth fan, central West Greenland margin

    Science.gov (United States)

    Hofmann, Julia C.; Knutz, Paul C.; Nielsen, Tove; Kuijpers, Antoon

    2016-09-01

    The present study is the first to document the large-scale glacigenic evolution of a West Greenland trough-mouth fan (TMF) system, i.e. the Disko Bay TMF, from onset of shelf-based glaciation to present. We have constrained the paleo-ice sheet configuration in the Disko Bay region and determine the controlling factors of ice-stream development using 2D- and 3D-seismic reflection data, seabed bathymetry and stratigraphic information from two exploration wells. This has revealed three stages of the Disko Bay TMF development. The early stage, probably of Pliocene-early Pleistocene age, marks the onset of a central depocentre located below the modern mid-shelf and constructed by sediment progradation delivered through at least two erosive pathways related to fast-flowing, grounded ice. At that time, ice-stream routing in the Disko Bay shelf region was strongly controlled by the pre-glacial topography and structural boundaries associated with fracture zones and deep-seated faults. During the middle evolutionary stage, the focus of deposition shifted from the mid-shelf to two elongate areas fringing the outer margin. The marginal depocentres were not only related to glacial processes but also alongslope deposition by contour currents, which may have developed as a consequence of basin subsidence surrounding the Davis Strait High and the Kangerluk Structure. The late stage of TMF development, presumably representing the late Pleistocene to Holocene, is characterized by the marginal depocentres becoming less significant and sediment aggradation occurring over wide parts of the mid-outer shelf, while features of subglacial erosion are generally absent. In contrast to the inferred fast-flowing ice streams of the early-middle evolutionary stages, this points to the existence of a rather thin and "lightly" grounded ice sheet, i.e. at the threshold of floatation. The "lightly" grounded ice sheet scenario, applying to the late Pleistocene interval of the Disko Bay TMF, was

  15. Nocturnal Fanning Suppresses Downy Mildew Epidemics in Sweet Basil.

    Science.gov (United States)

    Cohen, Yigal; Ben-Naim, Yariv

    2016-01-01

    Downy mildew is currently the most serious disease of sweet basil around the world. The oomycete causal agent Peronospora belbahrii requires ≥ 4h free leaf moisture for infection and ≥7.5h of water-saturated atmosphere (relative humidity RH≥95%) at night for sporulation. We show here that continued nocturnal fanning (wind speed of 0.4-1.5 m/s) from 8pm to 8am dramatically suppressed downy mildew development. In three experiments conducted during 2015, percent infected leaves in regular (non-fanned) net-houses reached a mean of 89.9, 94.3 and 96.0% compared to1.2, 1.7 and 0.5% in adjacent fanned net-houses, respectively. Nocturnal fanning reduced the number of hours per night with RH≥95% thus shortened the dew periods below the threshold required for infection or sporulation. In experiments A, B and C, the number of nights with ≥4h of RH≥95% was 28, 10 and 17 in the non-fanned net-houses compared to 5, 0 and 5 in the fanned net-houses, respectively. In the third experiment leaf wetness sensors were installed. Dew formation was strongly suppressed in the fanned net-house as compared to the non-fanned net-house. Healthy potted plants became infected and sporulated a week later if placed one night in the non-fanned house whereas healthy plants placed during that night in the fanned house remained healthy. Infected potted basil plants sporulated heavily after one night of incubation in the non-fanned house whereas almost no sporulation occurred in similar plants incubated that night in the fanned house. The data suggest that nocturnal fanning is highly effective in suppressing downy mildew epidemics in sweet basil. Fanning prevented the within-canopy RH from reaching saturation, reduced dew deposition on the leaves, and hence prevented both infection and sporulation of P. belbahrii.

  16. Comparison of turbidite facies associations in modern passive-margin Mississippi fan with ancient active-margin fans

    Science.gov (United States)

    Shanmugam, G.; Moiola, R. J.; McPherson, J. G.; O'Connell, S.

    1988-07-01

    Our comparison of the modern passive-margin Mississippi fan (DSDP Leg 96) with ancient active-margin fans (e.g. Eocene Hecho Group, Spain) reveals major differences in turbidite facies associations (Mutti and Ricci Lucchi scheme) and in seismic characteristics in the lower fan area. The lower (outer) Mississippi fan is composed of channel (Facies B and F) and non-channel facies (C? and D), whereas ancient fans are characterized by non-channelized, thickening-upward, depositional lobe facies (C and D). An absence of depositional lobes in the lower Mississippi fan is also suggested by a lack of convex-upward (mounded) seismic reflections with bidirectional downlap. Continuous seismic reflections of the lower Mississippi fan may represent "sheet sands", but not those of true depositional lobes with mounded character. Extensive channelization in modern passive-margin fans appears to be a product of the lateral shifting of a major sinuous distributary system, developed as a consequence of low gradients and the transport of sediment with a relatively low sand/mud ratio. In contrast, channels in active-margin fans are short and of low sinuosity as a result of high gradients and the transport of sediment with a relatively high sand/mud ratio. The turbidite facies association scheme, which was developed exclusively from ancient active-margin fans, should be applied to mature passive-margin fans with qualifications because of the differences in spatial distribution of turbidite facies and their associations.

  17. An Aerodynamic Analysis of a Robustly Redesigned Modern Aero-Engine Fan

    CERN Document Server

    Seshadri, Pranay; Shahpar, Shahrokh

    2016-01-01

    This paper documents results from a recent computational study aimed at de-sensitizing fan stage aerodynamics---in a modern, high bypass ratio aero-engine---to the effects of rear-seal leakage flows. These flows are the result of seal erosion between a rotor and stator disk in an engine, and deterioration over the life of an engine. The density-matching technique for optimization under uncertainty was applied to this problem. This involved RANS and adjoint flow solves of a full fan stage carried out at two different leakage conditions. Here a detailed analysis of the fan stage aerodynamics is carried out to determine why exactly the new design is more insensitive to the effects of leakage flows. Specifically, it is shown that this insensitivity is attributed to three main factors: a slight rearward shift in loading, and thus a reduction in incidence; a reduction in the cross-passage pressure gradient; and a re-acceleration of the flow towards the trailing edge, which prevented any corner separation.

  18. Fanning the Optimal Breeze with an Abanico

    Science.gov (United States)

    Goon, Grace; Marthelot, Joel; Reis, Pedro; MIT EGS Lab Team

    Flexible hand-held fans, or abanicos, are universally employed as cooling devices that are both portable and sustainable. Their to and fro axial motion about one's hand generates an airflow that increases the evaporation rate near the skin and refreshes. We study this problem in the context of fluid-structure interaction, through precision model experiments. We first characterize the elastic properties of a semi-circular thin plates with various thickness and evaluate their aerodynamic performance in a custom built apparatus. The air velocity profile that results from the flapping motion of the fan is characterized for different driving conditions. A systematic variation of the geometric and elastic parameters, along with an exploration of the parameter space of the periodic driving motion (amplitude and frequency), allows us to establish optimal design and operational conditions for maximal output of the generated airflow, while minimizing the input power.

  19. Polarization-fan high-order harmonics

    Science.gov (United States)

    Fleischer, Avner; Bordo, Eliyahu; Kfir, Ofer; Sidorenko, Pavel; Cohen, Oren

    2017-02-01

    We predict high-order harmonics in which the polarization within the spectral bandwidth of each harmonic varies with frequency continuously and significantly. For example, the interaction of counter-rotating circularly-polarized bichromatic drivers having close central frequencies with isotropic gas leads to the emission of polarization-fan harmonics where each harmonic in the spectrum has the following property: it is nearly circularly-polarized in one tail of the harmonic peak, linear in the center of the peak and nearly circular with the opposite helicity in the opposite tail. Also, we show that polarization-fan high harmonics with modulated ellipticity are obtained when elliptical drivers are used. Polarization-fan harmonics are obtained as a result of multiple (at least two) head-on recollisions of electrons with their parent ions occurring from different angles in a two-dimensional plane. The use of bichromatic drivers with close central frequencies largely preserves the single-cycle, single-atom and macroscopic physics of ‘ordinary’ high harmonic generation, where both the driver and high harmonics are linearly polarized. Thus, it should offer several attracting features, including (i) a direct route for extending the maximal photon energy of observed helical high harmonics to keV by using bichromatic drivers only in the mid-IR region and (ii) utilizing phase matching methods that were developed for ‘ordinary’ high harmonic generation driven by quasi-monochromatic pulses (e.g. pressure tuning phase matching). These polarization-fan harmonics may be utilized for exploring non-repetitive ultrafast chiral phenomena, e.g. dynamics of magnetic domains, in a single shot.

  20. Gigapixel Images Connect Sports Teams with Fans

    Science.gov (United States)

    2013-01-01

    Technology developed at Ames Research Center to take high-resolution imagery on Mars is now being used in baseball stadiums across the country. New York City-based Major League Baseball Advanced Media LP customized the platform to accommodate in-game shots that capture nearly the whole stadium. Fans navigate the photos online and tag themselves and their friends using social media tools.

  1. Fan edits and the legacy of The Phantom Edit

    Directory of Open Access Journals (Sweden)

    Joshua Wille

    2014-09-01

    Full Text Available A fan edit can generally be defined as an alternative version of a film or television text created by a fan. It offers a different viewing experience, much as a song remix offers a different listening experience. The contemporary wave of fan edits has emerged during the remix zeitgeist of digital media and at a time when digital video editing technology has become more affordable and popular. The increasing number of alternative versions of films and the works of revisionist Hollywood filmmakers such as George Lucas have contributed to a greater public understanding of cinema as a fluid medium instead of one that exists in a fixed form. The Phantom Edit (2000, a seminal fan edit based on Lucas's Star Wars Episode I: The Phantom Menace (1999, inspired new ranks of fan editors. However, critics have misunderstood fan edits as merely the work of disgruntled fans. In order to provide a critical and historical basis for studies in fan editing as a creative practice, I examine previous interpretations of fan edits in the context of relevant contemporary works, and I use an annotated chronology of The Phantom Edit to trace its influence on subsequent fan editing communities and uncover their relationship with intellectual property disputes.

  2. "Emotions-Only" versus "Special People": Genre in fan discourse

    Directory of Open Access Journals (Sweden)

    Louisa Ellen Stein

    2008-09-01

    Full Text Available This essay looks at genre as a complex set of discursive threads running unevenly through production, TV text, and fan reception. Through a case study of the reception of fan favorite Roswell, this essay interrogates the role of genre in spectatorship. In its mixing of teen and science fiction elements, Roswell trod upon contested generic spaces, eliciting strong reaction from its viewers. Connections between genre and gender came to the fore, as producer commentary linked science fiction with male audiences and teen romance with female audiences. Fans responded with analyses that greatly complicated and at times overtly rejected industrial suppositions regarding the gendered work of genre. Through these fan conversations, we can witness the complexity of genre as discursive thread moving through not only TV texts but also multivariant fan responses. I intend this essay to work at two levels. My analysis of fan responses to Roswell models the possibilities of a close study of genre discourse. At the same time, my case study probes the nature of genre in fan engagement, as genre discourses intersect with other fan concerns such as character identification, perceptions of textual quality, and questions of gender representation. While we cannot necessarily look to fan accounts for proof of how viewers engage with genre, they do tell us how fans frame their engagement with genre, how they incorporate genre into their performance of fannishness, and how they perform and thus enact genre itself as a shared cultural process.

  3. The aerodynamics of a wind-tunnel fan

    Science.gov (United States)

    Corson, Blake W

    1941-01-01

    The vortex blade-element theory modified to apply to an axial fan working in a duct is reviewed. Thrust and power coefficients for a fan are identified with the corresponding coefficients for airplane propellers. The relation of pressure produced by the fan to the blade-element coefficients is developed. The distribution of axial velocity of fluid through a fan is assumed to be controlled by the fan itself. The radial distribution of tangential velocity imported by the fan to fluid moving through the fan is shown to be independent of the axial-velocity distribution. A nondimensional coefficient, designated the rotation constant, is introduced. This constant is based solely upon design information. The use of the rotation constant in simplifying the design of a fan for a specific operating condition is demonstrated. Based on the use of the rotation constant, a graphical method is outlined by which the performance of a given fan in a given wind tunnel may be predicted and by which the distributions of axial velocity of the fluid through the fan under various operating conditions may be established.

  4. STUDY ON THE NUMERICAL SIMULATION OF MULTI-STAGE ROTARY FORGING OF A NON-AXISYMMETRIC PART AND THE CAE ANALYSIS OF THE DIE STRENGTH

    Institute of Scientific and Technical Information of China (English)

    H. Tian; J. Wang; W.P. Dong; J. Chen; Z. Zhao; G.M. Wu

    2005-01-01

    Traditionally a rotary forging process is a kind of metal forming method where a conic upper die, whose axis is deviated an angle from the axis of machine, forges a billet continuously and partially to finish the whole deformation. For the rotary forging process simulation, more researches were focused on simulating the simple stage forming process with axisymmetric part geometry. Whereas in this paper, the upper die is not cone-shaped, and the billet is non-axisymmetric. So the movement of the punch is much more complicated than ever. The 3D FEM simulation models for the preforming & final forming processes are set up after carefully studying the complicated movement pattern. Deform-3D is used to simulate the material flow, and the boundary nodal resisting forces calculated by the final stage process simulation is used to analyze the final forming die strength. The CAE analysis of the die shows that the design of the final forming die is not reasonable with lower pre-stress which is easy to crack at the critical comers. An optimum die design is also provided with higher pre-stress, and verified by CAE analysis.

  5. Saving energy for ventilation using decentralised duct fans

    DEFF Research Database (Denmark)

    Gunner, Amalie; Bergsøe, Niels Christian; Afshari, Alireza

    2014-01-01

    pressure drops which in turn will increase energy use. This paper presents a novel procedure for balancing CAV-systems using decentralised duct fans instead of flat plate dampers. The procedure will result in lower pressure drops and consequently in a reduction of energy use for ventilation when compared......In conventional mechanical ventilation systems with constant air volume (CAV) airflows are often balanced using balancing flat plate dampers. The purpose of the dampers is to obtain nominal airflows to the individual zones or rooms in the building. Unfortunately, this procedure leads to increased...... to a conventional mechanical ventilation system with flat plate dampers. Theoretical calculations and experimental observations for the investigated systems show that the power demand for distribution of air can be reduced about 30%. The work carried out forms part of an ongoing PhD-project on mechanical...

  6. A Fan-tastic Alternative to Bulbs: Learning Circuits with Fans

    Science.gov (United States)

    Ekey, Robert; Edwards, Andrea; McCullough, Roy; Reitz, William; Mitchell, Brandon

    2017-01-01

    The incandescent bulb has been a useful tool for teaching basic electrical circuits, as brightness is related to the current or power flowing through a bulb. This has led to the development of qualitative pedagogical treatments for examining resistive combinations in simple circuits using bulbs and batteries, which were first introduced by James Evans and thoroughly expanded upon by McDermott and others. This paper argues that replacing bulbs with small computer fans leads to similar, if not greater, insight of experimental results that can be qualitatively observed using a variety of senses. The magnitude of current through a fan is related to the frequency of the rotating fan blades, which can be seen, heard, and felt by the students. Experiments using incandescent bulbs only utilize vision, which is not ideal as the human eyes' perception of brightness is skewed because the response to light intensity is logarithmic rather than linear.

  7. 折扇中的日本文化%Japanese Culture in Folding Fan

    Institute of Scientific and Technical Information of China (English)

    白美云; 史文华

    2012-01-01

    At present,folding fans,just like sakura and Mount Fuji,have become a symbol of Japan.A small folding fan bears a lot of implications to Japanese,and reveals a colorful Japanese fan culture.And they were once the symbols of the identity and status at the beginning of the initiative.Later,Japanese people use it to drive away summer heat,ward off evil spirits and attract god,present friends and show social etiquette,and it is also a expressive prop on stage performances for its artistic value of the covering and the carvings of fan rib.Folding fan culture is the glittering treasure in Japan's traditional Culture.%时至今日,折扇如同樱花、富士山一样,已成为日本的象征。小小的一把折扇,对日本人来说却蕴藏着丰富多彩的内涵,彰显着绚烂多彩而又有日本特质的扇文化。日本折扇在创制之始曾一度是身份和地位的象征,之后日本人用它驱暑纳凉、招神辟邪、馈赠友人、礼仪社交。折扇还是舞台表演的传神道具,其扇面艺术和扇骨雕刻尽显其艺术价值。折扇文化是日本传统文化中熠熠生辉的瑰宝。

  8. Beam fanning effect and image storage in Ce: KNSBN crystal

    Institute of Scientific and Technical Information of China (English)

    LI PanLai; GUO QingLin; WANG ZhiJun; PANG LiBin; LIANG BaoLai

    2007-01-01

    A non-synchronously-numerating experimental system is applied in this research. The effect of the incident beam intensity Ⅰ and the beam incident angle θ on beam fanning effect is investigated with a singular beam incident on Ce:KNSBN crystal. The results show that the beam fanning effect strongly depends on Iand θ. The threshold effect of/for the beam fanning in Ce:KNSBN crystal is observed, and the threshold intensity of incident beam keeps the same value of 38.2 mW/cm2 for different θ, and the steady beam fanning intensity Ifsat reaches a peak at θ=15° under the same Ⅰ. In addition, the effect of the incident beam modulated on the beam fanning noise and holographic storage in Ce:KNSBN crystal is studied. And the results suggest that the beam fanning noise is effectively suppressed, and the quality of the reappearance image is greatly improved.

  9. Procedure for Balancing an Air Distribution System with Decentralised Fans

    DEFF Research Database (Denmark)

    Gunner, Amalie; Hultmark, Göran; Vorre, Anders

    2015-01-01

    of the fans. In conventional air distribution systems the fan provides the necessary pressure to overcome the resistance in the branch with the highest pressure resistance. This gives an unnecessary overpressure in the remaining branches that does not provide any useful purpose. In order to decrease the fan......This paper presents results from an on-going project concerning new design procedures for mechanical ventilation systems with low energy use. Conventional constant air volume (CAV) systems are usually balanced using flat plate dampers. The purpose of using balancing dampers is to intentionally...... pressure requirements the fan was dimensioned for the branch with the least pressure resistance. The decentralised fans then provided sufficient pressure to overcome the exact resistance in the corresponding branch. The results show that by using decentralised fans in duct systems instead of dampers...

  10. Procedure for Balancing an Air Distribution System with Decentralised Fans

    DEFF Research Database (Denmark)

    Gunner, Amalie; Hultmark, Göran; Vorre, Anders;

    2015-01-01

    This paper presents results from an on-going project concerning new design procedures for mechanical ventilation systems with low energy use. Conventional constant air volume (CAV) systems are usually balanced using flat plate dampers. The purpose of using balancing dampers is to intentionally...... flawed. This paper presents a new procedure for balancing of CAV systems in combination with decentralised fans. The new system was based on replacing the balancing dampers with decentralised fans. By replacing the balancing dampers with decentralised fans, airflows can be balanced by adjusting the speed...... of the fans. In conventional air distribution systems the fan provides the necessary pressure to overcome the resistance in the branch with the highest pressure resistance. This gives an unnecessary overpressure in the remaining branches that does not provide any useful purpose. In order to decrease the fan...

  11. "Once more a kingly quest": Fan games and the classic adventure genre

    Directory of Open Access Journals (Sweden)

    Anastasia Marie Salter

    2009-03-01

    Full Text Available The classic adventure games—part of the earliest traditions of interactive narrative—have not disappeared, although they no longer occupy space on the shelves at the local computer store. Even as changing hardware and operating systems render these games of the 1980s and 1990s literally unplayable without emulating the computer systems of the past, fans are keeping these stories alive. Authorship of these games has changed hands: it is now under the control of the fans, the former and current players. Through the online sharing of fan-created game design tool sets and of the fan-created games themselves, these new coauthors create a haven to revisit these decades-old games using fresh eyes and fresh systems. The products of these folk art–reminiscent efforts also offer a venue to reconsider video game fandom in light of genres. They also allow us to understand these "personal games," productions of one or more people that are not intended for commercial sale, as carrying the heritage of the classic era forward into the next generation of gaming.

  12. "Once more a kingly quest": Fan games and the classic adventure genre

    Directory of Open Access Journals (Sweden)

    Anastasia Marie Salter

    2009-03-01

    Full Text Available The classic adventure games—part of the earliest traditions of interactive narrative—have not disappeared, although they no longer occupy space on the shelves at the local computer store. Even as changing hardware and operating systems render these games of the 1980s and 1990s literally unplayable without emulating the computer systems of the past, fans are keeping these stories alive. Authorship of these games has changed hands: it is now under the control of the fans, the former and current players. Through the online sharing of fan-created game design tool sets and of the fan-created games themselves, these new coauthors create a haven to revisit these decades-old games using fresh eyes and fresh systems. The products of these folk art–reminiscent efforts also offer a venue to reconsider video game fandom in light of genres. They also allow us to understand these "personal games," productions of one or more people that are not intended for commercial sale, as carrying the heritage of the classic era forward into the next generation of gaming.

  13. On limited fan-in optimal neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Beiu, V.; Makaruk, H.E. [Los Alamos National Lab., NM (United States); Draghici, S. [Wayne State Univ., Detroit, MI (United States). Vision and Neural Networks Lab.

    1998-03-01

    Because VLSI implementations do not cope well with highly interconnected nets the area of a chip growing as the cube of the fan-in--this paper analyses the influence of limited fan in on the size and VLSI optimality of such nets. Two different approaches will show that VLSI- and size-optimal discrete neural networks can be obtained for small (i.e. lower than linear) fan-in values. They have applications to hardware implementations of neural networks. The first approach is based on implementing a certain sub class of Boolean functions, IF{sub n,m} functions. The authors will show that this class of functions can be implemented in VLSI optimal (i.e., minimizing AT{sup 2}) neural networks of small constant fan ins. The second approach is based on implementing Boolean functions for which the classical Shannon`s decomposition can be used. Such a solution has already been used to prove bounds on neural networks with fan-ins limited to 2. They generalize the result presented there to arbitrary fan-in, and prove that the size is minimized by small fan in values, while relative minimum size solutions can be obtained for fan-ins strictly lower than linear. Finally, a size-optimal neural network having small constant fan-ins will be suggested for IF{sub n,m} functions.

  14. The Mechanical Impact of Aerodynamic Stall on Tunnel Ventilation Fans

    Directory of Open Access Journals (Sweden)

    A. G. Sheard

    2012-01-01

    Full Text Available This paper describes work aimed at establishing the ability of a tunnel ventilation fan to operate without risk of mechanical failure in the event of aerodynamic stall. The research establishes the aerodynamic characteristics of a typical tunnel ventilation fan when operated in both stable and stalled aerodynamic conditions, with and without an anti-stall stabilisation ring, with and without a “nonstalling” blade angle and at full, half, and one quarter design speed. It also measures the fan’s peak stress, thus facilitating an analysis of the implications of the experimental results for mechanical design methodology. The paper concludes by presenting three different strategies for tunnel ventilation fan selection in applications where the selected fan will most likely stall. The first strategy selects a fan with a low-blade angle that is nonstalling. The second strategy selects a fan with a high-pressure developing capability. The third strategy selects a fan with a fitted stabilisation ring. Tunnel ventilation system designers each have their favoured fan selection strategy. However, all three strategies can produce system designs within which a tunnel ventilation fan performs reliably in-service. The paper considers the advantages and disadvantages of each selection strategy and considered the strengths and weaknesses of each.

  15. K-pop Reception and Participatory Fan Culture in Austria

    Directory of Open Access Journals (Sweden)

    Sang-Yeon Sung

    2013-12-01

    Full Text Available K-pop’s popularity and its participatory fan culture have expanded beyond Asia and become significant in Europe in the past few years. After South Korean pop singer Psy’s “Gangnam Style” music video topped the Austrian chart in October 2012, the number and size of K-pop events in Austria sharply increased, with fans organizing various participatory events, including K-pop auditions, dance festivals, club meetings, quiz competitions, dance workshops, and smaller fan-culture gatherings. In the private sector, longtime fans have transitioned from participants to providers, and in the public sector, from observers to sponsors. Through in-depth interviews with event organizers, sponsors, and fans, this article offers an ethnographic study of the reception of K-pop in Europe that takes into consideration local interactions between fans and Korean sponsors, perspectives on the genre, patterns of social integration, and histories. As a case study, this research stresses the local situatedness of K-pop fan culture by arguing that local private and public sponsors and fans make the reception of K-pop different in each locality. By exploring local scenes of K-pop reception and fan culture, the article demonstrates the rapidly growing consumption of K-pop among Europeans and stresses multidirectional understandings of globalization.

  16. A measuring stand for a ducted fan aircraft propulsion unit

    Directory of Open Access Journals (Sweden)

    Hlaváček David

    2014-03-01

    Full Text Available The UL-39 ultra-light aircraft which is being developed by the Department of Aerospace Engineering, Faculty of Mechanical Engineering, Czech Technical University in Prague, is equipped with an unconventional ducted fan propulsion unit. The unit consists of an axial fan driven by a piston engine and placed inside a duct ended with a nozzle. This article describes the arrangement of a modernised measuring stand for this highly specific propulsion unit which will be able to measure the fan pressure ratio and velocity field in front of and behind the fan and its characteristic curve.

  17. Experimental impact testing and analysis of composite fan cases

    Science.gov (United States)

    Vander Klok, Andrew Joe

    ) diameter single stage gas gun was developed. A thermodynamic based relationship between the required gas pressure and targeted velocity was proposed. The predicted velocity was within +/-7%. Quantitative measurements of force and displacement were attempted. The transmitted impact force was measured with load cells. The out-of-plane deformation was measured with a projection grating profilometry method. The composite panels and fan cases used in this work were made of S2-glass plain weave fabrics with API SC-15 toughened epoxy resin using the vacuum assisted resin transfer molding (VARTM) method. Using the gas gun, the impact behavior of the composite was investigated at velocities ranging from 984ft/s to 1502ft/s (300m/s to 458m/s) following a draft ASTM testing standard. To compare the ballistic protection capability of different materials, a new parameter EBL, the projectile kinetic energy at the target ballistic limit normalized by the contact area of the projectile, was proposed. S2-glass/epoxy composite is ranked very high in EBL per areal weight. Finally, a testing method for replicating spin pit testing with a gas gun test was developed. Major differences between the two tests are the initial conditions of the blade upon contact with the target. In spin testing, the released blade has two velocity components, rotational and translational whereas in gas gun testing, the projectile has only the translational velocity. To account for the influence of the rotational velocity, three projectile designs were experimentally investigated. The results show that to generate similar damage modes in gas gun testing, it is critical to ensure the deformation of the projectile before testing is similar to that of a released blade. With the pre-bent blade, the gas gun experiment was able to replicate the damage modes of the fan case in FBO test on flat composite panels.

  18. Gillies fan flap for the reconstruction of an upper lip defect caused by noma: case presentation

    Science.gov (United States)

    Bello, Seidu Adebayo

    2012-01-01

    The case of a 65-year-old noma patient with a defect involving her upper lip is presented. The defect also included missing teeth numbers eleven, twelve, 21, and 22 and the adjoining alveolus. One-stage lip reconstruction was carried out with Gillies fan flap followed by vestibuloplasty and commissuroplasty. An acrylic partial denture was subsequently fabricated to replace the missing teeth and thereby restore function. Even though the incidence of cancrum oris has reduced worldwide, cases are still being reported in Africa and can leave behind a significant facial defect. Whereas most cases of lip defects reported from the Western world are due to cancer, cancrum oris could be the cause of lip defects in sub-Saharan Africa. Gillies fan flap could be employed for the reconstruction of a relatively large defect of the lip and the disadvantage of microstomia could be minimized for the restoration of articulation, speech, and masticatory functions of the lip. PMID:23674921

  19. Assessment of intraoperative tube thoracostomy after diaphragmatic resection as part of debulking surgery for primary advanced-stage Müllerian cancer.

    Science.gov (United States)

    Kato, Kazuyoshi; Tate, Shinichi; Nishikimi, Kyoko; Shozu, Makio

    2013-10-01

    The present study assessed the use of an intraoperative tube thoracostomy for patients with primary advanced-stage ovarian, fallopian tube, or peritoneal cancer who underwent a diaphragmatic resection as part of debulking surgery and to define which patients are more likely to benefit from an intraoperative tube thoracostomy. All consecutive patients with stage IIIC-IV Müllerian cancer who underwent diaphragmatic resection at our institution between April 2008 and March 2013 were retrospectively reviewed. When a full-thickness resection of the diaphragm was performed and the thoracic cavity was opened, a chest tube was routinely placed during surgery. Patient-, disease-, and surgery-related data were collected from the patients' medical records. The data were evaluated with particular attention directed at pleural effusion after diaphragmatic resection. A total of 37 patients were included in this study. No complications associated with the intraoperative tube thoracostomy procedures occurred. An infection of the thoracic cavity occurred in one patient, following the presence of intra-abdominal abscess. The total volume of pleural drainage ranged from 88 to 2826 mL (median, 965 mL). The estimated blood loss, intraoperative blood transfusion, and area of the diaphragmatic opening were significantly associated with the total volume of pleural drainage in univariate analyses. In a multivariate analysis, the estimated blood loss was the only factor to be significantly associated with the total volume of pleural drainage. A prophylactic tube thoracostomy might be considered if the volume of the estimated blood loss is higher than usual. © 2013.

  20. Extreme Loading of Aircraft Fan Blade

    CERN Document Server

    Datta, Dibakar

    2013-01-01

    The response of an aircraft fan blade manufactured by composites under the action of static and impact load has been studied in this report. The modeling and analysis of the geometry has been done using CASTEM 2007 version. For the quasi static analysis, the pressure has been incrementally applied until it satisfies the failure criteria. The deformed configuration, strain, Von-Mises stress, and the deflection of the blade have been studied. The response of the system e.g. deformation time history due to the impact of the projectile has been studied where the Newmark method for the dynamic problem has been implemented.

  1. Condensate Accretion in Shock Tube's Expansion Fan

    Science.gov (United States)

    Mezonlin, Ephrem-Denis; DeSilva, Upul P.; Hunte, F.; Johnson, Joseph A., III

    1997-01-01

    It has been shown that turbulence and temperature influence the droplet sizes in expansion fan induced condensation by studying the Rayleigh scattering from one port in our shock tube's test section. We have modified our set-up so as to allow, using two ports, the real time measurement of the influence of turbulence and temperature on the rate at which these droplets grow. To do this, we looked at the Rayleigh scattering from two different ports for ten Reynolds numbers at five different temperatures. We modeled the time of flight of droplets, using the equations of one-dimensional gas dynamics and the measured shock wave speed in shock tube's driven section.

  2. Through flow analysis of pumps and fans

    Science.gov (United States)

    Neal, A. N.

    1980-08-01

    Incompressible through flow calculations in axial, mixed and centrifugal flow pumps and fans are described. An iterative scheme is used. A simple blade to blade model is applied on the surfaces of revolution defined by the meridional streamlines. This defines the fluid properties and the mean stream surface (S2 surface) for the next meridional solution. A computer program is available allowing the method to be applied for design purposes. APL is used for input and output and FORTRAN IV for computation. A typical calculation requires 30 sec of Univac 1100 time.

  3. Early to middle Miocene foraminifera from the deep-sea Congo Fan, offshore Angola

    OpenAIRE

    Kender, S; Kaminski, M.A.; Jones, R W

    2008-01-01

    Analysis of a 630m section of an exploration well penetrating the distal part of the Congo Fan (~2000m water depth) yielded high abundance and diversity assemblages of agglutinated and calcareous benthic foraminifera. Planktonic foraminifera constrain the age to Early – Middle Miocene, and \\delta 18O records reveal the Mi1 (~16.3 Ma) isotopic shift. Relatively few taxonomic studies of deep-water calcareous and agglutinated benthic foraminifera exist from this time period in this loca...

  4. 30 CFR 57.14107 - Moving machine parts.

    Science.gov (United States)

    2010-07-01

    ... parts shall be guarded to protect persons from contacting gears, sprockets, chains, drive, head, tail, and takeup pulleys, flywheels, coupling, shafts, fan blades; and similar moving parts that can cause...

  5. Seabed morphology and sedimentary processes on high-gradient trough mouth fans offshore Troms, northern Norway

    Science.gov (United States)

    Rydningen, Tom Arne; Laberg, Jan Sverre; Kolstad, Vidar

    2015-10-01

    Trough mouth fans (TMF) situated at the mouths of formerly glaciated cross-shelf troughs are important paleoclimatic archives. Whereas the sedimentary processes of large, low-gradient TMFs have received considerable interest, little attention has been paid to the other end member of this landform class, i.e. TMFs with higher slope gradients. Detailed swath-bathymetric data and seismic profiles from the continental margin offshore Troms, northern Norway cover three high-gradient TMFs (the Andfjorden, Malangsdjupet and Rebbenesdjupet TMFs; slope gradients generally between 1° and 15°), as well as inter-fan areas, which include two submarine canyons (the Andøya and Senja Canyon) and the Malangsgrunnen inter-fan slope. The present-day morphologies of the Andfjorden and Malangsdjupet TMFs have evolved from sediment transport and distribution through gully-channel complexes. The Andfjorden TMF has later been affected by a large submarine landslide that remobilized much of these complexes. The Rebbenesdjupet TMF is dominated by a number of small and relatively shallow slide scars, which are inferred to be related to small-scale sediment failure of glaciomarine and/or contouritic sediments. The canyons cut into the adjacent TMFs, and turbidity currents originating on the fans widened and deepened the canyons during downslope flow. The Malangsgrunnen shelf break and inter-fan slope acted as a funnel for turbidity currents originating on the upper slope, forming a dendritic pattern of gullies. A conceptual model for the high-gradient TMFs on the Troms margin has been compiled. The main sediment input onto the TMFs has occurred during peak glacials when the Fennoscandian Ice Sheet reached the shelf edge. The overall convex fan form and progradational seismic facies show that these glacigenic deposits were repeatedly distributed onto the fan. On the Andfjorden and Malangsdjupet TMFs, gully-channel complexes occur within such deposits. It is thus inferred that the steep

  6. Case study of French and Spanish fan reception of Game of Thrones

    Directory of Open Access Journals (Sweden)

    Mélanie Bourdaa

    2015-06-01

    Full Text Available The reception of the American TV show Game of Thrones (2011– by French and Spanish fans and nonfans is addressed via a qualitative methodology, the goal of which is to understand how European viewers perceive themselves as fans and what it means for them to be fans. Analysis of characteristics of a specifically European reception helps us learn what fan studies tell us about fans and what fans really think about fandoms.

  7. 10 CFR Appendix U to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Ceiling Fans

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Uniform Test Method for Measuring the Energy Consumption... Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of Ceiling Fans 1. Scope... significant digits as the previous step. Round the final energy consumption value to the nearest whole number...

  8. The Retarding Force on a Fan-Cart Reversing Direction

    Science.gov (United States)

    Aurora, Tarlok S.; Brunner, Bernard J.

    2011-01-01

    In introductory physics, students learn that an object tossed upward has a constant downward acceleration while going up, at the highest point and while falling down. To demonstrate this concept, a self-propelled fan cart system is used on a frictionless track. A quick push is given to the fan cart and it is allowed to move away on a track under…

  9. Female fans of men's football - a case study in Denmark

    DEFF Research Database (Denmark)

    Pfister, Gertrud Ursula; Lenneis, Verena; Mintert, Svenja-Maria

    2013-01-01

    to a 'man's world' and what are their roles in this 'male environment'? The statements of interviewees revealed that female fans have to cope with a measure of sexism, but that they can adopt the men's perspectives in order to be accepted as 'authentic fans'. Other women reacted on men's domination...

  10. Using Fan Fiction to Teach Critical Reading and Writing Skills

    Science.gov (United States)

    Kell, Tracey

    2009-01-01

    In this article, the author talks about fan fiction, which is defined by Jenkins (2008) as "original stories and novels which are set in the fictional universe of favorite television series, films, comics, games or other media properties." Fan fiction generally involves writing stories with a combination of established characters and established…

  11. Procedure for Balancing an Air Distribution System with Decentralised Fans

    DEFF Research Database (Denmark)

    Gunner, Amalie; Hultmark, Göran; Vorre, Anders

    2015-01-01

    there is a potential for energy saving. In this study the calculated saving in the power consumption for the main fan was found to be 40%. The results also show that when dampers are replaced with decentralised fans with the same efficiency the overall power saving potential was 16%. In the study a mock-up...

  12. Amateur mythographies: Fan fiction and the myth of myth

    Directory of Open Access Journals (Sweden)

    Ika Willis

    2016-03-01

    Full Text Available This paper draws on classical scholarship on myth in order to critically examine three ways in which scholars and fans have articulated a relationship between fan fiction and myth. These are (1 the notion of fan fiction as a form of folk culture, reclaiming popular story from corporate ownership; (2 the notion of myth as counterhegemonic, often feminist, discourse; (3 the notion of myth as a commons of story and a universal story world. I argue that the first notion depends on an implicit primitivizing of fan fiction and myth, which draws ultimately on the work of Gottfried von Herder in the 18th century and limits our ability to produce historically and politically nuanced understandings of fan fiction. The second notion, which is visible in the work of Henry Jenkins and Constance Penley, is more helpful because of its attention to the politics of narration. However, it is the third model of myth, as a universal story world, where we find the richest crossover between fan fiction's creative power and contemporary classical scholarship on myth, especially in relation to Sarah Iles Johnston's analysis of hyperserial narrative. I demonstrate this through some close readings of fan fiction from the Greek and Roman Mythology fandom on Archive of Our Own. I conclude the paper by extending Johnston's arguments to show that fan-fictional hyperseriality, specifically, can be seen as mythic because it intervenes not only in the narrative worlds of its source materials but also in the social world of its telling.

  13. Gender constructions and negotiations of female football fans

    DEFF Research Database (Denmark)

    Lenneis, Verena; Pfister, Gertrud Ursula

    2015-01-01

    aims to give insight into gender constructions and negotiations of female football fans in the stands. Drawing on a social constructivist perspective to gender and Bourdieu's (1984) approaches to field, capital and habitus, we explored the experiences and opinions of female fans. The methods employed...

  14. 76 FR 50739 - Hung Ta Fan: Debarment Order

    Science.gov (United States)

    2011-08-16

    ... bases this order on a finding that Mr. Fan was convicted of a felony under Federal law for conduct... law). FDA's finding that debarment is appropriate is based on the felony conviction referenced herein... Thailand, when in fact he knew that the honey originated in China. Mr. Fan's actions allowed him to avoid...

  15. Simpler Variable-Speed Drive for Fan or Pump

    Science.gov (United States)

    Obler, H. D.

    1982-01-01

    Static pressure developed by a fan or pump is used directly to control its speed in a new drive unit. System is simpler and more economical than many other speed controllers, although it is less accurate and has a narrower speed range. However, since very accurate control is not usually required for fans and pumps, unit would work well in many applications.

  16. Facilitating Attuned Interactions: Using the FAN Approach to Family Engagement

    Science.gov (United States)

    Gilkerson, Linda

    2015-01-01

    Erikson Institute's Fussy Baby Network® (FBN) is a national model prevention program known for its approach to family engagement called the FAN (Gilkerson & Gray, 2014; Gilkerson et al., 2012). The FAN is both a conceptual framework and a practical tool to facilitate attunement in helping relationships and promote reflective practice. This…

  17. Energy fan power consumption comparison of subway station HVAC system

    Institute of Scientific and Technical Information of China (English)

    JIANGYong; ZHUYingxin

    2003-01-01

    Subway thermal environment control system is a mass energy consumed system. The fan operation is the Key of energy saving. Some feasible fan operation modes are proposed and compared in this paper from the view of energy and operation cost saving. It is concluded that VAV is the optimal operation mode for metro system with highest energy saving.

  18. Nocturnal Fanning Suppresses Downy Mildew Epidemics in Sweet Basil.

    Directory of Open Access Journals (Sweden)

    Yigal Cohen

    Full Text Available Downy mildew is currently the most serious disease of sweet basil around the world. The oomycete causal agent Peronospora belbahrii requires ≥ 4h free leaf moisture for infection and ≥7.5h of water-saturated atmosphere (relative humidity RH≥95% at night for sporulation. We show here that continued nocturnal fanning (wind speed of 0.4-1.5 m/s from 8pm to 8am dramatically suppressed downy mildew development. In three experiments conducted during 2015, percent infected leaves in regular (non-fanned net-houses reached a mean of 89.9, 94.3 and 96.0% compared to1.2, 1.7 and 0.5% in adjacent fanned net-houses, respectively. Nocturnal fanning reduced the number of hours per night with RH≥95% thus shortened the dew periods below the threshold required for infection or sporulation. In experiments A, B and C, the number of nights with ≥4h of RH≥95% was 28, 10 and 17 in the non-fanned net-houses compared to 5, 0 and 5 in the fanned net-houses, respectively. In the third experiment leaf wetness sensors were installed. Dew formation was strongly suppressed in the fanned net-house as compared to the non-fanned net-house. Healthy potted plants became infected and sporulated a week later if placed one night in the non-fanned house whereas healthy plants placed during that night in the fanned house remained healthy. Infected potted basil plants sporulated heavily after one night of incubation in the non-fanned house whereas almost no sporulation occurred in similar plants incubated that night in the fanned house. The data suggest that nocturnal fanning is highly effective in suppressing downy mildew epidemics in sweet basil. Fanning prevented the within-canopy RH from reaching saturation, reduced dew deposition on the leaves, and hence prevented both infection and sporulation of P. belbahrii.

  19. Electrical Resistivity Tomography and Induced Polarization for Mapping the Subsurface of Alluvial Fans: A Case Study in Punata (Bolivia

    Directory of Open Access Journals (Sweden)

    Andres Gonzales Amaya

    2016-11-01

    Full Text Available Conceptual models of aquifer systems can be refined and complemented with geophysical data, and they can assist in understanding hydrogeological properties such as groundwater storage capacity. This research attempts to use geoelectrical methods, Electrical Resistivity Tomography and Induced Polarization parameters, for mapping the subsurface in alluvial fans and to demonstrate its applicability; the Punata alluvial fan was used as a case study. The resistivity measurements proved to be a good tool for mapping the subsurface in the fan, especially when used in combination with Induced Polarization parameters (i.e., Normalized Chargeability. The Punata alluvial fan characterization indicated that the top part of the subsurface is composed of boulders in a matrix of finer particles and that the grain size decreases with depth; the electrical resistivity of these deposits ranged from 200 to 1000 Ωm, while the values of normalized chargeability were lower than 0.05 mS/m. The bottom of the aquifer system consisted of a layer with high clay content, and the resistivity ranged from 10 to 100 Ωm, while the normalized chargeability is higher than 0.07 mS/m. With the integration of these results and lithological information, a refined conceptual model is proposed; this model gives a more detailed description of the local aquifer system. It can be concluded that geoelectrical methods are useful for mapping aquifer systems in alluvial fans.

  20. Variable pitch fan system for NASA/Navy research and technology aircraft

    Science.gov (United States)

    Ryan, W. P.; Black, D. M.; Yates, A. F.

    1977-01-01

    Preliminary design of a shaft driven, variable-pitch lift fan and lift-cruise fan was conducted for a V/STOL Research and Technology Aircraft. The lift fan and lift-cruise fan employed a common rotor of 157.5 cm diameter, 1.18 pressure ratio variable-pitch fan designed to operate at a rotor-tip speed of 284 mps. Fan performance maps were prepared and detailed aerodynamic characteristics were established. Cost/weight/risk trade studies were conducted for the blade and fan case. Structural sizing was conducted for major components and weights determined for both the lift and lift-cruise fans.

  1. Costs and benefits of energy efficiency improvements in ceiling fans

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Nihar; Sathaye, Nakul; Phadke, Amol; Letschert, Virginie [Lawrence Berkeley National Lab., CA (United States). Environmental Energy Technology Division

    2013-10-15

    Ceiling fans contribute significantly to residential electricity consumption, especially in developing countries with warm climates. The paper provides analysis of costs and benefits of several options to improve the efficiency of ceiling fans to assess the global potential for electricity savings and green house gas (GHG) emission reductions. Ceiling fan efficiency can be cost-effectively improved by at least 50% using commercially available technology. If these efficiency improvements are implemented in all ceiling fans sold by 2020, 70 terawatt hours per year could be saved and 25 million metric tons of carbon dioxide equivalent (CO2-e) emissions per year could be avoided, globally. We assess how policies and programs such as standards, labels, and financial incentives can be used to accelerate the adoption of efficient ceiling fans in order to realize potential savings.

  2. Portable Fan Assembly for the International Space Station

    Science.gov (United States)

    Jenkins, Arthur A.; Roman, Monsi C.

    1999-01-01

    NASA/ Marshall Space Flight Center (NASA/MSFC) is responsible for the design and fabrication of a Portable Fan Assembly (PFA) for the International Space Station (ISS). The PFA will be used to enhance ventilation inside the ISS modules as needed for crew comfort and for rack rotation. The PFA consists of the fan on-orbit replaceable unit (ORU) and two noise suppression packages (silencers). The fan ORU will have a mechanical interface with the Seat Track Equipment Anchor Assembly, in addition to the power supply module which includes a DC-DC converter, on/standby switch, speed control, power cable and connector. This paper provides a brief development history, including the criteria used for the fan, and a detailed description of the PFA operational configurations. Space Station requirements as well as fan performance characteristics are also discussed.

  3. Development of a Fan for Future Space Suit Applications

    Science.gov (United States)

    Paul. Heather L.; Converse, David; Dionne, Steven; Moser, Jeff

    2010-01-01

    NASA's next generation space suit system will place new demands on the fan used to circulate breathing gas through the ventilation loop of the portable life support system. Long duration missions with frequent extravehicular activities (EVAs), the requirement for significant increases in reliability and durability, and a mission profile that imposes strict limits on weight, volume and power create the basis for a set of requirements that demand more performance than is available from existing fan designs. This paper describes the development of a new fan to meet these needs. A centrifugal fan was designed with a normal operating speed of approximately 39,400 rpm to meet the ventilation flow requirements while also meeting the aggressive minimal packaging, weight and power requirements. The prototype fan also operates at 56,000 rpm to satisfy a second operating condition associated with a single fan providing ventilation flow to two spacesuits connected in series. This fan incorporates a novel nonmetallic "can" to keep the oxygen flow separate from the motor electronics, thus eliminating ignition potential. The nonmetallic can enables a small package size and low power consumption. To keep cost and schedule within project bounds a commercial motor controller was used. The fan design has been detailed and implemented using materials and approaches selected to address anticipated mission needs. Test data is presented to show how this fan performs relative to anticipated ventilation requirements for the EVA portable life support system. Additionally, data is presented to show tolerance to anticipated environmental factors such as acoustics, shock, and vibration. Recommendations for forward work to progress the technology readiness level and prepare the fan for the next EVA space suit system are also discussed.

  4. Alluvial Fan Morphology, distribution and formation on Titan

    Science.gov (United States)

    Birch, S. P. D.; Hayes, A. G.; Howard, A. D.; Moore, J. M.; Radebaugh, J.

    2016-05-01

    Titan is a hydrologically active world, with dozens of alluvial fans that are evidence of sediment transport from high to low elevations. However, the distribution and requirements for the formation of fans on Titan are not well understood. We performed the first global survey of alluvial fans on Titan using Cassini Synthetic Aperture Radar (SAR) data, which cover 61% of Titan's surface. We identified 82 fans with areas ranging from 28 km2 to 27,000 km2. A significant fraction (∼60%) of the fans are restricted to latitudes of ±50-80°, suggesting that fluvial sediment transport may have been concentrated in the near-polar terrains in the geologically recent past. The density of fans is also found to be correlated with the latitudes predicted to have the highest precipitation rates by Titan Global Circulation Models. In equatorial regions, observable fans are not generally found in proximity to dune fields. Such observations suggest that sediment transport in these areas is dominated by aeolian transport mechanisms, though with some degree of recent equatorial fluvial activity. The fan area-drainage area relationship on Titan is more similar to that on Earth than on Mars, suggesting that the fans on Titan are smaller than what may be expected, and that the transport of bedload sediment is limited. We hypothesize that this has led to the development of a coarse gravel-lag deposit over much of Titan's surface. Such a model explains both the morphology of the fans and their latitudinal concentration, yielding insight into the sediment transport regimes that operate across Titan today.

  5. Life, death and revival of debris-flow fans on Earth and Mars : fan dynamics and climatic inferences

    NARCIS (Netherlands)

    de Haas, T.

    2016-01-01

    Alluvial fans are ubiquitous landforms in high-relief regions on Earth and Mars. They have a semi-conical shape and are located at the transition between highlands and adjacent basins. Alluvial fans can form by a range of processes including debris flows, which are water-laden masses of soil and

  6. Life, death and revival of debris-flow fans on Earth and Mars : fan dynamics and climatic inferences

    NARCIS (Netherlands)

    de Haas, T.

    2016-01-01

    Alluvial fans are ubiquitous landforms in high-relief regions on Earth and Mars. They have a semi-conical shape and are located at the transition between highlands and adjacent basins. Alluvial fans can form by a range of processes including debris flows, which are water-laden masses of soil and roc

  7. Life, death and revival of debris-flow fans on Earth and Mars : fan dynamics and climatic inferences

    NARCIS (Netherlands)

    de Haas, T.

    2016-01-01

    Alluvial fans are ubiquitous landforms in high-relief regions on Earth and Mars. They have a semi-conical shape and are located at the transition between highlands and adjacent basins. Alluvial fans can form by a range of processes including debris flows, which are water-laden masses of soil and roc

  8. Surface exposure dating of moraines and alluvial fans in the Southern Central Andes

    Science.gov (United States)

    Terrizzano, Carla; Zech, Roland; García Morabito, Ezequiel; Haghipour, Negar; Christl, Marcus; Likermann, Jeremías; Tobal, Jonathan; Yamin, Marcela

    2016-04-01

    The role of tectonics versus climate in controlling the evolution of alluvial fans in discussed controversially. The southern Central Andes and their forelands provide a perfect setting to study climate versus tectonic control of alluvial fans. On the one hand, the region is tectonically active and alluvial fan surfaces are offset by faults. The higher summits, on the other hand, are glaciated today, and glacial deposits document past periods of lower temperatures and increased precipitation. We applied 10Be surface exposure dating on 5 fan terraces 4 moraines of the Ansilta range (31.6°S - 69.8°W) using boulders and amalgamated pebbles to explore their chronological relationship. From youngest to oldest, the alluvial fan terraces yield minimum ages of 15 ± 1 ka (T1), 97 ± 9 ka (T2), 141 ± 9 ka (T3), 286 ± 14 ka (T4) and 570 ± 57 ka (T5). Minimum ages derived from moraines are 14 ± 1 ka (M1), 22 ± 2 ka (M2), 157 ± 14 ka (M3) and 351 ± 33 ka (M4), all calculations assuming no erosion and using the scaling scheme for spallation based on Lal 1991, Stone 2000. The moraines document glacial advances during cold periods at the marine isotope stages (MIS) 2, 6 and 10. The terraces T1, T3 seem to be geomorphologic counterparts during MIS 2 and 6. We suggest that T2, T4 and T5 document aggradation during the cold periods MIS 5d, 8 and 14 in response to glacial advances, although the respective moraines are not preserved. Our results highlight: i) the arid climate in the Southern Central Andes favors the preservation of glacial and alluvial deposits allowing landscape and climate reconstructions back to ~570 ka), ii) alluvial deposits correlate with moraines or fall into cold glacial times, so that climate, and in particular the existence of glaciers, seems to be the main forcing of alluvial fan formation at our study site. References Lal, D., 1991: Cosmic ray labeling of erosion surfaces: In situ nuclide production rates and erosion models. Earth and Planetary

  9. Leading edge embedded fan airfoil concept -- A new powered high lift technology

    Science.gov (United States)

    Phan, Nhan Huu

    input. The CFD results show that airfoil circulation control is achieved by the varying the CFF intake flow rate and the momentum of the CFF exhaust jet (e.g. through airfoil AoA or fan rotational speed). The presence of the CFF has the effect of moving the stagnation point on the airfoil pressure surface from the CFF airfoil LE region near the CFF to as far back as the airfoil trailing edge. At high AoA operation, LE flow separation on the airfoil suction surface is delayed by flow entrainment of the high-energy jet leaving the CFF. Detailed analysis of the flow field through the crossflow fan and its housing were carried out to understand its fluid-dynamics behavior, and it is found that the airfoil geometry acts as inlet guide vanes to the crossflow fan as the angle-of-attack is varied, thus introducing pre-swirl or co-swirl into the first stage of the crossflow fan. An experimental study of the LEEF concept confirmed that the concept works and it is robust. Finally, as application examples, the LEEF technology is applied to a Remote Control model and to a generic tiltrotor aircraft similar in characteristics to DARPA's Aerial Reconfigurable Embedded System. These aircraft configurations were analyzed using 2D and 3D CFD.

  10. Quaternary fans and terraces in the Khumbu Himal south of Mount Everest: their characteristics, age and formation

    Science.gov (United States)

    Barnard, P.L.; Owen, L.A.; Finkel, R.C.

    2006-01-01

    Large fans and terraces are frequent in the Khumbu Himal within the high Himalayan valleys south of Mt. Everest. These features are composed of massive matrix- and clast-supported diamicts that were formed from both hyperconcentrated flows and coarse-grained debris flows. Cosmogenic radionuclide (CRN) exposure ages for boulders on fans and terraces indicate that periods of fan and terrace formation occurred at c. 16, c. 12, c. 8, c. 4 and c. 1.5 ka, and are broadly coincident with the timing of glaciation in the region. The dating precision is insufficient to resolve whether the surfaces formed before, during or after the correlated glacial advance. However, the sedimentology, and morphostratigraphic and geomorphological relationships suggest that fan and terrace sedimentation in this part of the Himalaya primarily occurs during glacier retreat and is thus paraglacial in origin. Furthermore, modern glacial-lake outburst floods and their associated deposits are common in the Khumbu Himal as the result of glacial retreat during historical times. We therefore suggest that Late Quaternary and Holocene fan and terrace formation and sediment transfer are probably linked to temporal changes in discharge and sediment load caused by glacier oscillations responding to climate change. The timing of major sedimentation events in this region can be correlated with fans and terraces in other parts of the Himalaya, suggesting that major sedimentation throughout the Himalaya is synchronous and tied to regional climatic oscillations. Bedrock incision rates calculated from strath terrace ages average c. 3.9 mm a−1, suggesting that the overall rate of incision is set by regional uplift.

  11. Gillies fan flap for the reconstruction of an upper lip defect caused by noma: case presentation

    Directory of Open Access Journals (Sweden)

    Bello SA

    2012-06-01

    Full Text Available Seidu Adebayo BelloDepartment of Dental and Maxillofacial Surgery, State House Medical Center, Asokoro, Abuja, NigeriaAbstract: The case of a 65-year-old noma patient with a defect involving her upper lip is presented. The defect also included missing teeth numbers eleven, twelve, 21, and 22 and the adjoining alveolus. One-stage lip reconstruction was carried out with Gillies fan flap followed by vestibuloplasty and commissuroplasty. An acrylic partial denture was subsequently fabricated to replace the missing teeth and thereby restore function. Even though the incidence of cancrum oris has reduced worldwide, cases are still being reported in Africa and can leave behind a significant facial defect. Whereas most cases of lip defects reported from the Western world are due to cancer, cancrum oris could be the cause of lip defects in sub-Saharan Africa. Gillies fan flap could be employed for the reconstruction of a relatively large defect of the lip and the disadvantage of microstomia could be minimized for the restoration of articulation, speech, and masticatory functions of the lip.Keywords: Gillies fan flap, reconstruction, upper lip, noma 

  12. Design, durability and low cost processing technology for composite fan exit guide vanes

    Science.gov (United States)

    Blecherman, S. S.

    1980-01-01

    A program was conducted to design, fabricate and test a durable, low cost, lightweight composite fan exit guide vane for high bypass ratio gas turbine engine application. Eight candidate material/design combinations were evaluated by NASTRAN finite element analysis. Four of these candidate systems were selected for composite vane fabrication by two vendors. A core and shell vane design was chosen in which the unidirectional graphite core fiber was the same for all candidates. The shell material, fiber orientation and ply configuration were varied. Material tests were performed on raw material and composite specimens to establish specification requirements. Composite vanes were nondestructively inspected and subsequently fatigue tested in both dry and 'wet' conditions. The program provided relevant data with respect to design analysis, materials properties, inspection standards, improved durability, weight benefits and part price of the composite fan exit guide vane.

  13. Croatian fan scene: Football in television beer commercials

    Directory of Open Access Journals (Sweden)

    Biti Ozren

    2016-01-01

    Full Text Available In this paper attention is given to the mutual synergy between sports, commercials and alcohol. Therefore, we approach the research topic specified in the title with regards to the cultural history of football and beer, the functioning of the commercial industry within consumer culture and the structural practices of consuming football and beer trough which, at specific places and in special occasions, masculinity is performed. This research relies primarily on discourse analysis of football-beer commercials. For the purpose of enriching the insights gained by this method, a semi-structured interview was conducted with a market expert specialized in branding and an autoethnographic approach is present. The central part of the study is based on a corpus of advertisements that were broadcast on national television programs in the last ten years and that have emerged as part of a market designed advertising campaigns for major breweries during the World and European football championships. For the most of them, the common denominator is putting football fans in the forefront, whether in stadiums, bars, town squares or at home. Also, in most cases, they exclusively present male protagonists during their leisure time, united by their passion for football and beer, as well as their desire for relaxed socialization and fun. Apart from gender, the national context is essential, since these commercials usually visually, audibly and textually refer to the national football team of Croatia.

  14. Aerodynamic Modelling and Optimization of Axial Fans

    DEFF Research Database (Denmark)

    Sørensen, Dan Nørtoft

    A numerically efficient mathematical model for the aerodynamics oflow speed axial fans of the arbitrary vortex flow type has been developed.The model is based on a blade-element principle, whereby therotor is divided into a number of annular streamtubes.For each of these streamtubes relations...... for velocity, pressure andradial position are derived from the conservationlaws for mass, tangential momentum and energy.The resulting system of equations is non-linear and, dueto mass conservation and pressure equilibrium far downstream of the rotor,strongly coupled.The equations are solved using the Newton...... distributionsof pitch angle and chord length have been chosen as independent variablesin the optimizations.Besides restricting the geometry of the rotor,constraints have been added to ensure a required pressure rise as well asnon-stalled flow conditions.Optimizations have been performed tomaximize the mean value...

  15. A generalization of Ky Fan's inequality

    Directory of Open Access Journals (Sweden)

    Peng Gao

    2001-01-01

    defined by f(x,y=0 and 0Fan's inequality. We also present some results on the comparison of Pn,sα(y−Pn,rα(y and Pn,sα(x−Pn,rα(x for s≥r, α∈ℝ.

  16. Failure analysis of air fan blades

    Institute of Scientific and Technical Information of China (English)

    WANG Yan-qing; JI Zhe; CUI Yong-li; CUI Chun-zhi; SUN Zhi

    2008-01-01

    The failure of all 12 blades of an air fan was investigated by metallurgical and mechanical experiments and an examina-tion of the fracture surface. The experimental results show that the cast aluminium-silicon alloy without any modification had a number of material defects, such as coarse grains, a loose structure, a large number of shrinkage holes, a long and thin bold-pin shaped silicon-phase, poor material strength and serious brittleness. In addition, installed on the spindle without elastic conjunction,blade No. 10 vibrated and inevitably.spun off due to the large centrifugal force. Therefore, blade No. 10 first cracked at the locking handle, then broke at the root, which caused all the other 11 blades to be broken by the crack of blade No.10.

  17. Climatic control of sediment transport from the Himalayas to the proximal NE Bengal Fan during the last glacial-interglacial cycle

    Science.gov (United States)

    Joussain, Ronan; Colin, Christophe; Liu, Zhifei; Meynadier, Laure; Fournier, Léa; Fauquembergue, Kelly; Zaragosi, Sébastien; Schmidt, Frédéric; Rojas, Virginia; Bassinot, Franck

    2016-09-01

    Clay mineralogy, siliciclastic grain-size, major elements, 87Sr/86Sr, and εNd analyses of deep-sea sediments cored in the north-eastern Bay of Bengal are used to reconstruct evolution of detrital sources and sediment transport to the proximal part of the Bengal deep-sea fan during the last climatic cycle. εNd values (-13.3 to -9.7) and 87Sr/86Sr ratios (0.721-0.733) indicate a mixture of sediments originating from the Ganges-Brahmaputra rivers and the Indo-Burman ranges. Interglacial Marine Isotopic Stages (MIS) 5 and 1 are associated with a higher contribution of sediments from the Ganges-Brahmaputra river system than is the case for glacial MIS 6, 4, 3, and 2. Siliciclasitic grain-size combined with Si/Al and Si/Fe ratios indicate coarser glacial sediments with numerous turbidite layers. Glacial turbidite layers display similar clay mineralogical compositions to hemipelagic sediments. Only few of turbidite layers (MIS 6, 4, and 2) are slightly unradiogenic (εNd -13.3), suggesting a higher contribution of Ganges-Brahmaputra river sediments. Independently of changes in the sedimentary sources, the smectite/(illite + chlorite) ratio of cores located on the NE Bengal Fan indicates higher inputs of primary minerals (illite and chlorite) from the highlands of the river basins (relief) during glacial MIS 6, 4, 3, and 2 and an increased contribution of pedogenic minerals (smectite and kaolinite) during interglacial MIS 5 and 1. Maximum smectite/(illite + chlorite) ratios during the warm sub-stages of MIS 5 suggest an intensification of summer monsoon rainfall associated with higher rates of physical erosion of the Indo-Gangetic flood-plain and/or dominant summer hydrological conditions transporting a higher proportion of sediments deriving from the Ganges-Brahmaputra rivers to the NE Bengal Fan. In addition, a higher production of smectite in soils of the Indo-Gangetic flood-plain during periods of intensification of monsoon rainfall cannot be excluded.

  18. Characteristics of unsteady flow field and flow-induced noise for an axial cooling fan used in a rack mount server computer Characteristics of unsteady flow field and flow-induced noise for an axial cooling fan used in a rack mount server computer

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Tae Gyun; Jeon, Wan Ho [Technical Research Lab., CEDIC Co., Seoul (Korea, Republic of); Minorikawa, Gaku [Dept. of f Mechanical Engineering, Faculty of Science and Engineering, Hosei University, Tokyo (Japan)

    2016-10-15

    The recent development of small and lightweight rack mount servers and computers has resulted in the decrease of the size of cooling fans. However, internal fans still need to achieve a high performance to release the heat generated from interior parts, and they should emit low noise. On the contrary, measurement data, such as flow properties and flow visualizations, cannot be obtained easily when cooling fans are small. Thus, a numerical analysis approach is necessary for the performance evaluation and noise reduction of small cooling fans. In this study, the noise of a small cooling fan used for computers or servers was measured and then compared with the aeroacoustic noise result based on a numerical analysis. Three-dimensional Navier-Stokes equations were solved to predict the unsteady flow field and surface pressure fluctuation according to the blades and casing surface used. The simplified Ffowcs Williams and Hawkings equation was used to predict aeroacoustic noise by assuming that a dipole is the major cause of fan noise. Results of the aeroacoustic noise analysis agreed well with that of the experiment, and a tonal noise whose frequency was lower than the first blade passing frequency could be identified in the noise spectrum. This phenomenon is caused by the shape of the bell mouth. A coherence analysis was performed to examine the correlation between the shape of the cooling fan and the noise.

  19. Soap operas and the history of fan discussion

    Directory of Open Access Journals (Sweden)

    Sam Ford

    2008-09-01

    Full Text Available For decades, fans of U.S. soap operas have formed social networks surrounding their shows, and they did so even before the concept entered the vernacular. Soap fans, who started on a geographically local scale and built their communities through grassroots efforts, have found a variety of venues to connect with one another over the past several decades. This study looks at the pre-Internet development of these social networks to show how that trajectory relates to the current online community of soap opera fans. Although several scholars have studied soap opera fandom, few have taken an historical approach at understanding the trajectory of soap fandom, a view especially necessary in an era where online social networks are at the center of audience studies and where cornerstone U.S. soap operas are struggling to retain relevance and audience. To fill this gap, I argue that understanding fan networks today requires looking back to previous methods of fan networking. Soaps' longevity (the youngest U.S. soap is more than 20 years old and frequency (all U.S. daytime soaps are daily make them crucial texts in demonstrating how the roots of fan social networks in a pre-Internet era helped shape that fandom's transition onto the Internet, and they also illustrate the continued evolution of these networks as fans move online.

  20. Experimental determination of tunnel ventilation axial ducted fan performance

    Directory of Open Access Journals (Sweden)

    Šekularac Milan B.

    2016-01-01

    Full Text Available To investigate traffic tunnel ventilation flows, a scaled model of a traffic tunnel with longitudinal ventilation system based on ducted fans is used. Flows in tunnels are influenced by tunnel geometry, fan characteristics, ventilation operation scenario, vehicle traffic, atmospheric factors, etc. To analyze flow fields of tunnels in detail, knowledge of tunnel jet-fan properties and turbulent flow characteristics at the fan exit are required, and can be used as input data for CFD boundary conditions of tunnel flow computation. For this purpose experimental measurements were done using the hot wire anemometry technique. The obtained results, trough ensemble-averaged and time averaged profiles of all velocity components, turbulence intensity, turbulent kinetic energy, integral flow length scales, available Reynolds stresses, Turbulent kinetic energy production rates and the fan thrust performance, are presented. These data allow us to analyze in more detail the influence of fan flow on energy and pollutant removal efficiencies of the tunnel ventilation and to evaluate accuracy of CFD studies on fan improvements.

  1. Reactive control of subsonic axial fan noise in a duct.

    Science.gov (United States)

    Liu, Y; Choy, Y S; Huang, L; Cheng, L

    2014-10-01

    Suppressing the ducted fan noise at low frequencies without varying the flow capacity is still a technical challenge. This study examines a conceived device consisting of two tensioned membranes backed with cavities housing the axial fan for suppression of the sound radiation from the axial fan directly. The noise suppression is achieved by destructive interference between the sound fields from the axial fan of a dipole nature and sound radiation from the membrane via vibroacoustics coupling. A two-dimensional model with the flow effect is presented which allows the performance of the device to be explored analytically. The air flow influences the symmetrical behavior and excites the odd in vacuo mode response of the membrane due to kinematic coupling. Such an asymmetrical effect can be compromised with off-center alignment of the axial fan. Tension plays an important role to sustain the performance to revoke the deformation of the membrane during the axial fan operation. With the design of four appropriately tensioned membranes covered by a cylindrical cavity, the first and second blade passage frequencies of the axial fan can be reduced by at least 20 dB. The satisfactory agreement between experiment and theory demonstrates that its feasibility is practical.

  2. Understanding Himalayan erosion and the significance of the Nicobar Fan

    Science.gov (United States)

    McNeill, Lisa C.; Dugan, Brandon; Backman, Jan; Pickering, Kevin T.; Pouderoux, Hugo F. A.; Henstock, Timothy J.; Petronotis, Katerina E.; Carter, Andrew; Chemale, Farid; Milliken, Kitty L.; Kutterolf, Steffen; Mukoyoshi, Hideki; Chen, Wenhuang; Kachovich, Sarah; Mitchison, Freya L.; Bourlange, Sylvain; Colson, Tobias A.; Frederik, Marina C. G.; Guèrin, Gilles; Hamahashi, Mari; House, Brian M.; Hüpers, Andre; Jeppson, Tamara N.; Kenigsberg, Abby R.; Kuranaga, Mebae; Nair, Nisha; Owari, Satoko; Shan, Yehua; Song, Insun; Torres, Marta E.; Vannucchi, Paola; Vrolijk, Peter J.; Yang, Tao; Zhao, Xixi; Thomas, Ellen

    2017-10-01

    A holistic view of the Bengal-Nicobar Fan system requires sampling the full sedimentary section of the Nicobar Fan, which was achieved for the first time by International Ocean Discovery Program (IODP) Expedition 362 west of North Sumatra. We identified a distinct rise in sediment accumulation rate (SAR) beginning ∼9.5 Ma and reaching 250-350 m/Myr in the 9.5-2 Ma interval, which equal or far exceed rates on the Bengal Fan at similar latitudes. This marked rise in SAR and a constant Himalayan-derived provenance necessitates a major restructuring of sediment routing in the Bengal-Nicobar submarine fan. This coincides with the inversion of the Eastern Himalayan Shillong Plateau and encroachment of the west-propagating Indo-Burmese wedge, which reduced continental accommodation space and increased sediment supply directly to the fan. Our results challenge a commonly held view that changes in sediment flux seen in the Bengal-Nicobar submarine fan were caused by discrete tectonic or climatic events acting on the Himalayan-Tibetan Plateau. Instead, an interplay of tectonic and climatic processes caused the fan system to develop by punctuated changes rather than gradual progradation.

  3. Reduction of the treated volume to involved node radiation therapy as part of combined modality treatment for early stage aggressive non-Hodgkin's lymphoma.

    NARCIS (Netherlands)

    Verhappen, M.H.; Poortmans, P.M.; Raaijmakers, E.; Raemaekers, J.M.M.

    2013-01-01

    BACKGROUND AND PURPOSE: This retrospective study investigated whether focused involved node radiation therapy (INRT) can safely replace involved field RT (IFRT) in patients with early stage aggressive NHL. PATIENTS AND METHODS: We included 258 patients with stage I/II aggressive NHL who received com

  4. Use of booster fans in underground coal mining to advantage

    Institute of Scientific and Technical Information of China (English)

    Habibi A; Gillies A D S

    2011-01-01

    A booster fan is an underground main fan which is installed in series with a main surface fan and used to boost the air pressure of the ventilation to overcome mine resistance.Currently booster fans are used in several major coal mining countries including the United Kingdom,Australia,Poland and China.In the United States booster fans are prohibited in coal mines although they are used in several metal and non-metal mines.A study has been undertaken to examine alternatives for ventilating an underground room and pillar coal mine system.A feasibility study of a hypothetical situation has shown that current ventilation facilities are incapable of fulfilling mine air requirements in the future due to increased seam methane levels.A current ventilation network model has been prepared and projected to a mine five years plan.“Ventsim visual” software simulations of different possible ventilation options have been conducted in which varying methane levels are found at working faces.The software can also undertake financial simulations and project present value total costs for the options under study.Several scenarios for improving the ventilation situation such as improving main surface fans,adding intake shafts,adding exhaust shafts and utilizing booster fans have been examined.After taking into account the total capital and operating costs for the five years mine plan the booster fan scenarios are recommended as being the best alternatives for further serious consideration by the mine.The optimum option is a properly sized and installed booster fan system that can be used to create safe work conditions,maintain adequate air quantity with lowest cost,generate a reduction in energy consumption and decrease mine system air leakage.

  5. Indirect Adaptive Attitude Control for a Ducted Fan Vertical Takeoff and Landing Microaerial Vehicle

    Directory of Open Access Journals (Sweden)

    Shouzhao Sheng

    2015-01-01

    Full Text Available The present paper addresses an attitude tracking control problem of a ducted fan microaerial vehicle. The proposed indirect adaptive controller can greatly reduce tracking error in the initial stage of the adaptive learning process by using an error compensation strategy and can achieve good capability to eliminate the adverse effect of measurement noises on the convergence of adjustable parameters. Moreover, the learning rate adaptation strategy is proposed to further minimize the adverse effect of large learning rates on the convergence of adjustable parameters. The experimental tests have illustrated the effectiveness of the proposed adaptive controller.

  6. Female fans of men's football - a case study in Denmark

    DEFF Research Database (Denmark)

    Pfister, Gertrud Ursula; Lenneis, Verena; Mintert, Svenja-Maria

    2013-01-01

    Football is an invention by men for men, and today, the majority of players and fans are men. There is an abundance of literature on football and fandom; however, gender is mostly not an issue in these publications. Research about female football supporters and fans is very limited. This is also...... to a ‘man’s world’ and what are their roles in this ‘male environment’? The statements of interviewees revealed that female fans have to cope with a measure of sexism, but that they can adopt the men’s perspectives in order to be accepted as ‘authentic fans’. Other women reacted on men’s domination...

  7. Performance Study and CFD Predictions of a Ducted Fan System

    Science.gov (United States)

    Abrego, Anita I.; Chang, I-Chung; Bulaga, Robert W.; Rutkowski, Michael (Technical Monitor)

    2002-01-01

    An experimental investigation was completed in the NASA Ames 7 by 10-Foot Wind Tunnel to study the performance characteristics of a ducted fan. The goal of this effort is to study the effect of ducted fan geometry and utilize Computational Fluid Dynamics (CFD) analysis to provide a baseline for correlation. A 38-inch diameter, 10-inch chord duct with a five-bladed fixed-pitch fan was tested. Duct performance data were obtained in hover, vertical climb, and forward flight test conditions. This paper will present a description of the test, duct performance results and correlation with CFD predictions.

  8. Introduction of a Cooling-Fan Efficiency Index

    DEFF Research Database (Denmark)

    Schiavon, S.; Melikov, Arsen Krikor

    2009-01-01

    , while cooling capacity and efficiency of energy use are unknown. To address this knowledge gap, this paper introduces the cooling-fan efficiency (CFE) index, defined as the ratio between the cooling effect (measured with a thermal manikin) generated by the device and its power consumption. The index...... cooling effect and an index for determining fan efficiency, such as the CFE index proposed in this study, need to be developed. The cooling fans generate a nonuniform velocity field around occupants, which cannot be described with a single air-velociry value. Therefore, it is not clear how to apply...

  9. COOLING FAN AND SYSTEM PERFORMANCE AND EFFICIENCY IMPROVEMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Ronald Dupree

    2005-07-31

    Upcoming emissions regulations (Tiers 3, 4a and 4b) are imposing significantly higher heat loads on the cooling system than lesser regulated machines. This work was a suite of tasks aimed at reducing the parasitic losses of the cooling system, or improving the design process through six distinct tasks: 1. Develop an axial fan that will provide more airflow, with less input power and less noise. The initial plan was to use Genetic Algorithms to do an automated fan design, incorporating forward sweep for low noise. First and second generation concepts could not meet either performance or sound goals. An experienced turbomachinery designer, using a specialized CFD analysis program has taken over the design and has been able to demonstrate a 5% flow improvement (vs 10% goal) and 10% efficiency improvement (vs 10% goal) using blade twist only. 2. Fan shroud developments, using an 'aeroshroud' concept developed at Michigan State University. Performance testing at Michigan State University showed the design is capable of meeting the goal of a 10% increase in flow, but over a very narrow operating range of fan performance. The goal of 10% increase in fan efficiency was not met. Fan noise was reduced from 0 to 2dB, vs. a goal of 5dB at constant airflow. The narrow range of fan operating conditions affected by the aeroshroud makes this concept unattractive for further development at this time 3. Improved axial fan system modeling is needed to accommodate the numbers of cooling systems to be redesigned to meet lower emissions requirements. A CFD fan system modeling guide has been completed and transferred to design engineers. Current, uncontrolled modeling practices produce flow estimates in some cases within 5% of measured values, and in some cases within 25% of measured values. The techniques in the modeling guide reduced variability to the goal of + 5% for the case under study. 4. Demonstrate the performance and design versatility of a high performance fan. A

  10. Nostalgic [re]remembering: film fan cultures and the affective reiteration of popular film histories.

    Directory of Open Access Journals (Sweden)

    Nathan Hunt

    2011-05-01

    Full Text Available

    Abstract: This article explores two central uses of memory narratives in film fan culture: Firstly; that fan magazines recycle and reiterate popular histories of film, with the extensive detailing of anecdotes and histories of productions serving to fix certain texts as canonical, cult or classic film artefacts whilst legitimating nostalgia as a mode of reading; secondly; that such films are historically positioned in terms of an appeal to fans via nostalgia as activating personal and affective histories of pleasurable film reception. This piece examines the various ways that commercial magazines discursively utilise nostalgia in their mediation between texts, institutions and fan audiences. At the same time it also explores that way that nostalgia resonates within the activities and discourses of fans as they engage with film.

     

    Résumé: Cet article analyse deux usages fondamentaux des souvenirs narratifs dans la culture des fans cinématographiques. D'une part, le recyclage et la reprise d'histoires populaires sur le cinéma, notamment, avec la mention très détaillée d'anecdotes et d'histoires sur l'histoire de

  11. Studies of two stage gas turbine combustor for biomass powder. Part 1, Atmospheric cyclone gasification experiments with wood powder. Technical report

    Energy Technology Data Exchange (ETDEWEB)

    Degerman, Bengt; Hedin, Johan; Fredriksson, Christian; Kjellstroem, Bjoern; Salman, Hassan [Luleaa Univ. of Technology (Sweden). Dept. of Mechanical Engineering

    2000-10-01

    This report summarises the research and development work regarding development of a two stage gas turbine combustor for wood powder carried out at the Luleaa University of Technology from July 1993 to December 1996. The process being studied is based on cyclone gasification of the wood powder and combustion of the product gas in a suitably adapted gas turbine combustion chamber, without other gas cleaning than that obtained by the cyclone. A critical issue to be studied in the project is if the burned gases from such a cyclone gasifier lead to acceptably low deposition rates for K- and Na-compounds in a gas turbine with 850 deg C inlet temperature. The project strategy has been to study wood powder feeding and cyclone gasification first at atmospheric pressure, then run separate pressurised cyclone gasification tests for studies of the possibilities to achieve stable operation when the air flow is supplied by a separate compressor and finally to run integrated gasifier/gas turbine tests for studies of the deposition problem in practical operation. During the period covered by this report the atmospheric test facility has been designed, built and commissioned. It has been used mainly for studies of injector feeding of wood powder into a cyclone gasifier and for gasification experiments where in particular the fate of ash elements introduced with the wood powder has been studied. The results of these experiments have shown that steam injection of wood powder is possible with a steam consumption of about 0.3 kg steam/kg wood. The effects of injector geometry on the performance has also been studied. The gasification experiments show clearly that ash elements, including K and Na remain in the ash until very late in the thermal conversion process, also at gas temperatures exceeding 900 deg C. The separation of K with the cyclone bottom char has been 50 - 60% and the separation of Na about 80% with the cyclone geometry and the wood powder tested. The resulting load of K

  12. Life, death and revival of debris-flow fans on Earth and Mars : fan dynamics and climatic inferences

    OpenAIRE

    Haas, T.

    2016-01-01

    Alluvial fans are ubiquitous landforms in high-relief regions on Earth and Mars. They have a semi-conical shape and are located at the transition between highlands and adjacent basins. Alluvial fans can form by a range of processes including debris flows, which are water-laden masses of soil and rock with volumetric sediment concentrations exceeding 40%. In this thesis, I aim to (1) unravel the formative dynamics of debris-flow fans and, building on these insights, to (2) reconstruct hydrolog...

  13. Seismic stratigraphic architecture of the Disko Bay trough-mouth fan system, West Greenland

    Science.gov (United States)

    Hofmann, Julia C.; Knutz, Paul C.

    2015-04-01

    succession has been divided into five seismic units, each representing different stages in the progradational accumulation of the TMF system. This poster and ongoing study will discuss how the ice-stream flow switching is linked to changes in depocentres of sedimentary sequences and further investigate the major controls, e.g. ice-sheet dynamics, ocean-climate changes, tectonic forcing and subglacial geology, that determined the evolution of the Disko Bay TMF. Essencial bibliography Mitchum, R.M. Jr., Vail, P.R., Sangree, J.B., 1977. Seismic stratigraphy and global changes of sea level, Part 6: Stratigraphic interpretation of seismic reflection patterns in depositional sequences. AAPG Memoir 26, 117-133. Ó Cofaigh, C., Andrews, J.T., Jennings, A.E., Dowdeswell, J.A., Hogan, K.A., Kilfeather, A.A., Sheldon, C., 2013. Glacimarine lithofacies, provenance and depositional processes on a West Greenland trough-mouth fan. Journal of Quaternary Science, 28(1), 13-26.

  14. 10 CFR Appendix V to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Ceiling Fan Light Kits

    Science.gov (United States)

    2010-01-01

    ... of Ceiling Fan Light Kits V Appendix V to Subpart B of Part 430 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS Test Procedures Pt. 430, Subpt. B, App. V Appendix V to Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of Ceiling...

  15. Sources of dissolved ammonia and iron in Borovnica alluvial fan groundwater

    Directory of Open Access Journals (Sweden)

    Janko Urbanc

    2014-07-01

    Full Text Available The article deals with chemical and isotopic properties of Borovnica alluvial fan groundwater. Increased concentrations of ammonium and iron were detected in well VB-3 of the Borovnica alluvial fan pumping station. On the basis of analyses it was found out that increased concentrations of both elements are linked to the hydrogeological conditions in the aquifer area. In the upper part of the Borovnica alluvial fan aquifer, layers of clay prevent the access of oxygen to groundwater. This fact, together with the presence of organic matter in the aquifer, creates reduction conditions causing the mobility of iron and manganese in groundwater and the transformation of nitrogen from nitrate into ammonium form. Water from the lower aquifer contains more dissolved oxygen, and on the basis of tritium presence it can be concluded that the water is old up to 50 years. Wells VB-5 and VB-6 capture water from the lower pleistocene aquifer, while well VB-3 recharges also with water from the upper holocene aquifer.

  16. Producción y lectura de fan fiction en la comunidad online de la serie Fringe: transmedialidad, competencia y alfabetización mediática

    Directory of Open Access Journals (Sweden)

    Mar Guerrero-Pico

    2015-01-01

    Full Text Available Este artículo analiza los efectos de la narrativa transmedia en la creación y consumo de una clase de fanwork como el fan ction a partir del estudio de la comunidad online de escritores y lectores dedicada a la serie de televi- sión Fringe (FOX, 2008-2013, una de las franquicias transmedia más re- levantes de los últimos años. Basándose en un cuestionario online de tipo cualitativo y la observación participante dentro de esta comunidad, la in- vestigación se centra en describir las características del fan ction en el pa- norama transmediático y explorar de forma complementaria la adquisición de competencias interpretativas y de destrezas mediáticas por parte de los fans. El trabajo concluye revelando la tibia inuencia que el conjunto de productos anexos a la serie tiene sobre el proceso creativo del fan ction , a la vez que identica su condición de práctica caractercéntrica , subrayan- do la importancia capital del personaje como el elemento sobre el que los fans construyen sus expansiones narrativas. Finalmente, también se consta- ta el valor del fan ction como herramienta para la alfabetización mediática.

  17. Is the turbidite facies association scheme valid for interpreting ancient submarine fan environments?

    Science.gov (United States)

    Shanmugam, G.; Damuth, J. E.; Moiola, R. J.

    1985-04-01

    Although turbidite facies reflect only processes of deposition, turbidite facies associations are routinely used to identify ancient submarine-fan subenvironments (e.g., upper fan, channel, lobe, etc.). The assumption that process of deposition also reflects environment of deposition may not be valid for the following reasons: (1) Mutti and Ricci Lucchi's facies association scheme for submarine fans has been developed exclusively from ancient turbidite sequences; however, the true relationship between such turbidite facies associations and related fan subenvironments has not been confirmed from modern fans; (2) individual channel-levee systems of many modern submarine fans are in many cases large enough to contain the entire ancient fan systems on which these facies associations are based; (3) large channel-levee systems comparable to those of modern fans have not been recognized in outcrops. Consequently, the validity of turbidite facies associations for interpreting ancient submarine-fan subenvironments must be considered tenuous until confirmed in modern fans.

  18. Autonomous Composite Fan Containment Integrity Monitoring (AUTOCONFIRM) System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — New engine fan blade containment structures are being manufactured with advanced composite structures such that they can withstand blade-out events. The use of...

  19. Redefining genderswap fan fiction: A Sherlock case study

    Directory of Open Access Journals (Sweden)

    Ann McClellan

    2014-09-01

    Full Text Available Using BBC Sherlock (2010– fan fiction as case study, this article looks at how fans use and understand such concepts as biological sex and gender in genderswap fan fiction, arguing that the label often minimizes the importance of the physical body in determining gender identity. The label genderswap, most often used to describe stories where characters have become differently sexed, reflects and reinforces common cultural misunderstandings about differences between sex and gender. By teasing out definitions of genderswap, sex, gender, cisgender, and transgender, the article analyzes what genderswap includes and excludes from discussions of gender and identity within contemporary fan fiction, ultimately arguing for a broader conceptual understanding that grounds the genre within contemporary transgender theory.

  20. Field testing the prototype BNL fan-atomized oil burner

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, R.; Celebi, Y. [Brookhaven National Lab., Upton, NY (United States)

    1995-04-01

    BNL has developed a new oil burner design referred to as the Fan Atomized burner System. The primary objective of the field study was to evaluate and demonstrate the reliable operation of the Fan Atomized Burner. The secondary objective was to establish and validate the ability of a low firing rate burner (0.3-0.4 gph) to fully satisfy the heating and domestic hot water load demands of an average household in a climate zone with over 5,000 heating-degree-days. The field activity was also used to evaluate the practicality of side-wall venting with the Fan Atomized Burner with a low stack temperature (300F) and illustrate the potential for very high efficiency with an integrated heating system approach based on the Fan Atomized Burner.

  1. Low Cost/Low Noise Variable Pitch Ducted Fan Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ACI proposes a design for a Propulsor (Low Cost/Low Noise Variable Pitch Ducted Fan) that has wide application in all sectors of Aviation. Propulsor hardware of this...

  2. Gender constructions and negotiations of female football fans

    DEFF Research Database (Denmark)

    Lenneis, Verena; Pfister, Gertrud Ursula

    2015-01-01

    While both the media and the academic literature focus primarily on male fans, in particular on violence and the prevention of hooliganism, little is known about female football supporters. This is also true of Denmark, a country that is known for its high degree of gender equality. This article...... "hypermasculinity" nor "emphasised femininity" in their gender performances. Female fans do not only comply with and reproduce the rules of conduct in the stadium but also apply different forms of resistance against sexism and the domination of men in the stadium – both on the field and in the stands. The founding...... aims to give insight into gender constructions and negotiations of female football fans in the stands. Drawing on a social constructivist perspective to gender and Bourdieu's (1984) approaches to field, capital and habitus, we explored the experiences and opinions of female fans. The methods employed...

  3. Modeling and ecodesigning crossflow ventilation fans with Mathematica

    CERN Document Server

    Argentini, Gianluca

    2010-01-01

    The efficiency of a simple model of crossflow fan is maximized when the geometry depends on a design parameter. The flow field is numerically computed using a Galerkin method for solving a Poisson partial differential equation.

  4. Pathological effects of cyanobacteria on sea fans in southeast Florida.

    Science.gov (United States)

    Kiryu, Y; Landsberg, J H; Peters, E C; Tichenor, E; Burleson, C; Perry, N

    2015-07-01

    In early August 2008, observations by divers indicated that sea fans, particularly Gorgonia ventalina, Gorgonia flabellum, and Iciligorgia schrammi, were being covered by benthic filamentous cyanobacteria. From August 2008 through January 2009 and again in April 2009, tissue samples from a targeted G. ventalina colony affected by cyanobacteria and from a nearby, apparently healthy (without cyanobacteria) control colony, were collected monthly for histopathological examination. The primary cellular response of the sea fan to overgrowth by cyanobacteria was an increase in the number of acidophilic amoebocytes (with their granular contents dispersed) that were scattered throughout the coenenchyme tissue. Necrosis of scleroblasts and zooxanthellae and infiltration of degranulated amoebocytes were observed in the sea fan surface tissues at sites overgrown with cyanobacteria. Fungal hyphae in the axial skeleton were qualitatively more prominent in cyanobacteria-affected sea fans than in controls.

  5. Noise Generation by Fans with Supersonic Tip Speeds

    Science.gov (United States)

    Glegg, Stewart; Envia, Edmane (Technical Monitor)

    2003-01-01

    Fan noise continues to be a significant issue for commercial aircraft engines and there still exists a requirement for improved understanding of the fundamental issues associated with fan noise source mechanisms. At the present time, most of the prediction methods identify the dominant acoustic sources to be associated with the stator vanes or blade trailing edges which are downstream of the fan face. However recent studies have shown that acoustic waves are significantly attenuated as they propagate upstream through a rotor, and if the appropriate corrections are applied, sound radiation from the engine inlet is significantly underpredicted. The prediction models can only be applied to fans with subsonic tip speeds. In contrast, most aircraft engines have fan tip speeds which are transonic and this implies an even higher attenuation for upstream propagating acoustic waves. Consequently understanding how sound propagates upstream through the fan is an important, and not well understood phenomena. The objective of this study is to provide improved insight into the upstream propagation effects through a rotor which are relevant to full scale engines. The focus of this study is on broadband fan noise generated by boundary layer turbulence interacting with the trailing edges of the fan blades. If this source mechanism is important upstream of the fan, the sound must propagate upstream through a transonic non uniform flow which includes large gradients and non linearities. Developing acoustic propagation models in this type of flow is challenging and currently limited to low frequency applications, where the frequency is of the same order as the blade passing frequency of the fan. For trailing edge noise, much higher frequencies are relevant and so a suitable approach needs to be developed, which is not limited by an unacceptably large computational effort. In this study we are in the process of developing a computational method which applies for the high frequencies of

  6. Should electric fans be used during a heat wave?

    Science.gov (United States)

    Jay, Ollie; Cramer, Matthew N; Ravanelli, Nicholas M; Hodder, Simon G

    2015-01-01

    Heat waves continue to claim lives, with the elderly and poor at greatest risk. A simple and cost-effective intervention is an electric fan, but public health agencies warn against their use despite no evidence refuting their efficacy in heat waves. A conceptual human heat balance model can be used to estimate the evaporative requirement for heat balance, the potential for evaporative heat loss from the skin, and the predicted sweat rate, with and without an electrical fan during heat wave conditions. Using criteria defined by the literature, it is clear that fans increase the predicted critical environmental limits for both the physiological compensation of endogenous/exogenous heat, and the onset of cardiovascular strain by an air temperature of ∼3-4 °C, irrespective of relative humidity (RH) for the young and elderly. Even above these critical limits, fans would apparently still provide marginal benefits at air temperatures as high as 51.1 °C at 10%RH for young adults and 48.1 °C at 10%RH for the elderly. Previous concerns that dehydration would be exacerbated with fan use do not seem likely, except under very hot (>40 °C) and dry (conditions, when predicted sweat losses are only greater with fans by a minor amount (∼20-30 mL/h). Relative to the peak outdoor environmental conditions reported during ten of the most severe heat waves in recent history, fan use would be advisable in all of these situations, even when reducing the predicted maximum sweat output for the elderly. The protective benefit of fans appears to be underestimated by current guidelines. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  7. On the Optimal Selection of Electrical Machines Fans

    Directory of Open Access Journals (Sweden)

    Mădălin Costin

    2014-09-01

    Full Text Available In this paper an analytic relationship for electrical machine fan design has been developed. In the particularly case of salient poles synchronous machine (with salient poles – for electromagnetic field excitation or surface mounded permanent magnet, this approach allowed to express the fan power as a function of machine middle axe air gap. This analytic foundation developed may leads to different optimization criteria as specific active materials or costs. Numerical simulations confirm our approach.

  8. Sport Fan Motivation: Are You Going To The Game?

    OpenAIRE

    Johannes A. Wiid; Cant, Michael C.

    2015-01-01

    Every individual or group consume sporting events for different reasons and are therefore motivated in different ways. People consuming sport events can be referred to as sport fans, someone who is enthusiastic about a particular sport, an athlete or someone who is motivated to make the effort to attend a live sporting event. Research on sport consumption motivation had led to the development of the Sport Fan Motivation Scale (SFMS), which consists of eight motives namely, eustress, self-este...

  9. Experimental and Numerical Investigation of a 60cm Diameter Bladeless Fan

    OpenAIRE

    mohammad jafari; Hossein Afshin; Bijan Farhanieh; Hamidreza bozorgasareh

    2016-01-01

    Bladeless fan is a novel type of fan with an unusual geometry and unique characteristics. This type of fan has been recently developed for domestic applications in sizes typically up to 30cm diameter. In the present study, a Bladeless fan with a diameter of 60cm was designed and constructed, in order to investigate feasibility of its usage in various industries with large dimensions. Firstly, flow field passed through this fan was studied by 3D modeling. Aerodynamic and aeroacoust...

  10. Potential Global Benefits of Improved Ceiling Fan Energy Efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Sathaye, Nakul [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Phadke, Amol [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Shah, Nihar [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Letschert, Virginie [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-10-31

    Ceiling fans contribute significantly to residential electricity consumption, both in an absolute sense and as a proportion of household consumption in many locations, especially in developing countries in warm climates. However, there has been little detailed assessment of the costs and benefits of efficiency improvement options for ceiling fans and the potential resulting electricity consumption and greenhouse gas (GHG) emissions reductions. We analyze the costs and benefits of several options to improve the efficiency of ceiling fans and assess the global potential for electricity savings and GHG emission reductions with more detailed assessments for India, China, and the U.S. We find that ceiling fan efficiency can be cost-effectively improved by at least 50% using commercially available technology. If these efficiency improvements are implemented in all ceiling fans sold by 2020, 70 terrawatt hours per year (TWh/year) could be saved and 25 million metric tons of carbon dioxide (CO2) emissions per year could be avoided, globally. We assess how policies and programs such as standards, labels, and financial incentives can be used to accelerate the adoption of efficient ceiling fans in order to realize this savings potential.

  11. COOLING FAN AND SYSTEM PERFORMANCE AND EFFICIENCY IMPROVEMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Ronald Dupree

    2005-07-31

    Upcoming emissions regulations (Tiers 3, 4a and 4b) are imposing significantly higher heat loads on the cooling system than lesser regulated machines. This work was a suite of tasks aimed at reducing the parasitic losses of the cooling system, or improving the design process through six distinct tasks: 1. Develop an axial fan that will provide more airflow, with less input power and less noise. The initial plan was to use Genetic Algorithms to do an automated fan design, incorporating forward sweep for low noise. First and second generation concepts could not meet either performance or sound goals. An experienced turbomachinery designer, using a specialized CFD analysis program has taken over the design and has been able to demonstrate a 5% flow improvement (vs 10% goal) and 10% efficiency improvement (vs 10% goal) using blade twist only. 2. Fan shroud developments, using an 'aeroshroud' concept developed at Michigan State University. Performance testing at Michigan State University showed the design is capable of meeting the goal of a 10% increase in flow, but over a very narrow operating range of fan performance. The goal of 10% increase in fan efficiency was not met. Fan noise was reduced from 0 to 2dB, vs. a goal of 5dB at constant airflow. The narrow range of fan operating conditions affected by the aeroshroud makes this concept unattractive for further development at this time 3. Improved axial fan system modeling is needed to accommodate the numbers of cooling systems to be redesigned to meet lower emissions requirements. A CFD fan system modeling guide has been completed and transferred to design engineers. Current, uncontrolled modeling practices produce flow estimates in some cases within 5% of measured values, and in some cases within 25% of measured values. The techniques in the modeling guide reduced variability to the goal of + 5% for the case under study. 4. Demonstrate the performance and design versatility of a high performance fan. A

  12. Broadband Liner Optimization for the Source Diagnostic Test Fan

    Science.gov (United States)

    Nark, Douglas M.; Jones, Michael G.

    2012-01-01

    The broadband component of fan noise has grown in relevance with the utilization of increased bypass ratio and advanced fan designs. Thus, while the attenuation of fan tones remains paramount, the ability to simultaneously reduce broadband fan noise levels has become more appealing. This paper describes a broadband acoustic liner optimization study for the scale model Source Diagnostic Test fan. Specifically, in-duct attenuation predictions with a statistical fan source model are used to obtain optimum impedance spectra over a number of flow conditions for three liner locations in the bypass duct. The predicted optimum impedance information is then used with acoustic liner modeling tools to design liners aimed at producing impedance spectra that most closely match the predicted optimum values. Design selection is based on an acceptance criterion that provides the ability to apply increased weighting to specific frequencies and/or operating conditions. Typical tonal liner designs targeting single frequencies at one operating condition are first produced to provide baseline performance information. These are followed by multiple broadband design approaches culminating in a broadband liner targeting the full range of frequencies and operating conditions. The broadband liner is found to satisfy the optimum impedance objectives much better than the tonal liner designs. In addition, the broadband liner is found to provide better attenuation than the tonal designs over the full range of frequencies and operating conditions considered. Thus, the current study successfully establishes a process for the initial design and evaluation of novel broadband liner concepts for complex engine configurations.

  13. THz Beam Shaper Realizing Fan-Out Patterns

    Science.gov (United States)

    Liebert, K.; Rachon, M.; Siemion, A.; Suszek, J.; But, D.; Knap, W.; Sypek, M.

    2017-08-01

    Fan-out elements create an array of beams radiating at particular angles along the propagation axis. Therefore, they are able to form a matrix of equidistant spots in the far-field diffraction region. In this work, we report on the first fan-out structures designed for the THz range of radiation. Two types of light-dividing fan-out structures are demonstrated: (i) the 3×1 matrix fan-out structure based on the optimized binary phase grating and (ii) the 3×3 fan-out structure designed on the basis of the well-known Dammann grating. The structures were generated numerically and manufactured using the 3D printing technique with polyamide PA12. To obtain equal powers and symmetry of diffracted beams, the computer-aided optimization algorithm was used. Diffractive optical elements designed for 140 and 282 GHz were evaluated experimentally at both these frequencies using illumination with the wavefront coming from the point-like source. Described fan-out elements formed uniform intensity and equidistant energy distribution in agreement with the numerical simulations.

  14. Fan Ky不等式的一个改进%A Refinement of Fan Ky's Inequality

    Institute of Scientific and Technical Information of China (English)

    周昱; 高明哲

    2007-01-01

    利用改进的H(o)lder不等式并借助于正交矩阵的行列式的积分表示法建立了Fan Ky不等式的一个有意义的改进.当A,B为n阶非奇异矩阵时,给出了新创建不等式的一个推广.特别当n=1时,得到了Young不等式的一个很强的结果.

  15. Dynamic Bowtie for Fan-beam CT

    CERN Document Server

    Liu, Fenglin; Cong, Wenxiang; Hsieh, Scott; Pelc, Norbert

    2013-01-01

    A bowtie is a filter used to shape an x-ray beam and equalize its flux reaching different detector channels. For development of spectral CT with energy-discriminative photon-counting (EDPC) detectors, here we propose and evaluate a dynamic bowtie for performance optimization based on a patient model or a scout scan. Our dynamic bowtie modifies an x-ray beam intensity profile by mechanical rotation and adaptive adjustment of the x-ray source flux. First, a mathematical model for dynamic bowtie filtering is established for an elliptical section in fan-beam geometry, and the contour of the optimal bowtie is derived. Then, numerical simulation is performed to compare the performance of the dynamic bowtie in the cases of an ideal phantom and a realistic cross-section relative to the counterparts without any bowtie and with a fixed bowtie respectively. Our dynamic bowtie can equalize the expected numbers of photons in the case of an ideal phantom. In practical cases, our dynamic bowtie can effectively reduce the dy...

  16. Characterisation of fan-beam collimators.

    Science.gov (United States)

    Pareto, D; Pavía, J; Falcón, C; Juvells, I; Cot, A; Ros, D

    2001-02-01

    Fan-beam collimators offer a good balance between resolution and noise. The collimator response may be included in iterative reconstruction algorithms in order to improve single-photon emission tomography (SPET) resolution. To this end, accurate determination of the focal region and characterisation of the collimator response as a function of the source co-ordinates must be performed. In this paper, a method to characterise fanbeam collimators is evaluated. First, we calculated the real focal region and the accuracy of the collimator convergence. Then, we confirmed the hypothesis that Gaussian distributions adequately fit the collimator responses, although no individualised treatment was performed for the tails of detector response which are associated with scattering and septal penetration. Finally, analytical functions were used to model the resolution and sensitivity. The parameter values in these functions were obtained from experimental measures by non-linear regression fitting. Our findings show differences of 1.43% between nominal and real focal length and standard deviations of 2.5 mm in the x-direction and 7.1 mm in the y-direction for the focal convergence. The correlation coefficients between experimental and predicted values were 0.994 for resolution and 0.991 for sensitivity. As a consequence, the proposed method can be used to characterise the collimator response.

  17. 30 CFR 56.14107 - Moving machine parts.

    Science.gov (United States)

    2010-07-01

    ... shall be guarded to protect persons from contacting gears, sprockets, chains, drive, head, tail, and takeup pulleys, flywheels, couplings, shafts, fan blades, and similar moving parts that can cause injury...

  18. Genes2FANs: connecting genes through functional association networks

    Directory of Open Access Journals (Sweden)

    Dannenfelser Ruth

    2012-07-01

    Full Text Available Abstract Background Protein-protein, cell signaling, metabolic, and transcriptional interaction networks are useful for identifying connections between lists of experimentally identified genes/proteins. However, besides physical or co-expression interactions there are many ways in which pairs of genes, or their protein products, can be associated. By systematically incorporating knowledge on shared properties of genes from diverse sources to build functional association networks (FANs, researchers may be able to identify additional functional interactions between groups of genes that are not readily apparent. Results Genes2FANs is a web based tool and a database that utilizes 14 carefully constructed FANs and a large-scale protein-protein interaction (PPI network to build subnetworks that connect lists of human and mouse genes. The FANs are created from mammalian gene set libraries where mouse genes are converted to their human orthologs. The tool takes as input a list of human or mouse Entrez gene symbols to produce a subnetwork and a ranked list of intermediate genes that are used to connect the query input list. In addition, users can enter any PubMed search term and then the system automatically converts the returned results to gene lists using GeneRIF. This gene list is then used as input to generate a subnetwork from the user’s PubMed query. As a case study, we applied Genes2FANs to connect disease genes from 90 well-studied disorders. We find an inverse correlation between the counts of links connecting disease genes through PPI and links connecting diseases genes through FANs, separating diseases into two categories. Conclusions Genes2FANs is a useful tool for interpreting the relationships between gene/protein lists in the context of their various functions and networks. Combining functional association interactions with physical PPIs can be useful for revealing new biology and help form hypotheses for further experimentation. Our

  19. RESOLVING THE FAN-SPINE RECONNECTION GEOMETRY OF A SMALL-SCALE CHROMOSPHERIC JET EVENT WITH THE NEW SOLAR TELESCOPE

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Zhicheng; Chen, Bin; Goode, Philip R.; Cao, Wenda [Center for Solar-Terrestrial Research, New Jersey Institute of Technology, 323 Martin Luther King Boulevard, Newark, NJ 07102 (United States); Ji, Haisheng [Big Bear Solar Observatory, 40386 North Shore Lane, Big Bear City, CA 92314 (United States)

    2016-03-01

    Jets are ubiquitously present in both quiet and active regions on the Sun. They are widely believed to be driven by magnetic reconnection. A fan-spine structure has been frequently reported in some coronal jets and flares, and has been regarded as a signature of ongoing magnetic reconnection in a topology consisting of a magnetic null connected by a fan-like separatrix surface and a spine. However, for small-scale chromospheric jets, clear evidence of such structures is rather rare, although it has been implied in earlier works that showed an inverted-Y-shaped feature. Here we report high-resolution (0.″16) observations of a small-scale chromospheric jet obtained by the New Solar Telescope (NST) using 10830 Å filtergrams. Bi-directional flows were observed across the separatrix regions in the 10830 Å images, suggesting that the jet was produced due to magnetic reconnection. At the base of the jet, a fan-spine structure was clearly resolved by the NST, including the spine and the fan-like surface, as well as the loops before and after the reconnection. A major part of this fan-spine structure, with the exception of its bright footpoints and part of the base arc, was invisible in the extreme ultraviolet and soft X-ray images (observed by the Atmosphere Imaging Assembly and the X-Ray Telescope, respectively), indicating that the reconnection occurred in the upper chromosphere. Our observations suggest that the evolution of this chromospheric jet is consistent with a two-step reconnection scenario proposed by Török et al.

  20. Supersonic Stall Flutter of High Speed Fans. [in turbofan engines

    Science.gov (United States)

    Adamczyk, J. J.; Stevens, W.; Jutras, R.

    1981-01-01

    An analytical model is developed for predicting the onset of supersonic stall bending flutter in axial flow compressors. The analysis is based on a modified two dimensional, compressible, unsteady actuator disk theory. It is applied to a rotor blade row by considering a cascade of airfoils whose geometry and dynamic response coincide with those of a rotor blade element at 85 percent of the span height (measured from the hub). The rotor blades are assumed to be unshrouded (i.e., free standing) and to vibrate in their first flexural mode. The effects of shock waves and flow separation are included in the model through quasi-steady, empirical, rotor total-pressure-loss and deviation-angle correlations. The actuator disk model predicts the unsteady aerodynamic force acting on the cascade blading as a function of the steady flow field entering the cascade and the geometry and dynamic response of the cascade. Calculations show that the present model predicts the existence of a bending flutter mode at supersonic inlet Mach numbers. This flutter mode is suppressed by increasing the reduced frequency of the system or by reducing the steady state aerodynamic loading on the cascade. The validity of the model for predicting flutter is demonstrated by correlating the measured flutter boundary of a high speed fan stage with its predicted boundary. This correlation uses a level of damping for the blade row (i.e., the log decrement of the rotor system) that is estimated from the experimental flutter data. The predicted flutter boundary is shown to be in good agreement with the measured boundary.

  1. Evaluation of advanced hydraulic turbomachinery for underground pumped hydroelectric storage. Part 2. Two-stage regulated pump/turbines for operating heads of 1000 to 1500 m

    Energy Technology Data Exchange (ETDEWEB)

    Blomquist, C.A.; Frigo, A.A.; Degnan, J.R.

    1979-10-01

    This UPHS report applies to Francis-type, reversible pump/turbines regulated with gating systems. The first report, however, covered single-stage regulations; this report covers two-stage regulations. Development of a two-stage regulated pump/turbine appears to be attractive because the proposed single-drop UPHS concept requires turbomachinery with a head range of 1000 to 2000 m. With turbomachinery of this range available, the single-drop scheme offers a simple and economic UPHS option. Six different two-stage, top-gated pump/turbines have been analyzed: three that generate 500 MW and three that generate 350 MW. In each capacity, one machine has an operating head of 1000 m, another has a head of 1250 m, and the third has a head of 1500 m. The rated efficiencies of the machines vary from about 90% (1000-m head) to about 88% (1500-m head). Costs in 1978 $/kW for the three 500-MW units are: 20.5 (1000 m), 16.5 (1250 m), and 13.5 (1500 m). Corresponding costs for the three 350-MW units are 23, 18, and 14 $/kW. No major turbomachinery obstacles are foreseen that could hamper development of these pump/turbines. Further model testing and development are needed before building them.

  2. Advanced Prototype Fan Operating Experience, Post Test Evaluation, and Refurbishment for PLSS 2.0 Test Use

    Science.gov (United States)

    Hodgson, Edward; Oehler, William; Dionne, Steve; Converse, David; Jennings, Mallory A.

    2012-01-01

    NASA s plans for Extravehicular Activity (EVA) portable life support systems for future exploration missions result in different design requirements than those which led to the combined fan / pump / separator in the current ISS Extravehicular Mobility Unit (EMU). To meet these new requirements, NASA contracted with Hamilton Sundstrand to provide two new prototype fans designed to meet anticipated future system requirements. Based on design trade studies, a high speed fan with mechanical bearing support of the rotating elements and a novel non-metallic barrier canned motor design was developed and implemented in the deliverable prototypes. The prototypes, which used two different bearing lubricants, have been extensively tested in both stand-alone and integrated system tests in NASA laboratories and proven to meet the anticipated performance requirements. Subsequently, they have been subjected to post test inspection and analysis in Hamilton Sundstrand laboratories to assess the effects of integrated operation and resultant exposure to vent loop contaminants. Results have confirmed expectations that one of the lubricants would be superior in this application and the prototype fans have been reassembled with new bearings with the superior lubricant. They have now been returned to the Johnson Space Center for further testing and maturation as part of NASA s PLSS 2.0 integrated test effort. This paper will discuss the test history of these units, resulting test data, the results of post test evaluation, and plans for further testing in the near future.

  3. "The rabid fans that take [Twilight] much too seriously": The construction and rejection of excess in Twilight antifandom

    Directory of Open Access Journals (Sweden)

    Jacqueline Marie Pinkowitz

    2011-09-01

    Full Text Available The group of Twilight antifans known as the Anti-Twilight Movement has constructed themselves as a safe "us" in relation to the threatening and inappropriate Other that they have defined through their characterization of "rabid" Twilight fans and antifans' "them." Fearful of a low ranking on the cultural hierarchy, they have created their own internal fan hierarchy that, according to cultural notions about the superiority of class, education, and the elite over the uneducated and the popular, as well as of the dismissability of girl culture, ensures the dominance and safety of their own affected rationality over the characterized emotional and excessive behavior of rabid Twilight fans and antifans. Part of the performance of such scholarly affectation involves appropriating discourses of academia into their literary criticism of Twilight, so as to overcome any negative connotations of excess or susceptibility to the mass media. Their often feminine-gendered constructions of rabid emotionality and irrationality, while also perhaps revealing some element of self-hatred, showcases a group of antifans attempting to assign the same policing and consequential narratives and discourses that have traditionally been assigned to fanatics by the dominant culture to certain "threatening" fans and antifans within their own community, the ultimate means of identity construction and self-preservation.

  4. Tectonic controls on the geomorphic evolution of alluvial fans in the Piedmont Zone of Ganga Plain, Uttarakhand, India

    Indian Academy of Sciences (India)

    Pradeep K Goswami; Charu C Pant; Shefali Pandey

    2009-06-01

    The Piedmont Zone is the least studied part of the Ganga Plain.The northern limit of the Piedmont Zone is defined by the Himalayan Frontal Thrust (HFT)along which the Himalaya is being thrust over the alluvium of the Ganga Plain.Interpretation of satellite imagery,Digital Terrain Models (DTMs)and field data has helped in the identification and mapping of various morpho-tectonic features in the densely forested and cultivated Piedmont Zone in the Kumaun region of the Uttarakhand state of India.The Piedmont Zone has formed as a result of coalescing alluvial fans,alluvial aprons and talus deposits.The fans have differential morphologies and aggradation processes within a common climatic zone and similar litho-tectonic setting of the catchment area. Morphotectonic analysis reveals that the fan morphologies and aggradation processes in the area are mainly controlled by the ongoing tectonic activities.Such activities along the HFT and transverse faults have controlled the accommodation space by causing differential subsidence of the basin,and aggradation processes by causing channel migration,channel incision and shifting of depocentres.The active tectonic movements have further modified the landscape of the area in the form of tilted alluvial fan,gravel ridges,terraces and uplifted gravels.

  5. The effect of fan speed control system on the inlet air temperature uniformity in a solar dryer

    Directory of Open Access Journals (Sweden)

    S. F Mousavi

    2015-09-01

    Full Text Available Introduction: Drying process of agricultural products, fruits and vegetables are highly energy demanding and hence are the most expensive postharvest operation. Nowadays, the application of control systems in different area of science and engineering plays a key role and is considered as the important and inseparable parts of any industrial process. The review of literature indicates that enormous efforts have been donefor the intelligent control of solar driers and in this regard some simulation models are used through computer programming. However, because of the effect of air velocity on the inlet air temperature in dryers, efforts have been made to control the fan speed based ont he temperature of the absorber plate in this study, and the behavior of this system was compared with an ordinary dryer without such a control system. Materials and methods: In this study, acabinet type solar dryer with forced convection and 5kg capacity of fresh herbs was used. The dryer was equipped with a fan in the outlet chamber (the chimney for creating air flow through the dryer. For the purpose of research methods and automatic control of fan speed and for adjusting the temperature of the drying inlet air, a control system consisting of a series of temperature and humidity sensors and a microcontroller was designed. To evaluatethe effect of the system with fan speed control on the uniformity of air temperature in the drying chamber and hence the trend of drying process in the solar dryer, the dryer has been used with two different modes: with and without the control of fan speed, each in twodays (to minimize the errors of almost the same ambient temperature. The ambient air temperature during the four days of experiments was obtained from the regional Meteorological Office. Some fresh mint plants (Mentha longifolia directly harvested from the farm in the morning of the experiment days were used as the drying materials. Each experimental run continued for 9

  6. Numerical and experimental investigation on aerodynamic performance of small axial flow fan with hollow blade root

    Science.gov (United States)

    Li, Zhang; Jin, Yingzi; Huashu, Dou; Yuzhen, Jin

    2013-10-01

    To reduce the influence of adverse flow conditions at the fan hub and improve fan aerodynamic performance, a modification of conventional axial fan blades with numerical and experimental investigation is presented. Hollow blade root is manufactured near the hub. The numerical and experimental results show that hollow blade root has some effect on the static performance. Static pressure of the modified fan is generally the same with that of the datum fan, while, the efficiency curve of the modified fan has a different trend with that of the datum fan. The highest efficiency of the modified fan is 10% greater than that of the datum fan. The orthogonal experimental results of fan noise show that hollow blade root is a feasible method of reducing fan noise, and the maximum value of noise reduction is about 2 dB. The factors affecting the noise reduction of hollow blade root are in the order of importance as follows: hollow blade margin, hollow blade height and hollow blade width. The much smoother pressure distribution of the modified fan than that of the datum fan is the main mechanism of noise reduction of hollow blade root. The research results will provide the proof of the parameter optimization and the structure design for high performance and low noise small axial fans.

  7. THE APPLICATION OF A JET FAN FOR THE CONTROL OF AIR AND METHANE STREAMS MIXING AT THE EXCAVATIONS CROSS – THE RESULTS OF NUMERICAL SIMULATION

    Directory of Open Access Journals (Sweden)

    Paweł WRONA

    2016-07-01

    Full Text Available The paper presents the results of numerical simulations into the distribution of methane concentration at the intersec-tion of two excavations with a fan (turned on giving the air stream to the area of the crossing. Assumed case represents emergency situation related to the unexpected flow of methane from an excavation and its mixing with fresh air. It is possible when sudden gas outburst takes place, methane leaks from methane drainage system or gas leaks out the pipelines of underground coal gasification devices. Three options were considered – corresponding to three different speeds of the jet fan. They represent three stages of fan work. First – low air speed is forced by a pneumatic fan, when electricity is cut off after high methane concentration detection. Medium speed can be forced by pneumatic-electric device when methane concentration allows to turn on the electricity. Third, the highest speed is for electric fans. Simula-tions were carried out in the Fire Dynamics Simulator (FDS belongs to the group of programs Computational Fluid Dy-namics (CFD. The governing equations are being solved in a numerical way. It was shown that proposed solution allows partial dilution of methane in every variant of speed what should allow escape of the miners from hazardous area.

  8. The potential of high arctic colluvial fan development and process regeneration as palaeoclimate proxies; Colluvial source area and sediment mapping within the CRYOSLOPE Svalbard framework.

    Science.gov (United States)

    Rubensdotter, L.; Stalsberg, K.; Christiansen, H.; Neumann, U.; Eckerstorfer, M.; Humlum, O.

    2009-04-01

    four developing phases according to the dominating process: i) old snow avalanche fan body, ii) old debris-flow imprint, iii) renewed overprinting of snow avalanche and rock fall deposition with a slightly different source area and finally, iv) renewed debris-flow activity post-1990, partly overprinting the second avalanche fan (iii). The two oldest fan systems (i and ii) show significant rock surface weathering with extensive lichen cover, and the old debris flow system (ii, containing more fines on the soil surface) show significant periglacial redistribution of material through up-freezing processes. These two examples of temporal shifts of dominating process in a colluvial fan system are different from the other multi-genetic fans, and shows how changes in the source area may be reflected in fan development: Backwards erosion of the source area of a wet debris-flow fan (ii) reached a more easily weathered bedrock unit. The sediment supply increased, and resulted in supra-imposed avalanche/rock fall deposits (iii) on top of a pre-existing "mature" debris-flow fan. This shows that it requires a thorough analysis and distinction between colluvial fan development controlled by climate change and changes induced by source area geology.

  9. Fan-structure wave as a source of earthquake instability

    Science.gov (United States)

    Tarasov, Boris

    2015-04-01

    Today frictional shear resistance along pre-existing faults is considered to be the lower limit on rock shear strength at confined compression corresponding to the seismogenic layer. This determines the lithospheric strength and the primary earthquake mechanism associated with frictional stick-slip instability on pre-existing faults. This paper introduces a recently identified shear rupture mechanism providing a paradoxical feature of hard rocks - the possibility of shear rupture propagation through the highly confined intact rock mass at shear stress levels significantly less than frictional strength. In the new mechanism the rock failure, associated with consecutive creation of small slabs (known as 'domino-blocks') from the intact rock in the rupture tip, is driven by a fan-shaped domino structure representing the rupture head. The fan-head combines such unique features as: extremely low shear resistance (below the frictional strength), self-sustaining stress intensification in the rupture tip (providing easy formation of new domino-blocks), and self-unbalancing conditions in the fan-head (making the failure process inevitably spontaneous and violent). An important feature of the fan-mechanism is the fact that for the initial formation of the fan-structure an enhanced local shear stress is required, however, after completion of the fan-structure it can propagate as a dynamic wave through intact rock mass at shear stresses below the frictional strength. Paradoxically low shear strength of pristine rocks provided by the fan-mechanism determines the lower limit of the lithospheric strength and favours the generation of new faults in pristine rocks in preference to frictional stick-slip instability along pre-existing faults. The new approach reveals an alternative role of pre-existing faults in earthquake activity: they represent local stress concentrates in pristine rock adjoining the fault where special conditions for the fan-mechanism nucleation are created

  10. Bifurcation analysis of fan casing under rotating air flow excitation

    Institute of Scientific and Technical Information of China (English)

    温登哲; 陈予恕

    2014-01-01

    A fan casing model of cantilever circular thin shell is constructed based on the geometric characteristics of the thin-walled structure of aero-engine fan casing. According to Donnelly’s shell theory and Hamilton’s principle, the dynamic equations are established. The dynamic behaviors are investigated by a multiple-scale method. The effects of casing geometric parameters and motion parameters on the natural frequency of the system are studied. The transition sets and bifurcation diagrams of the system are obtained through a singularity analysis of the bifurcation equation, showing that various modes of the system such as the bifurcation and hysteresis will appear in different parameter regions. In accordance with the multiple relationship of the fan speed and stator vibration frequency, the fan speed interval with the casing vibration sudden jump is calculated. The dynamic reasons of casing cracks are investigated. The possibility of casing cracking hysteresis interval is analyzed. The results show that cracking is more likely to appear in the hysteresis interval. The research of this paper provides a theoretical basis for fan casing design and system parameter optimization.

  11. Numerical Analysis of Erosion Caused by Biomimetic Axial Fan Blade

    Directory of Open Access Journals (Sweden)

    Jun-Qiu Zhang

    2013-01-01

    Full Text Available Damage caused by erosion has been reported in several industries for a wide range of situations. In the present work, a new method is presented to improve the erosion resistance of machine components by biomimetic method. A numerical investigation of solid particle erosion in the standard and biomimetic configuration blade of axial fan is presented. The analysis consists in the application of the discrete phase model, for modeling the solid particles flow, and the Eulerian conservation equations to the continuous phase. The numerical study employs computational fluid dynamics (CFD software, based on a finite volume method. User-defined function was used to define wear equation. Gas/solid flow axial fan was simulated to calculate the erosion rate of the particles on the fan blades and comparatively analyzed the erosive wear of the smooth surface, the groove-shaped, and convex hull-shaped biomimetic surface axial flow fan blade. The results show that the groove-shaped biomimetic blade antierosion ability is better than that of the other two fan blades. Thoroughly analyze of antierosion mechanism of the biomimetic blade from many factors including the flow velocity contours and flow path lines, impact velocity, impact angle, particle trajectories, and the number of collisions.

  12. Measurements of the unsteady flow field within the stator row of a transonic axial-flow fan. 1: Measurement and analysis technique

    Science.gov (United States)

    Suder, K. L.; Hathaway, M. D.; Okiishi, T. H.; Strazisar, A. J.; Adamczyk, J. J.

    1987-01-01

    This two-part paper presents laser anemometer measurements of the unsteady velocity field within the stator row of a transonic axial-flow fan. The objective is to provide additional insight into unsteady blade-row interactions within high speed compressors which affect stage efficiency, energy transfer, and other design considerations. Part 1 describes the measurement and analysis techniques used for resolving the unsteady flow field features. The ensemble-average and variance of the measured velocities are used to identify the rotor wake generated and unresolved unsteadiness, respectively. (Rotor wake generated unsteadiness refers to the unsteadiness generated by the rotor wake velocity deficit and the term unresolved unsteadiness refers to all remaining contributions to unsteadiness such as vortex shedding, turbulence, mass flow fluctuations, etc.). A procedure for calculating auto and cross correlations of the rotor wake generated and unresolved unsteady velocity fluctuations is described. These unsteady-velocity correlations have significance since they also result from a decomposition of the Navier-Stokes equations. This decomposition of the Navier-Stokes equations resulting in the velocity correlations used to describe the unsteady velocity field will also be outlined in this paper.

  13. Measurements of the unsteady flow field within the stator row of a transonic axial-flow fan. I - Measurement and analysis technique

    Science.gov (United States)

    Suder, K. L.; Strazisar, A. J.; Adamczyk, J. J.; Hathaway, M. D.; Okiishi, T. H.

    1987-01-01

    This two-part paper presents laser anemometer measurements of the unsteady velocity field within the stator row of a transonic axial-flow fan. The objective is to provide additional insight into unsteady blade-row interactions within highspeed compressors which affect stage efficiency, energy transfer, and other design considerations. Part 1 describes the measurement and analysis techniques used for resolving the unsteady flow field features. The ensemble-average and variance of the measured velocities are used to identify the rotor wake generated and unresolved unsteadiness, respectively. (Rotor wake generated unsteadiness refers to the unsteadiness generated by the rotor wake velocity deficit and the term unresolved unsteadiness refers to all remaining contributions to unsteadiness such as vortex shedding, turbulence, mass flow fluctutions, etc.). A procedure for calculating auto and cross correlations of the rotor wake generated and unresolved unsteady velocity fluctuations is described. These unsteady-velocity correlations have significance since they also result from a decomposition of the Navier-Stokes equations. This decomposition of the Navier-Stokes equations resulting in the velocity correlations used to describe the unsteady velocity field will also be outlined in this paper.

  14. Investigation of Sub-Assembly of Product for Environment Impact Assessment: Quantitative Evaluation of Shroud Fan Cover assembly and Cylinder Head Cover assembly

    Directory of Open Access Journals (Sweden)

    Ms. SUMAN SHARMA

    2011-09-01

    Full Text Available We live in a changing world. In many countries the systems are under change. The changes are largely driven by environmental considerations and one driving force is the threat of global climate change. When making new strategic decisions related to manufacturing any product it becomes important to consider the environmentalimplications. The total consumption of materials and energy during the Life cycle of product is greatly affecting the environment. The proper selection of engineering materials for manufacturing of a product can minimize the environmental impact. The environmental impact of products and processes has become a key issue that has led companies to investigate ways to minimize their effects on the environment. LCA is a means of deriving a quantitative evaluation of environmental impact of product design and thereby refining product quality and characteristics. The overall aim of the present work is to evaluate the environmental impact of some important sub-assembliesof a two wheeler for main stages of life cycle i.e. manufacturing stages of raw material and part manufacturing. An investigation has been done on two sub-assemblies of engine group of Activa i.e. shroud fan cover and cylinder head cover. It has been presented using EDIP (Environmental Design of Industrial Product as LCA method as per ISO 14040. The study reveals that the environmental impact is more in the case of manufacturing of steel and rubber parts as compared to plastic and aluminium parts of selected subassemblies and eco-toxicityand human toxicity is more as compared to other impact categories.

  15. Effect of Number of Blades on Performance of Ceiling Fans

    Directory of Open Access Journals (Sweden)

    Adeeb Ehsan

    2015-01-01

    Full Text Available In this paper, the effect of number of blades on ceiling fan performance is discussed. This approach helps to satisfy tradeoff between high air flow (performance and power consumption (energy efficiency. Specifically, variation from two to six blades is considered with nonlinear forward sweep profile. Reynolds Averaged Navier-Stokes (RANS technique is used to model the flow field induced by the ceiling fan inside a generic room. The performance is gauged through response parameters namely volumetric flow rate, mass flow rate, torque and energy efficiency. The results indicate that mass and volumetric flow rates are maximized for six blade configuration and energy efficiency is maximized for two blade configuration. The study indicates the importance of tradeoff between high air flow through ceiling fan and associated energy efficiency.

  16. Performance and Stability Analysis of a Shrouded-Fan UAV

    CERN Document Server

    de Divitiis, Nicola

    2009-01-01

    This paper deals with the estimation of the performance and stability for a shrouded-fan unmanned rotorcraft whose mission profile also prescribes the flight in ground effect. The not so simple estimation of the aerodynamic coefficients and of the thrust in the various situations makes the performance calculation and the stability analysis difficult tasks. This is due to the strong interaction between the fan flow and shroud that causes quite different flow structures about the airframe depending on flight conditions. A further difficulty is related to the ground effect which produces substantial modifications in the rotor thrust and aerodynamic coefficients. To evaluate performance and stability, two models have been developed. One determines the aerodynamic coefficients of the shroud, whereas the other one calculates thrust and moment of the rotors system. Both models take into account the mutual interference between fan flow and fuselage and ground effect. Performance and stability are then discussed with ...

  17. Using Mobile Marketing to Engage NASCAR Fans and Increase Sales

    Directory of Open Access Journals (Sweden)

    MARK DODDS

    2011-01-01

    Full Text Available Mobile marketing displays engage the consumer. This sponsorship activation tactic is highly visible at NASCAR races. Some common elements include show cars, interactive race simulators, video games and race suit/equipment displays. The authors of this study argue that by using mobile marketing effectively as a sponsorship activation tactic, the race fans derive more enjoyment from the race experience. This increased enjoyment links to higher product sales for the sponsor. The implications of this study show that sponsors in other sports should use mobile marketing to increase the fan satisfaction of the game experience in order to increase their product sales. Additionally, event mangers should support mobile marketing as a sponsorship activation tactic with the intention of increasing fan enjoyment and improving attendance.

  18. Particle trajectories and acceleration during 3D fan reconnection

    CERN Document Server

    Dalla, S; 10.1051/0004-6361:200809771

    2008-01-01

    Context. The primary energy release in solar flares is almost certainly due to magnetic reconnection, making this a strong candidate as a mechanism for particle acceleration. While particle acceleration in 2D geometries has been widely studied, investigations in 3D are a recent development. Two main classes of reconnection regimes at a 3D magnetic null point have been identified: fan and spine reconnection Aims. Here we investigate particle trajectories and acceleration during reconnection at a 3D null point, using a test particle numerical code, and compare the efficiency of the fan and spine regimes in generating an energetic particle population. Methods. We calculated the time evolution of the energy spectra. We discuss the geometry of particle escape from the two configurations and characterise the trapped and escaped populations. Results. We find that fan reconnection is less efficent than spine reconnection in providing seed particles to the region of strong electric field where acceleration is possible...

  19. Reflection on Chinese boys' love fans: An insider's view [symposium

    Directory of Open Access Journals (Sweden)

    Erika Junhui Yi

    2013-03-01

    Full Text Available The fandom of BL, as it is known in China, celebrates explicit homoerotic relationships between boys or men—fictional characters taken from mainstream media, real-life celebrities, and male personifications of day-to-day objects and animals, as well as original characters. Mainstream media reports on BL fandom and BL fan girls in China have never been favorable; this subculture and the fans within it are constantly represented in a negative and biased light. But because I am a BL fan girl myself, I can offer an insider's perspective. This essay is a reflection on my personal experiences and observations as a member of BL fandom, and a response to erroneous, stigmatizing claims and moral panic about this community in China.

  20. A velocity parameter for the correlation of axial fan noise

    Science.gov (United States)

    Wright, T.

    1982-08-01

    An aerodynamic parameter that relates subsonic axial fan noise to the fundamental flow behavior in the blade row of a fan is proposed. The parameter is the peak or maximum blade surface velocity in the rotating reference frame and includes, either explicitly or implicitly, the influence of tip speed, volume flow rate, pressure rise, shaft horsepower and efficiency. Correlation of the noise associated with a very broad range of axial fans yields good agreement and collapse of data when compared to currently used correlation methods. Use of this parameter, rather than those based on overall performance, allows trade-off studies to be made within a given performance requirement so that a minimum noise configuration may be designed or selected.

  1. Effect of inlet box on performance of axial flow fans

    Institute of Scientific and Technical Information of China (English)

    Jingyin LI; Hua TIAN; Xiaofang YUAN

    2008-01-01

    Numerical investigations on 3D flow fields in an axial flow fan with and without an inlet box have been extensively conducted, focusing on the variation of fan performance caused by the internal flow fields and the velocity evenness at the exit of the inlet box. It is interest-ing to find that although the inlet box is well designed in accordance with basic design principles, there is a flow separation region in it. Furthermore, this flow separation and the resulting uneven velocity distribution at the exit lead to some decrease in the efficiency and an increase in the total pressure rise of the fan. This research shows that the inlet box needs further improvement and such a check on the flow fields is of value for the design of inlet boxes.

  2. Fan filmmaking and copyright in a global world: Warhammer 40,000 fan films and the case of Damnatus

    Directory of Open Access Journals (Sweden)

    John Walliss

    2010-09-01

    Full Text Available The last decade has witnessed a proliferation, both online and off-line, of films produced by amateurs inspired by mainstream films, TV shows, and novels. As with much other fan production, fan films exist in, at best, a legally gray area since they are produced by amateurs, rather than by the media companies that own the copyrights to the films and novels that provide both their inspiration and settings. I examine the phenomenon of fan filmmaking, focusing on films produced by fans of the Warhammer 40,000 (W40K tabletop battle game. In particular, I examine the case of Damnatus: The Enemy Within (Damnatus: Feind Im Innern, 2005, a German-made fan film set in the W40K universe, which was banned from release by the game's rights holder, the UK company Games Workshop, in 2007. Damnatus offers an interesting case study in both the ongoing struggle between rights holders and textual poachers and the tensions that can exist between different legal understandings of copyright in an increasingly globalized world.

  3. A Two-stage approach for an optimum solution of the car assembly scheduling problem. Part 2. CLP solution and real-world example

    Directory of Open Access Journals (Sweden)

    Mazur Michał

    2015-09-01

    Full Text Available A Constraint Logic Programming (CLP tool for solving the problem discussed in Part 1 of the paper has been designed. It is outlined and discussed in the paper. The program has been used for solving a real-world car assembly scheduling problem.

  4. Arbuscular mycorrhiza-induced shifts in foliar metabolism and photosynthesis mirror the developmental stage of the symbiosis and are only partly driven by improved phosphate uptake.

    Science.gov (United States)

    Schweiger, Rabea; Baier, Markus C; Müller, Caroline

    2014-12-01

    In arbuscular mycorrhizal (AM) plants, the plant delivers photoassimilates to the arbuscular mycorrhizal fungus (AMF), whereas the mycosymbiont contributes, in addition to other beneficial effects, to phosphate (PO4(3-)) uptake from the soil. Thereby, the additional fungal carbon (C) sink strength in roots and improved plant PO4(3-) nutrition may influence aboveground traits. We investigated how the foliar metabolome of Plantago major is affected along with the development of root symbiosis, whether the photosynthetic performance is affected by AM, and whether these effects are mediated by improved PO4(3-) nutrition. Therefore, we studied PO4(3-)-limited and PO4(3-)-supplemented controls in comparison with mycorrhizal plants at 20, 30, and 62 days postinoculation with the AMF Rhizophagus irregularis. Foliar metabolome modifications were determined by the developmental stage of symbiosis, with changes becoming more pronounced over time. In a well-established stage of mature mutualism, about 60% of the metabolic changes and an increase in foliar CO2 assimilation were unrelated to the significantly increased foliar phosphorus (P) content. We propose a framework relating the time-dependent metabolic changes to the shifts in C costs and P benefits for the plant. Besides P-mediated effects, the strong fungal C sink activity may drive the changes in the leaf traits.

  5. Management of malignant pleural mesothelioma - part 1: epidemiology, diagnosis, and staging : Consensus of the Austrian Mesothelioma Interest Group (AMIG).

    Science.gov (United States)

    Geltner, Christian; Errhalt, Peter; Baumgartner, Bernhard; Ambrosch, Gerhard; Machan, Barbara; Eckmayr, Josef; Klikovits, Thomas; Hoda, Mir Alireza; Popper, Helmut; Klepetko, Walter

    2016-09-01

    Malignant pleural mesothelioma is a rare malignant disease that in the majority of cases is associated with asbestos exposure. The incidence in Europe is about 20 per million inhabitants and it is increasing worldwide. Initial symptoms are shortness of breath, pleural effusion, cough, and chest pain. The typical growth pattern is along the pleural surface; however, infiltration of the lung and/or mediastinal and chest wall structures can occur in a more advanced stage. Ultimately, distant metastases outside the chest can result. Several histological subtypes of pleural mesothelioma exist, which must be differentiated from either benign diseases or metastases in the pleural space by other tumor entities. This differential diagnosis can be very difficult and a large panel of immunohistochemical markers is required to establish the exact diagnosis. The standard procedure for confirming the disease and obtaining sufficient tissue for the diagnosis is videothoracoscopy. Full thickness biopsies are required, while transthoracic needle puncture of pleural fluid or tissue is considered to be insufficient for a cytological diagnosis. Complete and detailed staging is mandatory for categorization of the disease as well as for therapeutic decision making.

  6. The Boundary Layer Interaction with Shock Wave and Expansion Fan

    Institute of Scientific and Technical Information of China (English)

    MaratA.Goldfeld; RomanV.Nestoulia; 等

    2000-01-01

    The results of experimental investigation of a turbulent boundary layer on compression and expansion surfaces are presented.They include the study of the shock wave and /or expansion fan action upon the boundary layer,boundary layer sepqartion and its relaxation.Complex events of paired interactions and the flow on compression convex-concave surfaces were studied.The posibility and conditions of the boundary layer relaminarization behind the expansion fan and its effect on the relaxation length are presented.Different model configurations for wide range conditions were investigated.Comparison of results for different interactions was carried out.

  7. Novel stator design of fan motors using soft magnetic composites

    Science.gov (United States)

    Hsu, Yu-Sheng; Tsai, Mi-Ching; Hsieh, Min-Fu

    2008-04-01

    Cooling fans are an important device needed in consumer electronic products. To enhance the performance of cooling fans, this paper presents a novel brushless dc motor with a three dimensional stator structure using soft magnetic composite to reduce the hub size and allow more airflow. Four models are designed and their output characteristics are compared using finite element simulation. From the results, one of them is selected for prototyping whose performance appears to meet the requirement. The prototype has a 10% smaller diameter than that of conventional types. Moreover, the operation test shows that the required performance is achieved.

  8. On a Fixed Point Theorem of Ky Fan

    Institute of Scientific and Technical Information of China (English)

    DE BLASI Francesco S.; GEORGIEV Pando Gr.

    2002-01-01

    We generalize a theorem of Ky Fan about the nearest distance between a closed convex setD in a Banach space E and its image by a function f: D → E, in several directions: (1) for noncompactsets D, when f(D) precompact; (2) for compact D and upper semicontinuous multifunction f; andmore generally, (3) for noncompact D and upper semicontinuous multifunction f with f(D) Hausdorffprecompact.In particular, we prove a version of the fixed point theorem of Kakutani-Ky Fan for multifunctions,whose values are convex closed bounded, thus not necessarily compact.

  9. Supersonic stall flutter of high-speed fans

    Science.gov (United States)

    Adamczyk, J. J.; Stevans, W.; Jutras, R.

    1981-01-01

    An analytical model is proposed for predicting the onset of supersonic stall bending flutter in high-speed rotors. The analysis is based on a modified two-dimensional, compressible, unsteady actuator disk theory. The stability boundary predicted by the analysis is shown to be in good agreement with the measured boundary of a high speed fan. The prediction that the flutter mode would be a forward traveling wave sensitive to wheel speed and aerodynamic loading is confirmed by experimental measurements. In addition, the analysis shows that reduced frequency and dynamic head also play a significant role in establishing the supersonic stall bending flutter boundary of an unshrouded fan.

  10. The Female Vikings, a women's fan group in Denmark

    DEFF Research Database (Denmark)

    Mintert, Svenja-Maria; Pfister, Gertrud Ursula

    2014-01-01

    Traditionally, football and fandom have been male domains and celebrations of masculinity. So far there has been some sociological and historical research on women's football; however, little is known about women's fandom, in particular about its formation and development. This article focuses......'s world. Drawing on available information about football and fans in Denmark, we have reconstructed the developments of both Lyngby BK and its supporters. Special focus was placed on the histories and cultures as well as the experiences of female fans in this club. Insights into the foundation...

  11. Performance evaluation methods and instrumentation for mine ventilation fans

    Institute of Scientific and Technical Information of China (English)

    LI Man; WANG Xue-rong

    2009-01-01

    Ventilation fans are one of the most important pieces of equipment in coal mines. Their performance plays an important role in the safety of staff and production. Given the actual requirements of coal mine production, we instituted a research project on the measurement methods of key performance parameters such as wind pressure, amount of ventilation and power. At the end a virtual instrument for mine ventilation fans performance evaluation was developed using a USB interface. The practical perform-ance and analytical results of our experiments show that it is feasible, reliable and effective to use the proposed instrumentation for mine ventilation performance evaluation.

  12. "Cultural acupuncture": Fan activism and the Harry Potter Alliance

    Directory of Open Access Journals (Sweden)

    Henry Jenkins

    2012-06-01

    Full Text Available Fan activists have struggled to defend series from cancellation, defend themselves from cease and desist orders, promote alternative representations, and raise money for charity. Building on this background, this article examines how the Harry Potter Alliance encourages young people to speak out as fans on a broad range of human rights and social justice issues through what the group's leader, Andrew Slack, calls "cultural acupuncture." The group's practice of mapping the fictional content world onto real-world concerns helps empower young people to become civicly engaged and politically active.

  13. 30 CFR 57.22202 - Main fans (I-A, I-B, I-C, II-A, III, V-A, and V-B mines).

    Science.gov (United States)

    2010-07-01

    ... reverse airstream shall be approved by MSHA under the appliable requirements of 30 CFR part 18; (2) Drive... alloy fan blades shall not contain more than 0.5 percent magnesium. . (d) When an internal combustion... vented to the atomsphere so that exhaust cannot contaminate mine intake air. (e) For Subcategory...

  14. Networks with free actors : encouraging sustainable innovations animal husbandry by using the FAN approach (Free Actors in Networks) : networking is sensing opportunities!

    NARCIS (Netherlands)

    Wielinga, E.; Zaalmink, W.; Bergevoet, R.H.M.; Geerling-Eiff, F.A.; Holster, H.C.; Hoogerwerf, L.; Vrolijk, M.; Teenstra, E.D.

    2008-01-01

    After three-and-a-half years of experience with 120 networks of livestock farmers a new approach has arisen which offers good perspectives for encouraging sustainable innovations: the FAN approach (Free Actors in Networks), with actors focusing on energy and connections to steer things along. Part o

  15. ON A KIND OF GENERALIZED QUASI-VARIATIONAL INEQUALITIES AND FAN's MINIMAX INEQUALITY WITHOUT CONVEXITY

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper gives a Fan,s type minimax theorem, a nearst point theorem and two existence theorems of solutions for a kind of generalized quasi-variational inequalities in H-spaces without any linear structure.

  16. Experimental investigation of the noise emission of axial fans under distorted inflow conditions

    Science.gov (United States)

    Zenger, Florian J.; Renz, Andreas; Becher, Marcus; Becker, Stefan

    2016-11-01

    An experimental investigation on the noise emission of axial fans under distorted inflow conditions was conducted. Three fans with forward-skewed fan blades and three fans with backward-skewed fan blades and a common operating point were designed with a 2D element blade method. Two approaches were adopted to modify the inflow conditions: first, the inflow turbulence intensity was increased by two different rectangular grids and second, the inflow velocity profile was changed to an asymmetric characteristic by two grids with a distinct bar stacking. An increase in the inflow turbulence intensity affects both tonal and broadband noise, whereas a non-uniform velocity profile at the inlet influences mainly tonal components. The magnitude of this effect is not the same for all fans but is dependent on the blade skew. The impact is greater for the forward-skewed fans than for the backward-skewed and thus directly linked to the fan blade geometry.

  17. Design and Research of Intelligent Remote Control Fan Based on Single Chip Microcomputer and Bluetooth Technology

    National Research Council Canada - National Science Library

    Xue-Xia Zhang; You-Yun Dang; An-Ying Fu

    2017-01-01

    This paper is designed for intelligent remote control fans. The design of the microcontroller as the core, the sensor, Bluetooth and Andrews system applied to the design of intelligent remote control fan...

  18. A Computational Model for Two-stage 4K-Pulse Tube Cooler: Part I.Theoretical Model and Numerical Method

    Institute of Scientific and Technical Information of China (English)

    Y.L. Ju; A.T.A.M. de Waele

    2001-01-01

    A new mixed Eulerian-Lagrangian computational model for simulating and visualizing the internal processes and the variations of dynamic parameters of a two-stage pulse tube cooler (PTC) operating at 4 K-temperature region has been developed. We use the Lagrangian method, a set of moving grids, to follow the exact tracks of gas particles as they move with pressure oscillation in the pulse tube to avoid any numerical false diffusion. The Eulerian approach, a set of fixed computational grids, is used to simulate the variations of dynamic parameters in the regenerator. A variety of physical factors, such as real thermal properties of helium, multi-layered magnetic regenerative materials, pressure drop and heat transfer in the regenerator, and heat exchangers, are taken into account in this model. The present modeling is very effective for visualizing the internal physical processes in 4 K-pulse tube coolers.

  19. Americans Put Teacher Quality on Center Stage: The 46th Annual PDK/Gallup Poll of the Public's Attitudes toward the Public Schools. Part II

    Science.gov (United States)

    Bushaw, William J.; Calderon, Valerie J.

    2014-01-01

    In this, the second installment of a two-part report of the 46th annual PDK/Gallup Poll of the Public's Attitudes Toward the Public Schools, the report unveils what Americans are thinking about public schools--in particular their views of teachers and the classrooms where they work. Some findings were surprising, others were not. For example,…

  20. PSP Measurement of Stator Vane Surface Pressures in a High Speed Fan

    Science.gov (United States)

    Lepicovsky, Jan

    1998-01-01

    This paper presents measurements of static pressures on the stator vane suction side of a high-speed single stage fan using the technique of pressure sensitive paint (PSP). The paper illustrates development in application of the relatively new experimental technique to the complex environment of internal flows in turbomachines. First, there is a short explanation of the physics of the PSP technique and a discussion of calibration methods for pressure sensitive paint in the turbomachinery environment. A description of the image conversion process follows. The recorded image of the stator vane pressure field is skewed due to the limited optical access and must be converted to the meridional plane projection for comparison with analytical predictions. The experimental results for seven operating conditions along an off-design rotational speed line are shown in a concise form, including performance map points, mindspan static tap pressure distributions, and vane suction side pressure fields. Then, a comparison between static tap and pressure sensitive paint data is discussed. Finally, the paper lists shortcomings of the pressure sensitive paint technology and lessons learned in this high-speed fan application.

  1. Evaluation of advanced hydraulic turbomachinery for underground pumped hydroelectric storage. Part 1. Single-stage regulated pump turbines for operating heads of 500 to 1000 m

    Energy Technology Data Exchange (ETDEWEB)

    Frigo, A.A.; Blomquist, C.A.; Degnan, J.R.

    1979-10-01

    High-head, large-capacity turbomachinery is needed for the concept of underground pumped hydroelectric storage to be technically and economically attractive. Single-stage, reversible, Francis-type pump turbines with adjustable wicket gates appear to offer the most economically attractive option for heads between about 500 and 1000 m. The feasibility of developing these types of machines for capacities up to 500 MW and operating heads up to 1000 m has been evaluated. Preliminary designs have been generated for six single-stage pump turbines. The designs are for capacities of 350 and 500 MW and for operating heads of 500, 750, and 1000 m. The report contains drawings of the machines along with material specifications and hydraulic performance data. Mechanical, hydraulic, and economic analyses indicate that these machines will behave according to the criteria used to design them and that they can be built at a reasonable cost. The stress and deflection responses of the 500-MW, 100-m-head pump turbine, determined by detailed finite element analysis techniques, give solid evidence of the integrity of the conceptual designs of the six units and indicate no unsolvable problems. Results of a life expectancy analysis of the wicket gates indicate that a near infinite life can be expected for these components when they are subjected to normal design loads. Efficiencies of 90.7 and 91.4% in the generating and pumping modes, respectively, can be expected for the 500-MW, 1000-m-head unit. Performances of the other five machines are comparable. The specific costs of the pump turbines in mid-1978 US dollars per kW vary from 19.2 to 11.8 over a head range of from 500 to 1000 m for the 500-MW machines and from 20.0 to 12.3 for the 350-MW machines.

  2. Late Quaternary Alluvial Fans of Southern Baja California, Mexico: Relation to Eastern Pacific Tropical Cyclones

    Science.gov (United States)

    Antinao, J.; McDonald, E.

    2009-12-01

    In the arid, non-glaciated regions of the Southwestern USA and Northwestern Mexico, aggradation in alluvial fan systems has been traditionally linked to cold and humid periods (e.g., Last Glacial Maximum) or to the transition to warm periods (e.g., the Pleistocene-Holocene transition, PHT). However, major intervals of sediment transport and aggradation have also occurred during climatically warm periods in these regions. These periods have also been identified as portraying enhanced humidity or “monsoonal’ conditions. Investigations on the weather systems able to perform geomorphic work during predominantly warm periods, i.e. the North American Monsoon (NAM) and Eastern Pacific (EP) Tropical Cyclones (TCs), have concentrated mainly in the USA. To understand the relative contribution of these systems to sediment transport over millennial timescales, we have mapped and characterized preliminarily the alluvial fans in four different areas of the Southern Baja California peninsula, Mexico. This region is dominated by EPTC precipitation, which in turn is driving the sediment transport along alluvial channels. Detailed geomorphologic mapping shows that a distinct Late Quaternary chronostratigraphy of alluvial fan units can be developed using geochronological and pedological tools. Specifically, a soil chronosequence can be compared to sequences in the SW USA, allowing a correlation to Late Pleistocene - Holocene events in the region. At least five alluvial units can be identified. Older units have well defined gravel pediments, Av and B horizons and pervasive pedogenic carbonate morphology, with alluvial terraces that rise tens of meters above the present channel. Intermediate age units have developed B horizons and carbonate morphology at different stages. The younger units have thin soil horizons, no carbonate morphology in the soil profile, and some of them are subject to episodic flooding during TC activity. The chronosequence developed is the first step towards

  3. Process sedimentology of submarine fan deposits - new perspectives

    Science.gov (United States)

    Postma, George

    2017-04-01

    To link submarine fan process sedimentology with sand distribution, sand body architecture, texture and fabric, the field geologist studies sedimentary facies, facies associations (fan elements) and stratigraphy. Facies analysis resides on factual knowledge of modern fan morphodynamics and physical modelling of en-masse sediment transport. Where do we stand after 55 years of submarine research, i.e. the date when the first submarine fan model was launched by Arnold Bouma in 1962? Since that date students of submarine fans have worked on a number of important, recurring questions concerned with facies analysis of submarine successions in outcrop and core: 1. What type of sediment transport produced the beds? 2. What facies can be related to initial flow conditions? 3. What is the significance of grain size jumps and bounding surface hierarchy in beds consisting of crude and spaced stratification (traction carpets)? Do these point to multi flow events or to flow pulsations by one and the same event? 4. What facies associations relate to the basic elements of submarine fans? 5. What are the autogenic and allogenic signatures in submarine fans? Particularly in the last decade, the enormous technical advancement helped to obtain high-quality data from observations of density flows in modern canyons, deep basins and deep-water delta slopes (refs 1,2,3). In combination with both physical (refs 4,5) and numerical modelling (ref 6) these studies broke new ground into our understanding of density flow processes in various submarine environments and have led to new concepts of submarine fan building by super- and subcritical high-density flow (ref 7). Do these new concepts provide better answers to our recurrent questions related to the morphodynamics of submarine fans and prediction of sand body architecture? In discussing this open question, I shall 1. apply the new concepts to a modern and ancient example of a channel-lobe-transition-zone (ref 8); 2. raise the problem of

  4. A Critical Review of Computational Methods and Their Application in Industrial Fan Design

    OpenAIRE

    Alessandro Corsini; Giovanni Delibra; Sheard, Anthony G.

    2013-01-01

    Members of the aerospace fan community have systematically developed computational methods over the last five decades. The complexity of the developed methods and the difficulty associated with their practical application ensured that, although commercial computational codes date back to the 1980s, they were not fully exploited by industrial fan designers until the beginning of the 2000s. The application of commercial codes proved to be problematic as, unlike aerospace fans, industrial fans i...

  5. A secondary source configuration for control of a ventilation fan noise in ducts

    OpenAIRE

    Čudina, Mirko; Prezelj, Jurij

    2015-01-01

    The main noise source in heating, ventilation, and air conditioning systems is usually a ventilating fan. Noise, generated by the ventilating fan is transmitted through the duct into the living and working environment. A typical fan noise spectrum consists of a broadband noise, which is superimposed with pure tones. Different methods are available to reduce a transmission of such noise from the ventilating fan into the living and working environment. In this article it is demonstrated how a f...

  6. Cancer Staging

    Science.gov (United States)

    ... the tumor is to grow and spread The TNM Staging System The TNM system is the most widely used cancer staging system. Most hospitals and medical centers use the TNM system as their main method for cancer reporting. ...

  7. A Theory of Money and Financial Institutions. Part XI: Trade with Fiat Money But no Individual Trust. A Preliminary Stage Towards Banking,

    Science.gov (United States)

    The paper contains several simple models which in some cases are worked out in detail. The paper is written in the belief that general equilibrium theory has more or less reached a dead end. The proof of the existence of a price system in a static, complete information, non-institutional economy was a valuable result in the study of production and distribution. The proof was based on important but by no means sufficiently general conditions to be a decent representation of more than a small part of economic life.

  8. Surface morphology of fans in the high-Arctic periglacial environment of Svalbard : Controls and processes

    NARCIS (Netherlands)

    De Haas, Tjalling; Kleinhans, Maarten G.; Carbonneau, Patrice E.; Rubensdotter, Lena; Hauber, Ernst

    2015-01-01

    Fan-shaped landforms occur in all climatic regions on Earth. They have been extensively studied in many of these regions, but there are few studies on fans in periglacial, Arctic and Antarctic regions. Fans in such regions are exposed to many site-specific environmental conditions in addition to the

  9. 30 CFR 75.313 - Main mine fan stoppage with persons underground.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Main mine fan stoppage with persons underground... COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.313 Main mine fan stoppage with persons underground. (a) If a main mine fan stops while anyone is underground...

  10. Intertonguing of the Lower Part of the Uinta Formation with the Upper Part of the Green River Formation in the Piceance Creek Basin During the Late Stages of Lake Uinta

    Science.gov (United States)

    Donnell, John R.

    2009-01-01

    During most of middle Eocene time, a 1,500-mi2 area between the Colorado and White Rivers in northwestern Colorado was occupied by the Piceance lobe of Lake Uinta. This initially freshwater lake became increasingly saline throughout its history. Sediments accumulating in the lake produced mostly clay shale, limestone, and dolomite containing varying concentrations of organic matter. At the time of the maximum extent of the lake, the organic-rich Mahogany bed of the Green River Formation was deposited throughout the area. Shortly after its deposition, stream deposits began infilling the lake from the north through a series of contractions interspersed with minor expansions. This fluctuation of the shoreline resulted in the intertonguing of the stream sediments of the lower part of the overlying Uinta Formation with the lacustrine sediments of the upper part of the Green River over a distance of about 40 mi; construction of regional stratigraphic cross sections show the pattern of intertonguing in considerable detail. The data utilized in this study, which covered parts of Rio Blanco, Garfield, and Mesa counties, was derived from (1) geologic mapping of thirty-four 7 1/2-minute quadrangles and stratigraphic studies by geologists of the U.S. Geological Survey, and (2) shale-oil assay information from numerous cores. As a result of this previous work and the additional effort involved in the compilation here presented, more than a dozen Green River Formation tongues have been named, some formally, others informally. Middle Eocene strata above the Mahogany bed in the northern part of the study area are dominantly coarse clastics of the Uinta Formation. The sedimentary sequence becomes more calcareous and organic-rich to the south where, in a 400-mi2 area, a 250 ft-thick sequence of oil shale above the Mahogany bed contains an average of 16 gallons of oil per ton of shale and is estimated to contain 73 billion barrels of oil.

  11. [A new stage of development of gerontology and geriatrics in Russia: problems of creation of a geriatric care system. Part 1. Relevance, regulatory infrastructure].

    Science.gov (United States)

    Anisimov, V N; Serpov, V Yu; Finagentov, A V; Khavinson, V Kh

    2017-01-01

    This article is a 1st part of the analytical review, focused on a new step in development of geriatrics in Russia. Creation of state system geriatric care as important part of state politics in the area of enhancement of quality of life was proved. General aspects of improvement of social support of disable elderly persons in condition of restricted budget and interagency separation was presented. Establishment of unified system of medical social support and gerotechnologies for the elderly was substantiated, as a mechanism facilitated life activity and decreasing of demographic loading on economic status of regions of Russian Federation. Legislative and normative regulations of gerontology and geriatric development were observed as well. Accepted legislative and normative acts were analyzed for period since 1977 to 2014. The necessity of approaches to regulation modernization for elderly was demonstrated. Analytical review on number of legislative state documents issued after meeting of Presidium of State Council of the Russian Federation being in August 2014 was also presented. Applicability of these documents for realization new strategy of gerontology and geriatrics development in Russia was proved.

  12. Palaeoflow reconstruction from fan delta morphology on Mars

    NARCIS (Netherlands)

    Kleinhans, M.G.; Kasteele, H.E. van de; Hauber, E.

    2010-01-01

    Alluvial fans and deltas on Mars record past hydrological conditions. Until now these conditions have been inferred from the morphology of the feeder channels and the deposits from images and digital terrain models (DTMs), and from calculations of the bulk fluxes of water and sediment based on the d

  13. KKM and KY fan theorems in modular function spaces

    Directory of Open Access Journals (Sweden)

    Latif Abdul

    2011-01-01

    Full Text Available Abstract In modular function spaces, we introduce Knaster-Kuratowski-Mazurkiewicz mappings (in short KKM-mappings and prove an analogue to Ky Fan s fixed point theorem. 2010 Mathematics Subject Classification: Primary 46B20, 47H09; Secondary 47H10.

  14. The Nonrelativistic Scattering States of the Deng-Fan Potential

    Directory of Open Access Journals (Sweden)

    Bentol Hoda Yazarloo

    2013-01-01

    Full Text Available The approximately analytical scattering state solution of the Schrodinger equation is obtained for the Deng-Fan potential by using an approximation scheme to the centrifugal term. Energy eigenvalues, normalized wave functions, and scattering phase shifts are calculated. We consider and verify two special cases: the l=0 and the s-wave Hulthén potential.

  15. Modeling Fan Effects on the Time Course of Associative Recognition

    Science.gov (United States)

    Schneider, Darryl W.; Anderson, John R.

    2012-01-01

    We investigated the time course of associative recognition using the response signal procedure, whereby a stimulus is presented and followed after a variable lag by a signal indicating that an immediate response is required. More specifically, we examined the effects of associative fan (the number of associations that an item has with other items…

  16. Investigation of Cross Flow Fan Propulsion for Lightweight VTOL Aircraft

    Science.gov (United States)

    2000-12-01

    the aircraft longitudinal axis due to the total length of the unit. A total fan span of 20.6 inches is required to produce 690 lbf of thrust when...which are mounted parallel to the aircraft longitudinal axis and rest perpendicular, would be actuated as required to provide yaw control and aft

  17. Studying a Spacecraft Ventilation Fan: Progress and Possibilities

    Science.gov (United States)

    Koch, L. Denielle

    2011-01-01

    This document describes a presentation delivered to the Acoustics Technical Working Group at a meeting held in Cleveland, Ohio on April 21-22, 2011. The information contained in this presentation is considered to be preliminary, intended to begin a general discussion among audience members on the challenges associated with spacecraft ventilation fans and possible avenues of continued research.

  18. Propellers And Fans Based On The Moebius Strip

    Science.gov (United States)

    Seiner, John Milton; Gilinsky, Mikhail Markovich

    1996-01-01

    Moebius strip proposed as basis for optimally shaped airplane and boat propellers, fans, helicopter rotors, mixing screws, coffee grinders, and concrete mixers. Basic idea of optimal shaping of such device to increase working efficiency by increasing area for capture of still medium without increasing power needed for rotation.

  19. Intermittent Flow Regimes in a Transonic Fan Airfoil Cascade

    Directory of Open Access Journals (Sweden)

    J. Lepicovsky

    2004-01-01

    velocity.To date, this flow behavior has only been observed in a linear transonic cascade. Further research is necessary to confirm this phenomenon occurs in actual transonic fans and is not the by-product of an endwall restricted linear cascade.

  20. SOME GENERALIZATIONS OF KY FAN'S BEST APPROXIMATION THEOREM

    Institute of Scientific and Technical Information of China (English)

    A.R.Khan; N.Hussain; A.B.Thaheem

    2004-01-01

    We pressent new Ky Fan type best approximation theorems for a discontinuous multivalued map on metrizable topological vector spaces and hyperconvex spaces. In addition, fixed point results are derived for the map studied. Our work generalizes severl results in approximation theory.

  1. Così fan tutte: Brilliance or Buffoonery?

    Directory of Open Access Journals (Sweden)

    Sarah Whitfield

    2011-12-01

    Full Text Available Hardly any opera has endured more scrutiny and self-preserving apology than Mozart’s Così fan tutte. Flagrant opposition and a long string of “rescue” attempts shroud the receptive history of the work. Since its premiere, Così fan tutte has long been recognized as a problem opera. Many critics found it implausible that Mozart—the consummate composer and man that warranted their idolization—could have stooped so low as to agree to such an immoral plot. The great beauty in Mozart’s musical parody is that it at once mocks and transforms the supposed superficial experiment of Lorenzo Da Ponte’s libretto. The parody in Così fan tutte must be correctly interpreted. It is rampant, but it exists for much more than a perfunctory laugh. The beauty of Mozart’s music—in both moments of wild parody and heartfelt emotion—succeeds in giving Così fan tutte a depth that is both challenging and transforming.

  2. Sedimentology and hydrocarbon habitat of the submarine-fan deposits of the Central Carpathian Paleogene Basin (NE Slovakia)

    Energy Technology Data Exchange (ETDEWEB)

    Sotak, J. [Slovak Academy of Sciences, Banska Bystrica (Slovakia). Geological Institute; Pereszlenyi, M. [VVNP Research Oil Company for Exploration and Production, Bratislava (Slovakia); Marschalko, R.; Starek, D. [Slovak Academy of Sciences, Bratislava (Slovakia). Geological Institute; Milicka, J. [Comenius University, Bratislava (Slovakia). Dept. of Geochemistry

    2001-01-01

    The Central Carpathian Paleogene Basin accommodates a subsiding area of the destructive plate-margin. The basin history comprises marginal faulting and alluvial fan accumulation (E{sub 2}); transgressive onlap by shoreface sediments and carbonate platform deposits (E{sub 2}); glacio-eustatic regression induced by cooling (Terminal Eocene Event); forced regression, tectonic subsidence and growth-fault accumulation of basin-floor and slope fans (E{sub 3}); decelerating subsidence, aggradation and sea-level rising during the mud-rich deposition (O{sub 1}); high-magnitude drop in sea-level (Mid-Oligocene Event), retroarc backstep of depocenters and lowstand accumulation of sand-rich fans and suprafans (O{sub 2}-M{sub 1}); subduction-related shortening and basin inversion along the northern margins affected by backthrusting and transpressional deformation (O{sub 2}-M{sub 1}). The basin-fill sequence has poor (TOC {<=} 0.5%) to fair (TOC < 1.0%) quality of source rocks. Maturity of OM ranges from initial to relic stage of HC generation. Paleogene rock-extracts display a good correlation with scarce trapped oils. 'The presence of solid bitumens and HC-rich fluid inclusions indicates overpressure conditions during HC generation and migration. Potential HC reservoirs can be expected in porous lithologies (scarp breccias), in basement highs and traps related to backthrusting, fault-propagation folding and strike-slip tectonics. (author)

  3. Design of fan beam optical sensor and its application in mass flow rate measurement of pneumatically conveyed solids

    Institute of Scientific and Technical Information of China (English)

    LI Yang; ZHENG Ying-na; YUE Hong-wei

    2005-01-01

    The fan-beam optical sensor is made up of many semiconductor lasers and detectors fixed around the wall alternately at a cross section of pneumatically conveying pipe. When the sensor works, a scanning light source emits a 50° lamellar fan-beam through the gas-solid two phase flow, and the projection data resulting extinction effect of solid particles are detected at the same time. With the projection data, the flow rate mass can be calculated, and then the flow image can be reconstructed. In this paper, the design of the sensor including spatial arrangement of the structural parts, basic principle and measurement sensitivity distribution are introduced. The mathematical measurement model of solid mass flow rate is presented together with the testing results.

  4. First Test of Fan Active Noise Control (ANC) Completed

    Science.gov (United States)

    2005-01-01

    With the advent of ultrahigh-bypass engines, the space available for passive acoustic treatment is becoming more limited, whereas noise regulations are becoming more stringent. Active noise control (ANC) holds promise as a solution to this problem. It uses secondary (added) noise sources to reduce or eliminate the offending noise radiation. The first active noise control test on the low-speed fan test bed was a General Electric Company system designed to control either the exhaust or inlet fan tone. This system consists of a "ring source," an induct array of error microphones, and a control computer. Fan tone noise propagates in a duct in the form of spinning waves. These waves are detected by the microphone array, and the computer identifies their spinning structure. The computer then controls the "ring source" to generate waves that have the same spinning structure and amplitude, but 180 out of phase with the fan noise. This computer generated tone cancels the fan tone before it radiates from the duct and is heard in the far field. The "ring source" used in these tests is a cylindrical array of 16 flat-plate acoustic radiators that are driven by thin piezoceramic sheets bonded to their back surfaces. The resulting source can produce spinning waves up to mode 7 at levels high enough to cancel the fan tone. The control software is flexible enough to work on spinning mode orders from -6 to 6. In this test, the fan was configured to produce a tone of order 6. The complete modal (spinning and radial) structure of the tones was measured with two builtin sets of rotating microphone rakes. These rakes provide a measurement of the system performance independent from the control system error microphones. In addition, the far-field noise was measured with a semicircular array of 28 microphones. This test represents the first in a series of tests that demonstrate different active noise control concepts, each on a progressively more complicated modal structure. The tests are

  5. Modelling the Holocene Evolution of a Drift-dominated Alluvial-fan Coast

    Science.gov (United States)

    Hicks, M.; Dickson, M.; Coco, G.

    2007-12-01

    A numerical model is being developed to simulate shore evolution along an alluvial fan coast over the Holocene. The alluvial fan of the Waitaki River, on the east coast of New Zealand's South Island, was built by Pleistocene glacial advances but has been eroded back by waves over recent millennia. The retreat has left a cliffed shore fronted by a narrow beach of mixed sand and gravel and a gently sloping seabed with only a thin, patchy sand cover over the Pleistocene substrate. The study motivation is to examine the sensitivity of shoreline movements in this setting to wave-climate change, sea-level rise, and river sediment supplies. The modelling couples a profile evolution model with a shoreline model. The profile evolution model is operational and is driven by a series of coupled process models which include seabed scour, berm construction during normal waves, berm overtopping and subsequent beach-stripping and scour of the exposed substrate and cliff-toe notching by storm waves, gravity failure of the cliffs and talus construction, and beach sediment abrasion. Negative feedback regulates the rate of cliff erosion through the protection provided by the new material added into the beach from the eroding cliffs and substrate. The model is forced by two wave conditions: a normal swell and a randomly-varying storm wave. These operate for proportions of the yearly time step. The model was begun on a sloping fan surface inundated by the last stages of post-glacial sea-level rise (8000 yr BP). The initial response is for rapid growth of a gravel beach ridge fed by wave-excavation of the nearshore. As the nearshore profile nears equilibrium with the wave climate, the onshore feed wanes below the abrasion rate and the beach ridge loses volume. As sea level rises the beach ridge moves upward and landward, but its capacity to do so is limited by the rate of sediment feed from the nearshore. When the beach size reduces to a threshold at which storm waves periodically

  6. Experimental Evaluation of Installed Cooking Exhaust Fan Performance

    Energy Technology Data Exchange (ETDEWEB)

    Singer, Brett C.; Delp, William W.; Apte, Michael G.

    2010-11-01

    The installed performance of cooking exhaust fans was evaluated through residential field experiments conducted on a sample of 15 devices varying in design and other characteristics. The sample included two rear downdraft systems, two under-cabinet microwave over range (MOR) units, three different installations of an under-cabinet model with grease screens across the bottom and no capture hood, two devices with grease screens covering the bottom of a large capture hood (one under-cabinet, one wall-mount chimney), four under-cabinet open hoods, and two open hoods with chimney mounts over islands. Performance assessment included measurement of airflow and sound levels across fan settings and experiments to quantify the contemporaneous capture efficiency for the exhaust generated by natural gas cooking burners.Capture efficiency is defined as the fraction of generated pollutants that are removed through the exhaust and thus not available for inhalation of household occupants. Capture efficiency (CE) was assessed for various configurations of burner use (e.g., single front, single back, combination of one front and one back, oven) and fan speed setting. Measured airflow rates were substantially lower than the levels noted in product literature for many of the units. This shortfall was observed for several units costing in excess of $1000. Capture efficiency varied widely (from<5percent to roughly 100percent) across devices and across conditions for some devices. As expected, higher capture efficiencies were achieved with higher fan settings and the associated higher air flow rates. In most cases, capture efficiencies were substantially higher for rear burners than for front burners. The best and most consistent performance was observed for open hoods that covered all cooktop burners and operated at higher airflow rates. The lowest capture efficiencies were measured when a front burner was used with a rear backdraft system or with lowest fan setting for above the range

  7. Investigation of the Flow Physics Driving Stall-Side Flutter in Advanced Forward Swept Fan Designs

    Science.gov (United States)

    Sanders, Albert J.; Liu, Jong S.; Panovsky, Josef; Bakhle, Milind A.; Stefko, George; Srivastava, Rakesh

    2003-01-01

    Flutter-free operation of advanced transonic fan designs continues to be a challenging task for the designers of aircraft engines. In order to meet the demands of increased performance and lighter weight, these modern fan designs usually feature low-aspect ratio shroudless rotor blade designs that make the task of achieving adequate flutter margin even more challenging for the aeroelastician. This is especially true for advanced forward swept designs that encompass an entirely new design space compared to previous experience. Fortunately, advances in unsteady computational fluid dynamic (CFD) techniques over the past decade now provide an analysis capability that can be used to quantitatively assess the aeroelastic characteristics of these next generation fans during the design cycle. For aeroelastic applications, Mississippi State University and NASA Glenn Research Center have developed the CFD code TURBO-AE. This code is a time-accurate three-dimensional Euler/Navier-Stokes unsteady flow solver developed for axial-flow turbomachinery that can model multiple blade rows undergoing harmonic oscillations with arbitrary interblade phase angles, i.e., nodal diameter patterns. Details of the code can be found in Chen et al. (1993, 1994), Bakhle et al. (1997, 1998), and Srivastava et al. (1999). To assess aeroelastic stability, the work-per-cycle from TURBO-AE is converted to the critical damping ratio since this value is more physically meaningful, with both the unsteady normal pressure and viscous shear forces included in the work-per-cycle calculation. If the total damping (aerodynamic plus mechanical) is negative, then the blade is unstable since it extracts energy from the flow field over the vibration cycle. TURBO-AE is an integral part of an aeroelastic design system being developed at Honeywell Engines, Systems & Services for flutter and forced response predictions, with test cases from development rig and engine tests being used to validate its predictive

  8. Submarine fan sedimentation at a convergent margin: the cretaceous mangapokia formation, New Zealand

    Science.gov (United States)

    Barnes, Philip M.

    1988-10-01

    -concentration flows. Rare discontinuous graded bedded sandstones containing common flame structures (Facies 7) interbedded with conglomerate facies represent within-channel turbidites. A lower inner-submarine fan channel-overbank assemblage (Facies Association A), an inner-middle submarine fan channel-lobe assemblage (Facies Association B), and a mid-fan assemblage (Facies Association C) are distinguished. Two large-scale progradational suites of facies reflecting large-scale migration of the inner-fan channel complex are superimposed upon numerous small-scale depositional cycles resulting from lateral migration of numerous braided channels within the inner and mid-fan environments. The volumetrically minor ocean-floor assemblage is restricted to zones of melange. Chemically the basalts are tholeiitic, with trace element concentrations similar to modern ocean-floor basalts. Radiolarian-bearing cherts and coloured argillites are highly oxidised, and chemically similar to some modern oceanic pelagic sediments. The juxtaposition of relatively coherent, strongly folded and tectonically imbricated trench-fill submarine fan sediments and minor ocean-floor material is consistent with contemporaneous sedimentation and accretion at the base of the i inner trench slope in a convergent plate setting. The Mangapokia Formation is interpreted to represent the youngest part of the Torlesse terrane, and hence in southern North Island, Torlesse deposition and concurrent subduction tectonism were probably continuous at least until the middle Cretaceous.

  9. A focused ultrasound treatment system for moving targets (part I): generic system design and in-silico first-stage evaluation.

    Science.gov (United States)

    Schwenke, Michael; Strehlow, Jan; Demedts, Daniel; Haase, Sabrina; Barrios Romero, Diego; Rothlübbers, Sven; von Dresky, Caroline; Zidowitz, Stephan; Georgii, Joachim; Mihcin, Senay; Bezzi, Mario; Tanner, Christine; Sat, Giora; Levy, Yoav; Jenne, Jürgen; Günther, Matthias; Melzer, Andreas; Preusser, Tobias

    2017-01-01

    efficiency of the new treatment system is already suited for clinical applications. The simulation-based in-silico testing as a first-stage validation reduces the efforts of real-world testing. Due to the extensible modular design, the described approach might lead to faster translations from research to clinical practice.

  10. Fans and their applications in General Topology, Functional Analysis and Topological Algebra

    OpenAIRE

    Banakh, Taras

    2016-01-01

    A family of closed subsets of a topological space $X$ is called a (strict) $Cld$-fan in $X$ if this family is (strictly) compact-finite but not locally finite in $X$. Applications of (strict) $Cld$-fans are based on a simple observation that $k$-spaces contain no $Cld$-fan and Ascoli spaces contain no strict $Cld$-fan. In this paper we develop the machinery of (strict) fans and apply it to detecting the $k$-space and Ascoli properties in spaces that naturally appear in General Topology, Funct...

  11. Numerical investigation of geometric parameter effects on the aerodynamic performance of a Bladeless fan

    OpenAIRE

    Mohammad Jafari; Hossein Afshin; Bijan Farhanieh; Atta Sojoudi

    2016-01-01

    Aerodynamic performance of a Bladeless fan is numerically investigated considering the effect of five geometric parameters. Airflow through this fan was analyzed by simulating a Bladeless fan within a 2 m × 2 m × 4 m room. Analysis of the flow field inside the fan and the evaluation of its performance were obtained by solving conservations of mass and momentum equations for the aerodynamic investigations. In order to design the Bladeless fan an Eppler 473 airfoil profile was used as the cross...

  12. Reverse Flow Engine Core Having a Ducted Fan with Integrated Secondary Flow Blades

    Science.gov (United States)

    Kisska, Michael K. (Inventor); Princen, Norman H. (Inventor); Kuehn, Mark S. (Inventor); Cosentino, Gary B. (Inventor)

    2014-01-01

    Secondary air flow is provided for a ducted fan having a reverse flow turbine engine core driving a fan blisk. The fan blisk incorporates a set of thrust fan blades extending from an outer hub and a set of integral secondary flow blades extending intermediate an inner hub and the outer hub. A nacelle provides an outer flow duct for the thrust fan blades and a secondary flow duct carries flow from the integral secondary flow blades as cooling air for components of the reverse flow turbine engine.

  13. On the design and structural analysis of jet engine fan blade structures

    Science.gov (United States)

    Amoo, Leye M.

    2013-07-01

    Progress in the design and structural analysis of commercial jet engine fan blades is reviewed and presented. This article is motivated by the key role fan blades play in the performance of advanced gas turbine jet engines. The fundamentals of the associated physics are emphasized. Recent developments and advancements have led to an increase and improvement in fan blade structural durability, stability and reliability. This article is intended as a high level review of the fan blade environment and current state of structural design to aid further research in developing new and innovative fan blade technologies.

  14. Gas Turbine Engine Having Fan Rotor Driven by Turbine Exhaust and with a Bypass

    Science.gov (United States)

    Suciu, Gabriel L. (Inventor); Chandler, Jesse M. (Inventor)

    2016-01-01

    A gas turbine engine has a core engine incorporating a core engine turbine. A fan rotor is driven by a fan rotor turbine. The fan rotor turbine is in the path of gases downstream from the core engine turbine. A bypass door is moveable from a closed position at which the gases from the core engine turbine pass over the fan rotor turbine, and moveable to a bypass position at which the gases are directed away from the fan rotor turbine. An aircraft is also disclosed.

  15. On-chip grating coupler array on the SOI platform for fan-in/fan-out of MCFs with low insertion loss and crosstalk

    DEFF Research Database (Denmark)

    Ding, Yunhong; Ye, Feihong; Peucheret, Christophe

    2015-01-01

    We report the design and fabrication of a compact multi-core fiber fan-in/fan-out using a grating coupler array on the SOI platform. The grating couplers are fully-etched, enabling the whole circuit to be fabricated in a single lithography and etching step. Thanks to the apodized design for the g......We report the design and fabrication of a compact multi-core fiber fan-in/fan-out using a grating coupler array on the SOI platform. The grating couplers are fully-etched, enabling the whole circuit to be fabricated in a single lithography and etching step. Thanks to the apodized design...

  16. Depositional architecture and evolution of the Late Miocene slope channel-fan-system in the northeastern shelf-margin of South China Sea

    Science.gov (United States)

    Jiang, Jing; Lin, Changsong; Zhang, Zhongtao; Tian, Hongxun; Tao, Ze; Liu, Hanyao

    2016-04-01

    The Upper Miocene in the Pearl River Mouth Basin of northwestern shelf-margin of South China Sea Basin contains a series of slope channel - fan systems. Their depositional architecture and evolution are documented in this investigation based on an integrated analysis of cores, logs, and seismic data. Four depositional-palaeogeomorphological elements have been identified in the slope channel-fan systems as follows: broad, shallow and unconfined or partly confined outer-shelf to shelf-break channels; deeply incised and confined unidirectionally migrating slope channels; broad or U-shaped, unconfined erosional-depositional channels; frontal splays-lobes and nonchannelized sheets. The slope channels are mostly oriented NW-SE, which migrated unidirectionally northeastwards and intensively eroded almost the whole shelf-slope zone. The channel infillings are mainly mudstones, interbedded with siltstones. They might be formed by gravity flow erosion as bypassing channels. They were filled with limited gravity flow sediments at the base and mostly filled with lateral accretionary packages of bottom current deposits. At the end of the channels, a series of small-scale slope fans developed and coalesced into fan aprons along the base of the slope. The unconfined erosional-depositional channels at the upper parts of the fan-apron-systems display compound infill patterns, and commonly have concave erosional bases and convex tops. The frontal splays-lobes representing middle to distal deposits of fan-apron-systems have flat-mounded or gull-wing geometries, and the internal architectures include bidirectional downlap, progradation, and chaotic infillings. The distal nonchannelized turbidite sheets are characterized by thin-bedded, parallel to sub-parallel sheet-like geometries. Three major unconformities or obvious erosional surfaces in the channel-fan systems of the Upper Miocene are recognized, and indicate the falling of sea-level. The depositional architecture of sequences

  17. Investigation of Advanced Counterrotation Blade Configuration Concepts for High Speed Turboprop Systems. Task 3: Advanced Fan Section Grid Generator Final Report and Computer Program User's Manual

    Science.gov (United States)

    Crook, Andrew J.; Delaney, Robert A.

    1991-01-01

    A procedure is studied for generating three-dimensional grids for advanced turbofan engine fan section geometries. The procedure constructs a discrete mesh about engine sections containing the fan stage, an arbitrary number of axisymmetric radial flow splitters, a booster stage, and a bifurcated core/bypass flow duct with guide vanes. The mesh is an h-type grid system, the points being distributed with a transfinite interpolation scheme with axial and radial spacing being user specified. Elliptic smoothing of the grid in the meridional plane is a post-process option. The grid generation scheme is consistent with aerodynamic analyses utilizing the average-passage equation system developed by Dr. John Adamczyk of NASA Lewis. This flow solution scheme requires a series of blade specific grids each having a common axisymmetric mesh, but varying in the circumferential direction according to the geometry of the specific blade row.

  18. Flow control in axial fan inlet guide vanes by synthetic jets

    Directory of Open Access Journals (Sweden)

    Wurst P.

    2013-04-01

    Full Text Available Tested high pressure axial flow fan with hub/tip ratio of 0.70 and external diameter of 600 mm consisted of inlet guide vanes (IGV, rotor and stator blade rows. Fan peripheral velocity was 47 m/s. Air volume flow rate was changed by turning of rear part of the inlet guide vanes. At turning of 20 deg the flow was separated on the IGV profiles. The synthetic jets were introduced through radial holes in machine casing in the location before flow separation origin. Synthetic jet actuator was designed with the use of a speaker by UT AVCR. Its membrane had diameter of 63 mm. Excitation frequency was chosen in the range of 500 Hz – 700 Hz. Synthetic jets favourably influenced separated flow on the vane profiles in the distance of (5 – 12 mm from the casing surface. The reduction of flow separation area caused in the region near the casing the decrease of the profile loss coefficient approximately by 20%.

  19. Computational analysis of noise reduction devices in axial fans with stabilized finite element formulations

    Science.gov (United States)

    Corsini, A.; Rispoli, F.; Sheard, A. G.; Tezduyar, T. E.

    2012-12-01

    The paper illustrates how a computational fluid mechanic technique, based on stabilized finite element formulations, can be used in analysis of noise reduction devices in axial fans. Among the noise control alternatives, the study focuses on the use of end-plates fitted at the blade tips to control the leakage flow and the related aeroacoustic sources. The end-plate shape is configured to govern the momentum transfer to the swirling flow at the blade tip. This flow control mechanism has been found to have a positive link to the fan aeroacoustics. The complex physics of the swirling flow at the tip, developing under the influence of the end-plate, is governed by the rolling up of the jet-like leakage flow. The RANS modelling used in the computations is based on the streamline-upwind/Petrov-Galerkin and pressure-stabilizing/Petrov-Galerkin methods, supplemented with the DRDJ stabilization. Judicious determination of the stabilization parameters involved is also a part of our computational technique and is described for each component of the stabilized formulation. We describe the flow physics underlying the design of the noise control device and illustrate the aerodynamic performance. Then we investigate the numerical performance of the formulation by analysing the inner workings of the stabilization operators and of their interaction with the turbulence model.

  20. Flow control in axial fan inlet guide vanes by synthetic jets

    Science.gov (United States)

    Cyrus, V.; Trávníček, Z.; Wurst, P.; Kordík, J.

    2013-04-01

    Tested high pressure axial flow fan with hub/tip ratio of 0.70 and external diameter of 600 mm consisted of inlet guide vanes (IGV), rotor and stator blade rows. Fan peripheral velocity was 47 m/s. Air volume flow rate was changed by turning of rear part of the inlet guide vanes. At turning of 20 deg the flow was separated on the IGV profiles. The synthetic jets were introduced through radial holes in machine casing in the location before flow separation origin. Synthetic jet actuator was designed with the use of a speaker by UT AVCR. Its membrane had diameter of 63 mm. Excitation frequency was chosen in the range of 500 Hz - 700 Hz. Synthetic jets favourably influenced separated flow on the vane profiles in the distance of (5 - 12) mm from the casing surface. The reduction of flow separation area caused in the region near the casing the decrease of the profile loss coefficient approximately by 20%.

  1. The Alcyonacea (soft corals and sea fans of Antsiranana Bay, northern Madagascar

    Directory of Open Access Journals (Sweden)

    Alison J. Evans

    2011-06-01

    Full Text Available During the past two decades, the Alcyonacea (soft corals and sea fans of the western Indian Ocean have been the subject of numerous studies investigating their ecology and distribution. Comparatively, Madagascar remains understudied. This article provides the first record of the distribution of Alcyonacea on the shallow fringing reefs around Antsiranana Bay, northern Madagascar. Alcyonacea accounted for between one and 16 % of the reef benthos surveyed; 11 genera belonging to four families, and several unidentified gorgonians (sea fans were recorded. Abundant and diverse Alcyonacea assemblages were recorded on reefs that were exposed with high water clarity. However, abundant and diverse communities were also observed on sheltered reefs with low water clarity, high sediment cover and relatively low hard coral cover, implying potential competitive advantage under these conditions. Where prevailing environmental conditions were relatively moderate, the Alcyonacea assemblages were generally characterised by low diversity and an abundance of Sinularia and Sarcophyton. Because of the current lack of knowledge about the coral reefs in Antsiranana Bay, it was not possible to suggest any appropriate management actions. We propose that this account should be built upon with similar studies of other reef taxa. This series would address the paucity of published information from this part of the western Indian Ocean, and would provide the baseline information necessary to inform future management plans for the area.

  2. Aeroelastic Calculations of Quiet High- Speed Fan Performed

    Science.gov (United States)

    Bakhle, Milind A.; Srivastava, Rakesh; Mehmed, Oral; Min, James B.

    2002-01-01

    An advanced high-speed fan was recently designed under a cooperative effort between the NASA Glenn Research Center and Honeywell Engines & Systems. The principal design goals were to improve performance and to reduce fan noise at takeoff. Scale models of the Quiet High-Speed Fan were tested for operability, performance, and acoustics. During testing, the fan showed significantly improved noise characteristics, but a self-excited aeroelastic vibration known as flutter was encountered in the operating range. Flutter calculations were carried out for the Quiet High-Speed Fan using a three-dimensional, unsteady aerodynamic, Reynolds-averaged Navier-Stokes turbomachinery code named "TURBO." The TURBO code can accurately model the viscous flow effects that can play an important role in various aeroelastic problems such as flutter with flow separation, flutter at high loading conditions near the stall line (stall flutter), and flutter in the presence of shock and boundary-layer interaction. Initially, calculations were performed with no blade vibrations. These calculations were at a constant rotational speed and a varying mass flow rate. The mass flow rate was varied by changing the backpressure at the exit boundary of the computational domain. These initial steady calculations were followed by aeroelastic calculations in which the blades were prescribed to vibrate harmonically in a natural mode, at a natural frequency, and with a fixed interblade phase angle between adjacent blades. The AE-prep preprocessor was used to interpolate the in-vacuum mode shapes from the structural dynamics mesh onto the computational fluid dynamics mesh and to smoothly propagate the grid deformations from the blade surface to the interior points of the grid. The aeroelastic calculations provided the unsteady aerodynamic forces on the blade surface due to blade vibrations. These forces were vector multiplied with the structural dynamic mode shape to calculate the work done on the blade during

  3. Well staged

    Energy Technology Data Exchange (ETDEWEB)

    Budd, Godfrey

    2011-06-15

    Packers Plus Energy Services Inc. has commercially launched QuickFRAC, a multi-stage completition system which can fracture four to five isolated stages in one treatment and set up a record of 23-stage slickwater frac in less than 10 hours. It could take up to 40 days to do 100 fracture treatments with other systems. This technology makes it possible to distribute fluid at each port thanks to the limited entry system. In order to make multiple isolated stages within one treatment zone, each zone includes multiple QuickPORT sleeves with packers on either side. The other technology which made this possible is the repeater port system, it allows them to perform more frac stages. This technology could be useful in the future since the need for stages will be doubling soon with microdarcy shale oil extraction which is more difficult than gas.

  4. Quantitative analysis of the geometry of submarine channels: Implications for the classification of submarine fans

    Science.gov (United States)

    Clark, J. D.; Kenyon, N. H.; Pickering, K. T.

    1992-07-01

    Certain attributes of submarine channels measured from GLORIA sidescan sonar data from 16 different submarine fans indicate similarities with fluviatile systems. Channel width, depth, meander radius and wavelength, sinuosity, and gradient were measured. This approach makes it possible to identify high- sinuosity, low-gradient (e.g., Indus Fan channels) and low-sinuosity, high- gradient (e.g., Porcupine Seabight channels) channel systems as end members. Current classifications of submarine fans relate fan shape to grain size or sediment caliber and therefore are inadequate, principally because the shape of the fan is strongly controlled by the shape of the receiving basin, which in turn is dependent upon parameters such as tectonics and diapirism. Overall fan shape is almost invariably independent of the physics of sediment transport. Rather than fan shape, the geometry and other characteristics of submarine channels and canyons provide a more promising means of differentiating deep- marine turbidite systems.

  5. Submarine-fan facies associations of the Upper Cretaceous and Paleocene Gottero Sandstone, Ligurian Apennines, Italy

    Science.gov (United States)

    Nilsen, Tor H.; Abbate, Ernesto

    1984-06-01

    The Upper Cretaceous and Paleocene Gottero Sandstone was deposited as a small deep-sea fan on ophiolitic crust in a trench-slope basin. It was thrust northeastward as an allochthonous sheet in Early and Middle Cenozoic time. The Gottero, as thick as 1500 m, was probably derived from erosion of Hercynian granites and associated metamorphic rocks in northern Corsica. Outcrops of inner-fan channel, middle-fan channel and interchannel, outer-fan lobe, fan-fringe, and basin-plain facies associations indicate that the depositional model of Mutti and Ricci Lucchi for mixed-sediment deep-sea fans can be used. The original fan had a radius of 30 to 50 km.

  6. Human KIAA1018/FAN1 nuclease is a new mitotic substrate of APC/CCdh1

    Institute of Scientific and Technical Information of China (English)

    Fenju Lai; Kaishun Hu; Yuanzhong Wu; Jianjun Tang; Yi Sang; Jingying Cao; Tiebang Kang

    2012-01-01

    A recently identified protein,FAN1 (FANCD2-associated nuclease 1,previously known as KIAA1018),is a novel nuclease associated with monoubiquitinated FANCD2 that is required for cellular resistance against DNA interstrand crosslinking (ICL) agents.The mechanisms of FAN1 regulation have not yet been explored.Here,we provide evidence that FAN1 is degraded during mitotic exit,suggesting that FAN1 may be a mitotic substrate of the anaphase-promoting cyclosome complex (APC/C).Indeed,.Cdh1,but not Cdc20,was capable of regulating the protein level of FAN1 through the KEN box and the D-box.Moreover,the up- and down-regulation of FAN1 affected the progression to mitotic exit.Collectively,these data suggest that FAN1 may be a new mitotic substrate of APC/CCdh1 that plays a key role during mitotic e xit.

  7. Trading stages

    DEFF Research Database (Denmark)

    Steiner, Uli; Tuljapurkar, Shripad; Coulson, Tim

    2012-01-01

    Interest in stage-and age structured models has recently increased because they can describe quantitative traits such as size that are left out of age-only demography. Available methods for the analysis of effects of vital rates on lifespan in stage-structured models have not been widely applied ...... examples. Much of our approach relies on trading of time and mortality risk in one stage for time and risk in others. Our approach contributes to the new framework of the study of age- and stage-structured biodemography....

  8. Modal analysis of an aircraft engine fan noise

    Science.gov (United States)

    Gorodkova, Natalia; Chursin, Valeriy; Bersenev, Yuliy; Burdakov, Ruslan; Siner, Aleksandr; Viskova, Tatiana

    2016-10-01

    The fan is one of the main noise sources of an aircraft engine. To reduce fan noise and provide liner optimization in the inlet it is necessary to research modal structure of the fan noise. The present paper contains results of acoustic tests on installation for mode generation that consists of 34-channel generator and the inlet updated for mounting of 100 microphones, the experiments were provided in new anechoic chamber of Perm National Research Polytechnic University, the engine with the same inlet was also tested in the open test bench conditions, and results of the fan noise modal structure are presented. For modal structure educting, all 100 channels were synchronously registered in a given frequency range. The measured data were analyzed with PULSE analyzer using fast Fourier transform with a frequency resolution 8..16 Hz. Single modes with numbers from 0 to 35 at frequencies 500; 630; 800; 1000; 1250; 1600 Hz and different combinations of modes at frequencies 1000, 1600, 2000, 2500 Hz were set during tests. Modes with small enough numbers are generated well on the laboratory installation, high-number modes generate additional modes caused by a complicated interference pattern of sound field in the inlet. Open test bench results showed that there are also a lot of harmonic components at frequencies lower than fan BPF. Under 0.65 of cut off there is only one distinct mode, other modes with close and less numbers appear from 0.7 of cut off and above. At power regimes 0.76 and 0.94 of cut off the highest mode also changes from positive to negative mode number area. Numbers of the highest modes change smoothly enough with the growth of power regime. At power regimes with Mach>1 (0.7 of cut off and above) on circumference of blade wheel there is a well-defined noise of shock waves at rotor frequency harmonics that appears at the range between the first rotor frequency and fan blade passing frequency (BPF). It is planned to continue researching of sound field

  9. Analysis of Axial Flow Ventilation Fans by Vortex - Method.

    Science.gov (United States)

    Hardin, Richard Anthony

    A steady vortex-lattice method is used to solve the lifting surface equation for an axial flow fan. The type of fan studied is designed for industrial and ventilation applications and in thermofluid systems such as cooling towers. The fan blades are thin cambered surfaces manufactured from metal sheets. The numerical approach is inviscid and results in a boundary value problem with viscous effects partially accounted for by application of drag coefficient data. A non-linear wake alignment procedure is used to account for the effects of vorticity shedding in the wake and variation in wake geometry with operating conditions. The wake alignment procedure is semi-free with wake input parameters required for accurate use of the technique. A study of the wake parameters was conducted and gave trends in the variation of their values with flow rate. At "free-air" conditions, flow visualization estimates of these parameters were found to agree with those from the computations. Comparisons are made between the measured and predicted fan performance with and without a surrounding duct. The comparison of the results were especially good at the "free-air" condition using wake parameters determined from flow visualization and an inlet velocity profile measured using hot-wire anemometry. To enable better understanding of basic flow phenomena and to provide data for verification of numerical analyses, a method for measuring unsteady surface pressure on a rotating axial-flow fan blade was devised. Unsteadiness of pressure on the blade surfaces is due to the effects of upstream fan motor supports and other installation features. A pressure transducer and signal amplification circuit were mounted on a circuit board at the rotating hub with signals taken off the rotating shaft through copper disk-mercury slip rings. The pressure difference across the blade was determined and the data were corrected for time lag and distortion caused by the length of tubing. The pressure difference

  10. Active Control of Fan Noise: Feasibility Study. Volume 3; Active Fan Noise Cancellation in the NASA Lewis Active Noise Control Fan Facility

    Science.gov (United States)

    Pla, Frederic G.; Hu, Ziqiang; Sutliff, Daniel L.

    1996-01-01

    This report describes the Active Noise Cancellation (ANC) System designed by General Electric and tested in the NASA Lewis Research Center's (LERC) 48 inch Active Noise Control Fan (ANCF). The goal of this study is to assess the feasibility of using wall mounted secondary acoustic sources and sensors within the duct of a high bypass turbofan aircraft engine for global active noise cancellation of fan tones. The GE ANC system is based on a modal control approach. A known acoustic mode propagating in the fan duct is canceled using an array of flush-mounted compact sound sources. The canceling modal signal is generated by a modal controller. Inputs to the controller are signals from a shaft encoder and from a microphone array which senses the residual acoustic mode in the duct. The key results are that the (6,0) was completely eliminated at the 920 Hz design frequency and substantially reduced elsewhere. The total tone power was reduced 6.8 dB (out of a possible 9.8 dB). Farfield reductions of 15 dB (SPL) were obtained. The (4,0) and (4,1) modes were reduced simultaneously yielding a 15 dB PWL decrease. The results indicate that global attenuation of PWL at the target frequency was obtained in the aft quadrant using an ANC actuator and sensor system totally contained within the duct. The quality of the results depended on precise mode generation. High spillover into spurious modes generated by the ANC actuator array caused less than optimum levels of PWL reduction. The variation in spillover is believed to be due to calibration procedure, but must be confirmed in subsequent tests.

  11. Natures of Rotating Stall Cell in a Diagonal Flow Fan

    Institute of Scientific and Technical Information of China (English)

    N. SHIOMI; K. KANEKO; T. SETOGUCHI

    2005-01-01

    In order to clarify the natures of a rotating stall cell, the experimental investigation was carried out in a high specific-speed diagonal flow fan. The pressure field on the casing wall and the velocity fields at the rotor inlet and outlet were measured under rotating stall condition with a fast response pressure transducer and a single slant hot-wire probe, respectively. The data were processed using the "Double Phase-Locked Averaging (DPLA)"technique, which enabled to obtain the unsteady flow field with a rotating stall cell in the relative co-ordinate system fixed to the rotor. As a result, the structure and behavior of the rotating stall cell in a high specific-speed diagonal flow fan were shown.

  12. Pattern recognition: A dialogue on racism in fan communities [symposium

    Directory of Open Access Journals (Sweden)

    TWC Editor

    2009-11-01

    Full Text Available In early 2009, science fiction fandom's online landscape erupted with discussions of race. A post regarding cultural appropriation on author Elizabeth Bear's blog sparked a wide-ranging conversation that soon became acrimonious, with professional science fiction and fantasy writers and fans of science fiction literature and media weighing in. More recently, criticisms of Patricia C. Wrede's decision to set her young adult novel, The Thirteenth Child (2009, in an America empty of indigenous people have spearheaded new waves of discussion. Often the more widely read summaries of these debates have focused on what they mean for writers and aspiring writers who plan to represent minority cultures in their works. But what has their significance been for members of fan communities?

  13. Compressor-fan unitary structure for air conditioning system

    Science.gov (United States)

    Dreiman, N.

    2015-08-01

    An extremely compact, therefore space saving unitary structure of short axial length is produced by radial integration of a revolving piston rotary compressor and an impeller of a centrifugal fan. The unitary structure employs single motor to run as the compressor so the airflow fan and eliminates duality of motors, related power supply and control elements. Novel revolving piston rotary compressor which provides possibility for such integration comprises the following: a suction gas delivery system which provides cooling of the motor and supplies refrigerant into the suction chamber under higher pressure (supercharged); a modified discharge system and lubricating oil supply system. Axial passages formed in the stationary crankshaft are used to supply discharge gas to a condenser, to return vaporized cooling agent from the evaporator to the suction cavity of the compressor, to pass a lubricant and to accommodate wiring supplying power to the unitary structure driver -external rotor electric motor.

  14. Wake Management Strategies for Reduction of Turbomachinery Fan Noise

    Science.gov (United States)

    Waitz, Ian A.

    1998-01-01

    The primary objective of our work was to evaluate and test several wake management schemes for the reduction of turbomachinery fan noise. Throughout the course of this work we relied on several tools. These include 1) Two-dimensional steady boundary-layer and wake analyses using MISES (a thin-shear layer Navier-Stokes code), 2) Two-dimensional unsteady wake-stator interaction simulations using UNSFLO, 3) Three-dimensional, steady Navier-Stokes rotor simulations using NEWT, 4) Internal blade passage design using quasi-one-dimensional passage flow models developed at MIT, 5) Acoustic modeling using LINSUB, 6) Acoustic modeling using VO72, 7) Experiments in a low-speed cascade wind-tunnel, and 8) ADP fan rig tests in the MIT Blowdown Compressor.

  15. Advanced Trailing Edge Blowing Concepts for Fan Noise Control

    Directory of Open Access Journals (Sweden)

    Cezar RIZEA

    2012-03-01

    Full Text Available This study documents trailing edge blowing research performed to reduce rotor / stator interaction noise in turbofan engines. The existing technique of filling every velocity deficit requires a large amount of air and is therefore impractical. The purpose of this research is to investigate new blowing configurations in order to achieve noise reduction with lesser amounts of air. Using the new configurations air is not injected into every fan blade, but is instead varied circumferentially. For example, blowing air may be applied to alternating fan blades. This type of blowing configuration both reduces the amount of air used and changes the spectral shape of the tonal interaction noise. The original tones at the blade passing frequency and its harmonics are reduced and new tones are introduced between them. This change in the tonal spectral shape increases the performance of acoustic liners used in conjunction with trailing edge blowing.

  16. Study of Fan-Airpump Applicability to Two-Stage Air Cleaner Systems.

    Science.gov (United States)

    1985-06-01

    deieloped for the directly coupled case, which indicates that q decreases, or is at best stabilized , for Q 100 cfm. The on-vehicle data suggest 38 30 C 20 6...rubber hose 6 70-inch smooth rubber hose + 900 copper elbow + 35-inch smooth rubber tube 7 Sharp 900 elbow at entrance 8 120-inch EPDM * Elastomer...10 35-inch smooth rubber tube + 900 copper elbow + 35-inch smooth rubber tube 11 55-inch EPDM * Elastomer hose Type 494 a. .~)" .A b. direction of q

  17. Instrumentation for propulsion systems development. [high speed fans and turbines

    Science.gov (United States)

    Warshawsky, I.

    1978-01-01

    Apparatus and techniques developed or used by NASA-Lewis to make steady state or dynamic measurements of gas temperature, pressure, and velocity and of the temperature, tip clearance, and vibration of the blades of high-speed fans or turbines are described. The advantages and limitations of each instrument and technique are discussed and the possibility of modifying them for use in developing various propulsion systems is suggested.

  18. GENERALIZATIONS OF KY FAN'S THEOREM ON BEST APPROXIMATIONS

    Institute of Scientific and Technical Information of China (English)

    T.D.Narang

    2009-01-01

    In 1969, Ky Fan[3] proved that for any continuous function f from a compact convex subset M of a normed linear space X into X, there exists x ∈ M such that ||f(x)-x|| = dist(f(x),M). Since then, there have appeared several generalizations, extensions and applications of this result. This paper also deals with some extensions and generalizations of this result when the underlying spaces are convex metric spaces.

  19. The Diagonal Compression Field Method using Circular Fans

    DEFF Research Database (Denmark)

    Hansen, Thomas

    2005-01-01

    This paper presents a new design method, which is a modification of the diagonal compression field method, the modification consisting of the introduction of circular fan stress fields. The traditional method does not allow changes of the concrete compression direction throughout a given beam...... fields may be used whenever changes in the concrete compression direction are desired. To illustrate the new design method, a specific example of a prestressed concrete beam is calculated....

  20. Fans of Columbine shooters Eric Harris and Dylan Klebold

    OpenAIRE

    Andrew Ryan Rico

    2015-01-01

    On April 20, 1999, Eric Harris and Dylan Klebold murdered 12 students and one teacher at Columbine High School in Littleton, Colorado, in what was then the deadliest school shooting in American history. Despite causing a national panic and serving as a flash point for larger narratives on bullying, gun control, and media violence, both boys have gained active online fans. These fandoms dedicated to the Columbine shooters are widely referred to as dark examples of Internet communities, while t...

  1. Aerodynamic optimisation of an industrial axial fan blade

    OpenAIRE

    2006-01-01

    Numerical optimisation methods have successfully been used for a variety of aerodynamic design problems over quite a few years. However the application of these methods to the aerodynamic blade shape optimisation of industrial axial fans has received much less attention in the literature probably given the fact that the majority of resources available to develop these automated design approaches is to be found in the aerospace field. This work presents the develo...

  2. Stable fan filter design using two-variable reactance functions

    Science.gov (United States)

    Bruton, L. T.; Bartley, N. R.

    1982-03-01

    Two-variable reactance transformation (as proposed by King et al., 1982) for the design of stable two-dimensional recursive fan filters with narrow stopbands is compared with the design method proposed by Bruton et al. (1981) using numerical optimization of a resistively terminated (2 + n sub 1 + n sub 2)-port network. The method of King et al. is found to be definitely more simple to design.

  3. iFan iphone风力充电器

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    你还在每天为了寻找为iPhone充电的电源而烦恼么?这里有一款非常给力的iPhone手机配件——iFan iPhone风力充电器。在充当保护套之外它头顶上的风扇可以收集风能转化为电能给iPhone充电。

  4. Evaluation of Retrofit Variable-Speed Furnace Fan Motors

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, R.; Williamson, J.

    2014-01-01

    In conjunction with the New York State Energy Research and Development Authority (NYSERDA) and Proctor Engineering Group, Ltd. (PEG), the Consortium for Advanced Residential Buildings (CARB) has evaluated the Concept 3 (tm) replacement motors for residential furnaces. These brushless, permanent magnet (BPM) motors can use much less electricity than their PSC (permanent split capacitor) predecessors. This evaluation focuses on existing homes in the heating-dominated climate of upstate New York with the goals of characterizing field performance and cost-effectiveness. The results of this study are intended to be useful to home performance contractors, HVAC contractors, and home efficiency program stakeholders. The project includes eight homes in and near Syracuse, NY. Tests and monitoring was performed both before and after fan motors were replaced. Average fan power reductions were approximately 126 Watts during heating and 220 Watts during cooling operation. Over the course of entire heating and cooling seasons, these translated into average electric energy savings of 163 kWh. Average cost savings were $20 per year. Homes where the fan was used outside of heating and cooling mode saved an additional $42 per year on average. Results indicate that BPM replacement motors will be most cost-effective in HVAC systems with longer run times and relatively low duct static pressures. More dramatic savings are possible if occupants use the fan-only setting when there is no thermal load. There are millions of cold-climate, U.S. homes that meet these criteria, but the savings in most homes tested in this study were modest.

  5. Streaming Scholarship: Using Fan Vids to Teach "Harry Potter"

    Science.gov (United States)

    Winters, Sarah Fiona

    2013-01-01

    This article argues that Harry Potter fan vids can be used in the classroom as works of secondary criticism about J. K. Rowling's primary text. It makes two claims: the first is that vids can be read as criticism of a particular text (in this case Harry Potter) alongside other critical essays on that text; the second is that the practice of…

  6. Streaming Scholarship: Using Fan Vids to Teach "Harry Potter"

    Science.gov (United States)

    Winters, Sarah Fiona

    2013-01-01

    This article argues that Harry Potter fan vids can be used in the classroom as works of secondary criticism about J. K. Rowling's primary text. It makes two claims: the first is that vids can be read as criticism of a particular text (in this case Harry Potter) alongside other critical essays on that text; the second is that the practice of…

  7. Auxiliary lift propulsion system with oversized front fan

    Energy Technology Data Exchange (ETDEWEB)

    Castells, O.T.; Johnson, J.E.; Rundell, D.J.

    1980-09-16

    A propulsion system for use primarily in V/STOL aircraft is provided with a variable cycle, double bypass gas turbofan engine and a remote augmenter to produce auxiliary lift. The fan is oversized in air-pumping capability with respect to the cruise flight requirements of the remainder of the engine and a variable area, low pressure turbine is capable of supplying varying amounts of rotational energy to the oversized fan, thereby modulating its speed and pumping capability. During powered lift flight, the variable cycle engine is operated in the single bypass mode with the oversized fan at its maximum pumping capability. In this mode, substantially all of the bypass flow is routed as an auxiliary airstream to the remote augmenter where it is mixed with fuel, burned and exhausted through a vectorable nozzle to produce thrust for lifting. Additional lift is generated by the high energy products of combustion of the variable cycle engine which are further energized in an afterburner and exhausted through a thrust vectorable nozzle at the rear of the engine.

  8. Investigation of fatigue fracture of generator-rotor fan blades

    Energy Technology Data Exchange (ETDEWEB)

    Sameezadeh, Mahmood; Farhangi, Hassan [School of Metallurgy and Materials Engineering, Univ. of Tehran (Iran); Soltani, Nasser [School of Mechanical Engineering, Univ. of Tehran (Iran); Ataei, Peyman [Dept. of Metallurgy and Materials Engineering, South Tehran Branch of Azad Univ., Tehran (Iran)

    2009-11-15

    The failure of a rotating axial flow fan of a 123 MW electric power generator unit is analyzed. The fan was mounted on the generator-rotor at the turbine end. Initial investigations showed that three fan blades had fractured just about 11 h after resuming operation following the last overhaul, causing extensive damage to the unit. The failure of the blades was investigated using fractographic and microstructural characterization techniques as well as mechanical evaluations. Based on fractographic observations high cycle fatigue was identified as the failure mechanism. Formation of multiple primary cracks which coalesced during crack growth to form shallow and semi-elliptical crack geometry was indicative of the influence of additional bending stresses, probably resulting from excessive vibrations. Using fracture mechanics principles, the magnitude of the maximum stress at the time of final fracture of the first broken blade was estimated to be more than 3 times higher than the design operating stress. Furthermore, crack growth lifetime of the blades was evaluated using FRANC3D software. It was found that an operating period of just about one hour was required for small initial cracks to propagate to final failure under the action of excessive bending stresses. (orig.)

  9. Effects of Bifurcations on Aft-Fan Engine Nacelle Noise

    Science.gov (United States)

    Nark, Douglas M.; Farassat, Fereidoun; Pope, D. Stuart; Vatsa, Veer N.

    2004-01-01

    Aft-fan engine nacelle noise is a significant factor in the increasingly important issue of aircraft community noise. The ability to predict such noise within complex duct geometries is a valuable tool in studying possible noise attenuation methods. A recent example of code development for such predictions is the ducted fan noise propagation and radiation code CDUCT-LaRC. This work focuses on predicting the effects of geometry changes (i.e. bifurcations, pylons) on aft fan noise propagation. Beginning with simplified geometries, calculations show that bifurcations lead to scattering of acoustic energy into higher order modes. In addition, when circumferential mode number and the number of bifurcations are properly commensurate, bifurcations increase the relative importance of the plane wave mode near the exhaust plane of the bypass duct. This is particularly evident when the bypass duct surfaces include acoustic treatment. Calculations involving more complex geometries further illustrate that bifurcations and pylons clearly affect modal content, in both propagation and radiation calculations. Additionally, results show that consideration of acoustic radiation results may provide further insight into acoustic treatment effectiveness for situations in which modal decomposition may not be straightforward. The ability of CDUCT-LaRC to handle complex (non-axisymmetric) multi-block geometries, as well as axially and circumferentially segmented liners, allows investigation into the effects of geometric elements (bifurcations, pylons).

  10. Numerical investigation of geometric parameter effects on the aerodynamic performance of a Bladeless fan

    Directory of Open Access Journals (Sweden)

    Mohammad Jafari

    2016-03-01

    Full Text Available Aerodynamic performance of a Bladeless fan is numerically investigated considering the effect of five geometric parameters. Airflow through this fan was analyzed by simulating a Bladeless fan within a 2 m × 2 m × 4 m room. Analysis of the flow field inside the fan and the evaluation of its performance were obtained by solving conservations of mass and momentum equations for the aerodynamic investigations. In order to design the Bladeless fan an Eppler 473 airfoil profile was used as the cross section of the fan. Five distinct parameters, namely height of cross section of the fan, outlet angle of the flow relative to the fan axis, thickness of airflow outlet slit, hydraulic diameter, and aspect ratio for circular and quadratic cross sections were considered. Validating 3-D numerical results, experimental results of a round jet showed good agreement with those of the simulation data. The multiplier factor M is defined to show the ratio of the outlet flow rate to inlet flow rate from the fan. The obtained numerical results showed that the Discharge ratio has the maximum value for the height of 3 cm. The numerical outcomes of outlet thickness variation indicate that this parameter is one of the most influential parameters on the aerodynamic performance of a Bladeless fan. The results for the outlet thicknesses of 1, 2 and 3 mm showed that the Discharge ratio increased significantly when the outlet thickness decreased.

  11. Experimental and Numerical Investigation of a 60cm Diameter Bladeless Fan

    Directory of Open Access Journals (Sweden)

    mohammad jafari

    2016-01-01

    Full Text Available Bladeless fan is a novel type of fan with an unusual geometry and unique characteristics. This type of fan has been recently developed for domestic applications in sizes typically up to 30cm diameter. In the present study, a Bladeless fan with a diameter of 60cm was designed and constructed, in order to investigate feasibility of its usage in various industries with large dimensions. Firstly, flow field passed through this fan was studied by 3D modeling. Aerodynamic and aeroacoustic performance of the fan were considered via solving the conservation of mass and momentum equations in their unsteady form. To validate the acoustic code, NACA 0012 airfoil was simulated in a two dimension domain and the emitted noise was calculated for Re=2×105. Good agreement between numerical and experimental results was observed by applying FW-H equations for predicting noise of the fan. To validate the simulated aerodynamic results, a Bladeless fan with a 60cm diameter was constructed and experimentally tested. In addition, the difference between the experimental and numerical results was acceptable for this fan. Moreover, the experimental results in the present study showed that this fan is capable to be designed and used for various industrial applications.

  12. Health assessment of cooling fan bearings using wavelet-based filtering.

    Science.gov (United States)

    Miao, Qiang; Tang, Chao; Liang, Wei; Pecht, Michael

    2012-12-24

    As commonly used forced convection air cooling devices in electronics, cooling fans are crucial for guaranteeing the reliability of electronic systems. In a cooling fan assembly, fan bearing failure is a major failure mode that causes excessive vibration, noise, reduction in rotation speed, locked rotor, failure to start, and other problems; therefore, it is necessary to conduct research on the health assessment of cooling fan bearings. This paper presents a vibration-based fan bearing health evaluation method using comblet filtering and exponentially weighted moving average. A new health condition indicator (HCI) for fan bearing degradation assessment is proposed. In order to collect the vibration data for validation of the proposed method, a cooling fan accelerated life test was conducted to simulate the lubricant starvation of fan bearings. A comparison between the proposed method and methods in previous studies (i.e., root mean square, kurtosis, and fault growth parameter) was carried out to assess the performance of the HCI. The analysis results suggest that the HCI can identify incipient fan bearing failures and describe the bearing degradation process. Overall, the work presented in this paper provides a promising method for fan bearing health evaluation and prognosis.

  13. Health Assessment of Cooling Fan Bearings Using Wavelet-Based Filtering

    Directory of Open Access Journals (Sweden)

    Qiang Miao

    2012-12-01

    Full Text Available As commonly used forced convection air cooling devices in electronics, cooling fans are crucial for guaranteeing the reliability of electronic systems. In a cooling fan assembly, fan bearing failure is a major failure mode that causes excessive vibration, noise, reduction in rotation speed, locked rotor, failure to start, and other problems; therefore, it is necessary to conduct research on the health assessment of cooling fan bearings. This paper presents a vibration-based fan bearing health evaluation method using comblet filtering and exponentially weighted moving average. A new health condition indicator (HCI for fan bearing degradation assessment is proposed. In order to collect the vibration data for validation of the proposed method, a cooling fan accelerated life test was conducted to simulate the lubricant starvation of fan bearings. A comparison between the proposed method and methods in previous studies (i.e., root mean square, kurtosis, and fault growth parameter was carried out to assess the performance of the HCI. The analysis results suggest that the HCI can identify incipient fan bearing failures and describe the bearing degradation process. Overall, the work presented in this paper provides a promising method for fan bearing health evaluation and prognosis.

  14. Large scale application of vibration sensors for fan monitoring at commercial layer hen houses.

    Science.gov (United States)

    Chen, Yan; Ni, Ji-Qin; Diehl, Claude A; Heber, Albert J; Bogan, Bill W; Chai, Li-Long

    2010-01-01

    Continuously monitoring the operation of each individual fan can significantly improve the measurement quality of aerial pollutant emissions from animal buildings that have a large number of fans. To monitor the fan operation by detecting the fan vibration is a relatively new technique. A low-cost electronic vibration sensor was developed and commercialized. However, its large scale application has not yet been evaluated. This paper presents long-term performance results of this vibration sensor at two large commercial layer houses. Vibration sensors were installed on 164 fans of 130 cm diameter to continuously monitor the fan on/off status for two years. The performance of the vibration sensors was compared with fan rotational speed (FRS) sensors. The vibration sensors exhibited quick response and high sensitivity to fan operations and therefore satisfied the general requirements of air quality research. The study proved that detecting fan vibration was an effective method to monitor the on/off status of a large number of single-speed fans. The vibration sensor itself was $2 more expensive than a magnetic proximity FRS sensor but the overall cost including installation and data acquisition hardware was $77 less expensive than the FRS sensor. A total of nine vibration sensors failed during the study and the failure rate was related to the batches of product. A few sensors also exhibited unsteady sensitivity. As a new product, the quality of the sensor should be improved to make it more reliable and acceptable.

  15. Study on the performance improvement of multiblade fans. Effects of suction cones; Tayoku fan no seino kaizen ni kansuru kenkyu. Suction cone no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Kuratani, F.; Ogawa, T. [Hyogo University of Teacher Education, Hyogo (Japan); Yamamoto, S.

    1999-07-25

    In order to improve the performance of a multiblade fan, the effects of three types of suction cones of the fan casing on the fan efficiency and noise are investigated experimentally. The first type of the suction cone is the insertion type, which is inserted into the inside of the fan impeller. The second type is the extrusion type, which extrudes outside from the casing surface. The third type is the combination type of two types. The results of those three types are compared with those of the commonly used suction cone. The followings are made clear: (1) The insertion type and the extrusion type are effective in improving the efficiency and reducing noise. (2) The optimal lengths of the insertion and the extrusion exist. (3) The combination type is more effective in improving the efficiency. (4) The combination type with the skewed cutoff of the fan casing shows the best effect. (author)

  16. Golden Jubilee Event for Cinema Fans

    CERN Multimedia

    2004-01-01

    As part of the Organisation's Fiftieth Anniversary celebrations the CERN CineClub will be showing a special series of films beginning with works by British, French, German, Norwegian and Spanish directors. The Club hopes to include films from all of the Member States in the programme. CERN's linguistic and cultural diversity will be celebrated from mid-February onwards when the CERN CineClub, whose summer English language film season will be familiar to many of you, plans to show a series of films from CERN's 20 Member States. The programme marks the CineClub's contribution to CERN's fiftieth anniversary festivities. The first film, "Four weddings and a funeral" (Mike Newell, 1994), will be shown in the Main Auditorium on 12 February. Next in the series will be films from Germany (Himmel über Berlin, or "The Wings of Desire", by Wim Wenders, 1987), Spain (Los Lunes al Sol, or "Mondays in the Sun", by Fernando Leon de Aranoa, 2002), France ( Diva , by Jean Jacques Beinex, 1981) and Norway (Elling, b...

  17. The Tip Leakage Flow Structure of an Axial Fan with Tip Clearance

    Institute of Scientific and Technical Information of China (English)

    竺晓程; 杜朝辉; 林万来

    2003-01-01

    Experiment and numerical simulation technique are used to investigate the tip leakage flow in an axial fanwith tip clearance at the design condition. The flow field in the tip region of fan is measured using a PDA (ParticleDynamics Analysis) system. The flow is surveyed across the whole passage at fifteen axial locations (from the100% axial chord in front of the leading edge to the 100% axial chord behind the trailing edge), mainly focusing onthe outer 90% blade span. Both experiment measurement and numerical simulation indicates the leakage flow orig-inated from the tip clearance along the chord rolls-up into three-dimensional spiral structure to form leakage flowvortex. The interaction of leakage flow and main flow will produce the low velocity zone, and block the flow. Theleakage flow almost occupies the most part of flow passage behind the trailing edge.

  18. VELOCITY MEASUREMENTS FOR A SOLAR ACTIVE REGION FAN LOOP FROM HINODE/EIS OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Young, P. R. [College of Science, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States); O' Dwyer, B.; Mason, H. E. [Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA (United Kingdom)

    2012-01-01

    The velocity pattern of a fan loop structure within a solar active region over the temperature range 0.15-1.5 MK is derived using data from the EUV Imaging Spectrometer (EIS) on board the Hinode satellite. The loop is aligned toward the observer's line of sight and shows downflows (redshifts) of around 15 km s{sup -1} up to a temperature of 0.8 MK, but for temperatures of 1.0 MK and above the measured velocity shifts are consistent with no net flow. This velocity result applies over a projected spatial distance of 9 Mm and demonstrates that the cooler, redshifted plasma is physically disconnected from the hotter, stationary plasma. A scenario in which the fan loops consist of at least two groups of 'strands'-one cooler and downflowing, the other hotter and stationary-is suggested. The cooler strands may represent a later evolutionary stage of the hotter strands. A density diagnostic of Mg VII was used to show that the electron density at around 0.8 MK falls from 3.2 Multiplication-Sign 10{sup 9} cm{sup -3} at the loop base, to 5.0 Multiplication-Sign 10{sup 8} cm{sup -3} at a projected height of 15 Mm. A filling factor of 0.2 is found at temperatures close to the formation temperature of Mg VII (0.8 MK), confirming that the cooler, downflowing plasma occupies only a fraction of the apparent loop volume. The fan loop is rooted within a so-called outflow region that displays low intensity and blueshifts of up to 25 km s{sup -1} in Fe XII {lambda}195.12 (formed at 1.5 MK), in contrast to the loop's redshifts of 15 km s{sup -1} at 0.8 MK. A new technique for obtaining an absolute wavelength calibration for the EIS instrument is presented and an instrumental effect, possibly related to a distorted point-spread function, that affects velocity measurements is identified.

  19. Staging Mobilities

    DEFF Research Database (Denmark)

    Jensen, Ole B.

    that mobility is more than movement between point A and B. It explores how the movement of people, goods, information, and signs influences human understandings of self, other and the built environment. Moving towards a new understanding of the relationship between movement, interaction and environments......In recent years, the social sciences have taken a “mobilities turn.” There has been a developing realisation that mobilities do not “just happen.” Mobilities are carefully and meticulously designed, planned and staged (from above). However, they are equally importantly acted out, performed...... and lived as people are “staging themselves” (from below). Staging mobilities is a dynamic process between “being staged” (for example, being stopped at traffic lights) and the “mobile staging” of interacting individuals (negotiating a passage on the pavement). Staging Mobilities is about the fact...

  20. Seismic reflection survey in Omama fan area, Gunma prefecture; Gunma Omama senjochi ni okeru hanshaho jishin tansa

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, K.; Kano, N.; Yokokura, T.; Kiguchi, T.; Yokota, T.; Matsushima, J. [Geological Survey of Japan, Tsukuba (Japan)

    1996-10-01

    Seismic reflection survey was performed for the Medial Tectonic Line, an important geological tectonic line in the Kanto plains, at Kushibiki district, Saitama prefecture in the north-western part of the Kanto plains. It was estimated that movements of the basement were different in the individual sides of the active fault. In this study, the seismic reflection survey was performed at the Omama fan area, Gunma prefecture, which is located at the north-eastern extension of the Kushibiki plateau, to grasp the structure of basement to the depth of about 1.0 s of return travel time, and the upper sediments. Two traverse lines passing Ota city, Kiryu city, and Nitta town were used. Southern part of the traverse line-1 was in the bottom land in the middle of Tone river, and northern part was in the Omama fan area. The ground surface along the traverse line was flat. Hachioji heights are the heights elongating in the NW-SE direction and having relative height of 100 to 200 m against the surrounding plain. Another traverse line-2 was set on the steep slope having relative height more than 100 m. The Brute stack time section of each traverse line was characterized by the gradient reflection surface AA of the traverse line-1. It was suggested that the AA or intermittent parts of reflection surfaces deeper than AA may relate to the tectonic lines in the more ancient geological ages. 2 figs., 1 tab.

  1. Design and Research of Intelligent Remote Control Fan Based on Single Chip Microcomputer and Bluetooth Technology

    Directory of Open Access Journals (Sweden)

    Zhang Xue-Xia

    2017-01-01

    Full Text Available This paper is designed for intelligent remote control fans. The design of the microcontroller as the core, the sensor, Bluetooth and Andrews system applied to the design of intelligent remote control fan. According to the temperature sensor to achieve the indoor temperature collection, to achieve and set the temperature comparison, thus affecting the fan speed. At the same time, the system according to the infrared sensor components to detect external factors, in order to achieve the running or stopping of the fan, that is, to achieve intelligent control of the fan. In addition, the system achieve the Bluetooth and mobile phone Andrews system of effective combination, and through the software program to complete the fan remote operation and wind speed control.

  2. Numerical simulation of air flow field in high-pressure fan with splitter blades

    Institute of Scientific and Technical Information of China (English)

    Jianfeng LI; Junfu LU; Hai ZHANG; Qing LIU; Guangxi YUE

    2008-01-01

    For a deeper understanding of the flow char-acteristics in the high-pressure centrifugal blower of a fan of Model 9-26 with splitter blades, a three dimensional (3-D) numerical simulation of air flows in the fan was con-ducted with FLUENT software. The standard k-ε tur-bulent model and unstructured grids were used. The computational fluid dynamics (CFD) results showed that the performance of a fan could be improved by adding the splitter blades in the channel among the leaf blades. Under operational conditions, with the presence of splitter blades, the air flow rate of the fan increased about 5% and the total pressure at the outlet of the fan increased about 10% on average. It was also found that the length of the splitter blades affected the air flow and pressure drop. There is an optimal value for the length. The simulation results provide helpful information for improving the fan performance.

  3. “They All Lived Happily Ever After. Obviously.”: Realism and Utopia in Game of Thrones-Based Alternate Universe Fairy Tale Fan Fiction

    Directory of Open Access Journals (Sweden)

    Anne Kustritz

    2016-06-01

    Full Text Available Fan fiction alternate universe stories (AUs that combine Game of Thrones characters and settings with fairy tale elements construct a dialogue between realism and wonder. Realism performs a number of functions in various genres, but becomes a particularly tricky concept to tie down in fantasy. Deployments of realism in “quality TV” series like Game of Thrones often reinforce social stigmatization of feminine genres like the romance, melodrama, and fairy tale. The happily-ever-after ending receives significant feminist criticism partly because it falls within a larger framework of utopian politics and poetics, which are frequently accused of essentialism and authoritarianism. However, because fan fiction cultures place all stories in dialogue with numerous other equally plausible versions, the fairy tale happy ending can serve unexpected purposes. By examining several case studies in fairy tale AU fan fiction based on Game of Thrones characters, situations, and settings, this paper demonstrates the genre’s ability to construct surprising critiques of real social and historical situations through strategic deployment of impossible wishes made manifest through the magic of fan creativity.

  4. Major Holocene block-and-ash fan at the western slope of ice-capped Pico de Orizaba volcano, México: Implications for future hazards

    Science.gov (United States)

    Siebe, Claus; Abrams, Michael; Sheridan, Michael F.

    1993-12-01

    A major block-and-ash fan extends more than 14 km westward from the summit of Pico de Orizaba volcano in the eastern part of the Trans-Mexican Volcanic Belt. Radiocarbon dating of charcoal within the fan deposits yielded Holocene ages that range between 4040 ± 80 and 4660 ± 100 y.B.P. Stratigraphical, sedimentological, geochemical, and scanning electron microscope studies indicate that this fan originated within a relatively short time-span by multiple volcanic explosions at the summit crater. This activity produced a series of pyroclastic flows (mainly block-and-ash flows) and lahars which were channelized by a glacial cirque and connecting U-shaped valleys as they descended toward the base of the volcano. A recurrence of a similar eruption today would pose severe hazards to the population of more than 50,000 people, who live in a potentially dangerous zone. A detailed reconstruction of the sequence of events that led to the formation of the block-and-ash fan is presented to help mitigate the risk. Special attention is given to the effects of an ice-cap and the role of pre-existing glacial morphology on the distribution of products from such an eruption.

  5. Acoustic testing of a 1.5 pressure ratio low tip speed fan with a serrated rotor (QEP fan B scale model). [reduction of engine noise

    Science.gov (United States)

    Kazin, S. B.; Paas, J. E.; Minzner, W. R.

    1973-01-01

    A scale model of the bypass flow region of a 1.5 pressure ratio, single stage, low tip speed fan was tested with a serrated rotor leading edge to determine its effects on noise generation. The serrated rotor was produced by cutting teeth into the leading edge of the nominal rotor blades. The effects of speed and exhaust nozzle area on the scale models noise characteristics were investigated with both the nominal rotor and serrated rotor. Acoustic results indicate the serrations reduced front quadrant PNL's at takeoff power. In particular, the 200 foot (61.0 m) sideline noise was reduced from 3 to 4 PNdb at 40 deg for nominal and large nozzle operation. However, the rear quadrant maximum sideline PNL's were increased 1.5 to 3 PNdb at approach thust and up to 2 PNdb at takeoff thust with these serrated rotor blades. The configuration with the serrated rotor produced the lowest maximum 200 foot (61.0 m) sideline PNL for any given thust when the large nozzle (116% of design area) was employed.

  6. Tectonic and climatic controls on fan systems: The Kohrud mountain belt, Central Iran

    Science.gov (United States)

    Jones, Stuart J.; Arzani, Nasser; Allen, Mark B.

    2014-04-01

    Late Pleistocene to Holocene fans of the Kohrud mountain belt (Central Iran) illustrate the problems of differentiating tectonic and climatic drivers for the sedimentary signatures of alluvial fan successions. It is widely recognised that tectonic processes create the topography that causes fan development. The existence and position of fans along the Kohrud mountain belt, NE of Esfahan, are controlled by faulting along the Qom-Zefreh fault system and associated fault zones. These faults display moderate amounts of historical and instrumental seismicity, and so may be considered to be tectonically active. However, fluvial systems on the fans are currently incising in response to low Gavkhoni playa lake levels since the mid-Holocene, producing incised gullies on the fans up to 30 m deep. These gullies expose an interdigitation of lake deposits (dominated by fine-grained silts and clays with evaporites) and coarse gravels that characterise the alluvial fan sediments. The boundaries of each facies are mostly sharp, with fan sediments superimposed on lake sediments with little to no evidence of reworking. In turn, anhydrite-glauberite, mirabilite and halite crusts drape over the gravels, recording a rapid return to still water, shallow ephemeral saline lake sedimentation. Neither transition can be explained by adjustment of the hinterland drainage system after tectonic uplift. The potential influence in Central Iran of enhanced monsoons, the northward drift of the Intertopical Convergence Zone (ITCZ) and Mediterranean climates for the early Holocene (~ 6-10 ka) point to episodic rainfall (during winter months) associated with discrete high magnitude floods on the fan surfaces. The fan sediments were deposited under the general influence of a highstand playa lake whose level was fluctuating in response to climate. This study demonstrates that although tectonism can induce fan development, it is the sensitive balance between aridity and humidity resulting from changes in

  7. Seafloor-precipitated carbonate fans in the Neoproterozoic Rainstorm Member, Johnnie Formation, Death Valley Region, USA

    OpenAIRE

    Pruss, Sara Brady; Corsetti, Frank A.; Fischer, Woodward W.

    2008-01-01

    Cm-sized carbonate seafloor fans occur in the Neoproterozoic Rainstorm Member of the Johnnie Formation, Death Valley, USA. The fans formed in a mixed carbonate-clastic succession near storm wave base at the base of parasequences on a storm-dominated ramp. Petrographic observations indicate that the fans were originally precipitated as aragonite and later inverted to calcite during diagenesis. Although not directly dated, the Rainstorm Member preserves a large magnitude negative carbon isotopi...

  8. Alluvial fan flooding in the Department of Pocito, Province of San Juan, Argentina

    Institute of Scientific and Technical Information of China (English)

    LauraPatriciaPerucca; JuanParedes

    2004-01-01

    The study consists of the identification of landforms subject to alluvial fan flooding in active sectors of the Zonda range piedmont. In the Department of Pocito, located about 5 km southwest of San Juan City, a series of alluvial fans have been identified. These alluvial fans are located downstream of the natural drainage basins covering an area of approximately 130 km2 towards the eastern slopes of the Zonda range at a median elevation of 2,000 m a.s.l.

  9. Quantitative reconstruction of late Holocene surface evolution on an alpine debris-flow fan

    Science.gov (United States)

    Schürch, Peter; Densmore, Alexander L.; Ivy-Ochs, Susan; Rosser, Nick J.; Kober, Florian; Schlunegger, Fritz; McArdell, Brian; Alfimov, Vasili

    2016-12-01

    Debris-flow fans form a ubiquitous record of past debris-flow activity in mountainous areas, and may be useful for inferring past flow characteristics and consequent future hazard. Extracting information on past debris flows from fan records, however, requires an understanding of debris-flow deposition and fan surface evolution; field-scale studies of these processes have been very limited. In this paper, we document the patterns and timing of debris-flow deposition on the surface of the large and exceptionally active Illgraben fan in southwestern Switzerland. We use terrain analysis, radiocarbon dating of sediment fill in the Illgraben catchment, and cosmogenic 10Be and 36Cl exposure dating of debris-flow deposits on the fan to constrain the temporal evolution of the sediment routing system in the catchment and on the fan during the past 3200 years. We show that the fan surface preserves a set of debris-flow lobes that were predominantly deposited after the occurrence of a large rock avalanche near the fan apex at about 3200 years ago. This rock avalanche shifted the apex of the fan and impounded sediment within the Illgraben catchment. Subsequent evolution of the fan surface has been governed by both lateral and radial shifts in the active depositional lobe, revealed by the cosmogenic radionuclide dates and by cross-cutting geometrical relationships on the fan surface. This pattern of frequent avulsion and fan surface occupation provides field-scale evidence of the type of large-scale compensatory behavior observed in experimental sediment routing systems.

  10. Low-pressure reversible axial fan with straight profile blades and relatively high efficiency

    OpenAIRE

    2012-01-01

    The paper presents the design and operating characteristics of a model of reversible axial fan with only one impeller, whose reversibility is achieved by changing the direction of rotation. The fan is designed for the purpose of providing alternating air circulation in wood dryers in order to reduce the consumption of electricity for the fan and increase energy efficiency of the entire dryer. To satisfy the reversibility of flow, the shape of the blade profile is symmetrical along the l...

  11. Timing and nature of alluvial fan development along the Chajnantor Plateau, northern Chile

    Science.gov (United States)

    Cesta, Jason M.; Ward, Dylan J.

    2016-11-01

    Alluvial systems in the Atacama Desert provide a unique opportunity to elucidate the sedimentary response to climate variability, particularly changes in precipitation, in hyperarid environments. Alluvial fans along the eastern margin of the Salar de Atacama, adjacent to the Chajnantor Plateau in the Atacama Desert of northern Chile, provide an archive of climate-modulated sediment transfer and erosion at an extreme of Earth's climate. Three regional alluvial fan surfaces (Qf1 [oldest] to Qf3 [youngest]) were mapped along the western flank of the Chajnantor Plateau. The alluvial fans were examined with geomorphic and terrestrial cosmogenic 36Cl surface exposure dating methods to define the timing of alluvial fan formation and to determine the role of climatic processes on fan development in a hyperarid environment. Alluvial fans in the study area are comprised of hyperconcentrated flow and boulder-rich debris flow deposits that reflect deposition transitioning between cohesive and noncohesive regimes. Alluvial fan surfaces yield exposure ages that range from 49.6 ± 4.4 to 194 ± 12 ka, while debris flow boulders yield exposure ages ranging from 12.4 ± 2.1 to 229 ± 53 ka. Cosmogenic 36Cl exposure ages indicate that abandonment of alluvial fan surfaces Qf1, Qf2, and Qf3 date to 175 ± 22.6 ka (MIS 6), 134.5 ± 9.18 ka (MIS 6), and 20.07 ± 6.26 ka (MIS 2), respectively. A 36Cl concentration-depth profile through alluvial fan Qf1 suggests a simple depositional history with minimal nuclide inheritance implying relatively rapid aggradation (6 m in ca. 25 kyr) followed by surface abandonment ca. 180-200 ka. Our data support a strong climatic control on alluvial fan evolution in the region, and we propose that the alluvial fans along the margins of the Salar de Atacama form according to the humid model of fan formation.

  12. Multi-objective optimization design and experimental investigation of centrifugal fan performance

    Science.gov (United States)

    Zhang, Lei; Wang, Songling; Hu, Chenxing; Zhang, Qian

    2013-11-01

    Current studies of fan performance optimization mainly focus on two aspects: one is to improve the blade profile, and another is only to consider the influence of single impeller structural parameter on fan performance. However, there are few studies on the comprehensive effect of the key parameters such as blade number, exit stagger angle of blade and the impeller outlet width on the fan performance. The G4-73 backward centrifugal fan widely used in power plants is selected as the research object. Based on orthogonal design and BP neural network, a model for predicting the centrifugal fan performance parameters is established, and the maximum relative errors of the total pressure and efficiency are 0.974% and 0.333%, respectively. Multi-objective optimization of total pressure and efficiency of the fan is conducted with genetic algorithm, and the optimum combination of impeller structural parameters is proposed. The optimized parameters of blade number, exit stagger angle of blade and the impeller outlet width are seperately 14, 43.9°, and 21 cm. The experiments on centrifugal fan performance and noise are conducted before and after the installation of the new impeller. The experimental results show that with the new impeller, the total pressure of fan increases significantly in total range of the flow rate, and the fan efficiency is improved when the relative flow is above 75%, also the high efficiency area is broadened. Additionally, in 65% -100% relative flow, the fan noise is reduced. Under the design operating condition, total pressure and efficiency of the fan are improved by 6.91% and 0.5%, respectively. This research sheds light on the considering of comprehensive effect of impeller structrual parameters on fan performance, and a new impeller can be designed to satisfy the engineering demand such as energy-saving, noise reduction or solving air pressure insufficiency for power plants.

  13. Low-pressure reversible axial fan with straight profile blades and relatively high efficiency

    OpenAIRE

    Spasić Živan T.; Milanović Saša M.; Šušteršič Vanja M.; Nikolić Boban D.

    2012-01-01

    The paper presents the design and operating characteristics of a model of reversible axial fan with only one impeller, whose reversibility is achieved by changing the direction of rotation. The fan is designed for the purpose of providing alternating air circulation in wood dryers in order to reduce the consumption of electricity for the fan and increase energy efficiency of the entire dryer. To satisfy the reversibility of flow, the shape of the blade profile is symmetrical along the l...

  14. Serpentine Diffuser Performance with Emphasis on Future Introduction to a Transonic Fan (Postprint)

    Science.gov (United States)

    2013-01-01

    AFRL-RQ-WP-TP-2014-0168 SERPENTINE DIFFUSER PERFORMANCE WITH EMPHASIS ON FUTURE INTRODUCTION TO A TRANSONIC FAN (POSTPRINT) Chase A...June 2012 – 01 December 2012 4. TITLE AND SUBTITLE SERPENTINE DIFFUSER PERFORMANCE WITH EMPHASIS ON FUTURE INTRODUCTION TO A TRANSONIC FAN...resulting in an overall recovery factor of 0.983. Distortion descriptors are presented and discussed. 15. SUBJECT TERMS diffuser , transonic fan

  15. Vibration Characteristics Determined for Stainless Steel Sandwich Panels With a Metal Foam Core for Lightweight Fan Blade Design

    Science.gov (United States)

    Ghosn, Louis J.; Min, James B.; Raj, Sai V.; Lerch, Bradley A.; Holland, Frederic A., Jr.

    2004-01-01

    The goal of this project at the NASA Glenn Research Center is to provide fan materials that are safer, weigh less, and cost less than the currently used titanium alloy or polymer matrix composite fans. The proposed material system is a sandwich fan construction made up of thin solid face sheets and a lightweight metal foam core. The stiffness of the sandwich structure is increased by separating the two face sheets by the foam layer. The resulting structure has a high stiffness and lighter weight in comparison to the solid facesheet material alone. The face sheets carry the applied in-plane and bending loads (ref. 1). The metal foam core must resist the transverse shear and transverse normal loads, as well as keep the facings supported and working as a single unit. Metal foams have ranges of mechanical properties, such as light weight, impact resistance, and vibration suppression (ref. 2), which makes them more suitable for use in lightweight fan structures. Metal foams have been available for decades (refs. 3 and 4), but the difficulties in the original processes and high costs have prevented their widespread use. However, advances in production techniques and cost reduction have created a new interest in this class of materials (ref. 5). The material chosen for the face sheet and the metal foam for this study was the aerospace-grade stainless steel 17-4PH. This steel was chosen because of its attractive mechanical properties and the ease with which it can be made through the powder metallurgy process (ref. 6). The advantages of a metal foam core, in comparison to a typical honeycomb core, are material isotropy and the ease of forming complex geometries, such as fan blades. A section of a 17-4PH sandwich structure is shown in the following photograph. Part of process of designing any blade is to determine the natural frequencies of the particular blade shape. A designer needs to predict the resonance frequencies of a new blade design to properly identify a useful

  16. Staging atmospheres

    DEFF Research Database (Denmark)

    Bille, Mikkel; Bjerregaard, Peter; Sørensen, Tim Flohr

    2015-01-01

    The article introduces the special issue on staging atmospheres by surveying the philosophical, political and anthropological literature on atmosphere, and explores the relationship between atmosphere, material culture, subjectivity and affect. Atmosphere seems to occupy one of the classic...... localities of tensions between matter and the immaterial, the practical and the ideal, and subject and object. In the colloquial language there can, moreover, often seem to be something authentic or genuine about atmosphere, juxtaposing it to staging, which is implied to be something simulated or artificial....... This introduction seeks to outline how a number of scholars have addressed the relationship between staged atmospheres and experience, and thus highlight both the philosophical, social and political aspects of atmospheres...

  17. An experimental investigation of two 15 percent-scale wind tunnel fan-blade designs

    Science.gov (United States)

    Signor, David B.

    1988-01-01

    An experimental 3-D investigation of two fan-blade designs was conducted. The fan blades tested were 15 percent-scale models of blades to be used in the fan drive of the National Full-Scale Aerodynamic Complex at NASA Ames Research Center. NACA 65- and modified NACA 65-series sections incorporated increased thickness on the upper surface, between the leading edge and the one-half-chord position. Twist and taper were the same for both blade designs. The fan blades with modified 65-series sections were found to have an increased stall margin when they were compared with the unmodified blades.

  18. Two-dimensional model of a slow-mode expansion fan at Io

    Science.gov (United States)

    Krisko, P. H.; Hill, T. W.

    1991-01-01

    A 2D model for the standing slow-mode expansion fan that is expected to exist downstream of the Jovian moon Io is developed. The leading edge of the expansion fan makes an angle of 45 deg with the upstream magnetic field direction, and the fan width is about 114 deg. The plasma flow returns to its upstream direction by way of a slow-mode shock behind Io where the MHD parameters return asymptotically to their upstream conditions. The magnetic field perturbation within the fan is much smaller than that associated with the Alfven wing, which lies farther upstream.

  19. Numerical and experimental study on aerodynamic performance of small axial flow fan with splitter blades

    Science.gov (United States)

    Zhu, Lifu; Jin, Yingzi; Li, Yi; Jin, Yuzhen; Wang, Yanping; Zhang, Li

    2013-08-01

    To improve the aerodynamic performance of small axial flow fan, in this paper the design of a small axial flow fan with splitter blades is studied. The RNG k-ɛ turbulence model and SIMPLE algorithm were applied to the steady simulation calculation of the flow field, and its result was used as the initial field of the large eddy simulation to calculate the unsteady pressure field. The FW-H noise model was adopted to predict aerodynamic noise in the six monitoring points. Fast Fourier transform algorithm was applied to process the pressure signal. Experiment of noise testing was done to further investigate the aerodynamic noise of fans. And then the results obtained from the numerical simulation and experiment were described and analyzed. The results show that the static characteristics of small axial fan with splitter blades are similar with the prototype fan, and the static characteristics are improved within a certain range of flux. The power spectral density at the six monitoring points of small axial flow fan with splitter blades have decreased to some extent. The experimental results show sound pressure level of new fan has reduced in most frequency bands by comparing with prototype fan. The research results will provide a proof for parameter optimization and noise prediction of small axial flow fans with high performance.

  20. Experimental Investigation on Design Enhancement of Axial Fan Using Fixed Guide Vane

    Science.gov (United States)

    Munisamy, K. M.; Govindasamy, R.; Thangaraju, S. K.

    2015-09-01

    Airflow passes through the rotating blade in an axial flow fan will experience a helical flow pattern. This swirling effect leads the system to experience swirl energy losses or pressure drop yet reducing the total efficiency of the fan system. A robust tool to encounter this air spin past the blade is by introducing guide vane to the system. Owing to its importance, a new approach in designing outlet guide vane design for a commercial usage 1250mm diameter axial fan with a 30° pitch angle impeller has been introduced in this paper. A single line metal of proper curvature guide vane design technique has been adopted for this study. By choosing fan total efficiency as a target variable to be improved, the total and static pressure on the design point were set to be constraints. Therefore, the guide vane design was done based on the improvement target on the static pressure in system. The research shows that, with the improvement in static pressure by 29.63% through guide vane installation, the total fan efficiency is increased by 5.12%, thus reduces the fan power by 5.32%. Good agreement were found, that when the fan total efficiency increases, the power consumption of the fan is reduced. Therefore, this new approach of guide vane design can be applied to improve axial fan performance.