WorldWideScience

Sample records for air cushion vehicles

  1. Nuclear air cushion vehicles.

    Science.gov (United States)

    Anderson, J. L.

    1973-01-01

    This paper serves several functions. It identifies the 'state-of-the-art' of the still-conceptual nuclear air cushion vehicle, particularly the nuclear powerplant. Using mission studies and cost estimates, the report describes some of the advantages of nuclear power for large air cushion vehicles. The paper also summarizes the technology studies on mobile nuclear powerplants and conceptual ACV systems/missions studies that have been performed at NASA Lewis Research Center.

  2. Air cushion vehicles: A briefing

    Science.gov (United States)

    Anderson, J. L.; Finnegan, P. M.

    1971-01-01

    Experience and characteristics; the powering, uses, and implications of large air cushion vehicles (ACV); and the conceptual design and operation of a nuclear powered ACV freighter and supporting facilities are described.

  3. Air cushion vehicles - Any potential for Canada?

    Science.gov (United States)

    Laframboise, J. F.

    1987-09-01

    The present evaluation of air cushion vehicle (ACV) operational and commercial suitability in the Canadian context notes that the most successful and durable ACV applications are those in which only ACVs can perform the required mission. An important factor is the reliability of the craft being tested in a given field of operations. Because of their low ground pressure, ACVs can operate over low-cost trails with an efficiency that compares with that of trucks over conventional roads; this renders them especially attractive for transportation networks in the North West Territories.

  4. Air cushion vehicles for arctic operation

    Science.gov (United States)

    Koleser, J.; Lavis, D. R.

    1986-09-01

    Attention is given to the results of the NAVSEA FY85 Surface Ship Concept Formulation Design Study for an initial operational capability year-2000 air cushion vehicle (ACV) suitable for logistics and general search/rescue duties in the Arctic. Two designs were developed during the study; the first utilized an ACV design synthesis math model while the second evolved as a derivative of an existing U.S. production craft. Both are regarded as feasible from an engineering and naval architectural standpoint. Results of performance and cost trade-off studies suggest that, for an Arctic ACV, gas turbines are the preferred power plant choice and an aluminum alloy is the preferred hull structural material choice. The most appropriate skirt height is approximately 12 ft.

  5. Simulation study of plane motion of air cushion vehicle

    Institute of Scientific and Technical Information of China (English)

    ZHAO Shu-qin; SHI Xiao-cheng; SHI Yi-long; BIAN Xin-qian

    2003-01-01

    This research is on horizontal plane motion equations of Air Cushion Vehicle (ACV) and its simulation. To investigate this, a lot of simulation study including ACV's voyage and turning performance has been done. It was found that the voyage simulation results were accorded with ACV own characteristic and turning simulation results were accorded with USA ACV's movement characteristic basically.

  6. Simulation study of plane motion of air cushion vehicle

    Science.gov (United States)

    Zhao, Shu-Qin; Shi, Xiao-Cheng; Shi, Yi-Long; Bian, Xin-Qian

    2003-12-01

    This research is on horizontal plane motion equations of Air Cushion Vehicle (ACV) and its simulation. To investigate this, a lot of simulation study including ACV’s voyage and turning performance has been done. It was found that the voyage simulation results were accorded with ACV own characteristic and turning simulation results were accorded with USA ACV’s movement characteristic basically.

  7. Developments in skirt systems for air cushion vehicles

    Science.gov (United States)

    Inch, Peter; Prentice, Mark E.; Lewis, Carol Jean

    The present evaluation of the development status of air-cushion vehicle (ACV) skirts emphasizes the materials employed, with a view to the formulation of materials-performance requirements for next-generation AVCs and, in particular, an 'air-cushion catamaran' surface-effect ship (SES). Attention is given to novel skirt-design features which furnish substantial savings in maintenance costs. The employment of extant test rig data and the use of CAD methods are discussed, and the features of a novel system for the direct fixing of a bow finger onto an SES structure are noted.

  8. Northwest passage: Trade route for large air cushion vehicles

    Science.gov (United States)

    Anderson, J. L.

    1973-01-01

    A conceptual vehicle and powerplant (10,000-ton) nuclear-powered air-cushion vehicle (ACV) that could open the Northwest Passage and other Arctic passages to commercial traffic is identified. The report contains a description of the conceptual vehicle, including the powerplant and operations, an assessment of technical feasibility, estimates of capital and operating costs, and identification of eligible cargo and markets. A comparison of the nuclear ACV freighter with nuclear container ships shows that for containerized or roll-on/roll-off cargo the ACV would provide greatly reduced transit time between North Atlantic and North Pacific ports at a competitive cost.

  9. Thirty years of research and development of air cushion vehicles

    Science.gov (United States)

    Bertelsen, William R.

    This paper describes the conception of the air cushion vehicle (ACV) from experiments with the ground effect of a VTOL aircraft model. Then it describes the evolution of the ultimate ACV drive system through building and testing many models and 16 full-scale ACV to arrive at complete controllability. Adequate control of the frictionless craft, which are without inherent yaw stability, requires control force of the order of magnitude of propulsion. The derived gimbal fans provide such control force in the form of direct thrust, which is instantly available in any of 360 degrees, meterable, instantly cancelable, and reversible.

  10. Creating new cities through the large air-cushion vehicle.

    Science.gov (United States)

    Anderson, J. L.; Finnegan, P. M.

    1972-01-01

    The air-cushion vehicle (ACV) can travel over concrete roads, grass, sand, mud, swamp, snow, ice, and water. This mobility makes possible a totally new geographical freedom in choosing transportation routes, locating ports, and laying out a city. By the 1980s fleets of large ACV freighters could begin carrying ocean-going cargo. The mobility of an ACV fleet would allow placing hoverports away from areas now crowded. New cities could rise along shallow or reef-bound seacoasts and rivers, just as cities once rose around deep-water seaports.

  11. Computer-aided conceptual design of Air Cushion Vehicles

    Science.gov (United States)

    Band, E. G. U.; Lavis, D. R.

    This paper describes the development and use of a computer-aided design tool which has been used to explore preferred options for amphibious Air-Cushion Vehicle (ACV) and Surface-Effect Ship (SES) designs in support of U.S. Navy and U.S. Army programs. The tool, referred to as the ACV Design Synthesis Model (ADSM), is an interactive computer program which provides a description of feasible ACV or SES concepts that could be developed, by a competent design team, to perform the mission described by the input parameters. The paper discusses how the program was used to explore parametrically the design of a range of self-propelled hoverbarges to meet requirements of the U.S. Army Logistics Over the Shore (LOTS) phases of an amphibious landing. Examples of results are presented to illustrate the method used in determining design and performance trade-offs.

  12. Standing steady-state wave-making calculation method for air cushion vehicles; Air cushion vehicle no teijo zoha keisanho ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Eguchi, T. [Mitsui Engineering and Shipbuilding Co. Ltd., Tokyo (Japan)

    1996-04-10

    The pulse-height distribution of a cushion room of air cushion vehicle (ACV) has been tried to be approached by means of the panel shift type Rankine source method. When using this method, it was not required to introduce the pressure distribution model simulating the fall-off effect for the step-formed cushion pressure distribution. The wave form and wave making resistance could be estimated precisely by assigning the pressure gradient to one longitudinal direction panel in the calculation. The waveform shape within the cushion room could be calculated rather precisely by comparing with the analytic solution. This calculation method did have an ability providing the pulse-height information in the cushion room of ACV for seal design and configuration of ships. The analytic solution using for the comparison was sufficient for determining the pulse-height in the high speed region. However, it was hard to respond to non-linear problems or optional shape problems. It was pointed out to be further improved. 5 refs., 8 figs.

  13. Method for calculating steady-state waves in an air cushion vehicle. Part 2; Air cushion vehicle no teijo zoha keisanho ni tsuite. 2

    Energy Technology Data Exchange (ETDEWEB)

    Eguchi, T. [Mitsui Engineering and Shipbuilding Co. Ltd., Tokyo (Japan)

    1997-10-01

    Discussions were given on a method to estimate resistance constituents in wave resistance made in an air chamber of an air cushion vehicle (ACV). An orthogonal coordinate system is considered, which uses the center of a hull as the zero point and is made dimensionless by using cushion length. Flow around the ACV is supposed as an ideal flow, whereas speed potential is defined in the flow field. Then, a linear free surface condition is hypothesized on water surface Z = 0. Number and density of waves were used to introduce a condition to be satisfied by the speed potential. A numerical calculation method arranged a blow-out panel on the water surface, and used a panel shift type Rankine source method which satisfies the free surface condition at Z = 0. Cushion pressure distribution becomes a step-like discontinuous function, and mathematical infinity is generated in the differentiation values. Under an assumption that the pressure rises per one panel where pressure jump is present, the distribution was approximated by providing one panel with inclination of the finite quantity therein. Estimation on wave height distribution in the cushion chamber showed a tendency of qualitatively agreeing with the experimental result, but the wave heights shown in the experiment had the average level decreased as it goes toward the rear of the hull. 5 refs., 5 figs.

  14. An Analysis of Skill Requirements for Operators of Amphibious Air Cushion Vehicles (ACVs).

    Science.gov (United States)

    McKnight, A. James; And Others

    This report describes the skills required in the operation of an amphibious air cushion vehicle (ACV) in Army tactical and logistic missions. The research involved analyzing ACV characteristics, operating requirements, environmental effects, and results of a simulation experiment. The analysis indicates that ACV operation is complicated by an…

  15. Feasibility report: Operation of light air cushion vehicle at McMurdo Sound, Antarctica

    Science.gov (United States)

    Dibbern, J. S.

    1987-02-01

    This report explores the viability of the use of an air cushion vehicle (ACV) or hovercraft to perform logistic and scientific support in the area of McMurdo Station, Antarctica. After a review of personnel assets and facilities at McMurdo Station to support the ACV plus a reconnaissance of the five major routes selected, it appears that an air cushion vehicle in the 1 to 1 1/2 ton payload class would be of significant value to support operations. It would reduce transit times for surface vehicle traverses on the routes selected and reduce requirements for expenditure of helicopter flight time in others. Of major significance is the ability to handle passenger/shuttle requirements between the Scott Base transition and Williams Field Skiway. Use of the ACV for high frequency passenger operations would help preserve the snow road for cargo operations during periods of road deterioration.

  16. 小型 air cushion vehicle の試作研究

    OpenAIRE

    小倉, 一彦; 岡田, 幸夫; 木原, 勇; 土伏, 悌之

    2000-01-01

    In studying "Engineering" , the fundamental matter is "Manufacturing (Mono-zukuri)". But the students of Electric-Mechanical Engineering Department have little time for manufacturing the complete whole systems, except for Graduation Studies. In order to let the students experience "Manufacturing" of a whole system, we selected a Light Air Cushion Vehicle (ACV) as a subject of our study. In this paper, the process of manufacturing an ACV is reported.

  17. Theoretical investigation of heave dynamics of an air cushion vehicle bag and finger skirt

    Science.gov (United States)

    Chung, Joon

    This thesis describes a theoretical investigation of the nonlinear and linear heave dynamics of an air cushion vehicle (ACV) equipped with a bag and finger skirt system with the purpose of understanding the skirt's effect on the vehicle heave dynamics. Throughout the course of this work, the pure heave motion of a two dimensional section of the skirt is investigated using several mathematical models. Both the nonlinear and linearized analyses include a detailed model of the skirt geometry, which is modelled as a combination of inelastic membranes and links. Air flow processes from the bag to the cushion and from the cushion to the atmosphere are assumed to be quasisteady, and the bag and cushion volumes are modelled as lumped pneumatic capacitances. The modulation of the escaping cushion air by skirt-ground contact is also included. The nonlinear simulations reveal that characteristically nonlinear dynamical phenomena such as period doubling and chaos can be expected to occur during the normal operation of ACVs. Furthermore, a configuration representative of a 37 tonne vehicle shows a resonance at frequencies in the range for which humans are most sensitive. Although these results thus show that some aspects of the bag and finger skirt heave dynamics can be highly nonlinear, they indicate that under certain circumstances, standard linear techniques can yield useful insights. Results from the linear analysis suggest that changes in skirt geometry cannot be used to radically modify the undesirable heave response of the bag and finger skirt, but reducing the skirt mass is quite effective. The pneumatic capacitance of the bag and cushion volume proves to be an important factor in the heave response. In particular, it contributes to heave instability. The air compressibility also affects heave response at high frequencies, with the effect becoming more prominent as the flow rate is reduced. The importance of unsteady fan effects on ACV dynamics is investigated by the

  18. Parameter Estimation and Verification of Unmanned Air Cushion Vehicle (UACV System

    Directory of Open Access Journals (Sweden)

    Ab Rashid Mohd Zamzuri

    2017-01-01

    Full Text Available This project is mainly about the dynamic modelling and parameter estimation of Unmanned Air Cushion Vehicle (UACV. The purpose of developing mathematical model of the Unmanned Air Cushion Vehicle (UACV is due to its under actuated nonlinearities where it has less input compared to the output required. This system able to maneuver over land, water and other surfaces either at certain speed or maintain at a stationary position. In order to model the UACV, the system is set to have two propellers which are responsible to lift the vehicle by forcing high pressure air under the system. The air inflates the “skirt” under the vehicle, causing it to rise above the surface while another two propellers are used to steer the UACV forward. UACV system can be considered as under actuated since it possess fewer controller inputs that its degree of freedom. The system’s motions are defined by the six degrees of freedom which are; heaved, sway and surge. Another three components are rotational motions which can be elaborated as roll, pitch and yaw. The problem related to UACV is normally related to obtaining accurate parameters of the system to be included into the mathematical model of the system. This is due to the body inertia of the system during the static and moving condition. Besides, the air that flows into the UACV skirt to create the cushion causes imbalance and will affect the system stability and controllability. In this research, UACV need to be mathematically modelled using Euler-Lagrange method. Then, parameters of the system can be obtained through direct calculation and Solidworks software. The parameters acquired are compared and verified using simulation and experimental studies.

  19. Design criteria for light high speed desert air cushion vehicles

    Science.gov (United States)

    Abulnaga, B. E.

    An evaluation is made of the applicability and prospective performance of ACVs in trans-Saharan cargo transport, in view of the unique characteristics of the dry sand environment. The lightweight/high-speed ACV concept envisioned is essentially ground effect aircraftlike, with conventional wheels as a low-speed backup suspension system. A propeller is used in ground effect cruise. Attention is given to the effects on vehicle stability and performance of sandy surface irregularities of the desert topography and of cross-winds from various directions relative to vehicle movement.

  20. Sea Keeping Analysis of Air Cushion Vehicle with Different Wave Angles under the Operation Resistance

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jia; TANG Wen-yong; ZHANG Sheng-kun

    2009-01-01

    The air cushion vehicle (ACV) sea keeping characteristic under different wave directions with the operation resistance is discussed with the couples of the heave, pitch roll motion and the pressure of the cushion.In previous researches, only wave and cross wave direction were discussed. Then a Matlab program is made to calculate the united frequency responses of heave, pitch and roll amplitude of the craft, under different wave frequencies and different wave directions. The results of the research depict some dangerous situations under which the sympathetic vibration happens in heave, pitch and roll motion and the amplitudes are extremely higher than those under the ordinary conditions. These results will be helpful in ACV design and operation.

  1. A Study of Maneuvering Control for an Air Cushion Vehicle Based on Back Propagation Neural Network

    Institute of Scientific and Technical Information of China (English)

    LU Jun; HUANG Guo-liang; LI Shu-zhi

    2009-01-01

    A back propagation (BP) neural network mathematical model was established to investigate the maneuvering control of an air cushion vehicle (ACV). The calculation was based on four-freedom-degree model experiments of hydrodynamics and aerodynamics. It is necessary for the ACV to control the velocity and the yaw rate as well as the velocity angle at the same time. The yaw rate and the velocity angle must be controlled correspondingly because of the whipping, which is a special characteristic for the ACV. The calculation results show that it is an efficient way for the ACV's maneuvering control by using a BP neural network to adjust PID parameters online.

  2. Progress report on Bertelsen research and development of an air cushion crawler all-terrain vehicle

    Science.gov (United States)

    Bertelsen, W. R.

    1987-06-01

    The ACV is an exceptional amphibian but it is not, nor is any other existing craft, an all-terrain vehicle (ATV). Using the best elements of the ACV in an air-cushion crawler tractor, a true ATV can be attained. A conventional crawler drive train will propel two tracks as pressurized, propulsive pontoons. The key to a successful ATV is in perfecting efficient, durable, sliding seals to allow the belt to move in its orbit around the track unit and maintain its internal pressure. After deriving the adequate seal, a 12 inch wide x 86 inch long endless rubber belt was fitted bilateral seals and slide plates with internal guide wheels fore and aft with a 21 inch wheel base. From this approximately one-quarter scale model, full-scale air track crawlers, true ATVs, of any size and capacity can be produced.

  3. Proceedings of the 1994 CACTS conference on air cushion technology

    Energy Technology Data Exchange (ETDEWEB)

    Laframboise, J.E. [ed.

    1995-03-01

    The conference held by the Canadian Air Cushion Technology Society (CACTS) was attended by 56 specialists in the field from around the world. CACTS is devoted to the development and application of air cushion technology, primarily in the transportation domain, but also in industry and other fields where the technology may be of benefit. Some uses for the technology include rescue operations in natural disasters such as flooding and oil spill clean up operations in coastal waters. A total of 20 papers were presented at this meeting. Subjects included air cushion spray booms, amphibious transporters in oil spill events, unconventional propulsion systems for air cushion vehicles, ride control systems, and high-speed hovercraft design. Refs., tabs., figs.

  4. Air-cushioning in impact problems

    KAUST Repository

    Moore, M. R.

    2013-05-12

    This paper concerns the displacement potential formulation of the post-impact influence of an air-cushioning layer on the 2D impact of a liquid half-space by a rigid body. The liquid and air are both ideal and incompressible and attention is focussed on cases when the density ratio between the air and liquid is small. In particular, the correction to classical Wagner theory is analysed in detail for the impact of circular cylinders and wedges. © The Authors 2013. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

  5. 1986 CACTS International Conference on Air Cushion Technology, Toronto, Canada, Sept. 16-18, 1986, Preprints

    Science.gov (United States)

    MacEwen, W. R.

    The present conference on the design and development, innovative configurational concepts, test result analyses and operational characteristics of ACVs gives attention to design criteria for light, high-speed ACVs in desert environments, preliminary over-water tests of linear propellers, tests on high speed hovercraft icebreaking, and the performance of an air cushion crawler all-terrain vehicle. Also discussed are the use of ACVs as high speed ASW vehicles, performance criteria for air cushion heave dynamics, the bounce characteristics of an ACV's responsive skirt, and the use of hovercraft in ice enforcement.

  6. Air-cushion tankers for Alaskan North Slope oil

    Science.gov (United States)

    Anderson, J. L.

    1973-01-01

    A concept is described for transporting oil from the Arctic to southern markets in 10,000-ton, chemically fueled air-cushion vehicles (ACV's) configured as tankers. Based on preliminary cost estimates the conceptual ACV tanker system as tailored to the transportation of Alaskan North Slope oil could deliver the oil for about the same price per barrel as the proposed trans-Alaska pipeline with only one-third of the capital investment. The report includes the description of the conceptual system and its operation; preliminary cost estimates; an appraisal of ACV tanker development; and a comparison of system costs, versatility, vulnerability, and ecological effect with those of the trans-Alaska pipeline.

  7. EXPERIMENTAL AND NUMERICAL INVESTIGATION OF TURBULENT AIR-CUSHION-CASCADE

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Experimental and numerical studies of air-cushion-cascade were conducted and described. The SIMPLE algorithm combined with the normal k-ε turbulence model was adopted to simulate the air-phase flow. The experiment was carried out an IFA 300 anemometer. The flow field was measured for different ratios of main-stream velocity to jet velocity, different numbers of gaps and a couple of gap widths. The contur of the air-cushion was obtained, and the numerical calculations gave a closed-form result. The results show that the air-cushion thickness would increase with the increase of the jet volcoity, gap width and gap number mainly determined by the jet in the former half cascade. The possibility to achieve anti-erosion by the turbulent jet was examined and confirmed.

  8. A theoretical study of limit cycle oscillations of plenum air cushions

    Science.gov (United States)

    Hinchey, M. J.; Sullivan, P. A.

    1981-11-01

    Air cushion vehicles (ACV) are prone to the occurrence of dynamic instabilities which frequently appear as stable finite amplitude oscillations. The aim of this work is to ascertain if the non-linearities characteristics of ACV dynamics generate limit cycle oscillations for cushion systems operating at conditions for which a linear theory predicts instability. The types of non-linearity that can occur are discussed, and an analysis is presented for a single cell flexible skirted plenum chamber constrained to move in pure heave only. Two cushion feed cases are considered: a plenum box supply and a duct. The results obtained by a Galerkin/describing function analysis are compared with those generated by a full numerical simulation. For the plenum box supply system, it is shown that the limit cycles can be suppressed by using a piston to introduce high frequency small amplitude volume oscillations into the plenum chamber.

  9. Effect of air conditioning and chair cushion on scrotal temperature.

    Science.gov (United States)

    Song, Gook-Sup; Kim, Wonwoo; Seo, Ju Tae

    2008-08-01

    The hypothesis of this study is that the air conditioning temperature and thickness of the chair cushion affect a man's scrotal, and consequently testicular, temperature. Ten healthy male subjects volunteered for the study (age: 23.4 +/- 2.4 years; height: 173.8 +/- 5.09 cm; weight: 71.6 +/- 9.7 kg; body fat ratio: 18.6 +/- 4.1%). The air conditioning temperature was controlled at 18 degrees C to represent the heating season, and at 26 degrees C to represent the cooling season. The thickness of the chair cushions was varied from 0 to 8 cm at 2 cm intervals. The changes in the scrotal surface temperature (SST) and buttock skin temperature were measured for 120 min. At the ambient temperatures (t(a)) of 18 and 26 degrees C, the average SST were 33.76 +/- 1.28 and 35.02 +/- 0.54 degrees C for the chair cushion thickness (C(thk)) of 0 cm, 33.87 +/- 1.07 and 34.96 +/- 0.75 degrees C for C(thk) 2 cm, 33.91 +/- 0.84 and 35.03 +/- 0.85 degrees C for C(thk) 4 cm, 34.42 +/- 0.89 and 35.02 +/- 0.63 degrees C for C(thk) 6 cm, and 34.65 +/- 1.21 and 34.99 +/- 0.62 degrees C for C(thk) 8 cm respectively. SST was significantly affected by the air conditioning temperature (p < 0.001), but was not statistically correlated with the chair cushion thickness.

  10. Air cushion furnace technology for heat treatment of high quality aluminum alloy auto body sheet

    Institute of Scientific and Technical Information of China (English)

    Li Yong; Wang Zhaodong; Ma Mingtu; Wang Guodong; Fu Tianliang; Li Jiadong; Liang Xiong

    2014-01-01

    The process characteristics of heat treatment of aluminum alloy auto body sheet and the working prin-ciple of air cushion furnace were introduced. The process position and irreplaceable role of air cushion furnace in the aluminum alloy auto body sheet production was pointed out after the difficulty and key points in the whole production process of auto body sheet were studied. Then the development process of air cushion furnace line of aluminum alloy sheet was reviewed,summarized and divided to two stages. Based on the research of air cushion furnace,the key technology of it was analyzed,then the key points on process,equipment and control models of air cushion furnace for aluminum alloy auto body sheet in future were put forward. With the rapid de-velopment of automotive industry,there will be certainly a new upsurge of research and application of air cush-ion furnace for heat treatment of aluminum alloy auto body sheet.

  11. 全垫升式气垫船破冰过程的数值模拟%Numerical simulation for ice-breaking process of an amphibian air cushion vehicle

    Institute of Scientific and Technical Information of China (English)

    卢再华; 张志宏; 胡明勇; 姚俊; 张辽远

    2012-01-01

    A large floating ice sheet can be broken into small slabs with a heavy air cushion vehicle (ACV) traveling on it at a critical speed. Ice-breaking with ACV is a new ice-breaking method in in-land river, it has an important application in prevention of ice jam flood in Yellow River. Here, the ice-breaking process of an ACV was numerically simulated under conditions of shallow water and a thick ice sheet. The simulation results showed that an ACV traveling at a critical speed always chases after the wave crest ahead of it and pushes the waves; thus, the amplitude of the wave around ACV gradually increases due to the continuous push of ACV; initial crack of ice sheet appears at wave trough near the stern of ACV and extends along the axis of ACV in both forward and backward directions; lateral crack at the wave crest ahead of ACV is arisen when the initial crack extends forward to wave crest; an ice-breaking period is finished by ACV accordingly; the cracks behind ACV were shaped as an asterisk symbol along the sailing direction of ACV; the ice sheet breaks into triangular slabs when lateral cracks of different ice-breaking periods intersect with each other; ACV should sail in the same direction parallelly in order to cross the cracks of different ACV voyages and break the ice sheet further.%气垫船破冰是指采用大吨位气垫船以临界航速在冰面上航行进行破冰,是一种较新的内河破冰方法,可应用于黄河凌汛灾害的防治领域.对浅水厚冰层条件下气垫船破冰过程进行了数值模拟.计算结果表明:临界航速下,气垫船始终位于船首波峰后方,对所兴起的船波起持续的推波作用,在冰面上逐渐兴起幅值较大的船波.冰层在船尾波谷处最先产生纵向裂缝并向前后延伸,向前延伸至船首波峰处时引起冰层横向破裂并扩展,完成一个破冰周期.船身后方的裂缝沿气垫船轴线方向呈*号形状,不同破冰周期的横向裂缝交叉后,冰层破裂成

  12. Research of air-cushion isolation effects on high arch dam reservoir

    Science.gov (United States)

    Zhang, Shao-Jie; Chen, Jiang; Zhang, Yuan-Ze; Liu, Hao-Wu

    2011-10-01

    A three-dimensional (3D) finite element model of air-cushion isolated arch dam is presented with the nonlinear gas-liquid-solid multi-field dynamic coupling effect taken into account. In this model, the displacement formulation in Lagrange method, pressure formulation in Euler method, nonlinear contact model based on Coulomb friction law are applied to the air-cushion, reservoir and contraction joint domain, respectively. The dynamic response of Jinping I arch dam with a height of 305 m is analyzed using the seismic records of the Wenchuan Earthquake in 2008. Numerical results show that the air-cushion isolation reduces significantly the hydrodynamic pressure as well as the opening width for the contraction joints of high arch dam.

  13. The Development of Permanent Medical Standards for Landing Craft Air Cushion (LCAC) Crew Personnel.

    Science.gov (United States)

    1993-11-01

    5122 REPORT 93-26, SUPPORTED BY THE NAVAL SEA SYSTEMS COMMAND UNDER WORK UNIT NRAD REtaURsABLE. THE VIEWS EXPRESSED IN THIS ARTICLE ARE THIC, OF THE...Gastrointestinal System Some comments were made regarding the negative effects upon performance by any gastrointestinal problem, including gastritis , ulcers, or...3. LANDING CRAFT AIR CUSHION (LCAC) CREW MEDICAL STANDARDS (CHANGE 107) 87 88 Article 15-71A Manual of the Medical Department amination at a

  14. Assessing the Operational Readiness of Landing Craft Air Cushion Vessels Using Statistical Modeling

    Science.gov (United States)

    2010-09-01

    Beachmaster Unit ONE C/A Craft Alteration CASREP Casualty Report CBM Condition Based Maintenance CCI Corrosion Control Inspection CESE...Allowance List CSMP Current Ship Maintenance Project CSR Craft Status Report CRAFTALT Craft Alteration C4N Command, Control , Communications...Assault Craft Unit (ACU)-5 manages a fleet of 40 Landing Craft Air Cushion (LCAC) hovercrafts from its base at Marine Corps Base Camp Pendleton

  15. Control Systems for Platform Landings Cushioned by Air Bags

    Science.gov (United States)

    1987-07-01

    feedback control system (39) displayed behavior quite different from the other two controls. Many different pairs of values for Pi and P2 were found that...those of the paramameters. The control instructions, starting at line 23, are for the particular feedback control * " system studied in the report... feedback control system , see Equation (39) Pa Standard atmospheric pressure PC Critical (sonic) pressure in vent Q Dimensionless air-speed in vent q Air

  16. A Differential Thrust Controller for Air Cushion Landing System Aircraft

    Science.gov (United States)

    1974-12-01

    8217 control installed, for each of the five time-delay values. In all cases , the average mean square error was reduced approximately 70% by the addition...assistance with explanations of the ACLS. Credit should also be given to Lieutenant John Pinnel , a classmate at the Air Force Institute of Technology...the system with and without the control installed, for each of the five time-delay values. In all cases , the average mean square error was reduced

  17. Numerical simulation of displacement response of floating ice sheet induced by a moving air cushion vehicle in uniform depth%航行气垫船激励均匀水深浮冰层位移响应的数值模拟

    Institute of Scientific and Technical Information of China (English)

    丁志勇; 李宇辰; 张志宏; 卢再华

    2016-01-01

    在均匀水深条件下,基于 ALE算法对匀速航行气垫船激励浮冰层的位移响应问题进行数值模拟。计算不同气垫船速度和河道岸壁宽度条件下的冰层位移响应,获得对应于冰层最大垂向位移变形情况下的气垫船临界速度。计算结果与理论解和试验结果符合良好,验证计算方法的有效性。计算结果表明:在临界速度时冰层下陷位移达到最大,而河道岸壁的存在将会使临界速度减小。%Based on the ALE algorithm in uniform depth, the displacement response of floating ice sheet caused by a moving air cushion vehicle (ACV) was numerically simulated, the critical speed of moving load with maximum verticaldis-placement deformation of ice sheet were solved, the influence of river width on the displacement response and critical speed were analyzed. A good agreement exists among the numerical results and theoretical solutions as well as experimentalres-ults. The research shows that maximum depression deformation of ice sheet will appear at critical speed, and the existence of river bank will decrease the value of critical speed.

  18. 边界元-有限差分混合方法在气垫船破冰数值模拟中的应用%Application of mixed BEM and FDM in numerical simulation of ice-breaking by air cushion vehicle

    Institute of Scientific and Technical Information of China (English)

    刘巨斌; 张志宏; 张辽元; 姚俊

    2013-01-01

    A unified mathematical model was set up for different operating conditions (on pure water surface,on pure ice surface,on pure broken ice surface,and on semi-water-semi-ice surface) under which air cushion vehicles(ACV)do ice breaking.The numerical calculation method was based on the combination of BEM and FDM,and C language was applied to developing simulation software,which served the function of calculating the wave-making drag of ACV,wave patterns of water or ice and stresses in ice layer.In this software,INTEL MKL mathematical Lib was used to solve linear equations,and Matlab computing engine was used according to C code,to visualize computational grids and some results.OPENMP option was activated to carry out parallel computation on the multi-core computer.The mathematical model,the computing method and the developed software were proved to be effective by comparing the numerical results of the wave-making drag of ACV on total ice with those of the theoretical analysis and experiments mentioned in the existing documents.%对气垫船破冰作业的几种工况建立了统一的数学模型,提出了采用边界元法与有限差分法相结合的数值计算方法.采用C语言编制数值模拟程序,对气垫船兴波阻力、水面和冰面波形以及冰层内应力进行计算,通过调用Intel MKL数学库求解离散得到线性代数方程组;在C语言中调用Matlab计算引擎实现了计算网格和部分计算结果的显示;在多核计算机上采用OPENMP实现程序关键部分的并行计算,提高了计算速度.气垫船在全冰面上兴波阻力的计算结果与已有文献的理论分析计算结果和试验结果符合较好.

  19. Air Cushion Crash Rescue Vehicle (ACCRV) (Phase 1)

    Science.gov (United States)

    1985-11-01

    J J ) ) Ll 1 l l l ] .J ] J J J J Spray Skirt (Bag) Diameter ft <t Spray Skirt Tube I I . I r Out" Edg• of Tubo --/------- I...Water flowing through the eductor ( venturi ) draws agent into the flow which is subsequently mixed with the pump discharge water, most of which is...cab and communications 3-69 l l J 1 \\ J 1 l j J 1 J J j ] Suction Venturi System (3) Connections o 2 Supply (3) Humidifiers (3

  20. Air Cushion Vehicle Operator Training System (ACVOTS) Problem Analysis

    Science.gov (United States)

    1981-11-01

    Bays) - Close-in maneuvering (Long Point) - Overland operations (Crooked Island) - Open water operations (Gulf of Mexico ) Audio Visual Equipment...types of media are used to support their implementation. - programmed text/ storyboard text, - sound slide, - videotape, - computer based instruction...types which facilitate student knowledge learning. Examples of academic media include: instructor lecture, mediated lecture, storyboard text, program

  1. Effect of a responsive skirt on air cushion vehicle seakeeping

    Science.gov (United States)

    Zhou, W. L.; Ma, T.

    The skirt system, which will be excited to make a response motion under the outer disturbance, is treated as a passive control system, and the longitudinal motion equations of ACV are derived according to the control principle. The influence of the skirt response in waves on ACVs seaworthiness is analyzed in the paper. Some results are gotten that the greater vertical deflexion of skirt will make the response of heave, pitch motion and acceleration of the craft decreased a lot, but the horizontal deflexion will go the opposite way. The natural frequency of skirt plays an important role in seaworthiness improvement, the adoption of lower frequency skirt can make the frequency band of craft motion response narrower effectively. The matching of skirt parameters of bow and stern has a certain effect too.

  2. 1985 Joint International Conference on Air Cushion Technology, Rockville, MD, September 24-26, 1985, Preprints and Late Papers

    Science.gov (United States)

    Amyot, J. R.

    1985-12-01

    Papers are presented on the effect of a resonant skirt on ACV seakeeping, aerodynamic characteristics of a bag-cone skirt, and a calculation of the static forces acting on ACV bag-finger skirts. Also considered are tactical problems relating to the hovercraft application of marine gas turbines, development of the Air Cushion Equipment Transporter, prevention of propeller Foreign Object Damage, and air propellers and their environmental problems on ACVs. Other topics include the maneuvering simulation of an Antarctic hovercraft, computer-aided conceptual design of air ACVs, the use of model-test data for predicting full-scale ACV resistance, and passive control of air cushion heave dynamics. Papers are also presented on hovercraft in low enforcement, managing LCAC in the evolving acquisition environment, and SES and ACV for naval mission.

  3. Finding the optimal setting of inflated air pressure for a multi-cell air cushion for wheelchair patients with spinal cord injury.

    Directory of Open Access Journals (Sweden)

    Hamanami K

    2004-02-01

    Full Text Available Pressure distribution patterns of the seating interface on the multi-cell air cushion (ROHO High Profile of 36 adults with spinal cord injury (SCI (Neurological level Th3 -L1 were measured at different air pressure levels by a pressure mat measurement system. Stress distribution relative to the inflated air pressure in the air cushion on the patients' wheelchairs was analyzed to determine the appropriate inflated air pressure of the cushion for patients. The maximum pressure points in all subjects were at the areas of the ischial tuberosities (82 to 347 mmHg. The optimal reduction in interface pressure at the ischial tuberosities was obtained just before bottoming out. The cushion air pressure at that point was between 17 and 42 mmHg, and correlated well to body weight (r = 0.495, P = 0.0021. In contrast, the maximum pressure levels did not correlate to body weight or the Body Mass Index (BMI. Pressure at the ischial area could be reduced, but not eliminated, by adjusting the air pressure. The maximum pressure levels seemed to be related to the shape of the buttocks, especially the amount of soft tissue, and exceeded the defined threshold for pressure ulcers (> 80 g/cm2.

  4. Advancing a smart air cushion system for preventing pressure ulcers using projection Moiré for large deformation measurements

    Science.gov (United States)

    Cheng, Sheng-Lin; Tsai, Tsung-Heng; Lee, Carina Jean-Tien; Hsu, Yu-Hsiang; Lee, Chih-Kung

    2016-03-01

    A pressure ulcer is one of the most important concerns for wheelchair bound patients with spinal cord injuries. A pressure ulcer is a localized injury near the buttocks that bear ischial tuberosity oppression over a long period of time. Due to elevated compression to blood vessels, the surrounding tissues suffer from a lack of oxygen and nutrition. The ulcers eventually lead to skin damage followed by tissue necrosis. The current medical strategy is to minimize the occurrence of pressure ulcers by regularly helping patients change their posture. However, these methods do not always work effectively or well. As a solution to fundamentally prevent pressure ulcers, a smart air cushion system was developed to detect and control pressure actively. The air cushion works by automatically adjusting a patient's sitting posture to effectively relieve the buttock pressure. To analyze the correlation between the dynamic pressure profiles of an air cell with a patient's weight, a projection Moiré system was adopted to measure the deformation of an air cell and its associated stress distribution. Combining a full-field deformation imaging with air pressure measured within an air cell, the patient's weight and the stress distribution can be simultaneously obtained. By integrating a full-field optical metrology with a time varying pressure sensor output coupled with different active air control algorithms for various designs, we can tailor the ratio of the air cells. Our preliminary data suggests that this newly developed smart air cushion has the potential to selectively reduce localized compression on the tissues at the buttocks. Furthermore, it can take a patient's weight which is an additional benefit so that medical personnel can reference it to prescribe the correct drug dosages.

  5. Modeling, simulation & optimization of the landing craft air cushion fleet readiness.

    Energy Technology Data Exchange (ETDEWEB)

    Engi, Dennis

    2006-10-01

    The Landing Craft Air Cushion is a high-speed, over-the-beach, fully amphibious landing craft capable of carrying a 60-75 ton payload. The LCAC fleet can serve to transport weapons systems, equipment, cargo and personnel from ship to shore and across the beach. This transport system is an integral part of our military arsenal and, as such, its readiness is an important consideration for our national security. Further, the best way to expend financial resources that have been allocated to maintain this fleet is a critical Issue. There is a clear coupling between the measure of Fleet Readiness as defined by the customer for this project and the information that is provided by Sandia's ProOpta methodology. Further, there is a richness in the data that provides even more value to the analyst. This report provides an analytic framework for understanding the connection between Fleet Readiness and the output provided by Sandia's ProOpta software. Further, this report highlights valuable information that can also be made available using the ProOpta output and concepts from basic probability theory. Finally, enabling assumptions along with areas that warrant consideration for further study are identified.

  6. Personal Air Vehicle Research Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation is a low aspect ratio all-lifting configuration for personal air vehicles. This configuration uses an architecture fundamentally different from...

  7. A Comparative Study Between an Improved Novel Air-Cushion Sensor and a Wheeled Probe for Minimally Invasive Surgery

    Science.gov (United States)

    Challacombe, Benjamin; Li, Jichun; Seneviratne, Lakmal; Althoefer, Kaspar; Dasgupta, Prokar; Murphy, Declan

    2010-01-01

    Abstract Purpose We describe a comparative study between an enhanced air-cushion tactile sensor and a wheeled indentation probe. These laparoscopic tools are designed to rapidly locate soft-tissue abnormalities during minimally invasive surgery (MIS). Materials and Methods The air-cushion tactile sensor consists of an optically based sensor with a 7.8 mm sphere “floating” on a cushion of air at the tip of a shaft. The wheeled indentation probe is a 10 mm wide and 5 mm in diameter wheel mounted to a force/torque sensor. A continuous rolling indentation technique is used to pass the sensors over the soft-tissue surfaces. The variations in stiffness of the viscoelastic materials that are detected during the rolling indentations are illustrated by stiffness maps that can be used for tissue diagnosis. The probes were tested by having to detect four embedded nodules in a silicone phantom. Each probe was attached to a robotic manipulator and rolled over the silicone phantom in parallel paths. The readings of each probe collected during the process of rolling indentation were used to achieve the final results. Results The results show that both sensors reliably detected the areas of variable stiffness by accurately identifying the location of each nodule. These are illustrated in the form of two three-dimensional spatiomechanical maps. Conclusions These probes have the potential to be used in MIS because they could provide surgeons with information on the mechanical properties of soft tissue, consequently enhancing the reduction in haptic feedback. PMID:20624084

  8. Analysis of Trunk Flutter in an Air Cushion Landing System. User’s Manual.

    Science.gov (United States)

    1979-11-01

    b Vertical distance between inner and outer trunk attachment point CGAP C Discharge coefficient gap flow g CKK Polytropic expansion coefficient...at exit (separation) QFAN QFAN Fan flow QGAP QGAP Gap flow QIN QIN Flow to trunk 96 Program Variable Name Symbol Explanation QINT Momentum change...integral A QOUT Qout Flow, out of trunk QTA QTA Flow, trunk to atmosphere QTC QTC Flow, trunk to cushion QTOT Total gap flow QTRI1 QTR Flow, trim valve

  9. 混凝土重力坝气幕隔震效果研究%Air-cushion isolation effects on a concrete gravity dam

    Institute of Scientific and Technical Information of China (English)

    陈江; 熊峰

    2014-01-01

    The gas-liquid-solid tri-phase coupling numerical model for a concrete gravity dam based on air-cushion isolation control was presented here.In this model,the cracking behavior of dam concrete was considered.The radiation damping effect of the truncated boundary of the dam foundation was simulated with a visco-elastic artificial boundary condition.The 3D nonlinear simulation of air-cushion isolation effects on the concrete gravity dam was conducted for the first time.It was shown that the air-cushion reduces the hydrodynamic pressure and the acceleration response of the dam body effectively,so the cracking range of the dam body decreases;with increase in the thickness of the air-cushion,the reduction of hydrodynamic pressure and the acceleration response is more significant;the rate of reduction level decreases progressively;compared with the uniform-thickness air-cushion,the variable-thickness air-cushion can improve the utilization ratio and develop the air-cushion isolation effects more effectively.In the various cases here,the maximum hydrodynamic pressure is reduced by 50% approximately,the maximum dam peak acceleration is reduced by more than 30% with the variable-thickness air-cushion.%基于气幕隔震控制的气-液-固三相耦合数值模型,在该模型中考虑了坝体混凝土的开裂行为,采用黏弹性人工边界模拟坝基截断边界的辐射阻尼效应,首次完成了混凝土重力坝气幕隔震效果的三维非线性数值模拟。结果表明:气幕可以有效降低坝体上游面的动水压力及坝体加速度反应,从而减小坝体的开裂范围。随着气幕厚度的增大,动水压力和加速度削减越多,削减幅度的提高率递减。采用变厚度气幕能提高利用率,更有效地发挥气幕的隔震效果,该工况,变厚度气幕对混凝土重力坝动水压力极值的削减幅度约为50%,坝顶加速度峰值的消减幅度超过30%。

  10. Practicality study on air-powered vehicle

    Institute of Scientific and Technical Information of China (English)

    Lin LIU; Xiaoli YU

    2008-01-01

    To investigate the feasibility and outlook of air-powered vehicles including compressed air-powered vehicle and liquid nitrogen-powered vehicle, thermodyn-amic analysis and experiment data were used to analyze the energy density, performance, safety, running effi-ciency, fuel circulation economy and consumer accep-tance, etc. The results show that compressed air and liquid nitrogen have similar energy density as Ni-H battery; the characteristics of an air-powered engine is suitable for driving a vehicle; the circulation efficiency of liquid nitrogen is 3.6%-14% and that of compressed air is 25%-32.3% in practice, and existing technology can assure its safety. It is concluded that though the performance of an air-powered engine is inferior to that of the traditional inert combustion engine, an air-powered vehicle is fit for future green cars to realize the sustainable development of society and environment.

  11. Foam Cushioning

    Science.gov (United States)

    1988-01-01

    One innovation developed by a contractor at Ames Research Center was an open cell polymeric foam material with unusual properties. Intended as padding for aircraft seats the material offered better impact protection against accidents, and also enhanced passenger comfort because it distributed body weight evenly over the entire contact area. Called a slow springback foam, it flows to match the contour of the body pressing against it, and returns to its original shape once the pressure is removed. It has many applications including aircraft cushions and padding, dental stools, and athletic equipment. Now it's used by Dynamic Systems, Inc. for medical applications such as wheel chairs for severely disabled people which allow them to sit for 3-8 hours where they used to be uncomfortable in 15-30 minutes.

  12. 3-D simulation of transient flow patterns in a corridor-shaped air-cushion surge chamber based on computational fluid dynamics

    Institute of Scientific and Technical Information of China (English)

    XIA Lin-sheng; CHENG Yong-guang; ZHOU Da-qing

    2013-01-01

    The 3-D characteristics of the water-air flow patterns in a corridor-shaped air-cushion surge chamber during hydraulic transients need to be considered in the shape optimization.To verify the reliability of the water-air two-phase model,namely,the volume of fluid model,the process of charging water into a closed air chamber is successfully simulated.Using the model,the 3-D flow characteristics under the load rejection and acceptance conditions within the air-cushion surge chamber of a specific hydropower station are studied.The flee surface waves,the flow patterns,and the pressure changes during the surge wave process are analyzed in detail.The longitudinal flow of water in the long corridor-shaped surge chamber is similar to the open channel flow with respect to the wave propagation,reflection and superposition characteristics.The lumped parameters of the 3-D numerical simulation agree with the results of a 1-D calculation of hydraulic transients in the whole water conveying system,which validates the 3-D method.The 3-D flow structures obtained can be applied to the shape optimization of the chamber.

  13. Aerodynamic Efficiency Enhancements for Air Vehicles Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The need for aerodynamics-based efficiency enhancements for air vehicles is presented. Concepts are presented for morphing aircraft, to enable the aircraft to...

  14. Aerodynamic Efficiency Enhancements for Air Vehicles Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The need for aerodynamics-based efficiency enhancements for air vehicles is presented. The results of the Phase I investigation of concepts for morphing aircraft are...

  15. Vehicles and Particulate Air Pollution

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The current scene relating to particles and vehicular emissions in UK is reviewed. The active research topics are health effects of particles, particle size and composition, modeling the fate of particles and assessing individual exposure. There is a National Air Quality Strategy combined with local air quality management which includes monitoring and assessment, dispersion modeling and development of management plans.

  16. Analysis of Unmmanned Air Vehicles Communication Systems

    Directory of Open Access Journals (Sweden)

    Darius Rudinskas

    2011-04-01

    Full Text Available The analyzed questions of information security transferable by the radio connection link are presented in this article. This safety it is especially important for design of unmanned air vehicles (UAV and for other remote control vehicles. Also questions about UAV communication systems structure, security treats of radio connection system, possible menaces for secure information transferring, security and integrity are discussed in our presentation. Article in Lithuanian

  17. An Objective Evaluation Method for the Comfort of Foam Cushion in Vehicle Sea%汽车泡沫坐垫舒适性的客观评价方法

    Institute of Scientific and Technical Information of China (English)

    金晓萍; 袁向科; 王波; 陶鑫; 成波; 丁教霞; 李志辉

    2012-01-01

    介绍了评价汽车座椅泡沫坐垫舒适性的物理特性指标和体压分布指标,以及两者之间的关系.研究结果表明,体压分布能综合反映坐垫的舒适性,而物理特性则为坐垫材料的选取提供理论依据.因此在泡沫坐垫舒适性设计和评价中,宜综合使用上述两种评价指标.%Two indicators, physical characteristics and body pressure distribution, as well as their relationship are presented in this paper for evaluating the comfort of foam cushion in vehicle seat. The results of study show that body pressure distribution can comprehensively reflect the comfort of seat cushion, while physical characteristics provides the theoretical basis in selecting foam material. Thus it is appropriate to combine these two evaluation indicators in designing and evaluating the comfort of foam cushion in vehicle seat.

  18. Introduction of the air cushion vehicle 'Larus' to the North American market

    Science.gov (United States)

    Makinen, E.; Wainwright, J.

    The 'Larus' ACV, which currently operates as a ferry in the Northern Baltic with a payload of 25 tonnes and 46 passengers, will be refurbished for operations in the Canadian Arctic. These modifications will encompass the incorporation of an Arctic-grade rubber skirt, additional fire and thermal insulation, more heating and washrooms for passenger compartments, a fire extinghuishing system, a second radar unit, and satellite navigation. A development history and performance evaluation of the Larus are given.

  19. Covert air vehicle 2003 LDRD final report.

    Energy Technology Data Exchange (ETDEWEB)

    Spletzer, Barry Louis; Callow, Diane Schafer; Salton, Jonathan Robert; Fischer, Gary John

    2003-11-01

    This report describes the technical work carried out under a 2003 Laboratory Directed Research and Development project to develop a covert air vehicle. A mesoscale air vehicle that mimics a bird offers exceptional mobility and the possibility of remaining undetected during flight. Although some such vehicles exist, they are lacking in key areas: unassisted landing and launching, true mimicry of bird flight to remain covert, and a flapping flight time of any real duration. Current mainstream technology does not have the energy or power density necessary to achieve bird like flight for any meaningful length of time; however, Sandia has unique combustion powered linear actuators with the unprecedented high energy and power density needed for bird like flight. The small-scale, high-pressure valves and small-scale ignition to make this work have been developed at Sandia. We will study the feasibility of using this to achieve vehicle takeoff and wing flapping for sustained flight. This type of vehicle has broad applications for reconnaissance and communications networks, and could prove invaluable for military and intelligence operations throughout the world. Initial tests were conducted on scaled versions of the combustion-powered linear actuator. The tests results showed that heat transfer and friction effects dominate the combustion process at 'bird-like' sizes. The problems associated with micro-combustion must be solved before a true bird-like ornithopter can be developed.

  20. Model Identification of a Micro Air Vehicle

    Institute of Scientific and Technical Information of China (English)

    Jorge Ni(n)o; Flavius Mitrache; Peter Cosyn; Robin De Keyser

    2007-01-01

    This paper is focused on the model identification of a Micro Air Vehicle (MAV) in straight steady flight condition. The identification is based on input-output data collected from flight tests using both frequency and time dontain techniques. The vehicle is an in-house 40 cm wingspan airplane. Because of the complex coupled, multivariable and nonlinear dynamics of the aircraft, linear SISO structures for both the lateral and longitudinal models around a reference state were derived. The aim of the identification is to provide models that can be used in future development of control techniques for the MAV.

  1. Autonomous unmanned air vehicles (UAV) techniques

    Science.gov (United States)

    Hsu, Ming-Kai; Lee, Ting N.

    2007-04-01

    The UAVs (Unmanned Air Vehicles) have great potentials in different civilian applications, such as oil pipeline surveillance, precision farming, forest fire fighting (yearly), search and rescue, boarder patrol, etc. The related industries of UAVs can create billions of dollars for each year. However, the road block of adopting UAVs is that it is against FAA (Federal Aviation Administration) and ATC (Air Traffic Control) regulations. In this paper, we have reviewed the latest technologies and researches on UAV navigation and obstacle avoidance. We have purposed a system design of Jittering Mosaic Image Processing (JMIP) with stereo vision and optical flow to fulfill the functionalities of autonomous UAVs.

  2. 气垫隔声结构水中隔声性能分析%Analysis of Underwater Performance of Sound Insulation Structure with Air Cushion

    Institute of Scientific and Technical Information of China (English)

    周涛; 陈志坚

    2013-01-01

      提出气垫隔声结构形式,与以橡胶阻尼材料为基体的隔声去耦瓦相比,气垫隔声结构具有孔隙率大的特点,能更好的隔声去耦。用解析方法分析无限、有限气垫隔声结构在水中的隔声性能,研究板厚与中间层特性声阻抗对隔声量的影响并分析无限结构与有限结构的差别。结果表明:在水中的隔声曲线中没有在空气中因“质量―弹簧―质量”共振造成的隔声低谷现象,且在低频时有限结构的隔声性能较好。行波管声学试验测试了气垫双层板结构的低频隔声性能,证实气垫隔声结构在水中的隔声效果和其在水中声学性能的正确性。%The sound insulation structure with air cushion was presented. Compared with the sound-isolating decoupling tiles made of rubber damping material, this structure has better sound-isolating and decoupling effect due to its large porosity. The underwater sound insulation performances of infinite and finite double-layer panel structures with air cushions were studied respectively with analytical method. The influences of panel thickness and characteristic impedance of the middle layer on the sound-isolating performance were analyzed. The results show that the phenomenon of sound-isolation valley due to the mass-spring-mass resonance disappears and the finite-sized structure has a better sound-isolating performance in low frequency range. Finally, traveling wave tube test was carried out to investigate the finite-sized structure. The test results verified the correctness of this method for analyzing the underwater sound insulation performance of the structures.

  3. Ditching Simulation of Air and Space Vehicles

    Science.gov (United States)

    Patel, Mahesh; Mouillet, Jean-Baptiste; Burkhalter, Drew; Robert, Adrien; Schwoertzig, Thierry

    2014-06-01

    The impact on water of an aircraft or a re-entry space vehicle is a very complex event and considered as an important issue for the air and space industry. To ensure the safety of the crew and to limit the risks of loss of the vehicle, a prediction of its structural behaviour under various ditching configurations must be performed. Structural tests are very costly and must be limited in scale or number, so numerical simulations may be of great help for this purpose.Numerical simulations aim to predict the trajectory of the vehicle under impact, the pressure repartition on the body, structural stress, possible damages to the structure and occupant 'g' levels during impact. Physically, two types of configurations involving different phenomenon can be identified, vertical impacts and impacts with high horizontal components, where air entrapment, ventilation and cavitations can be the dimensioning factors.The purpose of this paper is to give an overview of the features of ALE (Arbitrary Lagrangian-Eulerian) transient dynamic explicit simulation methods to perform such simulations. This paper details analysis of the critical simulation parameters, fluid dynamic calculations, CPU and model size reduction techniques, Fluid-Structure contact modelling, examples of such simulations, correlation to physical tests using Explicit Finite Element based code RADIOSS from Altair Engineering. Two examples of re-entry and ditching numerical simulation are discussed in this paper with comparisons to physical test data.

  4. Mini Rukma Vimana Unmanned Air Vehicle

    Directory of Open Access Journals (Sweden)

    T. V. Vineeta

    2014-10-01

    Full Text Available Taking advantage of ancient Indian Knowledge of Vimanas, the Mini Rukma Vimana Unmanned Air Vehicle designs make a several advantages for many purposes as mentioned. The MRV UAV concept is proposed mainly to create VTOL, the lift fans configuration similar to Rukma vimana, hence the name Mini Rukma vimana Unmanned Air Vehicle. Lift fans are the main part of the MRV UAV. They can be used to go through mountainous regions. And fans are preferred other than wings for Vertical takeoff. The lift fans configuration is similar to Rukma vimana Mentioned in Vimanika shasthra. Based on Analysis for VTOL, UAVs are having lift fans embedded in Wings. But MRV UAV has simpler configuration, enabling the UAV to lift off with fans provided at the top of the UAV directly connected to the base of UAV with the help of Ducts. The Direction control can be achieved by operating the maneuvering fans acting as propellers, the UAV can move 360 degrees in at mid air in single position. Using the MRV UAV, the missions become much more simpler and easier to be carried out.

  5. Analysis and Experimental Study of Air-cushion Pressure Used to Cardboard Adhesive%一种用于纸板黏合的气垫压合分析及实验研究

    Institute of Scientific and Technical Information of China (English)

    高波

    2014-01-01

    Cushion has a wide range of applications in engineering. It is a new attempt to use it in the lamination process of corrugated cardboard adhesive, to get the theoretical analysis and experimental research. It is made to numerical simulation of multi-stoma pressure distribution from a single stomatal mathematical model by using ANSYS finite element software. It can be used to the experimental device that conveyor speed, air supply’s pressure and flow, and air-cushion thickness can be adjusted. Experiments show that the device can meet analysis results by a test system for relevant parameters. The result shows that the pressure of air distribution simulation is in good agreement with the measured results. The corrugated cardboard and pressing orthogonal ex-perimental results show that is the more appropriate for the pressure of air 1000Pa, air cushion thickness 2mm, pressing time 3min, air cushion pressure used in corrugated cardboard and pressing is feasible.%将气垫用于瓦楞纸板黏合的压合工艺是一种新的尝试,为了探讨气垫压力形成、压力分布及工艺效果,进行了理论分析和实验研究。利用ANSYS有限元软件,从单个气孔的压力分布数学模型出发,对多气孔的压力分布进行数值模拟,用一种供风压力、流量、气垫厚度都可调节的气垫压合实验装置,通过相关参数测试系统,验证了分析结果。结果表明:气垫压力分布模拟与实测结果吻合较好,瓦楞纸板黏合压合正交实验表明,选用气垫压力1000Pa、气垫厚度2mm、压合时间3min是比较合适的,气垫压合用于瓦楞纸黏合压合是可行的。

  6. 朝鲜不对称作战的利器——全垫升气垫船%North Korean Smart Weapons of Asymmetry Operation- the Air Cushion Craft

    Institute of Scientific and Technical Information of China (English)

    李中良; 徐清华; 漆巍; 英戈

    2015-01-01

    As the South Korea procured a lot new surface warships,increasing the surface combat strength,forming the maritime advantages against the North Korea,the North Korea has to take the asymmetry measures to respond the great pressure with building a lot air cushion crafts. The thesis describes the types,capabilities,characteristics and deployment of the North Korean air cushion crafts, analyzes why the North Korea develops this kind of surface ship. Its specific operation methods of landing forces delivery,special assault, maritime assault,setting mines and obstacles with the air cushion crafts,studies on the South Korea's fighting measures against the North Korean air cushion crafts,which include destroying bases, air-to-surface attack,area control, distance limitation,and dealing with the wild with accuracy.%随着韩国大力发展水面舰艇增强其海上作战能力,形成对朝鲜的海上优势,朝鲜则不得不采用不对称作战方式应对来自韩国的海上重重压力,大量建造全垫升气垫船.阐述了朝鲜装备全垫升气垫船类型、性能特点及基本部署情况,分析了朝鲜发展气垫船的缘由;剖析了朝鲜采用气垫船实施登陆输送、特种攻击、海上突击和布设水雷障碍的具体使用方法;研究了韩国在反击朝鲜气垫船采取击毁基地、以空制海、以面制点、以远制近、以精确应对粗放的5种战法应对举措.

  7. ICU intensive care unit application effect analysis of air-cushion pressure ulcers prevention%ICU重症监护病房应用防压疮气垫的效果分析

    Institute of Scientific and Technical Information of China (English)

    赵雪梅

    2013-01-01

    目的:探讨ICU重症监护病房应用防压疮气垫的护理效果。方法:将我院重症监护室发生压疮的高危患者40例随机分为观察组和对照组各20例,观察组给予防压疮气垫护理,对照组未采用防压疮气垫防护措施,比较两组的压疮发生率。结果:对照组患者的压疮发生率显著高于观察组,两组比较,差异具有统计学意义(P<0.05)。结论:防压疮气垫能显著降低患者的压疮发生率,是ICU防治高危压疮的有效措施之一。%Objective:To discuss the ICU intensive care unit using the nursing effect of preventing pressure ulcers mattress. Methods:to the intensive care unit 40 patients with higher risk of pressure ulcers were randomly divided into observation group and control group 20 cases, observation group was given care in the air-cushion pressure ulcers, adopt protective measures preventing pressure ulcers air cushion, the control group to compare two groups the incidence of pressure ulcers. Results:the observation group is significantly higher than the control group, the incidence of pressure ulcers in patients with two groups of comparison, the difference statistically significant(P<0.05). Conclusion:for patients with pressure ulcers prevention air cushion bed can significantly reduce the incidence of pressure ulcers, ICU is one of the effective measures of prevention and treatment of pressure ulcers in high-risk patients.

  8. INVESTIGATION OF PRESSURIED THE AIR CUSHION WITH MULTIPLE SUPPLY HOLES%多供气孔气垫平台气垫场压力的理论研究

    Institute of Scientific and Technical Information of China (English)

    侯文君; 王鹰

    2001-01-01

    应用流体的复势函数理论及缝隙流动理论,对具有多供气孔的矩形荷载的气垫场进行了理论分析。用大量的源和汇排列的方法找出了满足边界条件的势函数。从而建立了均匀分布的、任意布孔方式的、多供气孔矩形荷载的气垫压力场压力计算方法和公式,编制了计算气垫场任意一点的压力、气垫承载能力,压力中心和流量的计算程序,并用试验验证了理论分析的正确性。%The air cushion field′s pressured rectangular pad with multiple supply holes are analyzed theoretically by use of complex potential theory and slit flow theory. An appropriate potential function, which satisfies the boundary condition is found by using arrays of infinite sources and sinks. Then calculation formulas of this air cushion field′s pressure distribution with any evenly distributed air-supply holes are derived. A calculating program is worked out and theories mentioned are proved to be correct by tests.

  9. Fast 3D route-planning approach for air vehicle

    Science.gov (United States)

    Tu, Jilin; Ding, Mingyue; Zhou, Chengping; Ai, Haojun

    1997-06-01

    A fast 3-D route planning method for unmanned air vehicle is proposed which can generate physically realizable 3-D route within a reasonable time. Our method includes two steps: First, 2-D route planning generates a route which satisfies turning radius constraint(abbreviated as R-constrained below); second, 3-D route planning generates 3-D route in vertical profile of the 2-D route. To make 2-D route R-constrained, a method is proposed by supposing 2-D route of air vehicle is composed of a sequence of arc route segments and tangential points between neighboring arcs are searching nodes. 3 -D route planning is considered as optimal control problem, and its route can be determined by applying motion equations of air vehicle. The experiments show that our method can produce feasible 3-D routes within a reasonable time, and ensure the planned 3-D routes satisfy aerodynamics constraints of air vehicle.

  10. The constitutive sofa cushion

    DEFF Research Database (Denmark)

    Hanghøj, Sara

    2009-01-01

    , with the sitting room as a cultural and informal environment as its arena in 2006. The local and social network of the informant (born 1919) is traced through a detailed cultural analysis of the creation, usage and existence of the sofa cushion, including even the material interactions occurring between the human...... body, space and artefact, thereby revealing the materialization process. Based on results of the analysis, ANT (Actor-Network- Theory) is used in order to discuss how The Danish Folk High School's conception of simplicity as an aesthetic and gendered ideal in the formal education of female handcraft...

  11. 78 FR 20881 - Control of Air Pollution From Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards...

    Science.gov (United States)

    2013-04-08

    ... AGENCY 40 CFR Part 80 RIN 2060-AQ86 Control of Air Pollution From Motor Vehicles: Tier 3 Motor Vehicle... hearings to be held for the proposed rule ``Control of Air Pollution from Motor Vehicles: Tier 3 Motor... 2017, as part of a systems approach to addressing the impacts of motor vehicles and fuels on...

  12. Design and Control of Flapping Wing Micro Air Vehicles

    Science.gov (United States)

    2011-09-01

    Bar-Cohen, Y., Electroactive Polymer Actuators as Artificial Muscles: Reality, Potential and Challenges, International Society for Optical Engineering ...In 2004 he was assigned to the Air Force Academy where he taught courses in structures, dynamics, mechatronics and engineering design while...WING MICRO AIR VEHICLES DISSERTATION Presented to the Faculty Department of Aeronautics and Astronautics Graduate School of Engineering and

  13. 78 FR 29815 - Control of Air Pollution From Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards

    Science.gov (United States)

    2013-05-21

    ... Pollution From Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards; Proposed Rule #0;#0;Federal... Pollution From Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards AGENCY: Environmental... approach to addressing the impacts of motor vehicles and fuels on air quality and public health....

  14. The Multiple Unmanned Air Vehicle Persistent Surveillance Problem: A Review

    Directory of Open Access Journals (Sweden)

    Nikhil Nigam

    2014-01-01

    Full Text Available Control of autonomous vehicles for applications such as surveillance, search, and exploration has been a topic of great interest over the past two decades. In particular, there has been a rising interest in control of multiple vehicles for reasons such as increase in system reliability, robustness, and efficiency, with a possible reduction in cost. The exploration problem is NP hard even for a single vehicle/agent, and the use of multiple vehicles brings forth a whole new suite of problems associated with communication and cooperation between vehicles. The persistent surveillance problem differs from exploration since it involves continuous/repeated coverage of the target space, minimizing time between re-visits. The use of aerial vehicles demands consideration of vehicle dynamic and endurance constraints as well. Another aspect of the problem that has been investigated to a lesser extent is the design of the vehicles for particular missions. The intent of this paper is to thoroughly review the persistent surveillance problem, with particular focus on multiple Unmanned Air Vehicles (UAVs, and present some of our own work in this area. We investigate the different aspects of the problem and slightly digress into techniques that have been applied to exploration and coverage, but a comprehensive survey of all the work in multiple vehicle control for search, exploration, and coverage is beyond the scope of this paper.

  15. Effects of electric vehicles on air quality in street canyons

    Directory of Open Access Journals (Sweden)

    Tilmann Schöllnhammer

    2014-09-01

    Full Text Available Road traffic is one of the main causes of poor air quality in European cities. Electric vehicles (EV are often presented as climate friendly and as a solution for air quality problems in cities. The aim of this study is to investigate how much of this claim is true and to find out the necessary shares of electric vehicles of different types needed to solve air quality problems in street canyons. For example, the German government has formulated the ambitious goal of increasing the amount of electric vehicles in Germany to 1 million in 2020 and 6 million in 2030. Will this improve the air quality significantly? The focus of the present study is the air quality in street canyons, with a focus on PM10 and NO2 concentrations. We concentrate our investigation on road traffic, taking the fleet composition into account. A sensitivity study with a dispersion model was carried out for two street canyons in North Rhine-Westphalia, typical for moderately polluted street canyons in European cities. It is shown that the reduction potential is larger for NO2 than for PM10. The necessary share of electric vehicles to comply with the limit values lies at about 40 % for NO2 and 100 % for PM10, respectively. Thus, the share of electric vehicles needed to comply with the limit values is far above the goal of the German government.

  16. Biological Inspiration for Agile Autonomous Air Vehicles

    Science.gov (United States)

    2007-11-01

    vehicles in confined airspace will quickly exceed the abilities of a remote human operator, substantial autonomy is essential. The political, ethical ...and Kirschner, 1997 provide an in-depth but accessible discussion on the interplay of biochemistry, genetics and embryology in animal evolution

  17. Effect of Intake Air Filter Condition on Vehicle Fuel Economy

    Energy Technology Data Exchange (ETDEWEB)

    Norman, Kevin M [ORNL; Huff, Shean P [ORNL; West, Brian H [ORNL

    2009-02-01

    The U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy and the U.S. Environmental Protection Agency (EPA) jointly maintain a fuel economy website (www.fueleconomy.gov), which helps fulfill their responsibility under the Energy Policy Act of 1992 to provide accurate fuel economy information [in miles per gallon (mpg)] to consumers. The site provides information on EPA fuel economy ratings for passenger cars and light trucks from 1985 to the present and other relevant information related to energy use such as alternative fuels and driving and vehicle maintenance tips. In recent years, fluctuations in the price of crude oil and corresponding fluctuations in the price of gasoline and diesel fuels have renewed interest in vehicle fuel economy in the United States. (User sessions on the fuel economy website exceeded 20 million in 2008 compared to less than 5 million in 2004 and less than 1 million in 2001.) As a result of this renewed interest and the age of some of the references cited in the tips section of the website, DOE authorized the Oak Ridge National Laboratory (ORNL) Fuels, Engines, and Emissions Research Center (FEERC) to initiate studies to validate and improve these tips. This report documents a study aimed specifically at the effect of engine air filter condition on fuel economy. The goal of this study was to explore the effects of a clogged air filter on the fuel economy of vehicles operating over prescribed test cycles. Three newer vehicles (a 2007 Buick Lucerne, a 2006 Dodge Charger, and a 2003 Toyota Camry) and an older carbureted vehicle were tested. Results show that clogging the air filter has no significant effect on the fuel economy of the newer vehicles (all fuel injected with closed-loop control and one equipped with MDS). The engine control systems were able to maintain the desired AFR regardless of intake restrictions, and therefore fuel consumption was not increased. The carbureted engine did show a decrease in

  18. Design Optimization of a Micro Air Vehicle (MAV Fixed Wing

    Directory of Open Access Journals (Sweden)

    D.V.A. Rama Sastry

    2015-05-01

    Full Text Available Air vehicles are gaining attention due to their wide range of applications in civilian and defense fields. The wings of these vehicles generate a particular flow regime which is to be explored further. Since the theories on the aerodynamics of all affects are still to be investigated, simulation based computational fluid dynamics is a good approach rather than wind tunnel experiments which involves cost and long periods of experimentation. This study mainly emphasize on the lift, lift coefficient, drag and drag coefficient with respect to Reynold’s number and angle of attack, by modelling and analyzing the fixed wing of a micro air vehicle. The analysis has been done selecting NACA25411 air foil. Modelling has been done in Gambit and analysis is taken up using Fluent. Angle of attack and Reynold’s number have been optimized to increase the lift and decrease the drag.

  19. Electric Vehicle Preparedness - Implementation Approach for Electric Vehicles at Naval Air Station Whidbey Island. Task 4

    Energy Technology Data Exchange (ETDEWEB)

    Schey, Stephen [Idaho National Lab. (INL), Idaho Falls, ID (United States); Francfort, Jim [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-06-01

    Several U.S. Department of Defense base studies have been conducted to identify potential U.S. Department of Defense transportation systems that are strong candidates for introduction or expansion of plug-in electric vehicles (PEVs). This study is focused on the Naval Air Station Whidbey Island (NASWI) located in Washington State. Task 1 consisted of a survey of the non-tactical fleet of vehicles at NASWI to begin the review of vehicle mission assignments and types of vehicles in service. In Task 2, daily operational characteristics of vehicles were identified to select vehicles for further monitoring and attachment of data loggers. Task 3 recorded vehicle movements in order to characterize the vehicles’ missions. The results of the data analysis and observations were provided. Individual observations of the selected vehicles provided the basis for recommendations related to PEV adoption, i.e., whether a battery electric vehicle (BEV) or plug-in hybrid electric vehicle (PHEV) (collectively PEVs) can fulfill the mission requirements. It also provided the basis for recommendations related to placement of PEV charging infrastructure. This report focuses on an implementation plan for the near-term adoption of PEVs into the NASWI fleet.

  20. Design, Fabrication and Testing Of Flapping Wing Micro Air Vehicle

    Directory of Open Access Journals (Sweden)

    K. P. Preethi Manohari Sai

    2016-01-01

    Full Text Available Flapping flight has the potential to revolutionize micro air vehicles (MAVs due to increased aerodynamic performance, improved maneuverability and hover capabilities. The purpose of this project is to design and fabrication of flapping wing micro air vehicle. The designed MAV will have a wing span of 40cm. The drive mechanism will be a gear mechanism to drive the flapping wing MAV, along with one actuator. Initially, a preliminary design of flapping wing MAV is drawn and necessary calculation for the lift calculation has been done. Later a CAD model is drawn in CATIA V5 software. Finally we tested by Flying.

  1. Measurement of Vehicle Air Conditioning Pull-Down Period

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, John F [ORNL; Huff, Shean P [ORNL; Moore, Larry G [ORNL; West, Brian H [ORNL

    2016-08-01

    Air conditioner usage was characterized for high heat-load summer conditions during short driving trips using a 2009 Ford Explorer and a 2009 Toyota Corolla. Vehicles were parked in the sun with windows closed to allow the cabin to become hot. Experiments were conducted by entering the instrumented vehicles in this heated condition and driving on-road with the windows up and the air conditioning set to maximum cooling, maximum fan speed and the air flow setting to recirculate cabin air rather than pull in outside humid air. The main purpose was to determine the length of time the air conditioner system would remain at or very near maximum cooling power under these severe-duty conditions. Because of the variable and somewhat uncontrolled nature of the experiments, they serve only to show that for short vehicle trips, air conditioning can remain near or at full cooling capacity for 10-minutes or significantly longer and the cabin may be uncomfortably warm during much of this time.

  2. Air pollution and health risks due to vehicle traffic

    OpenAIRE

    Zhang, Kai; Batterman, Stuart

    2013-01-01

    Traffic congestion increases vehicle emissions and degrades ambient air quality, and recent studies have shown excess morbidity and mortality for drivers, commuters and individuals living near major roadways. Presently, our understanding of the air pollution impacts from congestion on roads is very limited. This study demonstrates an approach to characterize risks of traffic for on- and near-road populations. Simulation modeling was used to estimate on- and near-road NO2 concentrations and he...

  3. Micro- and Nano-Air Vehicles: State of the Art

    Directory of Open Access Journals (Sweden)

    Luca Petricca

    2011-01-01

    Full Text Available Micro- and nano air vehicles are defined as “extremely small and ultra-lightweight air vehicle systems” with a maximum wingspan length of 15 cm and a weight less than 20 grams. Here, we provide a review of the current state of the art and identify the challenges of design and fabrication. Different configurations are evaluated, such as fixed wings, rotary wings, and flapping wings. The main advantages and drawbacks for each typology are identified and discussed. Special attention is given to rotary-wing vehicles (helicopter concept; including a review of their main structures, such as the airframe, energy storage, controls, and communications systems. In addition, a review of relevant sensors is also included. Examples of existing and future systems are also included. Micro- and nano-vehicles with rotary wings and rechargeable batteries are dominating. The flight times of current systems are typically around 1 hour or less due to the limited energy storage capabilities of the used rechargeable batteries. Fuel cells and ultra capacitors are promising alternative energy supply technologies for the future. Technology improvements, mainly based on micro- and nanotechnologies, are expected to continue in an evolutionary way to improve the capabilities of future micro- and nano air vehicles, giving improved flight times and payload capabilities.

  4. Simulation of Structure Falling Slamming Process Affected by Air Cushion and Wind%空气垫与来风对结构物坠落砰击影响的仿真

    Institute of Scientific and Technical Information of China (English)

    朱良生; 于龙飞; 张善举; 李健华

    2015-01-01

    As the air cushion and the wind both greatly affect the falling process of marine structures from the sky into the water, this paper proposes an air-solid coupled mathematical model to describe the falling slamming process of 3D complex structures.In the investigation, the falling mechanism of structures is analyzed, the air damping and the 6DOF ( Degree of Freedom) motion characteristics are fully taken into consideration, and the three-dimension transient N-S equation, the turbulence dynamic equation, the energy equation and the rigid 6DOF kinematic equa-tion are comprehensively adopted.The proposed model is then applied to numerically simulate the falling slamming process of a structure from the air into the water, and the results are compared with those obtained by the physical model, finding that the proposed model is effective in simulating the falling slamming process.Moreover, from the simulated results obtained at different falling heights or in different wind blow environments, it is found that (1) the existence of air cushion changes not only the structure slamming speed but also the pressure distribution;( 2 ) the slamming may result in a temperature rise of the air cushion; and ( 3 ) the wind blow changes the falling pose of structures and makes the structures fall from the air with a “zigzag” pose and then slam into the water.%针对空气垫及来风对海洋结构物空中坠落入水过程产生重要影响的问题,在对结构物坠落机理进行分析的基础上,充分考虑结构物在空中坠落过程中所受到的空气阻尼及六自由度运动特点,结合流体三维瞬态N-S方程、湍流动力方程、能量方程和刚体6自由度运动方程,建立了三维复杂结构物空中坠落砰击入水的气-固耦合过程数学模型。对结构物坠落砰击入水的数值模拟结果与物模试验结果的比较表明,该数学模型能有效模拟空气中的坠落砰击过程。对不同高度以及来风时的

  5. Mechanically refuelable zinc/air electric vehicle cells

    Science.gov (United States)

    Noring, J.; Gordon, S.; Maimoni, A.; Spragge, M.; Cooper, J. F.

    1992-12-01

    Refuelable zinc/air batteries have long been considered for motive as well as stationary power because of a combination of high specific energy, low initial cost, and the possibility of mechanical recharge by electrolyte exchange and additions of metallic zinc. In this context, advanced slurry batteries, stationary packed bed cells, and batteries offering replaceable cassettes have been reported recently. The authors are developing self-feeding, particulate-zinc/air batteries for electric vehicle applications. Emissionless vehicle legislation in California motivated efforts to consider a new approach to providing an electric vehicle with long range (400 km), rapid refueling (10 minutes) and highway safe acceleration - factors which define the essential functions of common automobiles. Such an electric vehicle would not compete with emerging secondary battery vehicles in specialized applications (commuting vehicles, delivery trucks). Rather, different markets would be sought where long range or rapid range extension are important. Examples are: taxis, continuous-duty fork-lift trucks and shuttle busses, and general purpose automobiles having modest acceleration capabilities. In the long range, a mature fleet would best use regional plants to efficiently recover zinc from battery reaction products. One option would be to use chemical/thermal reduction to recover the zinc. The work described focuses on development of battery configurations which efficiently and completely consume zinc particles, without clogging or changing discharge characteristics.

  6. Impact of potential electric vehicle market penetration on air quality

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, III, M. J.

    1979-01-01

    Emissions to the air due to electric vehicles will result from several processes during the production, operation, and recycling and disposal of the vehicles. Some of these processes are significantly different than those for conventional vehicles. Mining and manufacturing impacts are different and larger than those for CVs due mainly to battery production and materials preparation. Battery charging will cause the greatest air pollution during the life cycle of the vehicle. Increases in SOx emissions from electric utilities in regions where coal is the major source of electricity could be significant. The CO, HC, and NOx emissions that would be produced at ground level for CVs are eliminated with EV use, however. Other battery charging emissions take place at the battery. Toxic and potentially explosive gases are emitted during charging of current technology batteries. Particulate re-entrainment by urban vehicles will not be discussed for EVs, as this phenomenon is not yet well understood in general, and because EVs are likely to be no different than CVs in this regard, but particulate emissions from tire wear are included. Emissions from recycling of the electrical component materials are likely to be recycled. Little is known about localized emissions due to vehicle accidents with battery rupture and fires.

  7. An Adaptive Path Planning Algorithm for Cooperating Unmanned Air Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Cunningham, C.T.; Roberts, R.S.

    2000-09-12

    An adaptive path planning algorithm is presented for cooperating Unmanned Air Vehicles (UAVs) that are used to deploy and operate land-based sensor networks. The algorithm employs a global cost function to generate paths for the UAVs, and adapts the paths to exceptions that might occur. Examples are provided of the paths and adaptation.

  8. Development of vehicle magnetic air conditioner (VMAC) technology. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Gschneidner, Karl A., Jr.; Pecharsky, V.K.; Jiles, David; Zimm, Carl B.

    2001-08-28

    The objective of Phase I was to explore the feasibility of the development of a new solid state refrigeration technology - magnetic refrigeration - in order to reduce power consumption of a vehicle air conditioner by 30%. The feasibility study was performed at Iowa State University (ISU) together with Astronautics Corporation of America Technology Center (ACATC), Madison, WI, through a subcontract with ISU.

  9. Death by a Thousand Cuts: Micro-Air Vehicles (MAV) in the Service of Air Force Missions

    Science.gov (United States)

    2001-04-01

    exotic approaches as air suction/injection along the wing surface (which might require micro -valves and micro - pumps ), wall heat transfer, or...AU/AWC/___/2001-4 AIR WAR COLLEGE AIR UNIVERSITY DEATH BY A THOUSAND CUTS: MICRO -AIR VEHICLES (MAV) IN THE SERVICE OF AIR FORCE MISSIONS by...Dates Covered (from... to) - Title and Subtitle Death by a thousand Cuts: Micro -Air Vehicles (MAV) in the Service of Air Force Missions Contract

  10. Production and exploitation of thermoelectric air conditioning systems for vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Dudnik, Vladimir [Conditioner Ltd, Gagarin (Russian Federation); Skipidarov, Sergey [SCTB NORD, Moskau (Russian Federation); Rapp, Axel [Quick-Ohm Kupper und Co. GmbH, Wuppertal-Cronenberg (Germany)

    2011-07-01

    In the paper more than 10-year experience of thermoelectric devices batch manufacturing is described for the field of their obvious advantages. This field of application includes thermoelectric air conditioning systems which have shown their competitive advantage when used in vehicles of elevated vibration where compressor equipment application is difficult because of leakage of refrigerant. Energy characteristics of air conditioners for tractors, excavators, tanks, locomotive driver's cabins and cranes are described. Thermoelectric (TE) air conditioners mechanical test data as well as operation experience in vehicles are presented. It is shown that consumption of tellurium, which is a strategic component for thermoelectric materials manufacturing, may be lowered to 40 grams per 1 kW of cooling. (orig.)

  11. Fuzzy Logic Unmanned Air Vehicle Motion Planning

    Directory of Open Access Journals (Sweden)

    Chelsea Sabo

    2012-01-01

    Full Text Available There are a variety of scenarios in which the mission objectives rely on an unmanned aerial vehicle (UAV being capable of maneuvering in an environment containing obstacles in which there is little prior knowledge of the surroundings. With an appropriate dynamic motion planning algorithm, UAVs would be able to maneuver in any unknown environment towards a target in real time. This paper presents a methodology for two-dimensional motion planning of a UAV using fuzzy logic. The fuzzy inference system takes information in real time about obstacles (if within the agent's sensing range and target location and outputs a change in heading angle and speed. The FL controller was validated, and Monte Carlo testing was completed to evaluate the performance. Not only was the path traversed by the UAV often the exact path computed using an optimal method, the low failure rate makes the fuzzy logic controller (FLC feasible for exploration. The FLC showed only a total of 3% failure rate, whereas an artificial potential field (APF solution, a commonly used intelligent control method, had an average of 18% failure rate. These results highlighted one of the advantages of the FLC method: its adaptability to complex scenarios while maintaining low control effort.

  12. Wheelchair cushions: a historical review.

    Science.gov (United States)

    Garber, S L

    1985-07-01

    An important objective of occupational therapy practice is to maximise functional potential in patients who have physical disabilities. Pressure sores are a major complication in the medical course of these individuals. Therefore, prevention, or at least the proper management, of these sores becomes an important focus for occupational therapists who treat the physically disabled patient. Occupational therapists often prescribe wheelchair cushions to relieve pressure and reduce the risk of ulceration. Unfortunately, occupational therapy literature offers few articles dealing with this significant problem. This paper presents a historical review of wheelchair cushions and details some of the physiological and clinical research efforts that are the basis of prescription practice today.

  13. Dynamic stiffness and transmissibility of commercially available wheelchair cushions using a laboratory test method

    Directory of Open Access Journals (Sweden)

    Yasmin Garcia-Mendez, BS

    2012-02-01

    Full Text Available Evidence suggests that wheelchair (WC users are exposed to unhealthy levels of vibration during WC use. Health risks associated with vibration exposure include vertebral disc degeneration and back pain, which may consequently decrease the function and independence of WC users. Some evidence suggests that the cushions used in WCs may amplify vibrations, although conclusive evidence has not been presented in the literature. This study evaluated and compared the transmissibility of commercially available WC cushions with two laboratory test methods: (1 direct measurement of transmissibility while human subjects propelled a WC over a road course with different cushions and (2 characterization of cushions with a material testing system (MTS combined with mathematical models of the apparent mass of the human body. Results showed that although dynamic characterization of WC cushions is possible with an MTS, the results did not correlate well with the transmissibility obtained in the WC road course. Significant differences were found for transmissibility among the cushions tested, with the air-based cushions having lower transmissibility than the foam- or gel-based cushions.

  14. Episodic air quality impacts of plug-in electric vehicles

    Science.gov (United States)

    Razeghi, Ghazal; Carreras-Sospedra, Marc; Brown, Tim; Brouwer, Jack; Dabdub, Donald; Samuelsen, Scott

    2016-07-01

    In this paper, the Spatially and Temporally Resolved Energy and Environment Tool (STREET) is used in conjunction with University of California Irvine - California Institute of Technology (UCI-CIT) atmospheric chemistry and transport model to assess the impact of deploying plug-in electric vehicles and integrating wind energy into the electricity grid on urban air quality. STREET is used to generate emissions profiles associated with transportation and power generation sectors for different future cases. These profiles are then used as inputs to UCI-CIT to assess the impact of each case on urban air quality. The results show an overall improvement in 8-h averaged ozone and 24-h averaged particulate matter concentrations in the South Coast Air Basin (SoCAB) with localized increases in some cases. The most significant reductions occur northeast of the region where baseline concentrations are highest (up to 6 ppb decrease in 8-h-averaged ozone and 6 μg/m3 decrease in 24-h-averaged PM2.5). The results also indicate that, without integration of wind energy into the electricity grid, the temporal vehicle charging profile has very little to no effect on urban air quality. With the addition of wind energy to the grid mix, improvement in air quality is observed while charging at off-peak hours compared to the business as usual scenario.

  15. Particulate Air Pollution from Motor Vehicles: A Putative Proallergic Hazard?

    Directory of Open Access Journals (Sweden)

    Riccardo Polosa

    1999-01-01

    Full Text Available Air pollution generated from motor vehicle exhaust has become a major cause for scientific and public concern worldwide over recent years. The rapid and marked increase in the motor vehicle traffic and its associated emissions in urban areas have paralleled a sharp increase in the prevalence of allergic diseases such as asthma and rhinitis. Epidemiological studies have demonstrated a strong association between people living in close proximity to roads with high traffic density and increased allergic symptoms, reduced lung function and increased sensitization to common aeroallergens. Several laboratory-based studies have demonstrated that pollutants emitted from motor vehicles can induce allergic inflammation and increase airway hyperresponsiveness, which may provide an underlying mechanism for the increasing prevalence of allergic diseases. Although the detrimental effects of air pollution on human health have been brought to public attention, it appears that less attention has been given to the potential role of road traffic fumes in the induction of the allergic state. Legislators should consider pollutants emitted from motor vehicle exhausts as a potential pro-allergic hazard, before making important changes in environmental policy.

  16. Unsteady Low Reynolds Number Aerodynamics for Micro Air Vehicles (MAVs)

    Science.gov (United States)

    2010-05-01

    horizontal model. The first has advantages of placing t he force balance above the water line and thus solving the balance waterproofing i ssues , an d h...ABSTRACT This work introduces the Micro Air Vehicle (MAV) problem from the viewpoint of aerodynamics. Water tunnels are assessed as tools for MAV...aerodynamics. The design, construction and instrumentation of RB’s “Horizontal Free-surface Water Tunnel” is documented. Experiments in steady

  17. High Performance Piezoelectric Actuators and Wings for Nano Air Vehicles

    Science.gov (United States)

    2012-08-26

    beam bending actuators[88] cite Ballas’s book too. Unimorph. bimorph, and multilayer beam bending actuators have been studied extensively. Models of the...Scalable Design of Flapping Micro-Air Vehicles Inspired by Insect Flight, Springer - Verlag Berlin Heidelberg. URL http://dx.doi.org/10.1007/978-3-540...RSJ International Conference on, IEEE, pp. 1107–1114. [39] Dudley, R. (2002) The biomechanics of insect flight: form, function, evo- lution

  18. Cooling System Design for PEM Fuel Cell Powered Air Vehicles

    Science.gov (United States)

    2010-06-18

    radiator #7. The fan blades and shroud were formed using stereo lithography; the fan motor was a brushless DC motor with motor controller. These...Naval Research Laboratory Washington, DC 20375-5320 NRL/MR/6110--10-9253 Cooling System Design for PEM Fuel Cell Powered Air Vehicles June 18, 2010...Stroman, Michael W. Schuette,* and Gregory S. Page† Naval Research Laboratory 4555 Overlook Avenue, SW Washington, DC 20375-5342 NRL/MR/6110--10-9253

  19. Flisht mechanism and design of biomimetic micro air vehicles

    Institute of Scientific and Technical Information of China (English)

    ANG HaiSong; XIAO TianHang; DUAN WenBo

    2009-01-01

    This paper summaries the investigations on natural flyers and development of bio-mimetic micro air vehicles(MAVs)at NUAA,China,where the authors have led a group to conduct research for a decade.The investigations include the studies of low Reynolds number aerodynamics,unsteady computational fluid dynamics and flight control for the fixed-wing MAVs,the bird-like MAVs,the dragonfly-like MAVs and the bee-like MAVs.

  20. Flight mechanism and design of biomimetic micro air vehicles

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    This paper summaries the investigations on natural flyers and development of bio-mimetic micro air vehicles(MAVs)at NUAA,China,where the authors have led a group to conduct research for a decade. The investigations include the studies of low Reynolds number aerodynamics,unsteady computational fluid dynamics and flight control for the fixed-wing MAVs,the bird-like MAVs,the dragonfly-like MAVs and the bee-like MAVs.

  1. Potential impacts of electric vehicles on air quality in Taiwan.

    Science.gov (United States)

    Li, Nan; Chen, Jen-Ping; Tsai, I-Chun; He, Qingyang; Chi, Szu-Yu; Lin, Yi-Chiu; Fu, Tzung-May

    2016-10-01

    The prospective impacts of electric vehicle (EV) penetration on the air quality in Taiwan were evaluated using an air quality model with the assumption of an ambitious replacement of current light-duty vehicles under different power generation scenarios. With full EV penetration (i.e., the replacement of all light-duty vehicles), CO, VOCs, NOx and PM2.5 emissions in Taiwan from a fleet of 20.6 million vehicles would be reduced by 1500, 165, 33.9 and 7.2Ggyr(-1), respectively, while electric sector NOx and SO2 emissions would be increased by up to 20.3 and 12.9Ggyr(-1), respectively, if the electricity to power EVs were provided by thermal power plants. The net impacts of these emission changes would be to reduce the annual mean surface concentrations of CO, VOCs, NOx and PM2.5 by about 260, 11.3, 3.3ppb and 2.1μgm(-3), respectively, but to increase SO2 by 0.1ppb. Larger reductions tend to occur at time and place of higher ambient concentrations and during high pollution events. Greater benefits would clearly be attained if clean energy sources were fully encouraged. EV penetration would also reduce the mean peak-time surface O3 concentrations by up to 7ppb across Taiwan with the exception of the center of metropolitan Taipei where the concentration increased by <2ppb. Furthermore, full EV penetration would reduce annual days of O3 pollution episodes by ~40% and PM2.5 pollution episodes by 6-10%. Our findings offer important insights into the air quality impacts of EV and can provide useful information for potential mitigation actions.

  2. 75 FR 15620 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Science.gov (United States)

    2010-03-30

    ... National Highway Traffic Safety Administration 49 CFR Part 571 RIN 2127-AK62 Federal Motor Vehicle Safety... that amended the Federal motor vehicle safety standard for air brake systems by requiring substantial... 37122) amending Federal Motor Vehicle Safety Standard (FMVSS) No. 121, Air Brake Systems, to...

  3. 76 FR 44829 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Science.gov (United States)

    2011-07-27

    ... Administration 49 CFR Part 571 [Docket No. NHTSA-2009-0175] RIN 2127-AK84 Federal Motor Vehicle Safety Standards... published a final rule that amended the Federal motor vehicle safety standard for air brake systems by... Federal Motor Vehicle Safety Standard (FMVSS) No. 121, Air Brake Systems, to require improved...

  4. GPS Auto-Navigation Design for Unmanned Air Vehicles

    Science.gov (United States)

    Nilsson, Caroline C. A.; Heinzen, Stearns N.; Hall, Charles E., Jr.; Chokani, Ndaona

    2003-01-01

    A GPS auto-navigation system is designed for Unmanned Air Vehicles. The objective is to enable the air vehicle to be used as a test-bed for novel flow control concepts. The navigation system uses pre-programmed GPS waypoints. The actual GPS position, heading, and velocity are collected by the flight computer, a PC104 system running in Real-Time Linux, and compared with the desired waypoint. The navigator then determines the necessity of a heading correction and outputs the correction in the form of a commanded bank angle, for a level coordinated turn, to the controller system. This controller system consists of 5 controller! (pitch rate PID, yaw damper, bank angle PID, velocity hold, and altitude hold) designed for a closed loop non-linear aircraft model with linear aerodynamic coefficients. The ability and accuracy of using GPS data, is validated by a GPS flight. The autopilots are also validated in flight. The autopilot unit flight validations show that the designed autopilots function as designed. The aircraft model, generated on Matlab SIMULINK is also enhanced by the flight data to accurately represent the actual aircraft.

  5. The Allure of Technology: How France and California Promoted Electric Vehicles to Reduce Urban Air Pollution

    OpenAIRE

    Calef, David; Goble, Robert

    2005-01-01

    All advanced industrialized societies face the problem of air pollution produced by motor vehicles. In spite of striking improvements in internal combustion engine technology, air pollution in most urban areas is still measured at levels determined to be harmful to human health. Throughout the 1990s and beyond, California and France both chose to improve air quality by means of technological innovation, adopting legislation that promoted clean vehicles, prominently among them, electric vehicl...

  6. Flexible Wing Base Micro Aerial Vehicles: Micro Air Vehicles (MAVs) for Surveillance and Remote Sensor Delivery

    Science.gov (United States)

    Ifju, Peter

    2002-01-01

    Micro Air Vehicles (MAVs) will be developed for tracking individuals, locating terrorist threats, and delivering remote sensors, for surveillance and chemical/biological agent detection. The tasks are: (1) Develop robust MAV platform capable of carrying sensor payload. (2) Develop fully autonomous capabilities for delivery of sensors to remote and distant locations. The current capabilities and accomplishments are: (1) Operational electric (inaudible) 6-inch MAVs with novel flexible wing, providing superior aerodynamic efficiency and control. (2) Vision-based flight stability and control (from on-board cameras).

  7. A Structurally-Integrated Ice Detection and De-Icing System for Unmanned Air Vehicles Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Unmanned air vehicles (UAVs) are becoming more prevalent for Suborbital Scientific Earth Exploration, which often involves high altitude, long endurance flight...

  8. THE STATUS OF MEASURES TO COMBAT MOTOR VEHICLE AIR POLLUTION AND OUTSTANDING ISSUES IN JAPAN

    Directory of Open Access Journals (Sweden)

    Yasuji SUZUKI

    2000-01-01

    Full Text Available In the quarter century since fiscal 1970, air pollution generated by motor vehicles has not improved sufficiently, and the state is severe, particularly in major cities. This is caused directly by the increasing volume of motor vehicle traffic that is, in turn, a result of the fact that contemporary socio-economic systems and lifestyles depend largely on the use of the motor vehicle. Social cost of air pollution must be internalized to solve the air pollution problem and the total volume of motor vehicle emission must be reduced and controlled to meet environmental quality standards, not just regulated on a vehicle-by-vehicle basis. This will require a review of the prevailing vehicle-dependent socio-economic systems and lifestyles, and necessitate that we look at a set of drastic measures which strike at the fundamentals of our vehicle usage.

  9. Research on Tension Control System for Aluminum Strip Air-cushion Heat Treatment line%铝带气垫式热处理线张力控制系统研究

    Institute of Scientific and Technical Information of China (English)

    付天亮; 韦云松; 王昭东; 李家栋

    2015-01-01

    针对国内某厂铝合金汽车板用气垫式连续热处理线,分析主要工艺设备张力工作特点,采用间接、直接两种张力控制模式对传动系统实施速度和转矩控制,建立了典型工艺设备张力控制方法及整线张力平衡控制策略,构建了以工艺数学模型为核心的张力控制系统.实测表明,静态张力控制精度为-0.05%~0.65%,动态张力控制精度为-3.65%~3.75%,满足热处理线对张力控制精度的需求.%Based on domestic air-cushion continuous heat treatment line for aluminum alloy automobile sheet, tension work characteristics of the main process equipment is analyzed, indirect and direct tension control mode are adopted for dirve system's velocity and torque control. And tension control method for typical process equipment and whole line tension balance control strategy are established, tension control system which centered on process mathematic model is constructed. The results show that static tension control precision is -0.05%~0.65%, and dynamic tension control percision is -3.65%~3.75%, both of which meet the needs of heat treatment line for tension control percision.

  10. A Time Study of Scientists & Engineers (S&Es) in the Air Vehicles Directorate

    Science.gov (United States)

    2010-01-01

    A TIME STUDY OF SCIENTISTS & ENGINEERS (S&Es) IN THE AIR VEHICLES DIRECTORATE JoAnn McCabe and Col John Wissler, USAF The Air Vehicles...Defense Acquisition University www.dau.mil Keywords: Time Study of Scientists and Engineers, Air Force Research Laboratory (AFRL) Research, Air...Force Research Laboratory Time Study , How Scientists and Engineers Spend Their Time, Technology-Focused Research Organizations, Value and Non-Value

  11. Gas cushion control of OVJP print head position

    Energy Technology Data Exchange (ETDEWEB)

    Forrest, Stephen R

    2014-10-07

    An OVJP apparatus and method for applying organic vapor or other flowable material to a substrate using a printing head mechanism in which the print head spacing from the substrate is controllable using a cushion of air or other gas applied between the print head and substrate. The print head is mounted for translational movement towards and away from the substrate and is biased toward the substrate by springs or other means. A gas cushion feed assembly supplies a gas under pressure between the print head and substrate which opposes the biasing of the print head toward the substrate so as to form a space between the print head and substrate. By controlling the pressure of gas supplied, the print head separation from the substrate can be precisely controlled.

  12. Air pollution and health risks due to vehicle traffic

    Science.gov (United States)

    Zhang, Kai; Batterman, Stuart

    2014-01-01

    Traffic congestion increases vehicle emissions and degrades ambient air quality, and recent studies have shown excess morbidity and mortality for drivers, commuters and individuals living near major roadways. Presently, our understanding of the air pollution impacts from congestion on roads is very limited. This study demonstrates an approach to characterize risks of traffic for on- and near-road populations. Simulation modeling was used to estimate on- and near-road NO2 concentrations and health risks for freeway and arterial scenarios attributable to traffic for different traffic volumes during rush hour periods. The modeling used emission factors from two different models (Comprehensive Modal Emissions Model and Motor Vehicle Emissions Factor Model version 6.2), an empirical traffic speed–volume relationship, the California Line Source Dispersion Model, an empirical NO2–NOx relationship, estimated travel time changes during congestion, and concentration–response relationships from the literature, which give emergency doctor visits, hospital admissions and mortality attributed to NO2 exposure. An incremental analysis, which expresses the change in health risks for small increases in traffic volume, showed non-linear effects. For a freeway, “U” shaped trends of incremental risks were predicted for on-road populations, and incremental risks are flat at low traffic volumes for near-road populations. For an arterial road, incremental risks increased sharply for both on- and near-road populations as traffic increased. These patterns result from changes in emission factors, the NO2–NOx relationship, the travel delay for the on-road population, and the extended duration of rush hour for the near-road population. This study suggests that health risks from congestion are potentially significant, and that additional traffic can significantly increase risks, depending on the type of road and other factors. Further, evaluations of risk associated with congestion

  13. Air pollution and health risks due to vehicle traffic.

    Science.gov (United States)

    Zhang, Kai; Batterman, Stuart

    2013-04-15

    Traffic congestion increases vehicle emissions and degrades ambient air quality, and recent studies have shown excess morbidity and mortality for drivers, commuters and individuals living near major roadways. Presently, our understanding of the air pollution impacts from congestion on roads is very limited. This study demonstrates an approach to characterize risks of traffic for on- and near-road populations. Simulation modeling was used to estimate on- and near-road NO2 concentrations and health risks for freeway and arterial scenarios attributable to traffic for different traffic volumes during rush hour periods. The modeling used emission factors from two different models (Comprehensive Modal Emissions Model and Motor Vehicle Emissions Factor Model version 6.2), an empirical traffic speed-volume relationship, the California Line Source Dispersion Model, an empirical NO2-NOx relationship, estimated travel time changes during congestion, and concentration-response relationships from the literature, which give emergency doctor visits, hospital admissions and mortality attributed to NO2 exposure. An incremental analysis, which expresses the change in health risks for small increases in traffic volume, showed non-linear effects. For a freeway, "U" shaped trends of incremental risks were predicted for on-road populations, and incremental risks are flat at low traffic volumes for near-road populations. For an arterial road, incremental risks increased sharply for both on- and near-road populations as traffic increased. These patterns result from changes in emission factors, the NO2-NOx relationship, the travel delay for the on-road population, and the extended duration of rush hour for the near-road population. This study suggests that health risks from congestion are potentially significant, and that additional traffic can significantly increase risks, depending on the type of road and other factors. Further, evaluations of risk associated with congestion must

  14. Integration of an Autopilot for a Micro Air Vehicle

    Science.gov (United States)

    Platanitis, George; Shkarayev, Sergey

    2005-01-01

    Two autopilots providing autonomous flight capabilities are presented herein. The first is the Pico-Pilot, demonstrated for the 12-inch size class of micro air vehicles. The second is the MicroPilot MP2028(sup g), where its integration into a 36-inch Zagi airframe (tailless, elevons only configuration) is investigated and is the main focus of the report. Analytical methods, which include the use of the Advanced Aircraft Analysis software from DARCorp, were used to determine the stability and control derivatives, which were then validated through wind tunnel experiments. From the aerodynamic data, the linear, perturbed equations of motion from steady-state flight conditions may be cast in terms of these derivatives. Using these linear equations, transfer functions for the control and navigation systems were developed and feedback control laws based on Proportional, Integral, and Derivative (PID) control design were developed to control the aircraft. The PID gains may then be programmed into the autopilot software and uploaded to the microprocessor of the autopilot. The Pico-Pilot system was flight tested and shown to be successful in navigating a 12-inch MAV through a course defined by a number of waypoints with a high degree of accuracy, and in 20 mph winds. The system, though, showed problems with control authority in the roll and pitch motion of the aircraft: causing oscillations in these directions, but the aircraft maintained its heading while following the prescribed course. Flight tests were performed in remote control mode to evaluate handling, adjust trim, and test data logging for the Zagi with integrated MP2028(sup g). Ground testing was performed to test GPS acquisition, data logging, and control response in autonomous mode. Technical difficulties and integration limitations with the autopilot prevented fully autonomous flight from taking place, but the integration methodologies developed for this autopilot are, in general, applicable for unmanned air

  15. 78 FR 9623 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Science.gov (United States)

    2013-02-11

    ... National Highway Traffic Safety Administration 49 CFR Part 571 RIN 2127-AL11 Federal Motor Vehicle Safety... published a final rule that amended the Federal motor vehicle safety standard for air brake systems by... published a final rule in the Federal Register amending Federal Motor Vehicle Safety Standard (FMVSS)...

  16. 40 CFR 86.1832-01 - Optional equipment and air conditioning for test vehicles.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Optional equipment and air conditioning for test vehicles. 86.1832-01 Section 86.1832-01 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES (CONTINUED) General...

  17. Ground control stations for unmanned air vehicles (Review Paper

    Directory of Open Access Journals (Sweden)

    G. Natarajan

    2001-07-01

    Full Text Available "During the last five decades, the world has witnessed tremendous growth in the military aircraft technology and the air defence weapons technology. Use of manned aircraft for routine reconnaissance/surveillance missions has become a less preferred option due to possible high attrition rate. Currently, the high political cost of human life has practically earmarked the roles of reconnaissance and surveillance missions to the unmanned air vehicles (UAVs. Almost every major country has a UAV program of its own and this interest has spawned intensive research in the field of UAVs. Presently, the UAVs come in all shapes and sizes, from palm top micro UAVs to giant strategic UAVs that can loiter over targets for extended periods of time. Though UAVs are capable of operating at different levels of autonomy, these are generally controlled from a ground control station (GCS. The GCS is the nerve centre of activity during UAV missions and provides necessary capability to plan and execute UAV missions. The GCS incorporates facilities, such as communication, displays, mission planning and data exploitation. The GCS architecture is highly processor-oriented and hence the computer hardware and software technologies play a major role in the realisation of this vital system. This paper gives an overview of the GCS, its architecture and the current state-of-the-art in various subsystem technologies.

  18. H-CANYON AIR EXHAUST TUNNEL INSPECTION VEHICLE DEVELOPMENT

    Energy Technology Data Exchange (ETDEWEB)

    Minichan, R.; Fogle, R.; Marzolf, A.

    2011-05-24

    The H-Canyon at Savannah River Site is a large concrete structure designed for chemical separation processes of radioactive material. The facility requires a large ventilation system to maintain negative pressure in process areas for radioactive contamination control and personnel protection. The ventilation exhaust is directed through a concrete tunnel under the facility which is approximately five feet wide and 8 feet tall that leads to a sand filter and stack. Acidic vapors in the exhaust have had a degrading effect on the surface of the concrete tunnels. Some areas have been inspected; however, the condition of other areas is unknown. Experience from historical inspections with remote controlled vehicles will be discussed along with the current challenge of inspecting levels below available access points. The area of interest in the exhaust tunnel must be accessed through a 14 X 14 inch concrete plug in the floor of the hot gang valve corridor. The purpose for the inspection is to determine the condition of the inside of the air tunnel and establish if there are any structural concerns. Various landmarks, pipe hangers and exposed rebar are used as reference points for the structural engineers when evaluating the current integrity of the air tunnel.

  19. Impact of Solar Control PVB Glass on Vehicle Interior Temperatures, Air-Conditioning Capacity, Fuel Consumption, and Vehicle Range

    Energy Technology Data Exchange (ETDEWEB)

    Rugh, J.; Chaney, L.; Venson, T.; Ramroth, L.; Rose, M.

    2013-04-01

    The objective of the study was to assess the impact of Saflex1 S-series Solar Control PVB (polyvinyl butyral) configurations on conventional vehicle fuel economy and electric vehicle (EV) range. The approach included outdoor vehicle thermal soak testing, RadTherm cool-down analysis, and vehicle simulations. Thermal soak tests were conducted at the National Renewable Energy Laboratory's Vehicle Testing and Integration Facility in Golden, Colorado. The test results quantified interior temperature reductions and were used to generate initial conditions for the RadTherm cool-down analysis. The RadTherm model determined the potential reduction in air-conditioning (A/C) capacity, which was used to calculate the A/C load for the vehicle simulations. The vehicle simulation tool identified the potential reduction in fuel consumption or improvement in EV range between a baseline and modified configurations for the city and highway drive cycles. The thermal analysis determined a potential 4.0% reduction in A/C power for the Saflex Solar PVB solar control configuration. The reduction in A/C power improved the vehicle range of EVs and fuel economy of conventional vehicles and plug-in hybrid electric vehicles.

  20. Development of the NWPU20 Micro Air Vehicle

    Institute of Scientific and Technical Information of China (English)

    Li Zhanke; Song Bifeng; Zhang Yafeng; Zhang Wei; Zhang Yizhe

    2005-01-01

    This paper reports the design, construction, and operation of NWPU20 Micro Air Vehicle (MAV), which is the smallest that has, up to now, been developed in PR China. The miniaturization level in PR China makes smaller MAV, in our opinion, not possible to implement. The NWPU20 is a 20-centimeter span, battery powered, fixed-wing aircraft with an off-the-shelf color video camera that can transmit live video back to the ground station. The on-board electronic subsystems are smallest and lightest among the commercial products, including an 8-gram wireless video camera, an 8-gram receiver, a 5-gram electronic speed controller (ESC), two 4.5-gram fully proportional radio frequency control servos, and the total mass of NWPU20 is less than 80 grams. An experimental model was fabricated and tested in the Low Turbulent Flow Wind Tunnel (LTFWT) at Northwestern Polytechnical University (NWPU) to research low Reynolds number flow characteristics of the NWPU20. The result of the wind tunnel test shows that stall angle of attack of NWPU20 can reach 30°, which is higher than that of the general aircrafts, and the maximum lift-to-drag ratio of NWPU20 can nearly reach 6 at the angle of attack of 10°, which can satisfy design requirements of the NWPU20. A small-sized propulsion/torque testing system was developed to measure and analyze the propulsion and torque performances of the motor-propeller combination used in the NWPU20. A center of gravity (c.g.) testing apparatus was developed and used to adjust the c.g. of the NWPU20 so that it has good longitudinal static stability and control. The NWPU20 prototype has undergone successfully flight tests many times; it flies at 32 kilometers per hour, with an endurance of 15 minutes, and a maximum communications range of 300 meters. With the color video camera, NWPU20 successfully transmits real-time video back to the ground station. The success of NWPU20 proves preliminarily that 20-centimeter span micro air vehicle is feasible and

  1. Aerial networking communication solutions using Micro Air Vehicle (MAV)

    Science.gov (United States)

    Balasubramanian, Shyam; de Graaf, Maurits; Hoekstra, Gerard; Corporaal, Henk; Wijtvliet, Mark; Cuadros Linde, Javier

    2014-10-01

    The application of a Micro Air Vehicle (MAV) for wireless networking is slowly gaining significance in the field of network robotics. Aerial transport of data requires efficient network protocols along with accurate positional adjustment of the MAV to minimize transaction times. In our proof of concept, we develop an Aerial networking protocol for data transfer using the technology of Disruption Tolerant Networks (DTN), a store-and-forward approach for environments that deals with disrupted connectivity. Our results show that close interaction between networking and flight behavior helps in efficient data exchange. Potential applications are in areas where network infrastructure is minimal or unavailable and distances may be large. For example, forwarding video recordings during search and rescue, agriculture, swarm communication, among several others. A practical implementation and validation, as described in this paper, presents the complex dynamics of wireless environments and poses new challenges that are not addressed in earlier work on this topic. Several tests are evaluated in a practical setup to display the networking MAV behavior during such an operation.

  2. Air Cushion Craft Development. First Revision.

    Science.gov (United States)

    1980-01-01

    in Florida. .. ................. 31 20 - Bell-Canada Voyageur and Viking .. .................32 21 - Generalized Breguet Range Chart...continue development. 27 IA-Po Figure 16 -SKMR-1 with and without Skirts 28 The Surface Effect Ships for Ocean Commerce (SESOC) Committee met with...between the U.S. Navy and the Department of Commerce and, as a result, the Joint Surface Effect Ship Program Office (JSESPO) was set up in 1966 to

  3. Unmanned air vehicle (UAV) ultra-persitence research

    Energy Technology Data Exchange (ETDEWEB)

    Dron, S. B.

    2012-03-01

    Sandia National Laboratories and Northrop Grumman Corporation Integrated Systems, Unmanned Systems (NGIS UMS) collaborated to further ultra-persistence technologies for unmanned air vehicles (UAVs). The greatest shortfalls in UAV capabilities have been repeatedly identified as (1) insufficient flight persistence or 'hang time,' (2) marginal electrical power for running higher power avionics and payload systems, and (3) inadequate communications bandwidth and reach. NGIS UMS requested support from Sandia to develop an ultra-persistent propulsion and power system (UP3S) for potential incorporation into next generation UAV systems. The team members tried to determine which energy storage and power generation concepts could most effectively push UAV propulsion and electrical power capabilities to increase UAV sortie duration from days to months while increasing available electrical power at least two-fold. Primary research and development areas that were pursued included these goals: perform general system engineering and integration analyses; develop initial thermal and electrical power estimates; provide mass, volume, dimensional, and balance estimates; conduct preliminary safety assessments; assess logistics support requirements; perform, preliminary assessments of any security and safeguards; evaluate options for removal, replacement, and disposition of materials; generally advance the potential of the UP3S concept. The effort contrasted and compared eight heat sources technologies, three power conversion, two dual cycle propulsion system configurations, and a single electrical power generation scheme. Overall performance, specific power parameters, technical complexities, security, safety, and other operational features were successfully investigated. Large and medium sized UAV systems were envisioned and operational flight profiles were developed for each concept. Heat source creation and support challenges for domestic and expeditionary operations were

  4. Variable-Fidelity Conceptual Design System for Advanced Unconventional Air Vehicles Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Ongoing work in unconventional air-vehicles, i.e. deformable mold-lines and bio-mimetics, is beginning to provide the insight necessary to exploit performance...

  5. Affordable High Power Density Engine Designs for Personal Air Vehicles Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Next generation General Aviation (GA) Sport Class air vehicles limited to 1200lbs, represent the first opportunity to overhaul the FAA certification process...

  6. Assessing the Link between Environmental Concerns and Consumers' Decisions to Use Clean-Air Vehicles

    Science.gov (United States)

    Plax, Timothy G.; Kearney, Patricia; Ross, Ted J.; Jolly, J. Christopher

    2008-01-01

    A consulting contract with the California Air Resources Board led to a project examining how California drivers' and fleet managers' perceptions, attitudes, and consumer behavior regarding Clean Vehicle Technologies influenced their own energy choices when it came to purchasing vehicles. The consultants examined archival research, conducted focus…

  7. Vehicle inspection and maintenance, and air pollution in Mexico City

    Energy Technology Data Exchange (ETDEWEB)

    Riveros, Hector G.; Cabrera, Enrique; Ovalle, Pilar [Universidad Nacional Autonoma de Mexico, Inst. de Fisica, Mexico City (Mexico)

    2002-07-01

    Information from the Mandatory Inspection and Maintenance (I/M) Program carried out in October 1996 and the first semester of 1998 provides a useful emission database for Mexico City. Carbon monoxide (CO) and hydrocarbon (HC) exhaust emission levels were measured for at least a million private and public transportation vehicle. Analysis of this database leads us to conclude that this information can be used to test anti-pollutant policies, and is useful as a performance quality index for vehicle manufacturers. Some of the results of this analysis include: the finding of a typical exhaust emission distribution curve for each vehicle manufacturer, with differences for each brand and model for the same manufacturer, the fact that not all new vehicles pass the I/M test; and public transportation vehicles in Mexico City have almost useless catalytic converters. (Author)

  8. An Evaluation of Personality Testing and the Five-Factor Model in the Selection of Landing Craft Air Cushion Vehicle Crew Members.

    Science.gov (United States)

    1993-07-30

    Orientation (Helmreich and Spence, 1978), Personality Attributes Questionnaire (Spence, Helmreich, & Holahan , 1979), Locus of Control (Rotter, 1966...Psychological Assessment, 5, 41- 52. Spence, J. T., Helmreich, R. L., & Holahan , C. K. (1979). Negative and positive components of psychological

  9. Allergenic sesquiterpene lactones from cushion bush (Leucophyta brownii Cass.)

    DEFF Research Database (Denmark)

    Paulsen, Evy; Gade Hyldgaard, Mette; Andersen, Klaus E.

    2017-01-01

    BACKGROUND: The Australian cushion bush (Leucophyta brownii) of the Compositae family of plants has become a popular pot and container plant. The plant produces the sesquiterpene lactone allergen calocephalin. OBJECTIVES: To assess the sensitizing potential of sesquiterpene lactones from cushion ...

  10. Cooling Performance Characteristics on Mobile Air-Conditioning System for Hybrid Electric Vehicles

    OpenAIRE

    Ho-Seong Lee; Moo-Yeon Lee

    2013-01-01

    This study investigates the cooling performance characteristics of the mobile air-conditioning system using R744 (CO2) for the hybrid electric vehicle as an alternative to both the R-134a and the conventional air-conditioning system. The developed air-conditioning system is operated with an electric driven compressor in the battery driving mode and a belt driven compressor in the engine driving mode. The cooling performance characteristics of the developed system have been analyzed by experim...

  11. Consequential life cycle air emissions externalities for plug-in electric vehicles in the PJM interconnection

    Science.gov (United States)

    Weis, Allison; Jaramillo, Paulina; Michalek, Jeremy

    2016-02-01

    We perform a consequential life cycle analysis of plug-in electric vehicles (PEVs), hybrid electric vehicles (HEVs), and conventional gasoline vehicles in the PJM interconnection using a detailed, normative optimization model of the PJM electricity grid that captures the change in power plant operations and related emissions due to vehicle charging. We estimate and monetize the resulting human health and environmental damages from life cycle air emissions for each vehicle technology. We model PJM using the most recent data available (2010) as well as projections of the PJM grid in 2018 and a hypothetical scenario with increased wind penetration. We assess a range of sensitivity cases to verify the robustness of our results. We find that PEVs have higher life cycle air emissions damages than gasoline HEVs in the recent grid scenario, which has a high percentage of coal generation on the margin. In particular, battery electric vehicles with large battery capacity can produce two to three times as much air emissions damage as gasoline HEVs, depending on charge timing. In our future 2018 grid scenarios that account for predicted coal plant retirements, PEVs would produce air emissions damages comparable to or slightly lower than HEVs.

  12. Regional and local effects of electric vehicles on air quality and noise

    Directory of Open Access Journals (Sweden)

    Sabine Wurzler

    2016-06-01

    Full Text Available Road traffic is one of the main causes of poor air quality in European cities. The air pollution burden due to road traffic in a street canyon consists of shares from local traffic and contributions of vehicles driving elsewhere in the city as well as elsewhere on a larger scale. Are electric vehicles a solution for air quality problems in cities? Do they reduce noise levels in street canyons significantly? The aim of this sensitivity study is to investigate the regional and local effects of electric vehicles on noise and air quality taking possible effects of additional electricity production into account. Focus of the present study lies for air quality on the regional scale in North Rhine-Westphalia and the overall effect in some selected street canyons, to be more precise the annual average PM10 and NO2 concentrations. A sensitivity study using the chemistry transport model EURAD and a screening model for street canyons was carried out. The influence on noise levels was analysed based on measurements of vehicles at different speeds. It turns out that road traffic has a significant impact on the regional air pollution levels. Furthermore it is shown that the reduction potential is bigger for NO2 than for PM10. With regard to EC limit value compliance a major share of electric vehicles could be a solution for the NO2 problems in moderately polluted street canyons. One of our findings is that if the additional electricity need causes additional emissions these counteract the possible reduction, especially for PM10. The noise reduction potential of electric vehicles is only significant for vehicles moving at low speeds.

  13. Valuation of plug-in vehicle life-cycle air emissions and oil displacement benefits.

    Science.gov (United States)

    Michalek, Jeremy J; Chester, Mikhail; Jaramillo, Paulina; Samaras, Constantine; Shiau, Ching-Shin Norman; Lave, Lester B

    2011-10-01

    We assess the economic value of life-cycle air emissions and oil consumption from conventional vehicles, hybrid-electric vehicles (HEVs), plug-in hybrid-electric vehicles (PHEVs), and battery electric vehicles in the US. We find that plug-in vehicles may reduce or increase externality costs relative to grid-independent HEVs, depending largely on greenhouse gas and SO(2) emissions produced during vehicle charging and battery manufacturing. However, even if future marginal damages from emissions of battery and electricity production drop dramatically, the damage reduction potential of plug-in vehicles remains small compared to ownership cost. As such, to offer a socially efficient approach to emissions and oil consumption reduction, lifetime cost of plug-in vehicles must be competitive with HEVs. Current subsidies intended to encourage sales of plug-in vehicles with large capacity battery packs exceed our externality estimates considerably, and taxes that optimally correct for externality damages would not close the gap in ownership cost. In contrast, HEVs and PHEVs with small battery packs reduce externality damages at low (or no) additional cost over their lifetime. Although large battery packs allow vehicles to travel longer distances using electricity instead of gasoline, large packs are more expensive, heavier, and more emissions intensive to produce, with lower utilization factors, greater charging infrastructure requirements, and life-cycle implications that are more sensitive to uncertain, time-sensitive, and location-specific factors. To reduce air emission and oil dependency impacts from passenger vehicles, strategies to promote adoption of HEVs and PHEVs with small battery packs offer more social benefits per dollar spent.

  14. Mechanical Cushion Design Influence on Cylinder Dynamics

    DEFF Research Database (Denmark)

    Borghi, Massimo; Milani, Massimo; Conrad, Finn

    2005-01-01

    The paper deals with the simulation and the experimental verification of the dynamic behaviour of a linear actuator equipped with different configurations of mechanical cushion. A numerical model, developed and tailored to describe the influence of different modulation of the discharged flow-rate...

  15. An Advanced Open-Source Aircraft Design Platform for Personal Air Vehicle Geometry, Aerodynamics, and Structures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Innovators working to revolutionize air travel through personal aviation pioneers need innovative aircraft design tools. Vehicle Sketch Pad (VSP) is an aircraft...

  16. COLD STORAGE-SUPPORTED AIR CONDITIONING SYSTEM IN URBAN TRANSPORT VEHICLES

    Directory of Open Access Journals (Sweden)

    Wojciech Jarzyna

    2016-11-01

    Full Text Available A bottleneck for the development of public transport vehicles is their electricity supply. Electric buses are almost exclusively equipped with electrochemical batteries, while nearly 40% of the energy is used in the processes of air conditioning. For this reason, we developed and built a demonstration system for storing thermal energy in public transport vehicles. The most important effects are: significant reduction of financial expenses and of the total weight of all batteries with the same amount of stored energy.

  17. An Expert Fault Diagnosis System for Vehicle Air Conditioning Product Development

    Science.gov (United States)

    Tan, C. F.; Tee, B. T.; Khalil, S. N.; Chen, W.; Rauterberg, G. W. M.

    2015-09-01

    The paper describes the development of the vehicle air-conditioning fault diagnosis system in automotive industries with expert system shell. The main aim of the research is to diagnose the problem of new vehicle air-conditioning system development process and select the most suitable solution to the problems. In the vehicle air-conditioning manufacturing industry, process can be very costly where an expert and experience personnel needed in certain circumstances. The expert of in the industry will retire or resign from time to time. When the expert is absent, their experience and knowledge is difficult to retrieve or lost forever. Expert system is a convenient method to replace expert. By replacing the expert with expert system, the accuracy of the processes will be increased compared to the conventional way. Therefore, the quality of product services that are produced will be finer and better. The inputs for the fault diagnosis are based on design data and experience of the engineer.

  18. Unmanned air/ground vehicles heterogeneous cooperative techniques:Current status and prospects

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Multiple unmanned air/ground vehicles heterogeneous cooperation is a novel and challenging filed.Heterogeneous cooperative techniques can widen the application fields of unmanned air or ground vehicles,and enhance the effectiveness of implementing detection,search and rescue tasks.This paper mainly focused on the key issues in multiple unmanned air/ground vehicles heterogeneous cooperation,including heterogeneous flocking,formation control,formation stability,network control,and actual applications.The main problems and future directions in this field were also analyzed in detail.These innovative technologies can significantly enhance the effectiveness of implementing complicated tasks,which definitely provide a series of novel breakthroughs for the intelligence,integration and advancement of future robot systems.

  19. Piezoelectric energy harvesting from morphing wing motions for micro air vehicles

    KAUST Repository

    Abdelkefi, Abdessattar

    2013-09-10

    Wing flapping and morphing can be very beneficial to managing the weight of micro air vehicles through coupling the aerodynamic forces with stability and control. In this letter, harvesting energy from the wing morphing is studied to power cameras, sensors, or communication devices of micro air vehicles and to aid in the management of their power. The aerodynamic loads on flapping wings are simulated using a three-dimensional unsteady vortex lattice method. Active wing shape morphing is considered to enhance the performance of the flapping motion. A gradient-based optimization algorithm is used to pinpoint the optimal kinematics maximizing the propellent efficiency. To benefit from the wing deformation, we place piezoelectric layers near the wing roots. Gauss law is used to estimate the electrical harvested power. We demonstrate that enough power can be generated to operate a camera. Numerical analysis shows the feasibility of exploiting wing morphing to harvest energy and improving the design and performance of micro air vehicles.

  20. Multi-Disciplinary Design Optimization of Hypersonic Air-Breathing Vehicle

    Science.gov (United States)

    Wu, Peng; Tang, Zhili; Sheng, Jianda

    2016-06-01

    A 2D hypersonic vehicle shape with an idealized scramjet is designed at a cruise regime: Mach number (Ma) = 8.0, Angle of attack (AOA) = 0 deg and altitude (H) = 30kms. Then a multi-objective design optimization of the 2D vehicle is carried out by using a Pareto Non-dominated Sorting Genetic Algorithm II (NSGA-II). In the optimization process, the flow around the air-breathing vehicle is simulated by inviscid Euler equations using FLUENT software and the combustion in the combustor is modeled by a methodology based on the well known combination effects of area-varying pipe flow and heat transfer pipe flow. Optimization results reveal tradeoffs among total pressure recovery coefficient of forebody, lift to drag ratio of vehicle, specific impulse of scramjet engine and the maximum temperature on the surface of vehicle.

  1. Modeling and Analysis of an Air-Breathing Flexible Hypersonic Vehicle

    Directory of Open Access Journals (Sweden)

    Xi-bin Zhang

    2014-01-01

    Full Text Available By using light-weighted material in hypersonic vehicle, the vehicle body can be easily deformed. The mutual couplings in aerodynamics, flexible structure, and propulsion system will bring great challenges for vehicle modeling. In this work, engineering estimated method is used to calculate the aerodynamic forces, moments, and flexible modes to get the physics-based model of an air-breathing flexible hypersonic vehicle. The model, which contains flexible effects and viscous effects, can capture the physical characteristics of high-speed flight. To overcome the analytical intractability of the model, a simplified control-oriented model of the hypersonic vehicle is presented with curve fitting approximations. The control-oriented model can not only reduce the complexity of the model, but also retain aero-flexible structure-propulsion interactions of the physics-based model and can be applied for nonlinear control.

  2. Distributed pheromone-based swarming control of unmanned air and ground vehicles for RSTA

    Science.gov (United States)

    Sauter, John A.; Mathews, Robert S.; Yinger, Andrew; Robinson, Joshua S.; Moody, John; Riddle, Stephanie

    2008-04-01

    The use of unmanned vehicles in Reconnaissance, Surveillance, and Target Acquisition (RSTA) applications has received considerable attention recently. Cooperating land and air vehicles can support multiple sensor modalities providing pervasive and ubiquitous broad area sensor coverage. However coordination of multiple air and land vehicles serving different mission objectives in a dynamic and complex environment is a challenging problem. Swarm intelligence algorithms, inspired by the mechanisms used in natural systems to coordinate the activities of many entities provide a promising alternative to traditional command and control approaches. This paper describes recent advances in a fully distributed digital pheromone algorithm that has demonstrated its effectiveness in managing the complexity of swarming unmanned systems. The results of a recent demonstration at NASA's Wallops Island of multiple Aerosonde Unmanned Air Vehicles (UAVs) and Pioneer Unmanned Ground Vehicles (UGVs) cooperating in a coordinated RSTA application are discussed. The vehicles were autonomously controlled by the onboard digital pheromone responding to the needs of the automatic target recognition algorithms. UAVs and UGVs controlled by the same pheromone algorithm self-organized to perform total area surveillance, automatic target detection, sensor cueing, and automatic target recognition with no central processing or control and minimal operator input. Complete autonomy adds several safety and fault tolerance requirements which were integrated into the basic pheromone framework. The adaptive algorithms demonstrated the ability to handle some unplanned hardware failures during the demonstration without any human intervention. The paper describes lessons learned and the next steps for this promising technology.

  3. UNMANNED AIR VEHICLE STABILIZATION BASED ON NEURAL NETWORK REGULATOR

    Directory of Open Access Journals (Sweden)

    S. S. Andropov

    2016-09-01

    Full Text Available A problem of stabilizing for the multirotor unmanned aerial vehicle in an environment with external disturbances is researched. A classic proportional-integral-derivative controller is analyzed, its flaws are outlined: inability to respond to changing of external conditions and the need for manual adjustment of coefficients. The paper presents an adaptive adjustment method for coefficients of the proportional-integral-derivative controller based on neural networks. A neural network structure, its input and output data are described. Neural networks with three layers are used to create an adaptive stabilization system for the multirotor unmanned aerial vehicle. Training of the networks is done with the back propagation method. Each neural network produces regulator coefficients for each angle of stabilization as its output. A method for network training is explained. Several graphs of transition process on different stages of learning, including processes with external disturbances, are presented. It is shown that the system meets stabilization requirements with sufficient number of iterations. Described adjustment method for coefficients can be used in remote control of unmanned aerial vehicles, operating in the changing environment.

  4. Configuration Studies of Personal Air Vehicles. Personal Air Vehicle and Flying Jeep Concepts: A Commentary on Promising Approaches or What Goes Around Comes Around (About Every Twenty Years)

    Science.gov (United States)

    Hall, David W.

    2001-01-01

    The NASA/Langley Personal Air Vehicle (PAV) Exploration (PAVE) and the DARPA (Defense Advanced Research Projects Agency) Dual Air/Road Transportation System (DARTS) projects were established to investigate the feasibility of creating vehicles which could replace, or at the very least augment, personal ground and air transportation schemes. This overall goal implies integrating several technology areas with practical everyday transportation requirements to design a class of vehicles which will achieve the following goals: (1) Vertical, Extremely Short, or Short Takeoff and Landing (VTOL, ESTOL, STOL) capability; (2) Operation at block speeds markedly faster than current combinations of land and air transportation, particularly in critical market areas; (3) Unit cost comparable to current luxury cars and small general aviation aircraft; (4) Excellent reliability; (5) Excellent safety; (6) Ability to integrate with existing land and air transportation systems. The conclusions of these configuration studies are summarized as follows: (1) Creation of the five assigned configurations prompted added explorations, some of which were dead-ends; (2) Some components could be common to all configurations such as avionics and dual-mode suspension schemes; (3) Single-Mode PAVs can be created by removing dual-mode-specific items; (4) Aviation history provided some intriguing starting points, as in what goes around comes around; (5) CTOL (Conventional Take-off and Landing) and STOL dual-mode PAVs look feasible with single-mode PAVs being simplifications of the dual-mode approach; (6) VTOL PAVs will require development; (7) More exotic collapsing mechanisms mechanisms need development; (8) As a teaching tool, PAVs are not yet a well-enough bounded design problem.

  5. Analysis and optimization of an adsorption air conditioner for electric vehicle applications

    Energy Technology Data Exchange (ETDEWEB)

    Aceves, S.M.

    1994-07-27

    This paper shows an analysis of the applicability of an adsorption system for electric vehicle (EV) air conditioning. Adsorption systems are designed and optimized to provide the required cooling for four combinations of vehicle characteristics and driving cycles. The resulting adsorption systems are compared with vapor compression air conditioners that can satisfy the cooling load. The objective function is the overall system weight, which includes the cooling system weight and the weight of the battery necessary to provide energy for air conditioner operation. The system with the minimum overall weight is considered to be the best. The results show the optimum values of all the variables, as well as temperatures and amounts adsorbed, for the adsorption and desorption processes. The results indicate that, for the conditions analyzed in this paper, vapor compression air conditioners are superior to adsorption systems, not only because they are lighter, but also because they have a higher COP and are more compact.

  6. Comparative Studies on Vehicle Related Policies for Air Pollution Reduction in Ten Asian Countries

    Directory of Open Access Journals (Sweden)

    Keiko Hirota

    2010-01-01

    Full Text Available Asian countries are facing major air pollution problems due to rapid economic growth, urbanization and motorization. Mortality and respiratory diseases caused by air pollution are believed to be endemic in major cities of these countries. Regulations and standards are the first requirement for reducing emissions from both fixed and mobile sources. This paper emphasizes monitoring problems such as vehicle registration systems, inspection and maintenance (I/M systems and fuel quality monitoring systems for vehicles in use. Monitoring problems in developing countries share similar characteristics such as a weakness in government initiatives and inadequate operation of government agencies, which results from a lack of human resources and availability of adequate facilities. Finally, this paper proposes a method to assure air quality improvements under the different shares of emission regulations in these Asian countries and introduces an example of an evaluation method based on a policy survey to improve air quality.

  7. Vehicle height and posture control of the electronic air suspension system using the hybrid system approach

    Science.gov (United States)

    Sun, Xiaoqiang; Cai, Yingfeng; Chen, Long; Liu, Yanling; Wang, Shaohua

    2016-03-01

    The electronic air suspension (EAS) system can improve ride comfort, fuel economy and handling safety of vehicles by adjusting vehicle height. This paper describes the development of a novel controller using the hybrid system approach to adjust the vehicle height (height control) and to regulate the roll and pitch angles of the vehicle body during the height adjustment process (posture control). The vehicle height adjustment system of EAS poses challenging hybrid control problems, since it features different discrete modes of operation, where each mode has an associated linear continuous-time dynamic. In this paper, we propose a novel approach to the modelling and controller design problem for the vehicle height adjustment system of EAS. The system model is described firstly in the hybrid system description language (HYSDEL) to obtain a mixed logical dynamical (MLD) hybrid model. For the resulting model, a hybrid model predictive controller is tuned to improve the vehicle height and posture tracking accuracy and to achieve the on-off statuses direct control of solenoid valves. The effectiveness and performance of the proposed approach are demonstrated by simulations and actual vehicle tests.

  8. Improving the aluminum-air battery system for use in electrical vehicles

    Science.gov (United States)

    Yang, Shaohua

    The objectives of this study include improvement of the efficiency of the aluminum/air battery system and demonstration of its ability for vehicle applications. The aluminum/air battery system can generate enough energy and power for driving ranges and acceleration similar to that of gasoline powered cars. Therefore has the potential to be a power source for electrical vehicles. Aluminum/air battery vehicle life cycle analysis was conducted and compared to that of lead/acid and nickel-metal hydride vehicles. Only the aluminum/air vehicles can be projected to have a travel range comparable to that of internal combustion engine vehicles (ICE). From this analysis, an aluminum/air vehicle is a promising candidate compared to ICE vehicles in terms of travel range, purchase price, fuel cost, and life cycle cost. We have chosen two grades of Al alloys (Al alloy 1350, 99.5% and Al alloy 1199, 99.99%) in our study. Only Al 1199 was studied extensively using Na 2SnO3 as an electrolyte additive. We then varied concentration and temperature, and determined the effects on the parasitic (corrosion) current density and open circuit potential. We also determined cell performance and selectivity curves. To optimize the performance of the cell based on our experiments, the recommended operating conditions are: 3--4 N NaOH, about 55°C, and a current density of 150--300 mA/cm2. We have modeled the cell performance using the equations we developed. The model prediction of cell performance shows good agreement with experimental data. For better cell performance, our model studies suggest use of higher electrolyte flow rate, smaller cell gap, higher conductivity and lower parasitic current density. We have analyzed the secondary current density distributions in a two plane, parallel Al/air cell and a wedge-type Al/air cell. The activity of the cathode has a large effect on the local current density. With increases in the cell gap, the local current density increases, but the increase is

  9. On-Line Trajectory Optimization for Autonomous Air Vehicles

    Science.gov (United States)

    2007-07-31

    equations of motion to handle cooperative path planning for multi-vehicles. • Application of genetic algorithms (GA) to solve multiple initial...1 17 1 165 sinsincos D vDD D uDDD Kg yy y xyy ψ λ ψψ λλ& (2.24) where 32 3 11 AAD = (2.25) 322 AfVfD −= (2.26) y yx ffBVAfffVABAVAD...value was needed, a variable step sweep was employed to find it. Otherwise the GA was used[26-28]. To begin the genetic algorithm, a set of 48

  10. 77 FR 73459 - California State Motor Vehicle Pollution Control Standards; Notice of Waiver of Clean Air Act...

    Science.gov (United States)

    2012-12-10

    ... AGENCY California State Motor Vehicle Pollution Control Standards; Notice of Waiver of Clean Air Act..., challenging the need for CARB's own motor vehicle pollution control program based on lack of compelling and... Administrator shall waive preemption for California to enforce new motor vehicle emissions standards...

  11. Autonomous Soaring for Improved Endurance of a Small Uninhabited Air Vehicle

    Science.gov (United States)

    Allen, Michael J.

    2005-01-01

    A relatively unexplored method to improve the endurance of an autonomous aircraft is to use buoyant plumes of air found in the lower atmosphere called thermals or updrafts. Glider pilots and birds commonly use updrafts to improve range, endurance, or cross-country speed. This report presents a quantitative analysis of a small electric-powered uninhabited air vehicle using updrafts to extend its endurance over a target location. A three-degree-of-freedom simulation of the uninhabited air vehicle was used to determine the yearly effect of updrafts on performance. Surface radiation and rawinsonde balloon measurements taken at Desert Rock, Nevada, were used to determine updraft size, strength, spacing, shape, and maximum height for the simulation. A fixed-width spiral path was used to search for updrafts at the same time as maintaining line-of-sight to the surface target position. Power was used only when the aircraft was flying at the lower-altitude limit in search of updrafts. Results show that an uninhabited air vehicle with a nominal endurance of 2 hours can fly a maximum of 14 hours using updrafts during the summer and a maximum of 8 hours during the winter. The performance benefit and the chance of finding updrafts both depend on what time of day the uninhabited air vehicle is launched. Good endurance and probability of finding updrafts during the year was obtained when the uninhabited air vehicle was launched 30 percent into the daylight hours after sunrise each day. Yearly average endurance was found to be 8.6 hours with these launch times.

  12. Design of an air sampler for a small unmanned aerial vehicle.

    Science.gov (United States)

    Peräjärvi, K; Lehtinen, J; Pöllänen, R; Toivonen, H

    2008-01-01

    In the aftermath of a nuclear accident or malevolent act, it is of paramount importance to have the capability to monitor airborne radioactive substances by collecting air samples. For potentially dangerous missions, the Radiation and Nuclear Safety Authority of Finland (STUK) has developed an air sampler to be used on a small unmanned aerial vehicle. When a Petrianov or Fluoropore filter is used in the sampler and the air velocity is 71 km h(-1), the air flow rate through the filter is 0.73 m(3) h(-1) or 0.23 m(3) h(-1), respectively. The present article introduces the developed air sampler using fluid dynamic simulations and wind tunnel data. The operation of the system was validated by collecting airborne radioactive aerosols from air.

  13. Cooling Performance Characteristics on Mobile Air-Conditioning System for Hybrid Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Ho-Seong Lee

    2013-01-01

    Full Text Available This study investigates the cooling performance characteristics of the mobile air-conditioning system using R744 (CO2 for the hybrid electric vehicle as an alternative to both the R-134a and the conventional air-conditioning system. The developed air-conditioning system is operated with an electric driven compressor in the battery driving mode and a belt driven compressor in the engine driving mode. The cooling performance characteristics of the developed system have been analyzed by experiments under various operating conditions of inlet air temperature, air flow rates for the gas cooler side and evaporator side, and electric compressor revolution respectively. As a result, cooling performances of the tested air-conditioning system for the EDC driving mode (electricity driven compressor were better than those for the BDC driving mode (belt driven compressor. The cooling capacity and cooling COP of the tested air-conditioning system for both driving modes were over 5.0 kW and 2.0, respectively. The observed cooling performance of the tested air-conditioning system may be sufficient for the cabin cooling of hybrid electric vehicles.

  14. CFD based aerodynamic modeling to study flight dynamics of a flapping wing micro air vehicle

    Science.gov (United States)

    Rege, Alok Ashok

    The demand for small unmanned air vehicles, commonly termed micro air vehicles or MAV's, is rapidly increasing. Driven by applications ranging from civil search-and-rescue missions to military surveillance missions, there is a rising level of interest and investment in better vehicle designs, and miniaturized components are enabling many rapid advances. The need to better understand fundamental aspects of flight for small vehicles has spawned a surge in high quality research in the area of micro air vehicles. These aircraft have a set of constraints which are, in many ways, considerably different from that of traditional aircraft and are often best addressed by a multidisciplinary approach. Fast-response non-linear controls, nano-structures, integrated propulsion and lift mechanisms, highly flexible structures, and low Reynolds aerodynamics are just a few of the important considerations which may be combined in the execution of MAV research. The main objective of this thesis is to derive a consistent nonlinear dynamic model to study the flight dynamics of micro air vehicles with a reasonably accurate representation of aerodynamic forces and moments. The research is divided into two sections. In the first section, derivation of the nonlinear dynamics of flapping wing micro air vehicles is presented. The flapping wing micro air vehicle (MAV) used in this research is modeled as a system of three rigid bodies: a body and two wings. The design is based on an insect called Drosophila Melanogaster, commonly known as fruit-fly. The mass and inertial effects of the wing on the body are neglected for the present work. The nonlinear dynamics is simulated with the aerodynamic data published in the open literature. The flapping frequency is used as the control input. Simulations are run for different cases of wing positions and the chosen parameters are studied for boundedness. Results show a qualitative inconsistency in boundedness for some cases, and demand a better

  15. DEFINITION OF OUTPUT ENERGY PARAMETERS OF A VEHICLE WITH AIR MOTOR

    Directory of Open Access Journals (Sweden)

    Voronkov, A.

    2013-06-01

    Full Text Available It was made trailer-speed motion analysis of minibus GAZ-2217 with air motor instead of the internal combustion engine and recommendations allowing to determine the output power of the power plant parameters for vehicle movement at low speed in urban cycle.

  16. Experimental Methods to Characterize Nonlinear Vibration of Flapping Wing Micro Air Vehicles

    Science.gov (United States)

    2007-03-01

    the following terminology when referring to flapping wing MAVs; bird flight machines are also known as ornithopters and robotic insects are also...15. SUBJECT TERMS Flapping Wing Micro Air Vehicle, flapping-wing MAV, MAV, ornithopter , entomopter, nonlinear vibration, beam resonance

  17. Aerodynamics of flapping-wing Micro-Air-Vehicle: An integrated experimental and numerical study

    NARCIS (Netherlands)

    Deng, S.

    2016-01-01

    The interest in Micro Air Vehicles (MAVs) has stimulated continuous research activities, in view of their potential in civilian and military applications. An autonomous MAV with dedicated onboard sensors would be capable of executing mission in closed environments, such as surveillance, in door insp

  18. Reliable Force Predictions for a Flapping-wing Micro Air Vehicle : A "Vortex-lift" Approach

    NARCIS (Netherlands)

    Thielicke, W.; Kesel, A. B.; Stamhuis, Eize

    2011-01-01

    Vertical and horizontal force of a flapping-wing micro air vehicle (MAV) has been measured in slow-speed forward flight using a force balance. Detailed information on kinematics was used to estimate forces using a blade-element analysis. Input variables for this analysis are lift and drag coefficien

  19. The scalable design of flapping micro air vehicles inspired by insect flight

    NARCIS (Netherlands)

    Lentink, D.; Jongerius, S.R.; Bradshaw, N.L.

    2009-01-01

    Here we explain how flapping micro air vehicles (MAVs) can be designed at different scales, from bird to insect size. The common believe is that micro fixed wing airplanes and helicopters outperform MAVs at bird scale, but become inferior to flapping MAVs at the scale of insects as small as fruit fl

  20. Laser Dot Projection Photogrammetry and Force Balance Measurement Techniques for Flapping Wing Micro Air Vehicles

    Science.gov (United States)

    2008-03-01

    Parameters of Force Balance Channels ............................................................. 39  1 BIOMIMETIC MICRO AIR VEHICLE...used two high speed cameras to research the flight of butterflies in their natural habitat. They set-up the cameras in a butterfly vivarium and...captured images of multiple butterflies performing multiple flight maneuvers. Images were captured at 100-200 Hz. Using software, certain body parts

  1. Easy 3D mapping for indoor navigation of unmanned micro air vehicles

    DEFF Research Database (Denmark)

    Schiøler, Henrik; Totu, Luminita Cristiana; La Cour-Harbo, Anders

    2017-01-01

    Indoor operation of micro air vehicles (UAS or UAV) is significantly simplified with the availability of some means for indoor localization as well as a sufficiently precise 3D map of the facility. Creation of 3D maps based on the available architectural information should on the one hand provide...

  2. 为启动座椅坐垫倾角调节机构的汽车制动模式识别策略的研究%A Research on Vehicle Braking Pattern Recognition Strategy for Actuating Seat Cushion Adjuster

    Institute of Scientific and Technical Information of China (English)

    朱文婷; 葛如海; 臧绫

    2011-01-01

    为准确地判定紧急制动状态,以便及时启动座椅坐垫倾角调节机构,对汽车制动模式判别策略进行研究.选取在汽车中低速行驶下的缓慢、点刹、紧急制动3种模式,采用正交试验设计方法,选用不同驾驶员以不同车速进行了制动实验.在对实验数据进行分析的基础上,采用了踏板力峰值法与踏板力变化率法两种判别算法.实验结果发现,两种算法都存在局限性.为此,又尝试了基于RBF神经网络模式识别算法.结果表明,这种算法能准确地判别制动模式.%For accurately ascertaining the state of emergency braking in order to promptly actuate seat cushion inclined angle adjuster, a research on vehicle braking pattern recognition strategy is conducted.Firstly by using orthogonal experimental design method, different drivers are chosen to carry ont braking experiments with slow, intermittent and emergency three braking modes at different medium and low speeds.On the base of analyzing test data, two discrimination algorithms, based on peak pedal force and the changing rate of pedal force respectively, are adopted.The results of experiment indicate that both algorithms have certain limitation.Accordingly a RBF neural network-based pattern recognition algorithm is attempted.The results show that the algorithm can accurately discriminate braking patterns.

  3. Fire resistant resilient foams. [for seat cushions

    Science.gov (United States)

    Gagliani, J.

    1976-01-01

    Primary program objectives were the formulation, screening, optimization and characterization of open-cell, fire resistant, low-smoke emitting, thermally stable, resilient polyimide foams suitable for seat cushions in commercial aircraft and spacecraft. Secondary program objectives were to obtain maximum improvement of the tension, elongation and tear characteristics of the foams, while maintaining the resiliency, thermal stability, low smoke emission and other desirable attributes of these materials.

  4. Road user charges for heavy goods vehicles (HGV). Tables with external costs of air pollution

    Energy Technology Data Exchange (ETDEWEB)

    Skou Andersen, M.

    2013-02-15

    In this report, the European Environment Agency (EEA) presents updated estimates of the external costs of air pollution for different categories of heavy goods vehicles (HGVs). The amended Eurovignette Directive (2011/76/EU) relating to the charging of HGVs for use of major European motorways prescribes that from 2013, Member States may include air pollution costs in any charging structure for roads under the Trans-European Network (TEN-T) and for comparable domestic motorways. The tables published here provide the basis for the inclusion of a vehicle-specific air pollution component in road user charges. Air pollution costs have been calculated on the basis of the formula prescribed in the directive, taking into account the fact that road transport emissions are mixed in a low volume of air. Following Article 9 in the Eurovignette Directive, additional revenues from external-cost charges must be used by Member States to benefit the transport sector and promote sustainable mobility. Making use of scientific developments subsequent to the 2007 Handbook of external costs (Maibach et al., 2008), the EEA is able to provide an updated estimate of the external costs of air pollution from road transport. The tables in this report indicate for each country and for the relevant vehicle categories, estimates of the external costs of air pollution in 2010 prices. The high level of detail gives member countries an informed basis to group the vehicle categories for administrative purposes. The tables also include estimates for three non-EU member countries of the EEA, of which one (Switzerland) pioneered the first HGV road user charge in Europe. (LN)

  5. Liquid Hydrogen Fuel System for Small Unmanned Air Vehicles

    Science.gov (United States)

    2013-01-07

    propulsion plant comprised a hydrogen fuel cell system, built by Protonex Technology Corporation, which weighed 2.5 lbs and produced a maximum of 550... NASA for flight on long-endurance UAVs. 9 Aluminum was selected for both the inner and outer walls of the LH2 dewar because of its low H2...impact of cooling from air flow would ordinarily be tested in a wind tunnel, LH2 safety complicates indoor testing in a wind tunnel, as

  6. 78 FR 32223 - Control of Air Pollution From Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards

    Science.gov (United States)

    2013-05-29

    ... Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards AGENCY: Environmental Protection Agency... Pollution from Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards'' (the proposed rule...

  7. Seacoaster advanced marine vehicle. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Burg, D.

    1998-08-18

    The Seacoaster combines the high efficiencies of Surface Effect Ships (SES) with simple catamaran hull construction. It has blower pressurized air cushions that support some 80-90 percent of displacement and hence the high efficiencies. However, unlike the SES, there are no expensive and high maintenance flexible seals. Each catamaran sidehull has a simple recess molded or built into its underside. Powered blowers direct pressurized air into such recesses and thereby create lifting air cushions. There are no flexible seals of any kind and there is no air cushion between the sidehulls. Extensive towed model tests were conducted that showed the viability of the invention.

  8. Wheelchair cushions for persons with spinal cord injury: an update.

    Science.gov (United States)

    Garber, S L; Dyerly, L R

    1991-06-01

    Occupational therapists frequently prescribe wheelchair cushions to reduce the risk of pressure sores in patients with spinal cord injury. In an earlier study (Garber, 1985b), Roho cushions were prescribed for the greatest number of subjects studied. The present study of 197 subjects updates these data and describes current prescription patterns, the use of cushions over time, satisfaction with prescribed cushions, and the occurrence of pressure sores with prescribed cushions. The study shows that the Jay cushion was prescribed most frequently for the current subjects, although it was not recommended for all persons with spinal cord injury. In the second phase of the present study, involving 30 subjects, 30% of the subjects discontinued use of the prescribed cushion. Skin breakdown and the discovery of alternative solutions were given as primary reasons. There was no significant difference in the incidence of pressure sores between subjects who continued to use their prescribed cushions and those who did not. This research supports the conclusion of earlier studies that no one wheelchair cushion is universally effective for all persons and that individual evaluation and routine reassessment are essential in reducing the occurrence of pressure sores.

  9. Performance of Used Tire Cushion Layer under Rockfall Impact

    Directory of Open Access Journals (Sweden)

    Jianhu Sun

    2016-01-01

    Full Text Available Rock shed is widely used in traffic lines against rockfall. In order to cushion rockfall impact and dissipate impact energy, cushion layer is usually adopted in rock shed. Used tire cushion layer is proposed in this paper and it can cushion rockfall impact utilizing large radial deformation of tire. Reinforced concrete structure model is built with used tire cushion layer and artificial rockfall test is carried out. Twelve tests are divided into 4 sets with different rockfall mass, rockfall height, and tire filling material. Simplified calculation model with spring-damper is derived from radial repeated compression test of used tire, which improves the calculation efficiency. Test and numerical simulation show that application of used tire cushion layer in rock shed can cushion rockfall impact and effectively reduce peak acceleration and the maximum impact force. Filling sand and gravel in tire can improve tire stiffness and energy absorption capacity but will decrease cushion effect due to its large density. With the same impact energy, light rockfall is more destructive than weight rockfall for used tire cushion layer.

  10. PV-ETFE 气枕结构温度实测研究%Field measurement of temperature of PV-ETFE cushion structures

    Institute of Scientific and Technical Information of China (English)

    胡建辉; 陈务军; 赵兵; 宋浩

    2015-01-01

    To investigate temperature characteristics of the ethylene‐tetra‐fluoro‐ethylene (ETFE) cushion integrated flexible amorphous silicon photovoltaic panels (PV‐ETFE for short), two types of PV‐ETFE cushions were designed. Cushion 1 was a three‐layer ETFE cushion integrated PV on sur‐face of its middle layer and cushion 2 was a double‐layer ETFE cushion integrated PV on surface of its top layer. Then, temperature of the two PV‐ETFE cushions in summer was field‐measured. The re‐sults show that temperature differences between the two PV‐ETFE cushions were 35. 4 ℃ for PV and 26. 2℃ for ETFE foils, the major influencing factors for ETFE foil of cushion 1, ETFE foil of cushion 2 and PV are the air temperature in cushion 1, air flow outside the cushion 2, and shade and angle of incidence of the solar irradiance, respectively.%为了研究柔性非晶硅薄膜光伏电池‐乙烯四氟乙烯共聚物(简称PV‐ETFE)气枕结构的温度特征,设计了由三层ET FE气枕与集成于其中层膜上表面PV组成的气枕1及由双层ET FE气枕与集成于其上层膜上表面PV组成的气枕2,实测了两种气枕的PV和ET FE薄膜的夏季温度数据.通过分析得到:两种气枕的PV和ET FE薄膜温度差分别为35.4℃和26.2℃;气枕1和气枕2 ET FE薄膜受气枕内空气温度和气枕外空气流动影响明显;PV温度受阴影及太阳光入射角影响.

  11. Impact of aeroelasticity on propulsion and longitudinal flight dynamics of an air-breathing hypersonic vehicle

    Science.gov (United States)

    Raney, David L.; Mcminn, John D.; Pototzky, Anthony S.; Wooley, Christine L.

    1993-01-01

    Many air-breathing hypersonic aerospacecraft design concepts incorporate an elongated fuselage forebody acting as the aerodynamic compression surface for a hypersonic combustion module, or scram jet. This highly integrated design approach creates the potential for an unprecedented form of aero-propulsive-elastic interaction in which deflections of the vehicle fuselage give rise to propulsion transients, producing force and moment variations that may adversely impact the rigid body flight dynamics and/or further excite the fuselage bending modes. To investigate the potential for such interactions, a math model was developed which included the longitudinal flight dynamics, propulsion system, and first seven elastic modes of a hypersonic air-breathing vehicle. Perturbation time histories from a simulation incorporating this math model are presented that quantify the propulsive force and moment variations resulting from aeroelastic vehicle deflections. Root locus plots are presented to illustrate the effect of feeding the propulsive perturbations back into the aeroelastic model. A concluding section summarizes the implications of the observed effects for highly integrated hypersonic air-breathing vehicle concepts.

  12. Concentrations of air toxics in motor vehicle-dominated environments.

    Science.gov (United States)

    Fujita, Eric M; Campbell, David E; Zielinska, Barbara; Arnott, William P; Chow, Judith C

    2011-02-01

    We at the Desert Research Institute (DRI*) measured volatile organic compounds (VOCs), including several mobile-source air toxics (MSATs), particulate matter with a mass mean aerodynamic diameter model calculations attributed the sum of BTEX almost exclusively to gasoline engine exhaust for on-road samples and all but 5% to 10% of the BTEX at the three near-road sites. CMB analysis attributed 46% to 52% (+/- 7) of the ambient total particulate carbon (TC) at the three near-road sites to diesel exhaust and 10% to 17% (+/- 7) to gasoline exhaust; it attributed about 90% of the ambient elemental carbon (EC) concentrations (measured as refractory carbon using the thermal evolution method) to diesel exhaust. Diesel particulate carbon (DPC) concentrations were estimated by multiplying the mean ratio of TC to EC from the source-dominated ambient samples collected on road on Terminal Island (1.30 +/- 0.28), which is located between the Long Beach and Los Angeles ports, with the measured ambient EC concentrations at the three near-road sites. DPC estimates from EC measurements correlate well with the diesel source contributions calculated with the CMB model. The indication from these apportionments that BC or EC is a good surrogate for diesel exhaust is further supported by the positive correlation of on-road BC concentrations with volumes of truck traffic. Traffic counts have been used in past health assessment studies as surrogates for estimating near-road exposure concentrations with appropriate weighting for proximity to the road. However, the results of this study show that it is necessary to account for the proportion of diesel trucks to total vehicular traffic because of the disproportionate contribution of diesel exhaust to BC and to directly emitted PM. Alternatively, easily measured pollutants such as CO and BC can serve as reasonable surrogates for MSATs (e.g., BTEX and BD) and DPC, respectively. Measuring CO and BC is a reasonably cost-effective approach to

  13. Efficient supersonic air vehicle design using the Service-Oriented Computing Environment (SORCER

    Directory of Open Access Journals (Sweden)

    Burton Scott A.

    2014-01-01

    Full Text Available The Air Force Research Lab’s Multidisciplinary Science and Technology Center is investigating conceptual design processes and computing frameworks that could significantly impact the design of the next generation efficient supersonic air vehicle (ESAV. The ESAV conceptual design process must accommodate appropriate fidelity multidisciplinary engineering analyses (MDAs to assess the impact of new air vehicle technologies. These analyses may be coupled and computationally expensive, posing a challenge due to the large number of air vehicle configurations analyzed during conceptual design. In light of these observations, a design process using the Service-Oriented Computing Environment (SORCER software is implemented to combine propulsion, structures, aerodynamics, aeroelasticity, and performance in an integrated MDA. The SORCER software provides the automation and tight integration to grid computing resources necessary to achieve the volume of appropriate fidelity analyses required. Two design studies are performed using a gradient-based optimization method to produce long and short range ESAV wing designs. The studies demonstrate the capability of the ESAV MDA, the optimization algorithm, and the computational scalability and reliability of the SORCER software.

  14. Assessment of air quality in a commercial cattle transport vehicle in Swedish summer and winter conditions.

    Science.gov (United States)

    Wikner, I; Gebresenbet, G; Nilsson, C

    2003-03-01

    Transport by road can induce significant stress in cattle. Thermal stress is among the main stress producing factors during transport. The provision of ventilation in livestock transport vehicles is usually through openings along the sides of the vehicle. The incoming air will affect air quality inside by regulating temperature, relative humidity, gas levels and levels of other contaminants. The aim of the present investigation was to map out the air quality in a commercial cattle transport vehicle under various climatic conditions and with varying stocking densities and transport times. Distributions of air temperature, relative humidity and concentrations of ammonia, carbon dioxide, oxygen and methane have been determined during 35 experimental journeys. In average the mean temperature inside the compartment was about 3 degrees C and 6 degrees C higher than outside temperature in summer (+7.8(-)+24.0 degrees C) and winter (-24.3(-)+12.7 degrees C) conditions respectively. The temperature increment inside, as could be expected from theory, increased with reduced ventilation and increased animal density. Many stops to load new animals lowered the temperature increment and relative humidity in winter time. In summer more stops made the compartment temperature and relative humidity increase. The inside temperature distribution was less than about 3 degrees C during both summer and winter season. Average ammonia level varied between 3 and 6 ppm depending on stocking density and number of stops with a maximum value of 18 ppm. No detectable methane levels could be found inside the compartment at any time.

  15. Ornithopter Type Flapping Wings for Autonomous Micro Air Vehicles

    Directory of Open Access Journals (Sweden)

    Sutthiphong Srigrarom

    2015-05-01

    Full Text Available In this paper, an ornithopter prototype that mimics the flapping motion of bird flight is developed, and the lift and thrust generation characteristics of different wing designs are evaluated. This project focused on the spar arrangement and material used for the wings that could achieves improved performance. Various lift and thrust measurement techniques are explored and evaluated. Various wings of insects and birds were evaluated to understand how these natural flyers with flapping wings are able to produce sufficient lift to fly. The differences in the flapping aerodynamics were also detailed. Experiments on different wing designs and materials were conducted and a paramount wing was built for a test flight. The first prototype has a length of 46.5 cm, wing span of 88 cm, and weighs 161 g. A mechanism which produced a flapping motion was fabricated and designed to create flapping flight. The flapping flight was produced by using a single motor and a flexible and light wing structure. A force balance made of load cell was then designed to measure the thrust and lift force of the ornithopter. Three sets of wings varying flexibility were fabricated, therefore lift and thrust measurements were acquired from each different set of wings. The lift will be measured in ten cycles computing the average lift and frequency in three different speeds or frequencies (slow, medium and fast. The thrust measurement was measure likewise but in two cycles only. Several observations were made regarding the behavior of flexible flapping wings that should aid in the design of future flexible flapping wing vehicles. The wings angle or phase characteristic were analyze too and studied. The final ornithopter prototype weighs only 160 g, has a wing span of 88.5 cm, that could flap at a maximum flapping frequency of 3.869 Hz, and produce a maximum thrust and lift of about 0.719 and 0.264 N respectively. Next, we proposed resonance type flapping wing utilizes the near

  16. The Digital Twin Paradigm for Future NASA and U.S. Air Force Vehicles

    Science.gov (United States)

    Glaessgen, Edward H.; Stargel, D. S.

    2012-01-01

    Future generations of NASA and U.S. Air Force vehicles will require lighter mass while being subjected to higher loads and more extreme service conditions over longer time periods than the present generation. Current approaches for certification, fleet management and sustainment are largely based on statistical distributions of material properties, heuristic design philosophies, physical testing and assumed similitude between testing and operational conditions and will likely be unable to address these extreme requirements. To address the shortcomings of conventional approaches, a fundamental paradigm shift is needed. This paradigm shift, the Digital Twin, integrates ultra-high fidelity simulation with the vehicle s on-board integrated vehicle health management system, maintenance history and all available historical and fleet data to mirror the life of its flying twin and enable unprecedented levels of safety and reliability.

  17. Laboratory vehicle for air-pollution measurements with computer-controlled data acquisition and navigation system

    Energy Technology Data Exchange (ETDEWEB)

    Wevelsiep, K.; Heinze, G.; Ruesch, J. (Battelle-Institut e.V., Frankfurt am Main (Germany, F.R.))

    1979-02-01

    The technical equipment of a vehicle for air-pollution measurements is described. This vehicle allows for continuous measurements of extensive SO/sub 2/ and NO/sub 2/ gas flows in the atmosphere. This is accomplished by a correlation spectrometer, which utilizes the optical absorption that is typical of the gas under observation. The instrument operates with natural sky light. The spectrometer output signals are evaluated by a computerized measuring system. The SO/sub 2/ and NO/sub 2/ data, together with the navigational data obtained from an on-board navigation system, are temporarily stored, displayed and permanently stored on paper tape for off-line evaluation and filling. Thus this highly automated system permits countinuous measurement while the vehicle is moving. The evaluation process yields report format data.

  18. Intersociety Advanced Marine Vehicles Conference and Exhibit, Arlington, VA, June 5-7, 1989, Technical Papers

    Science.gov (United States)

    The present conference on advanced marine vehicles discusses advancements in surface-effect ship (SES) technologies, small waterplane-area twin-hull (SWATH) ship operations, advanced marine vehicle concepts, ocean systems and subsurface vehicles, air-cushion vehicle (ACV) concepts, seaplane technologies, advanced hull hydrodynamics, wing-in-ground effect (WIGE) aircraft, competition-craft aerodynamics, and marine propulsion. Attention is given to military applications of the 'NES 200' SES platform, experiences over 16 years of SWATH ship operations, hydrofoil catamarans for military and civilian applications, SES passenger ferries for the N.Y.C. metropolitan area, advanced submarine concepts, parametric studies in SWATH ship design, ACV experience in Antarctica, the CL-215 seaplane, large-scale WIGE vehicles, an ocean spacecraft-launch facility, an ACV Arctic icebreaker, and 'marinizing' methods for gas turbine engines.

  19. Interactions between Flight Dynamics and Propulsion Systems of Air-Breathing Hypersonic Vehicles

    Science.gov (United States)

    2013-01-01

    states (x) and control variables (u) h = specific enthalpy [J/kg] H = reference height [m] I = moment or product of inertia divided by vehicle mass [m2...rad] ψE = elevon dihedral angle [rad] ω̇ = chemical reaction rate [kmol/m2·s] ωab = angular velocity vector between frames a and b [rad/s] Ωab...Rocket Theoretical maximum Hydrocarbon fuel in air Theoretical maximum Hydrogen fuel in air Figure 1.1: Approximate efficiency (specific impulse) as a

  20. Emissions of halocarbons from mobile vehicle air conditioning system in Hong Kong.

    Science.gov (United States)

    Yan, H H; Guo, H; Ou, J M

    2014-08-15

    During the implementation of Montreal Protocol, emission inventories of halocarbons in different sectors at regional scale are fundamental to the formulation of relevant management strategy and inspection of the implementation efficiency. This study investigated the emission profile of halocarbons used in the mobile vehicle air conditioning system, the leading sector of refrigeration industry in terms of the refrigerant bank, market and emission, in the Hong Kong Special Administrative Region, using a bottom-up approach developed by 2006 IPCC Good Practice Guidance. The results showed that emissions of CFC-12 peaked at 53 tons ODP (Ozone Depletion Potential) in 1992 and then gradually diminished, whereas HFC-134a presented an increasing emission trend since 1990s and the emissions of HFC-134a reached 65,000 tons CO2-equivelant (CO2-eq) by the end of 2011. Uncertainty analysis revealed relatively high levels of uncertainties for special-purpose vehicles and government vehicles. Moreover, greenhouse gas (GHG) abatements under different scenarios indicated that potential emission reduction of HFC-134a ranged from 4.1 to 8.4 × 10(5)tons CO2-eq. The findings in this study advance our knowledge of halocarbon emissions from mobile vehicle air conditioning system in Hong Kong.

  1. Inertial attitude control of a bat-like morphing-wing micro air vehicle

    OpenAIRE

    2013-01-01

    This article presents a novel bat-like micro air vehicle inspired by the morphing-wing mechanism of bats. The goal of this paper is twofold. Firstly, a modelling framework is introduced for analysing how the robot should maneuver by means of changing wing morphology. This allows the definition of requirements for achieving forward and turning flight according to the kinematics of the wing modulation. Secondly, an attitude controller named backstepping+DAF is proposed. Motivated by the biologi...

  2. Nonlinear Response of Strong Nonlinear System Arisen in Polymer Cushion

    Directory of Open Access Journals (Sweden)

    Jun Wang

    2013-01-01

    Full Text Available A dynamic model is proposed for a polymer foam-based nonlinear cushioning system. An accurate analytical solution for the nonlinear free vibration of the system is derived by applying He's variational iteration method, and conditions for resonance are obtained, which should be avoided in the cushioning design.

  3. 21 CFR 872.3540 - OTC denture cushion or pad.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3540 OTC denture cushion or pad. (a...-counter. (b) Classification. (1) Class I if the device is made of wax-impregnated cotton cloth that the... denture cushion or pad is made of a material other than wax-impregnated cotton cloth or if the...

  4. Optimization and Analysis on Trajectory with Multiple Constraints for Hypersonic Air-vehicle

    Directory of Open Access Journals (Sweden)

    Wei Changzhu

    2015-01-01

    Full Text Available The trajectory optimization technology is one of the key technologies for hypersonic air-vehicle. There are multiple constraints in the process of hypersonic flight, such as uncertainty of flight environment, thermal current, dynamic pressure and overload. The trajectory optimization of hypersonic air-vehicle is facing with a great challenge. This article studies the direct shooting method, the Gauss pseudo spectral method and sequential gradient-restoration algorithm, among which the direct shooting method simply makes the control variables discrete in the time domain, and obtains the status value by explicit numerical integration; Gauss pseudo spectral method makes the status variable and control variable discrete in a series of Gauss points, and constructs multinomial to approximate to the status and control variable by taking the discrete points as the nodes; sequential gradient-restoration algorithm uses iteration to meet the constraints and minimize the increment of initial value of control and status variable in order to constantly approximate to the optimal solution on condition that the constraints meet first order approximation. Finally this article conducts a numerical simulation by taking the diving segment of hypersonic air-vehicle as an example for comparative analysis on those three algorithms respectively from, such as, the initial value selection, constraint handling, convergence speed and calculation accuracy. The simulation result indicates Gauss pseudo spectral method is a method with fairly good comprehensive performance.

  5. “Team Play” between Renewable Energy Sources and Vehicle Fleet to Decrease Air Pollution

    Directory of Open Access Journals (Sweden)

    Michela Longo

    2015-12-01

    Full Text Available The reduction of air pollutants for the purpose of maintaining or improving air quality across the globe is a fundamental concern to which all modern governments are allocating varying amounts of attention and resources. The successful amelioration of air pollution requires strategic investments in the commercialization and adoption of “clean energy technologies” by both private and public entities, the conversion of contemporary houses to “smart houses”, the diffusion of Renewable Energy Sources (RES including photovoltaic systems (PV, wind farms, and different forms of bioenergy, and the integration of electric-powered vehicles. In concert with these ideas, this paper aims to discuss the possibility of undertaking a feasibility study in two countries Canada and Italy concerning the integration of electric vehicles (EVs and electric motorcycles (EMs. The proposed feasibility study would seek to assess the prospect of replacing the current vehicle fleets in these two countries with EVs in a manner that utilizes renewable energy sources and, thus, does not generate new toxic emissions. In conclusion, this study demonstrated that a pronounced introduction and distribution of RES, EVs, and EMs can operate as a great opportunity for both the environment and the capacities and needs of energy production. Today, the EV is not widespread. With this contribution, it is shown how EVs can be well integrated with renewable energy. Therefore, it is the duty of governments to implement policy strategies, in order to spread them across more territory.

  6. Air Quality Impacts of Electrifying Vehicles and Equipment Across the United States.

    Science.gov (United States)

    Nopmongcol, Uarporn; Grant, John; Knipping, Eladio; Alexander, Mark; Schurhoff, Rob; Young, David; Jung, Jaegun; Shah, Tejas; Yarwood, Greg

    2017-02-21

    U.S.-wide air quality impacts of electrifying vehicles and off-road equipment are estimated for 2030 using 3-D photochemical air quality model and detailed emissions inventories. Electrification reduces tailpipe emissions and emissions from petroleum refining, transport, and storage, but increases electricity demand. The Electrification Case assumes approximately 17% of light duty and 8% of heavy duty vehicle miles traveled and from 17% to 79% of various off-road equipment types considered good candidates for electrification is powered by electricity. The Electrification Case raises electricity demand by 5% over the 2030 Base Case but nitrogen oxide (NOx) emissions decrease by 209 thousand tons (3%) overall. Emissions of other criteria pollutants also decrease. Air quality benefits of electrification are modest, mostly less than 1 ppb for ozone and 0.5 μg m(-3) for fine particulate matter (PM2.5), but widespread. The largest reductions for ozone and PM occur in urban areas due to lower mobile source emissions. Electrifying off-road equipment yields more benefits than electrifying on-road vehicles. Reduced crude oil imports and associated marine vessel emissions cause additional benefits in port cities. Changes in other gas and PM emissions, as well as impacts on acid and nutrient deposition, are discussed.

  7. Anti-rebound Cushion Device for Hydraulic Breaker

    Institute of Scientific and Technical Information of China (English)

    Zhao Hongqiang

    2005-01-01

    This paper analyzes the phenomenon of rebound impact and its negative influence on the present hydraulic breaker. To get over its shortcomings, a new anti-rebound cushion device has been designed to prevent the phenomenon of rebound impact. A hydraulic cushion is used to absorb the rebound impact energy, which can be released for the next stroke of the hydraulic breaker. Thus, there is little loss of energy, and the efficiency of the impact system can be increased by 5 %. The absorption effect of the hydraulic anti-rebound cushion increases the service life of breaker components by up to twice as long as in the current breaker. A dynamic model and a motion equation of the anti-rebound cushion device are presented, and the optimum frequency and damping ratio are obtained, providing optimum design parameters for the anti-rebound cushion device.

  8. Residual settlement calculation of geocell cushion over gravel piles

    Institute of Scientific and Technical Information of China (English)

    陈昌富; 杨宇; 肖淑君; 周志军

    2008-01-01

    The calculation of residual settlement of bidirectional reinforced composite foundation, which is composed of geocell cushion over gravel piles, was studied. The geocell cushion was modeled as a thin flexible plate with large deflection. Based on the Kirchhoff hypothesis, the governing differential equations and boundary conditions of the deformation of geocell cushion under working load were founded using von Karman method and solved by Galerkin method. On theses bases, the gravel piles and inter-pile soils were assumed as Winkler ground with variable spring stiffness so as to execute the approximate calculation of the residual settlement of the bidirectional reinforced composite foundation. The calculation method was verified by two laboratory experiments concerning settlement of embankments. One experiment was with just geocell cushion installed to treat the soft clay under embankments; another one was with both geocell cushion and gravel piles installed. The results show that the calculated settlement curve and the maximum settlement are closed to the observed ones.

  9. Plume-based analysis of vehicle fleet air pollutant emissions and the contribution from high emitters

    Directory of Open Access Journals (Sweden)

    J. M. Wang

    2015-03-01

    Full Text Available An automated identification and integration method has been developed to investigate in-use vehicle emissions under real-world conditions. This technique was applied to high time resolution air pollutant measurements of in-use vehicle emissions performed under real-world conditions at a near-road monitoring station in Toronto, Canada during four seasons, through month-long campaigns in 2013–2014. Based on carbon dioxide measurements, over 100 000 vehicle-related plumes were automatically identified and fuel-based emission factors for nitrogen oxides; carbon monoxide; particle number, black carbon; benzene, toluene, ethylbenzene, and xylenes (BTEX; and methanol were determined for each plume. Thus the automated identification enabled the measurement of an unprecedented number of plumes and pollutants over an extended duration. Emission factors for volatile organic compounds were also measured roadside for the first time using a proton transfer reaction time-of-flight mass spectrometer; this instrument provided the time resolution required for the plume capture technique. Mean emission factors were characteristic of the light-duty gasoline dominated vehicle fleet present at the measurement site, with mean black carbon and particle number emission factors of 35 mg kg−1 and 7.7 × 1014 kg−1, respectively. The use of the plume-by-plume analysis enabled isolation of vehicle emissions, and the elucidation of co-emitted pollutants from similar vehicle types, variability of emissions across the fleet, and the relative contribution from heavy emitters. It was found that a small proportion of the fleet (< 25% contributed significantly to total fleet emissions; 95, 93, 76, and 75% for black carbon, carbon monoxide, BTEX, and particle number, respectively. Emission factors of a single pollutant may help classify a vehicle as a high emitter. However, regulatory strategies to more efficiently target multi-pollutants mixtures may be better developed by

  10. Ambient particulate air pollution from vehicles promotes lipid peroxidation and inflammatory responses in rat lung

    Directory of Open Access Journals (Sweden)

    C.E.L. Pereira

    2007-10-01

    Full Text Available Oxidative stress plays a major role in the pathogenesis of particle-dependent lung injury. Ambient particle levels from vehicles have not been previously shown to cause oxidative stress to the lungs. The present study was conducted to a determine whether short-term exposure to ambient levels of particulate air pollution from vehicles elicits inflammatory responses and lipid peroxidation in rat lungs, and b determine if intermittent short-term exposures (every 4 days induce some degree of tolerance. Three-month-old male Wistar rats were exposed to ambient particulate matter (PM from vehicles (N = 30 for 6 or 20 continuous hours, or for intermittent (5 h periods during 20 h for 4 consecutive days or to filtered air (PM <10 µm; N = 30. Rats continuously breathing polluted air for 20 h (P-20 showed a significant increase in the total number of leukocytes in bronchoalveolar lavage compared to control (C-20: 2.61 x 105 ± 0.51;P-20: 5.01 x 105 ± 0.81; P < 0.05 and in lipid peroxidation ([MDA] nmol/mg protein: C-20: 0.148 ± 0.01; P-20: 0.226 ± 0.02; P < 0.05. Shorter exposure (6 h and intermittent 5-h exposures over a period of 4 days did not cause significant changes in leukocytes. Lipid damage resulting from 20-h exposure to particulate air pollution did not cause a significant increase in lung water content. These data suggest oxidative stress as one of the mechanisms responsible for the acute adverse respiratory effects of particles, and suggest that short-term inhalation of ambient particulate air pollution from street with high automobile traffic represents a biological hazard.

  11. Simulation and Optimization of Air-Cooled PEMFC Stack for Lightweight Hybrid Vehicle Application

    Directory of Open Access Journals (Sweden)

    Jingming Liang

    2015-01-01

    Full Text Available A model of 2 kW air-cooled proton exchange membrane fuel cell (PEMFC stack has been built based upon the application of lightweight hybrid vehicle after analyzing the characteristics of heat transfer of the air-cooled stack. Different dissipating models of the air-cooled stack have been simulated and an optimal simulation model for air-cooled stack called convection heat transfer (CHT model has been figured out by applying the computational fluid dynamics (CFD software, based on which, the structure of the air-cooled stack has been optimized by adding irregular cooling fins at the end of the stack. According to the simulation result, the temperature of the stack has been equally distributed, reducing the cooling density and saving energy. Finally, the 2 kW hydrogen-air air-cooled PEMFC stack is manufactured and tested by comparing the simulation data which is to find out its operating regulations in order to further optimize its structure.

  12. Improving the accuracy of vehicle emissions profiles for urban transportation greenhouse gas and air pollution inventories.

    Science.gov (United States)

    Reyna, Janet L; Chester, Mikhail V; Ahn, Soyoung; Fraser, Andrew M

    2015-01-01

    Metropolitan greenhouse gas and air emissions inventories can better account for the variability in vehicle movement, fleet composition, and infrastructure that exists within and between regions, to develop more accurate information for environmental goals. With emerging access to high quality data, new methods are needed for informing transportation emissions assessment practitioners of the relevant vehicle and infrastructure characteristics that should be prioritized in modeling to improve the accuracy of inventories. The sensitivity of light and heavy-duty vehicle greenhouse gas (GHG) and conventional air pollutant (CAP) emissions to speed, weight, age, and roadway gradient are examined with second-by-second velocity profiles on freeway and arterial roads under free-flow and congestion scenarios. By creating upper and lower bounds for each factor, the potential variability which could exist in transportation emissions assessments is estimated. When comparing the effects of changes in these characteristics across U.S. cities against average characteristics of the U.S. fleet and infrastructure, significant variability in emissions is found to exist. GHGs from light-duty vehicles could vary by -2%-11% and CAP by -47%-228% when compared to the baseline. For heavy-duty vehicles, the variability is -21%-55% and -32%-174%, respectively. The results show that cities should more aggressively pursue the integration of emerging big data into regional transportation emissions modeling, and the integration of these data is likely to impact GHG and CAP inventories and how aggressively policies should be implemented to meet reductions. A web-tool is developed to aide cities in improving emissions uncertainty.

  13. Health effects associated with passenger vehicles: monetary values of air pollution.

    Science.gov (United States)

    Marzouk, Mohamed; Madany, Magdy

    2012-01-01

    Air pollution is regarded as one of the highest priorities in environmental protection in both developed and developing countries. High levels of air pollution have adverse effects on human health that might cause premature death. This study presents the monetary value estimates for the adverse human health effects resulted from ambient air pollution. It aids decision makers to set priorities in the public health relevance of pollution abatement. The main driver of policymaker is the need to reduce the avoidable cardiopulmonary morbidity and mortality from pollutant exposures. The monetary valuation involves 2 steps: (i) relate levels of pollutants to mortality and morbidity (concentration-response relationships) and (ii) apply unit economic values. Cost of air pollution associated with passenger vehicles running over a major traffic bridge (6th of October Elevated Highway) is presented as a case study to demonstrate the use of monetary value of air pollution. The study proves that the cost of air pollution is extremely high and should not be overlooked.

  14. An Overview of Small Unmanned Aerial Vehicles for Air Quality Measurements: Present Applications and Future Prospectives.

    Science.gov (United States)

    Villa, Tommaso Francesco; Gonzalez, Felipe; Miljievic, Branka; Ristovski, Zoran D; Morawska, Lidia

    2016-07-12

    Assessment of air quality has been traditionally conducted by ground based monitoring, and more recently by manned aircrafts and satellites. However, performing fast, comprehensive data collection near pollution sources is not always feasible due to the complexity of sites, moving sources or physical barriers. Small Unmanned Aerial Vehicles (UAVs) equipped with different sensors have been introduced for in-situ air quality monitoring, as they can offer new approaches and research opportunities in air pollution and emission monitoring, as well as for studying atmospheric trends, such as climate change, while ensuring urban and industrial air safety. The aims of this review were to: (1) compile information on the use of UAVs for air quality studies; and (2) assess their benefits and range of applications. An extensive literature review was conducted using three bibliographic databases (Scopus, Web of Knowledge, Google Scholar) and a total of 60 papers was found. This relatively small number of papers implies that the field is still in its early stages of development. We concluded that, while the potential of UAVs for air quality research has been established, several challenges still need to be addressed, including: the flight endurance, payload capacity, sensor dimensions/accuracy, and sensitivity. However, the challenges are not simply technological, in fact, policy and regulations, which differ between countries, represent the greatest challenge to facilitating the wider use of UAVs in atmospheric research.

  15. An Overview of Small Unmanned Aerial Vehicles for Air Quality Measurements: Present Applications and Future Prospectives

    Science.gov (United States)

    Villa, Tommaso Francesco; Gonzalez, Felipe; Miljievic, Branka; Ristovski, Zoran D.; Morawska, Lidia

    2016-01-01

    Assessment of air quality has been traditionally conducted by ground based monitoring, and more recently by manned aircrafts and satellites. However, performing fast, comprehensive data collection near pollution sources is not always feasible due to the complexity of sites, moving sources or physical barriers. Small Unmanned Aerial Vehicles (UAVs) equipped with different sensors have been introduced for in-situ air quality monitoring, as they can offer new approaches and research opportunities in air pollution and emission monitoring, as well as for studying atmospheric trends, such as climate change, while ensuring urban and industrial air safety. The aims of this review were to: (1) compile information on the use of UAVs for air quality studies; and (2) assess their benefits and range of applications. An extensive literature review was conducted using three bibliographic databases (Scopus, Web of Knowledge, Google Scholar) and a total of 60 papers was found. This relatively small number of papers implies that the field is still in its early stages of development. We concluded that, while the potential of UAVs for air quality research has been established, several challenges still need to be addressed, including: the flight endurance, payload capacity, sensor dimensions/accuracy, and sensitivity. However, the challenges are not simply technological, in fact, policy and regulations, which differ between countries, represent the greatest challenge to facilitating the wider use of UAVs in atmospheric research. PMID:27420065

  16. Fuzzy logic speed control for the engine of an air-powered vehicle

    Directory of Open Access Journals (Sweden)

    Qihui Yu

    2016-03-01

    Full Text Available To improve the condition of air and eliminate exhaust gas pollution, this article proposes a compressed air power system. Instead of an internal combustion engine, the automobile is equipped with a compressed air engine, which transforms the energy of compressed air into mechanical motion energy. A prototype was built, and the compressed air engine was tested on an experimental platform. The output torque and energy efficiency were obtained from experimental results. When the supply pressure was set at 2 MPa and the speed was 420 r min−1, the output torque, the output power, and the energy efficiency were 56 N m, 1.93 kW, and 25%, respectively. To improve the efficiency of the system, a fuzzy logic speed control strategy is proposed and simulated. The experimental study verified that the theoretical evaluation of the system was reasonable, and this research can be referred to as the design and control of air-powered vehicles.

  17. Comparative biomechanical evaluation of different wheelchair seat cushions.

    Science.gov (United States)

    Ferrarin, M; Andreoni, G; Pedotti, A

    2000-01-01

    The aim of the present study was to perform a comparative biomechanical analysis of four antidecubitus wheelchair cushions. Thirty wheelchair users were considered divided into three groups: paraplegic subjects (with no cutaneous sensation), neurologic subjects (with intact cutaneous sensation), and elderly subjects. The biomechanical evaluation was performed using a piezoresistive sensor matrix system to quantify parameters referred to pressure distribution, seating surface and posture. Dedicated software was developed for the automatic elaboration of the raw data and the computation of the parameters of interest. Differences among cushion types and subject groups were analyzed. An analysis of time-transient behaviors was also performed. Results showed that no significant differences in pressure peak reduction were found among the four cushions. Moreover, no time-transient behavior was shown by any cushions. However, both the location of pressure peaks and posture were dependent on cushion types. Comparison of the three subject groups showed that elderly subjects had the highest mean pressure and the lowest contact surface, while paraplegics presented the highest pressure peaks. This procedure appears indicated for individualizing the prescription of a wheelchair cushion and even for customizing a cushion to induce a specific posture.

  18. 车用空调系统在农用车辆上的应用%Application of Vehicle Air-conditioning System in Farm Vehicle

    Institute of Scientific and Technical Information of China (English)

    彭高宏

    2011-01-01

    Aimming at the structure,principle and general requirement of air-conditioning system,the practical methods for adding air conditioner on farm vehicles are introduced.%依据车用空调系统的结构和原理,以及加装空调的一般要求,介绍了农用车辆加装空调的具体方法。

  19. Optimization of a Localized Air Conditioning System Using Thermoelectric Coolers for Commercial Vehicles

    Science.gov (United States)

    Wan, Qiushi; Deng, Yadong; Su, Chuqi; Wang, Yiping

    2016-11-01

    To improve the thermal comfort and energy saving of commercial vehicles, an auxiliary air conditioning (AC) system has been constructed. Several distributed components using thermoelectric coolers were applied in a localized AC system to adjust the microclimate around the driver only. A computational fluid dynamics model of a commercial vehicle cabin with a driver was built, the temperature field of the cabin investigated, and the thermal comfort analyzed. Based on the results of the simulations, the temperature around the cold side of the thermoelectric coolers is discussed and optimized by means of the response surface methodology and a multiobjective genetic algorithm. To validate the simulation and optimization results, a bench test was carried out; the results obtained from the simulation showed good agreement with the experimental results.

  20. Design of a Six-link Mechanism for a Micro Air Vehicle

    Directory of Open Access Journals (Sweden)

    S. Mukherjee

    2004-07-01

    Full Text Available Micro air vehicle (MAV is a small flight vehicle that uses lift-generating mechanism different from the mechanism used for a larger aircraft. The MAV may require configurations that are more unusual and approaches, ranging from low aspect ratio fixed wings to rotary wings, or even flapping wings. One of the most efficient lift-generating mechanism in small geometries is observed in the one species of insects Encarsia formosa, as reported by Weis Fogh. This is achieved by generating lift prior to setting up of net circulation. In this paper, the design of a flapping mechanism used to realise the Weis Fogh mechanism of lift generation is described. A single-drive design using concepts of motion synthesis by kinematic inversion technique, followed by dynamic analysis, is presented. This simplification opens the way for future miniaturisation of these devices at economic costs.

  1. Emissions of halocarbons from mobile vehicle air conditioning system in Hong Kong

    Energy Technology Data Exchange (ETDEWEB)

    Yan, H.H.; Guo, H., E-mail: ceguohai@polyu.edu.hk; Ou, J.M.

    2014-08-15

    Highlights: • Halocarbon emissions from MVACS were characterized using bottom up approach. • Quantification of emission inventory was revealed using AUV Tools. • Potential emission reduction was estimated under 3 possible mitigation scenarios. • The results are useful for the policy makers to formulate and implement future phase-out schedule. - Abstract: During the implementation of Montreal Protocol, emission inventories of halocarbons in different sectors at regional scale are fundamental to the formulation of relevant management strategy and inspection of the implementation efficiency. This study investigated the emission profile of halocarbons used in the mobile vehicle air conditioning system, the leading sector of refrigeration industry in terms of the refrigerant bank, market and emission, in the Hong Kong Special Administrative Region, using a bottom-up approach developed by 2006 IPCC Good Practice Guidance. The results showed that emissions of CFC-12 peaked at 53 tons ODP (Ozone Depletion Potential) in 1992 and then gradually diminished, whereas HFC-134a presented an increasing emission trend since 1990s and the emissions of HFC-134a reached 65,000 tons CO{sub 2}-equivelant (CO{sub 2}-eq) by the end of 2011. Uncertainty analysis revealed relatively high levels of uncertainties for special-purpose vehicles and government vehicles. Moreover, greenhouse gas (GHG) abatements under different scenarios indicated that potential emission reduction of HFC-134a ranged from 4.1 to 8.4 × 10{sup 5} tons CO{sub 2}-eq. The findings in this study advance our knowledge of halocarbon emissions from mobile vehicle air conditioning system in Hong Kong.

  2. Comprehensive modeling and control of flexible flapping wing micro air vehicles

    Science.gov (United States)

    Nogar, Stephen Michael

    Flapping wing micro air vehicles hold significant promise due to the potential for improved aerodynamic efficiency, enhanced maneuverability and hover capability compared to fixed and rotary configurations. However, significant technical challenges exist to due the lightweight, highly integrated nature of the vehicle and coupling between the actuators, flexible wings and control system. Experimental and high fidelity analysis has demonstrated that aeroelastic effects can change the effective kinematics of the wing, reducing vehicle stability. However, many control studies for flapping wing vehicles do not consider these effects, and instead validate the control strategy with simple assumptions, including rigid wings, quasi-steady aerodynamics and no consideration of actuator dynamics. A control evaluation model that includes aeroelastic effects and actuator dynamics is developed. The structural model accounts for geometrically nonlinear behavior using an implicit condensation technique and the aerodynamic loads are found using a time accurate approach that includes quasi-steady, rotational, added mass and unsteady effects. Empirically based parameters in the model are fit using data obtained from a higher fidelity solver. The aeroelastic model and its ingredients are compared to experiments and computations using models of higher fidelity, and indicate reasonable agreement. The developed control evaluation model is implemented in a previously published, baseline controller that maintains stability using an asymmetric wingbeat, known as split-cycle, along with changing the flapping frequency and wing bias. The model-based controller determines the control inputs using a cycle-averaged, linear control design model, which assumes a rigid wing and no actuator dynamics. The introduction of unaccounted for dynamics significantly degrades the ability of the controller to track a reference trajectory, and in some cases destabilizes the vehicle. This demonstrates the

  3. Heat pump air conditioning system for pure electric vehicle at ultra-low temperature

    Directory of Open Access Journals (Sweden)

    Li Hai-Jun

    2014-01-01

    Full Text Available When the ordinary heat pump air conditioning system of a pure electric vehicle runs at ultra-low temperature, the discharge temperature of compressor will be too high and the heating capacity of the system will decay seriously, it will lead to inactivity of the heating system. In order to solve this problem, a modification is put forward, and an experiment is also designed. The experimental results show that in the same conditions, this new heating system increases more than 20% of the heating capacity; when the outside environment temperature is negative 20 degrees, the discharge temperature of compressor is below 60 degrees.

  4. A RISK MEASUREMENT AND MANAGEMENT MODEL FOR PREVENTING UNMANNED AIR VEHICLE ACCIDENTS

    Directory of Open Access Journals (Sweden)

    Hüdayim BAŞAK

    2008-01-01

    Full Text Available In this study, it is aimed to investigate operationally risky areas by analyzing dangers which can arise during the maintenance and flight activities of Unmanned Air Vehicles (UAVs. For this purpose, a risk analysis methodology was introduced and then within the framework of the application, a sample of risk management model was developed. During the development of the model, personal experiences in the area of UAVs were benefited and a risk management technique consisting of five steps used by pioneering international aviation companies in fliht safety was utilized.

  5. A Framework for Systematic Design and Construction of an Unmanned Small-scale Air-Land-Water Vehicle

    Directory of Open Access Journals (Sweden)

    Arhami Arhami

    2011-09-01

    Full Text Available In this paper, we present a framework for systematic design and construction of an unmanned small-scale air-land-water vehicle. The systematic design procedure includes design and integration, hardware component selection, as well as experimental evaluation are used to construct a fully functional unmanned small-scale air-land-water vehicle, namely Unmanned Small-scale Air-Land-Water Vehicle (USALWaV. Various component to support maneuver on the ground, flight, and cruising on surface of water feature has been constructed to verify the feasibility and reliability of USALWaV. Double blade axial rotor, propeller set, and pontoon propel the vehicle while fly on-air, move on-land, and float on-water. A control algorithm has also been proposed to allow the USALWaV to travel from its current location to another location specified with changeable channel on Tx Modulator. The results can be followed and used for build a small-scale air-land-water vehicle for research and development purposes.

  6. Multi-sensor fusion techniques for state estimation of micro air vehicles

    Science.gov (United States)

    Donavanik, Daniel; Hardt-Stremayr, Alexander; Gremillion, Gregory; Weiss, Stephan; Nothwang, William

    2016-05-01

    Aggressive flight of micro air vehicles (MAVs) in unstructured, GPS-denied environments poses unique challenges for estimation of vehicle pose and velocity due to the noise, delay, and drift in individual sensor measurements. Maneuvering flight at speeds in excess of 5 m/s poses additional challenges even for active range sensors; in the case of LIDAR, an assembled scan of the vehicles environment will in most cases be obsolete by the time it is processed. Multi-sensor fusion techniques which combine inertial measurements with passive vision techniques and/or LIDAR have achieved breakthroughs in the ability to maintain accurate state estimates without the use of external positioning sensors. In this paper, we survey algorithmic approaches to exploiting sensors with a wide range of nonlinear dynamics using filter and bundle-adjustment based approaches for state estimation and optimal control. From this foundation, we propose a biologically-inspired framework for incorporating the human operator in the loop as a privileged sensor in a combined human/autonomy paradigm.

  7. Internal air flow analysis of a bladeless micro aerial vehicle hemisphere body using computational fluid dynamic

    Energy Technology Data Exchange (ETDEWEB)

    Othman, M. N. K., E-mail: najibkhir86@gmail.com, E-mail: zuradzman@unimap.edu.my, E-mail: hazry@unimap.edu.my, E-mail: khairunizam@unimap.edu.my, E-mail: shahriman@unimap.edu.my, E-mail: s.yaacob@unimap.edu.my, E-mail: syedfaiz@unimap.edu.my, E-mail: abadal@unimap.edu.my; Zuradzman, M. Razlan, E-mail: najibkhir86@gmail.com, E-mail: zuradzman@unimap.edu.my, E-mail: hazry@unimap.edu.my, E-mail: khairunizam@unimap.edu.my, E-mail: shahriman@unimap.edu.my, E-mail: s.yaacob@unimap.edu.my, E-mail: syedfaiz@unimap.edu.my, E-mail: abadal@unimap.edu.my; Hazry, D., E-mail: najibkhir86@gmail.com, E-mail: zuradzman@unimap.edu.my, E-mail: hazry@unimap.edu.my, E-mail: khairunizam@unimap.edu.my, E-mail: shahriman@unimap.edu.my, E-mail: s.yaacob@unimap.edu.my, E-mail: syedfaiz@unimap.edu.my, E-mail: abadal@unimap.edu.my; Khairunizam, Wan, E-mail: najibkhir86@gmail.com, E-mail: zuradzman@unimap.edu.my, E-mail: hazry@unimap.edu.my, E-mail: khairunizam@unimap.edu.my, E-mail: shahriman@unimap.edu.my, E-mail: s.yaacob@unimap.edu.my, E-mail: syedfaiz@unimap.edu.my, E-mail: abadal@unimap.edu.my; Shahriman, A. B., E-mail: najibkhir86@gmail.com, E-mail: zuradzman@unimap.edu.my, E-mail: hazry@unimap.edu.my, E-mail: khairunizam@unimap.edu.my, E-mail: shahriman@unimap.edu.my, E-mail: s.yaacob@unimap.edu.my, E-mail: syedfaiz@unimap.edu.my, E-mail: abadal@unimap.edu.my; Yaacob, S., E-mail: najibkhir86@gmail.com, E-mail: zuradzman@unimap.edu.my, E-mail: hazry@unimap.edu.my, E-mail: khairunizam@unimap.edu.my, E-mail: shahriman@unimap.edu.my, E-mail: s.yaacob@unimap.edu.my, E-mail: syedfaiz@unimap.edu.my, E-mail: abadal@unimap.edu.my; Ahmed, S. Faiz, E-mail: najibkhir86@gmail.com, E-mail: zuradzman@unimap.edu.my, E-mail: hazry@unimap.edu.my, E-mail: khairunizam@unimap.edu.my, E-mail: shahriman@unimap.edu.my, E-mail: s.yaacob@unimap.edu.my, E-mail: syedfaiz@unimap.edu.my, E-mail: abadal@unimap.edu.my [Centre of Excellence for Unmanned Aerial Systems, Universiti Malaysia Perlis, 01000 Kangar, Perlis (Malaysia); and others

    2014-12-04

    This paper explain the analysis of internal air flow velocity of a bladeless vertical takeoff and landing (VTOL) Micro Aerial Vehicle (MAV) hemisphere body. In mechanical design, before produce a prototype model, several analyses should be done to ensure the product's effectiveness and efficiency. There are two types of analysis method can be done in mechanical design; mathematical modeling and computational fluid dynamic. In this analysis, I used computational fluid dynamic (CFD) by using SolidWorks Flow Simulation software. The idea came through to overcome the problem of ordinary quadrotor UAV which has larger size due to using four rotors and the propellers are exposed to environment. The bladeless MAV body is designed to protect all electronic parts, which means it can be used in rainy condition. It also has been made to increase the thrust produced by the ducted propeller compare to exposed propeller. From the analysis result, the air flow velocity at the ducted area increased to twice the inlet air. This means that the duct contribute to the increasing of air velocity.

  8. Internal air flow analysis of a bladeless micro aerial vehicle hemisphere body using computational fluid dynamic

    Science.gov (United States)

    Othman, M. N. K.; Zuradzman, M. Razlan; Hazry, D.; Khairunizam, Wan; Shahriman, A. B.; Yaacob, S.; Ahmed, S. Faiz; Hussain, Abadalsalam T.

    2014-12-01

    This paper explain the analysis of internal air flow velocity of a bladeless vertical takeoff and landing (VTOL) Micro Aerial Vehicle (MAV) hemisphere body. In mechanical design, before produce a prototype model, several analyses should be done to ensure the product's effectiveness and efficiency. There are two types of analysis method can be done in mechanical design; mathematical modeling and computational fluid dynamic. In this analysis, I used computational fluid dynamic (CFD) by using SolidWorks Flow Simulation software. The idea came through to overcome the problem of ordinary quadrotor UAV which has larger size due to using four rotors and the propellers are exposed to environment. The bladeless MAV body is designed to protect all electronic parts, which means it can be used in rainy condition. It also has been made to increase the thrust produced by the ducted propeller compare to exposed propeller. From the analysis result, the air flow velocity at the ducted area increased to twice the inlet air. This means that the duct contribute to the increasing of air velocity.

  9. Measurement of in-vehicle volatile organic compounds under static conditions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The types and quantities of volatile organic compounds (VOCs) inside vehicles have been determined in one new vehicle and two old vehicles under static conditions using the Thermodesorber-Gas Chromatograph/Mass Spectrometer (TD-GC/MS). Air sampling and analysis was conducted under the requirement of USEPA Method TO-17. A room-size, environment test chamber was utilized to provide stable and accurate control of the required environmental conditions (temperature, humidity, horizontal and vertical airflow velocity, and background VOCs concentration). Static vehicle testing demonstrated that although the amount of total volatile organic compounds (TVOC) detected within each vehicle was relatively distinct (4940 μg/m3 in the new vehicle A, 1240 μg/m3 in used vehicle B, and 132 μg/m3 in used vehicle C), toluene, xylene, some aromatic compounds, and various C7-C12 alkanes were among the predominant VOC species in all three vehicles tested. In addition, tetramethyl succinonitrile, possibly derived from foam cushions was detected in vehicle B. The types and quantities of VOCs varied considerably according to various kinds of factors, such as, vehicle age,vehicle model, temperature, air exchange rate, and environment airflow velocity. For example, if the airflow velocity increases from 0.1m/s to 0.7 m/s, the vehicle's air exchange rate increases from 0.15 h-1 to 0.67 h-1, and in-vehicle TVOC concentration decreases from 1780 to 1201 μg/m3.

  10. Experimental Investigation of a Shrouded Rotor Micro Air Vehicle in Hover and in Edgewise Gusts

    Science.gov (United States)

    Hrishikeshavan, Vikram

    Due to the hover capability of rotary wing Micro Air Vehicles (MAVs), it is of interest to improve their aerodynamic performance, and hence hover endurance (or payload capability). In this research, a shrouded rotor configuration is studied and implemented, that has the potential to offer two key operational benefits: enhanced system thrust for a given input power, and improved structural rigidity and crashworthiness of an MAV platform. The main challenges involved in realising such a system for a lightweight craft are: design of a lightweight and stiff shroud, and increased sensitivity to external flow disturbances that can affect flight stability. These key aspects are addressed and studied in order to assess the capability of the shrouded rotor as a platform of choice for MAV applications. A fully functional shrouded rotor vehicle (disk loading 60 N/ m2) was designed and constructed with key shroud design variables derived from previous studies on micro shrouded rotors. The vehicle weighed about 280 g (244 mm rotor diameter). The shrouded rotor had a 30% increase in power loading in hover compared to an unshrouded rotor. Due to the stiff, lightweight shroud construction, a net payload benefit of 20-30 g was achieved. The different components such as the rotor, stabilizer bar, yaw control vanes and the shroud were systematically studied for system efficiency and overall aerodynamic improvements. Analysis of the data showed that the chosen shroud dimensions was close to optimum for a design payload of 250 g. Risk reduction prototypes were built to sequentially arrive at the final configuration. In order to prevent periodic oscillations in ight, a hingeless rotor was incorporated in the shroud. The vehicle was successfully ight tested in hover with a proportional-integralderivative feedback controller. A flybarless rotor was incorporated for efficiency and control moment improvements. Time domain system identification of the attitude dynamics of the flybar and

  11. Investigations on an energy efficient air conditioning of hybrid vehicles and electric-powered vehicles; Untersuchungen zur energieeffizienten Klimatisierung von Hybrid- und Elektrofahrzeugen

    Energy Technology Data Exchange (ETDEWEB)

    Aurich, Joerg; Baumgart, Rico; Danzer, Christoph; Unwerth, Thomas von [Technische Univ. Chemnitz (Germany). Professur Alternative Fahrzeugantriebe

    2012-11-01

    The energy-efficient air conditioning of passenger cells is an ever-increasing challenge in the development of electric vehicles because the electric heating in particular reduces the cruising range significantly. For this reason, a simulation model has been developed at Chemnitz University of Technology, which simulates the whole air conditioning system including the passenger cell and the complete powertrain in electric cars. Using this model, different optimization approaches have been analyzed and evaluated concerning the cruising range. This paper first illustrates how much the cruising range of an exemplary electric vehicle is reduced by using the electric heating under different wintery weather conditions. Afterwards, the exploitation of the waste heat produced by the powertrain components (electric motor and power electronics) will be explained. Finally, it shall be described to what extent this exploitation increases the cruising range. (orig.)

  12. Novel adaptive neural control of flexible air-breathing hypersonic vehicles based on sliding mode differentiator

    Directory of Open Access Journals (Sweden)

    Bu Xiangwei

    2015-08-01

    Full Text Available A novel adaptive neural control strategy is exploited for the longitudinal dynamics of a generic flexible air-breathing hypersonic vehicle (FAHV. By utilizing functional decomposition method, the dynamics of FAHV is decomposed into the velocity subsystem and the altitude subsystem. For each subsystem, only one neural network is employed for the unknown function approximation. To further reduce the computational burden, minimal-learning parameter (MLP technology is used to estimate the norm of ideal weight vectors rather than their elements. By introducing sliding mode differentiator (SMD to estimate the newly defined variables, there is no need for the strict-feedback form and virtual controller. Hence the developed control law is considerably simpler than the ones derived from back-stepping scheme. Finally, simulation studies are made to illustrate the effectiveness of the proposed control approach in spite of the flexible effects, system uncertainties and varying disturbances.

  13. Robust tracking control design for a flexible air-breathing hypersonic vehicle

    Institute of Scientific and Technical Information of China (English)

    张垚; 鲜斌; 刁琛; 赵勃; 郭建川

    2014-01-01

    A nonlinear robust controller was presented to improve the tracking control performance of a flexible air-breathing hypersonic vehicle (AHV) which is subjected to system parametric uncertainties and unknown additive time-varying disturbances. The longitudinal dynamic model for the flexible AHV was used for the control development. High-gain observers were designed to compensate for the system uncertainties and additive disturbances. Small gain theorem and Lyapunov based stability analysis were utilized to prove the stability of the closed loop system. Locally uniformly ultimately bounded tracking of the vehicle’s velocity, altitude and attack angle were achieved under aeroelastic effects, system parametric uncertainties and unknown additive disturbances. Matlab/Simulink simulation results were provided to validate the robustness of the proposed control design. The simulation results demonstrate that the tracking errors stay in a small region around zero.

  14. Flight Control of Biomimetic Air Vehicles Using Vibrational Control and Averaging

    Science.gov (United States)

    Tahmasian, Sevak; Woolsey, Craig A.

    2016-09-01

    A combination of vibrational inputs and state feedback is applied to control the flight of a biomimetic air vehicle. First, a control strategy is developed for longitudinal flight, using a quasi-steady aerodynamic model and neglecting wing inertial effects. Vertical and forward motion is controlled by modulating the wings' stroke and feather angles, respectively. Stabilizing control parameter values are determined using the time-averaged dynamic model. Simulations of a system resembling a hawkmoth show that the proposed controller can overcome modeling error associated with the wing inertia and small parameter uncertainties when following a prescribed trajectory. After introducing the approach through an application to longitudinal flight, the control strategy is extended to address flight in three-dimensional space.

  15. NASA Innovation Fund 2010 Project Elastically Shaped Future Air Vehicle Concept

    Science.gov (United States)

    Nguyen, Nhan

    2010-01-01

    This report describes a study conducted in 2010 under the NASA Innovation Fund Award to develop innovative future air vehicle concepts. Aerodynamic optimization was performed to produce three different aircraft configuration concepts for low drag, namely drooped wing, inflected wing, and squashed fuselage. A novel wing shaping control concept is introduced. This concept describes a new capability of actively controlling wing shape in-flight to minimize drag. In addition, a novel flight control effector concept is developed to enable wing shaping control. This concept is called a variable camber continuous trailing edge flap that can reduce drag by as much as 50% over a conventional flap. In totality, the potential benefits of fuel savings offered by these concepts can be significant.

  16. A review of compliant transmission mechanisms for bio-inspired flapping-wing micro air vehicles.

    Science.gov (United States)

    Zhang, C; Rossi, C

    2017-02-15

    Flapping-wing micro air vehicles (FWMAVs) are a class of unmanned aircraft that imitate flight characteristics of natural organisms such as birds, bats, and insects, in order to achieve maximum flight efficiency and manoeuvrability. Designing proper mechanisms for flapping transmission is an extremely important aspect for FWMAVs. Compliant transmission mechanisms have been considered as an alternative to rigid transmission systems due to their lower the number of parts, thereby reducing the total weight, lower energy loss thanks to little or practically no friction among parts, and at the same time, being able to store and release mechanical power during the flapping cycle. In this paper, the state-of-the-art research in this field is dealt upon, highlighting open challenges and research topics. An optimization method for designing compliant transmission mechanisms inspired by the thoraxes of insects is also introduced.

  17. INTEGRATED USE OF RAPID PROTOTYPING AND METAL PLATING TECHNIQUES FOR DEVELOPMENT OF MICRO AIR VEHICLES

    Directory of Open Access Journals (Sweden)

    Dr. K. ELANGOVAN,

    2011-01-01

    Full Text Available This paper describes the synergistic application of rapid prototyping and metal plating technologies for development of micro air vehicles (MAV with high strength-to-weight characteristic. Stereolithography and fused deposition techniques are employed to fabricate complex thermoplastic MAV prototypes with significant time-compression in production cycle. Electroless and electrolytic deposition processes are custom developed to deposit thin metallic foils of nickel and chromium over thermoplastic MAV prototypes. Plating plant with inherent provision for variation of process parameters is established and proof-of-concept studies are carried on plating of MAV prototypes. Experiments are conducted on metal plated thermoplastic test specimens for evaluating the mechanical behaviour and structural integrity properties. Present study is a conclusive demonstration of the use of layered manufacturing techniques in quick realisation of flight-worthy MAV systems.

  18. Adaptive Neural Back-Stepping Control with Constrains for a Flexible Air-Breathing Hypersonic Vehicle

    Directory of Open Access Journals (Sweden)

    Pengfei Wang

    2015-01-01

    Full Text Available The design of an adaptive neural back-stepping control for a flexible air-breathing hypersonic vehicle (AHV in the presence of input constraint and aerodynamic uncertainty is discussed. Based on functional decomposition, the dynamics can be decomposed into the velocity subsystem and the altitude subsystem. To guarantee the exploited controller’s robustness with respect to parametric uncertainties, neural network (NN is applied to approximate the lumped uncertainty of each subsystem of AHV model. The exceptional contribution is that novel auxiliary systems are introduced to compensate both the tracking errors and desired control laws, based on which the explored controller can still provide effective tracking of velocity and altitude commands when the actuators are saturated. Finally, simulation studies are made to illustrate the effectiveness of the proposed control approach in spite of the flexible effects, system uncertainties, and varying disturbances.

  19. Continuous high order sliding mode controller design for a flexible air-breathing hypersonic vehicle.

    Science.gov (United States)

    Wang, Jie; Zong, Qun; Su, Rui; Tian, Bailing

    2014-05-01

    This paper investigates the problem of tracking control with uncertainties for a flexible air-breathing hypersonic vehicle (FAHV). In order to overcome the analytical intractability of this model, an Input-Output linearization model is constructed for the purpose of feedback control design. Then, the continuous finite time convergence high order sliding mode controller is designed for the Input-Output linearization model without uncertainties. In addition, a nonlinear disturbance observer is applied to estimate the uncertainties in order to compensate the controller and disturbance suppression, where disturbance observer and controller synthesis design is obtained. Finally, the synthesis of controller and disturbance observer is used to achieve the tracking for the velocity and altitude of the FAHV and simulations are presented to illustrate the effectiveness of the control strategies.

  20. Q-learning approach to automated unmanned air vehicle (UAV) demining

    Science.gov (United States)

    Ferrari, Silvia; Daugherty, Greyson

    2010-04-01

    This paper develops a Q-learning approach to Unmanned Air Vehicle (UAV) navigation, or path planning, for sensing applications in which an infrared (IR) sensor or camera is installed onboard the UAV for the purpose of detecting and classifying multiple, stationary ground targets. The problem can be considered as a geometric sensor-path planning problem, because the geometry and position of the sensor's field of view (FOV) determines what targets can be detected and classified at any given time. The advantage of this approach over existing path planning techniques is that the optimal guidance policy is learned via the Q-function, without explicit knowledge of the system models and environmental conditions. The approach is demonstrated through a demining application in which a UAV-based IR sensor is capable of determining the optimal altitude for properly detecting and classifying targets buried in a complex region of interest.

  1. Life cycle air emissions impacts and ownership costs of light-duty vehicles using natural gas as a primary energy source.

    Science.gov (United States)

    Luk, Jason M; Saville, Bradley A; MacLean, Heather L

    2015-04-21

    This paper aims to comprehensively distinguish among the merits of different vehicles using a common primary energy source. In this study, we consider compressed natural gas (CNG) use directly in conventional vehicles (CV) and hybrid electric vehicles (HEV), and natural gas-derived electricity (NG-e) use in plug-in battery electric vehicles (BEV). This study evaluates the incremental life cycle air emissions (climate change and human health) impacts and life cycle ownership costs of non-plug-in (CV and HEV) and plug-in light-duty vehicles. Replacing a gasoline CV with a CNG CV, or a CNG CV with a CNG HEV, can provide life cycle air emissions impact benefits without increasing ownership costs; however, the NG-e BEV will likely increase costs (90% confidence interval: $1000 to $31 000 incremental cost per vehicle lifetime). Furthermore, eliminating HEV tailpipe emissions via plug-in vehicles has an insignificant incremental benefit, due to high uncertainties, with emissions cost benefits between -$1000 and $2000. Vehicle criteria air contaminants are a relatively minor contributor to life cycle air emissions impacts because of strict vehicle emissions standards. Therefore, policies should focus on adoption of plug-in vehicles in nonattainment regions, because CNG vehicles are likely more cost-effective at providing overall life cycle air emissions impact benefits.

  2. Comparison and Evaluation of a New Innovative Drive Concept for the Air Conditioning Compressor of Electric Vehicles

    OpenAIRE

    2014-01-01

    The development of an energy efficient air conditioning system for electric vehicles is an ever increasing challenge, because the cooling as well as the heating of the passenger cell reduces the cruising range dramatically. Almost always the compressor of the air conditioning system in electric cars is a scroll compressor with a separate electric motor and appropriate power electronics. However, this solution is critical in terms of the installation space, the weight and also the costs. There...

  3. Research of Contact Stresses between Seat Cushion and Human Body

    Directory of Open Access Journals (Sweden)

    Pervan Stjepan

    2010-06-01

    Full Text Available Design optimization of seat cushions is associated with the need to investigate their softness using, for this purpose, various kinds of loading pads. The aim of the investigation was: to determine seat cushion stiffness of a chair selected from a set of dining-room furniture, to determine values and distributions of contact strains on the seat surface caused by loading pad of different hardness, numerical calculation of contact strains between the seat cushion and the loading pad and to verify the results of these calculations with the results of laboratory experiments. The performed tests showed that the assessment of the seat cushion stiffness and the evaluation of contact stresses on their surface should be carried out using an equally stiff loading pad. In numerical calculations, polyurethane foams should be modeled as hyperfoam bodies of σ=f(ε characteristics determined in an axial compression test. Contact stresses between the seat cushion and the user’s body should be reduced as a result of application of a frictionless connection of thin layers of polyurethane foams with foam forming the proper elastic layer of the seat.

  4. A refuelable zinc/air battery for fleet electric vehicle propulsion

    Science.gov (United States)

    Cooper, John F.; Fleming, Dennis; Hargrove, Douglas; Koopman, Ronald; Peterman, Keith

    1995-04-01

    We report the development and on-vehicle testing of an engineering prototype zinc/air battery. The battery is refueled by periodic exchange of spent electrolyte for zinc particles entrained in fresh electrolyte. The technology is intended to provide a capability for nearly continuous vehicle operation, using the fleet's home base for 10 minute refuelings and zinc recycling instead of commercial infrastructure. In the battery, the zinc fuel particles are stored in hoppers, from which they are gravity fed into individual cells and completely consumed during discharge. A six-celled (7V) engineering prototype battery was combined with a 6 V lead/acid battery to form a parallel hybrid unit, which was tested in series with the 216 V battery of an electric shuttle bus over a 75 mile circuit. The battery has an energy density of 140 Wh/kg and a mass density of 1.5 kg/L. Cost, energy efficiency, and alternative hybrid configurations are discussed.

  5. Aeroservoelastic modeling and analysis of a canard-configured air-breathing hypersonic vehicles

    Institute of Scientific and Technical Information of China (English)

    Zeng Kaichun; Xiang Jinwu; Li Daochun

    2013-01-01

    Air-breathing hypersonic vehicles (HSVs) are typically characterized by interactions ofelasticity,propulsion and rigid-body flight dynamics,which may result in intractable aeroservoelas-tic problem.When canard is added,this problem would be even intensified by the introduction oflow-frequency canard pivot mode.This paper concerns how the aeroservoelastic stability of acanard-configured HSV is affected by the pivot stiffnesses of all-moveable horizontal tail (HT)and canard.A wing/pivot system model is developed by considering the pivot torsional flexibility,fuselage vibration,and control input.The governing equations of the aeroservoelastic system areestablished by combining the equations of rigid-body motion,elastic fuselage model,wing/pivotsystem models and actuator dynamics.An unsteady aerodynamic model is developed by steadyShock-Expansion theory with an unsteady correction using local piston theory.A baseline control-ler is given to provide approximate inflight characteristics of rigid-body modes.The vehicle istrimmed for equilibrium state,around which the linearized equations are derived for stability anal-ysis.A comparative study of damping ratios,closed-loop poles and responses are conducted withvarying controller gains and pivot stiffnesses.Available bandwidth for control design is discussedand feasible region for pivot stiffnesses of HT and canard is given.

  6. An adaptive dual-optimal path-planning technique for unmanned air vehicles

    Directory of Open Access Journals (Sweden)

    Whitfield Clifford A.

    2016-01-01

    Full Text Available A multi-objective technique for unmanned air vehicle path-planning generation through task allocation has been developed. The dual-optimal path-planning technique generates real-time adaptive flight paths based on available flight windows and environmental influenced objectives. The environmentally-influenced flight condition determines the aircraft optimal orientation within a downstream virtual window of possible vehicle destinations that is based on the vehicle’s kinematics. The intermittent results are then pursued by a dynamic optimization technique to determine the flight path. This path-planning technique is a multi-objective optimization procedure consisting of two goals that do not require additional information to combine the conflicting objectives into a single-objective. The technique was applied to solar-regenerative high altitude long endurance flight which can benefit significantly from an adaptive real-time path-planning technique. The objectives were to determine the minimum power required flight paths while maintaining maximum solar power for continual surveillance over an area of interest (AOI. The simulated path generation technique prolonged the flight duration over a sustained turn loiter flight path by approximately 2 months for a year of flight. The potential for prolonged solar powered flight was consistent for all latitude locations, including 2 months of available flight at 60° latitude, where sustained turn flight was no longer capable.

  7. Stereo vision-based obstacle avoidance for micro air vehicles using an egocylindrical image space representation

    Science.gov (United States)

    Brockers, R.; Fragoso, A.; Matthies, L.

    2016-05-01

    Micro air vehicles which operate autonomously at low altitude in cluttered environments require a method for onboard obstacle avoidance for safe operation. Previous methods deploy either purely reactive approaches, mapping low-level visual features directly to actuator inputs to maneuver the vehicle around the obstacle, or deliberative methods that use on-board 3-D sensors to create a 3-D, voxel-based world model, which is then used to generate collision free 3-D trajectories. In this paper, we use forward-looking stereo vision with a large horizontal and vertical field of view and project range from stereo into a novel robot-centered, cylindrical, inverse range map we call an egocylinder. With this implementation we reduce the complexity of our world representation from a 3D map to a 2.5D image-space representation, which supports very efficient motion planning and collision checking, and allows to implement configuration space expansion as an image processing function directly on the egocylinder. Deploying a fast reactive motion planner directly on the configuration space expanded egocylinder image, we demonstrate the effectiveness of this new approach experimentally in an indoor environment.

  8. Estimation of road vehicle exhaust emissions from 1992 to 2010 and comparison with air quality measurements in Genoa, Italy

    Science.gov (United States)

    Zamboni, Giorgio; Capobianco, Massimo; Daminelli, Enrico

    An investigation into road transport exhaust emissions in the Genoa urban area was performed by comparing the quantities of carbon monoxide (CO), nitrogen oxides (NO x), nitrogen dioxide (NO 2) and particulate matter (PM) emitted by different vehicle categories with air quality measurements referred to the same pollutants. Exhaust emissions were evaluated by applying the PROGRESS (computer PROGramme for Road vehicle EmiSSions evaluation) code, developed by the Internal Combustion Engines Group of the University of Genoa, to eight different years (from 1992 to 2010), considering spark ignition and Diesel passenger cars and light duty vehicles, heavy duty vehicles and buses, motorcycles and mopeds. Changes in terms of vehicles number, mileage and total emissions are presented together with relative distributions among the various vehicle categories. By comparing 1992 and 2010 data, calculated trends show a 7% increase in the number of vehicles, with total mileage growing at a faster rate (approx. 22%); total emissions decrease considerably, by approximately 50% for NO x and PM, 70% for HC and 80% for CO, due to improvements in engines and fuels forced by the stricter European legislation and the fleet renewal, while primary NO 2 emission will be very close to 1992 level, after a decrease of about 18% in 2000. Air quality was analysed by selecting traffic and background measuring stations from the monitoring network managed by the Environmental Department of the Province of Genoa: average annual concentrations of considered pollutants from 1994 to 2007 were calculated in order to obtain the relative historical trends and compare them with European public health limits and with road vehicle emissions. Though an important reduction in pollutant concentrations has been achieved as a consequence of cleaner vehicles, some difficulties in complying with present and/or future NO 2 and PM 10 limits are also apparent, thus requiring suitable measures to be taken by the local

  9. Development of a vehicle emission inventory with high temporal-spatial resolution based on NRT traffic data and its impact on air pollution in Beijing - Part 2: Impact of vehicle emission on urban air quality

    Science.gov (United States)

    He, Jianjun; Wu, Lin; Mao, Hongjun; Liu, Hongli; Jing, Boyu; Yu, Ye; Ren, Peipei; Feng, Cheng; Liu, Xuehao

    2016-03-01

    A companion paper developed a vehicle emission inventory with high temporal-spatial resolution (HTSVE) with a bottom-up methodology based on local emission factors, complemented with the widely used emission factors of COPERT model and near-real-time (NRT) traffic data on a specific road segment for 2013 in urban Beijing (Jing et al., 2016), which is used to investigate the impact of vehicle pollution on air pollution in this study. Based on the sensitivity analysis method of switching on/off pollutant emissions in the Chinese air quality forecasting model CUACE, a modelling study was carried out to evaluate the contributions of vehicle emission to the air pollution in Beijing's main urban areas in the periods of summer (July) and winter (December) 2013. Generally, the CUACE model had good performance of the concentration simulation of pollutants. The model simulation has been improved by using HTSVE. The vehicle emission contribution (VEC) to ambient pollutant concentrations not only changes with seasons but also changes with time. The mean VEC, affected by regional pollutant transports significantly, is 55.4 and 48.5 % for NO2 and 5.4 and 10.5 % for PM2.5 in July and December 2013 respectively. Regardless of regional transports, relative vehicle emission contribution (RVEC) to NO2 is 59.2 and 57.8 % in July and December 2013, while it is 8.7 and 13.9 % for PM2.5. The RVEC to PM2.5 is lower than the PM2.5 contribution rate for vehicle emission in total emission, which may be due to dry deposition of PM2.5 from vehicle emission in the near-surface layer occuring more easily than from elevated source emission.

  10. Networking Multiple Autonomous Air and Ocean Vehicles for Oceanographic Research and Monitoring

    Science.gov (United States)

    McGillivary, P. A.; Borges de Sousa, J.; Rajan, K.

    2013-12-01

    Autonomous underwater and surface vessels (AUVs and ASVs) are coming into wider use as components of oceanographic research, including ocean observing systems. Unmanned airborne vehicles (UAVs) are now available at modest cost, allowing multiple UAVs to be deployed with multiple AUVs and ASVs. For optimal use good communication and coordination among vehicles is essential. We report on the use of multiple AUVs networked in communication with multiple UAVs. The UAVs are augmented by inferential reasoning software developed at MBARI that allows UAVs to recognize oceanographic fronts and change their navigation and control. This in turn allows UAVs to automatically to map frontal features, as well as to direct AUVs and ASVs to proceed to such features and conduct sampling via onboard sensors to provide validation for airborne mapping. ASVs can also act as data nodes for communication between UAVs and AUVs, as well as collecting data from onboard sensors, while AUVs can sample the water column vertically. This allows more accurate estimation of phytoplankton biomass and productivity, and can be used in conjunction with UAV sampling to determine air-sea flux of gases (e.g. CO2, CH4, DMS) affecting carbon budgets and atmospheric composition. In particular we describe tests in July 2013 conducted off Sesimbra, Portugal in conjunction with the Portuguese Navy by the University of Porto and MBARI with the goal of tracking large fish in the upper water column with coordinated air/surface/underwater measurements. A thermal gradient was observed in the infrared by a low flying UAV, which was used to dispatch an AUV to obtain ground truth to demonstrate the event-response capabilities using such autonomous platforms. Additional field studies in the future will facilitate integration of multiple unmanned systems into research vessel operations. The strength of hardware and software tools described in this study is to permit fundamental oceanographic measurements of both ocean

  11. 75 FR 39251 - Control of Air Pollution From New Motor Vehicles: Announcement of Public Workshop for Heavy-Duty...

    Science.gov (United States)

    2010-07-08

    ... AGENCY Control of Air Pollution From New Motor Vehicles: Announcement of Public Workshop for Heavy-Duty... manufacturers have recently begun utilizing a NO X emission control technology called selective catalyst... ensure, among other things, that SCR-equipped engines are designed to properly control emissions...

  12. A New High-Resolution Direction Finding Architecture Using Photonics and Neural Network Signal Processing for Miniature Air Vehicle Applications

    Science.gov (United States)

    2015-09-01

    dimensional circular array real-time phase interferometer algorithm and its correction,” in Int. Conf. on Image Signal Process . (CISP), Tianjin, China...NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited A NEW HIGH...RESOLUTION DIRECTION FINDING ARCHITECTURE USING PHOTONICS AND NEURAL NETWORK SIGNAL PROCESSING FOR MINIATURE AIR VEHICLE APPLICATIONS by Robert

  13. The impact of China's vehicle emissions on regional air quality in 2000 and 2020: a scenario analysis

    Directory of Open Access Journals (Sweden)

    E. Saikawa

    2011-09-01

    Full Text Available The number of vehicles in China has been increasing rapidly. We evaluate the impact of current and possible future vehicle emissions from China on Asian air quality. We modify the Regional Emission Inventory in Asia (REAS for China's road transport sector in 2000 using updated Chinese data for the number of vehicles, annual mileage, and emission factors. We develop two scenarios for 2020: a scenario where emission factors remain the same as they were in 2000 (No-Policy, NoPol, and a scenario where Euro 3 vehicle emission standards are applied to all vehicles (except motorcycles and rural vehicles. The Euro 3 scenario is an approximation of what may be the case in 2020 as, starting in 2008, all new vehicles in China (except motorcycles were required to meet the Euro 3 emission standards. Using the Weather Research and Forecasting model coupled with Chemistry (WRF/Chem, we examine the regional air quality response to China's vehicle emissions in 2000 and in 2020 for the NoPol and Euro 3 scenarios. We evaluate the 2000 model results with observations in Japan, China, Korea, and Russia. Under NoPol in 2020, emissions of carbon monoxide (CO, nitrogen oxides (NOx, non-methane volatile organic compounds (NMVOCs, black carbon (BC, and organic carbon (OC from China's vehicles more than double compared to the 2000 baseline. If all vehicles meet the Euro 3 regulations in 2020, however, these emissions are reduced by more than 50% relative to NoPol. The implementation of stringent vehicle emission standards leads to a large, simultaneous reduction of the surface ozone (O3 mixing ratios and particulate matter (PM2.5 concentrations. In the Euro 3 scenario, surface O3 is reduced by more than 10 ppbv and surface PM2.5 is reduced by more than 10 μg m−3 relative to NoPol in Northeast China in all seasons. In spring, surface O3 mixing ratios and PM2.5 concentrations in

  14. Australian Air Breathing Propulsion Research for Hypersonic, Beamed Energy-Propelled Vehicles

    Science.gov (United States)

    Froning, David

    2010-05-01

    A three year laser-propelled vehicle analysis and design investigation has been begun in June, 2009 by Faculty and graduate students at the University of Adelaide under a Grant/Cooperative Agreement Award to the University of Adelaide by the Asian Office of Aerospace Research and Development (AOARD). The major objectives of thsis investigation are: (a) development of hypersonic, air breathing "lightcraft" with innovative air inlets that enable acceptable airflow capture and combustion, and acceptable cowl-lip heating rates during hot, high-speed, high angle-of-attack hypersonic flight; (b) yest of the most promising lightcraft and inlet design in the high power laser beam that is part of the shock tunnel facility at CTO Instituto in Brazil; and (c) plan a series of laser guided and propelled flights that achieve supersonic or higher speed at the Woomera Test Facility (WTF) in South Australia—using the existing WTF launching and tracking facilities and sponsor-provided laser pointing and tracking and illumination systems.

  15. Control and design of multiple unmanned air vehicles for persistent surveillance

    Science.gov (United States)

    Nigam, Nikhil

    Control of multiple autonomous aircraft for search and exploration, is a topic of current research interest for applications such as weather monitoring, geographical surveys, search and rescue, tactical reconnaissance, and extra-terrestrial exploration, and the need to distribute sensing is driven by considerations of efficiency, reliability, cost and scalability. Hence, this problem has been extensively studied in the fields of controls and artificial intelligence. The task of persistent surveillance is different from a coverage/exploration problem, in that all areas need to be continuously searched, minimizing the time between visitations to each region in the target space. This distinction does not allow a straightforward application of most exploration techniques to the problem, although ideas from these methods can still be used. The use of aerial vehicles is motivated by their ability to cover larger spaces and their relative insensitivity to terrain. However, the dynamics of Unmanned Air Vehicles (UAVs) adds complexity to the control problem. Most of the work in the literature decouples the vehicle dynamics and control policies, but their interaction is particularly interesting for a surveillance mission. Stochastic environments and UAV failures further enrich the problem by requiring the control policies to be robust, and this aspect is particularly important for hardware implementations. For a persistent mission, it becomes imperative to consider the range/endurance constraints of the vehicles. The coupling of the control policy with the endurance constraints of the vehicles is an aspect that has not been sufficiently explored. Design of UAVs for desirable mission performance is also an issue of considerable significance. The use of a single monolithic optimization for such a problem has practical limitations, and decomposition-based design is a potential alternative. In this research high-level control policies are devised, that are scalable, reliable

  16. A model to assess the comfort of automotive seat cushions.

    Science.gov (United States)

    Jiaxing, Zhan; Fard, Mohammad; Jazar, Reza

    2014-01-01

    A large number of independent and interacting factors affect seating comfort such as seat shape, stability, lumbar support and seat height. Although many subjective comfort studies have been conducted, few of them considered seating comfort from its subassembly level. This paper analyzed the automotive seat cushion designed with geared four-bar linkage for the seat height adjustment. The operation torque and lift distance of this mechanism was investigated as 2 major comfort factors. Ten cushions with this kind of design in the market were compared and assessed.

  17. Integration of Advanced Concepts and Vehicles Into the Next Generation Air Transportation System. Volume 1; Introduction, Key Messages, and Vehicle Attributes

    Science.gov (United States)

    Zellweger, Andres; Resnick, Herbert; Stevens, Edward; Arkind, Kenneth; Cotton William B.

    2010-01-01

    Raytheon, in partnership with NASA, is leading the way in ensuring that the future air transportation continues to be a key driver of economic growth and stability and that this system provides an environmentally friendly, safe, and effective means of moving people and goods. A Raytheon-led team of industry and academic experts, under NASA contract NNA08BA47C, looked at the potential issues and impact of introducing four new classes of advanced aircraft into the next generation air transportation system -- known as NextGen. The study will help determine where NASA should further invest in research to support the safe introduction of these new air vehicles. Small uncrewed or unmanned aerial systems (SUAS), super heavy transports (SHT) including hybrid wing body versions (HWB), very light jets (VLJ), and supersonic business jets (SSBJ) are the four classes of aircraft that we studied. Understanding each vehicle's business purpose and strategy is critical to assessing the feasibility of new aircraft operations and their impact on NextGen's architecture. The Raytheon team used scenarios created by aviation experts that depict vehicles in year 2025 operations along with scripts or use cases to understand the issues presented by these new types of vehicles. The information was then mapped into the Joint Planning and Development Office's (JPDO s) Enterprise Architecture to show how the vehicles will fit into NextGen's Concept of Operations. The team also identified significant changes to the JPDO's Integrated Work Plan (IWP) to optimize the NextGen vision for these vehicles. Using a proven enterprise architecture approach and the JPDO s Joint Planning Environment (JPE) web site helped make the leap from architecture to planning efficient, manageable and achievable. Very Light Jets flying into busy hub airports -- Supersonic Business Jets needing to climb and descend rapidly to achieve the necessary altitude Super-heavy cargo planes requiring the shortest common flight

  18. Emission factors of air pollutants from CNG-gasoline bi-fuel vehicles: Part II. CO, HC and NOx.

    Science.gov (United States)

    Huang, Xiaoyan; Wang, Yang; Xing, Zhenyu; Du, Ke

    2016-09-15

    The estimation of emission factors (EFs) is the basis of accurate emission inventory. However, the EFs of air pollutants for motor vehicles vary under different operating conditions, which will cause uncertainty in developing emission inventory. Natural gas (NG), considered as a "cleaner" fuel than gasoline, is increasingly being used to reduce combustion emissions. However, information is scarce about how much emission reduction can be achieved by motor vehicles burning NG (NGVs) under real road driving conditions, which is necessary for evaluating the environmental benefits for NGVs. Here, online, in situ measurements of the emissions from nine bi-fuel vehicles were conducted under different operating conditions on the real road. A comparative study was performed for the EFs of black carbon (BC), carbon monoxide (CO), hydrocarbons (HCs) and nitrogen oxides (NOx) for each operating condition when the vehicles using gasoline and compressed NG (CNG) as fuel. BC EFs were reported in part I. The part II in this paper series reports the influence of operating conditions and fuel types on the EFs of CO, HC and NOx. Fuel-based EFs of CO showed good correlations with speed when burning CNG and gasoline. The correlation between fuel-based HC EFs and speed was relatively weak whether burning CNG or gasoline. The fuel-based NOx EFs moderately correlated with speed when burning CNG, but weakly correlated with gasoline. As for HC, the mileage-based EFs of gasoline vehicles are 2.39-12.59 times higher than those of CNG vehicles. The mileage-based NOx EFs of CNG vehicles are slightly higher than those of gasoline vehicles. These results would facilitate a detailed analysis of the environmental benefits for replacing gasoline with CNG in light duty vehicles.

  19. Autonomous Landing and Ingress of Micro-Air-Vehicles in Urban Environments Based on Monocular Vision

    Science.gov (United States)

    Brockers, Roland; Bouffard, Patrick; Ma, Jeremy; Matthies, Larry; Tomlin, Claire

    2011-01-01

    Unmanned micro air vehicles (MAVs) will play an important role in future reconnaissance and search and rescue applications. In order to conduct persistent surveillance and to conserve energy, MAVs need the ability to land, and they need the ability to enter (ingress) buildings and other structures to conduct reconnaissance. To be safe and practical under a wide range of environmental conditions, landing and ingress maneuvers must be autonomous, using real-time, onboard sensor feedback. To address these key behaviors, we present a novel method for vision-based autonomous MAV landing and ingress using a single camera for two urban scenarios: landing on an elevated surface, representative of a rooftop, and ingress through a rectangular opening, representative of a door or window. Real-world scenarios will not include special navigation markers, so we rely on tracking arbitrary scene features; however, we do currently exploit planarity of the scene. Our vision system uses a planar homography decomposition to detect navigation targets and to produce approach waypoints as inputs to the vehicle control algorithm. Scene perception, planning, and control run onboard in real-time; at present we obtain aircraft position knowledge from an external motion capture system, but we expect to replace this in the near future with a fully self-contained, onboard, vision-aided state estimation algorithm. We demonstrate autonomous vision-based landing and ingress target detection with two different quadrotor MAV platforms. To our knowledge, this is the first demonstration of onboard, vision-based autonomous landing and ingress algorithms that do not use special purpose scene markers to identify the destination.

  20. Aerodynamics of a bio-inspired flexible flapping-wing micro air vehicle.

    Science.gov (United States)

    Nakata, T; Liu, H; Tanaka, Y; Nishihashi, N; Wang, X; Sato, A

    2011-12-01

    MAVs (micro air vehicles) with a maximal dimension of 15 cm and nominal flight speeds of around 10 m s⁻¹, operate in a Reynolds number regime of 10⁵ or lower, in which most natural flyers including insects, bats and birds fly. Furthermore, due to their light weight and low flight speed, the MAVs' flight characteristics are substantially affected by environmental factors such as wind gust. Like natural flyers, the wing structures of MAVs are often flexible and tend to deform during flight. Consequently, the aero/fluid and structural dynamics of these flyers are closely linked to each other, making the entire flight vehicle difficult to analyze. We have recently developed a hummingbird-inspired, flapping flexible wing MAV with a weight of 2.4-3.0 g and a wingspan of 10-12 cm. In this study, we carry out an integrated study of the flexible wing aerodynamics of this flapping MAV by combining an in-house computational fluid dynamic (CFD) method and wind tunnel experiments. A CFD model that has a realistic wing planform and can mimic realistic flexible wing kinematics is established, which provides a quantitative prediction of unsteady aerodynamics of the four-winged MAV in terms of vortex and wake structures and their relationship with aerodynamic force generation. Wind tunnel experiments further confirm the effectiveness of the clap and fling mechanism employed in this bio-inspired MAV as well as the importance of the wing flexibility in designing small flapping-wing MAVs.

  1. Fully self-contained vision-aided navigation and landing of a micro air vehicle independent from external sensor inputs

    Science.gov (United States)

    Brockers, Roland; Susca, Sara; Zhu, David; Matthies, Larry

    2012-06-01

    Direct-lift micro air vehicles have important applications in reconnaissance. In order to conduct persistent surveillance in urban environments, it is essential that these systems can perform autonomous landing maneuvers on elevated surfaces that provide high vantage points without the help of any external sensor and with a fully contained on-board software solution. In this paper, we present a micro air vehicle that uses vision feedback from a single down looking camera to navigate autonomously and detect an elevated landing platform as a surrogate for a roof top. Our method requires no special preparation (labels or markers) of the landing location. Rather, leveraging the planar character of urban structure, the landing platform detection system uses a planar homography decomposition to detect landing targets and produce approach waypoints for autonomous landing. The vehicle control algorithm uses a Kalman filter based approach for pose estimation to fuse visual SLAM (PTAM) position estimates with IMU data to correct for high latency SLAM inputs and to increase the position estimate update rate in order to improve control stability. Scale recovery is achieved using inputs from a sonar altimeter. In experimental runs, we demonstrate a real-time implementation running on-board a micro aerial vehicle that is fully self-contained and independent from any external sensor information. With this method, the vehicle is able to search autonomously for a landing location and perform precision landing maneuvers on the detected targets.

  2. Emission factors of air pollutants from CNG-gasoline bi-fuel vehicles: Part I. Black carbon.

    Science.gov (United States)

    Wang, Yang; Xing, Zhenyu; Xu, Hui; Du, Ke

    2016-12-01

    Compressed natural gas (CNG) is considered to be a "cleaner" fuel compared to other fossil fuels. Therefore, it is used as an alternative fuel in motor vehicles to reduce emissions of air pollutants in transportation. To quantify "how clean" burning CNG is compared to burning gasoline, quantification of pollutant emissions under the same driving conditions for motor vehicles with different fuels is needed. In this study, a fleet of bi-fuel vehicles was selected to measure the emissions of black carbon (BC), carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NOx) for driving in CNG mode and gasoline mode respectively under the same set of constant speeds and accelerations. Comparison of emission factors (EFs) for the vehicles burning CNG and gasoline are discussed. This part of the paper series reports BC EFs for bi-fuel vehicles driving on the real road, which were measured using an in situ method. Our results show that burning CNG will lead to 54%-83% reduction in BC emissions per kilometer, depending on actual driving conditions. These comparisons show that CNG is a cleaner fuel than gasoline for motor vehicles in terms of BC emissions and provide a viable option for reducing BC emissions cause by transportation.

  3. A survey of wheelchair use by paraplegic individuals in Japan. Part 1: Characteristics of wheelchair cushions.

    Science.gov (United States)

    Sumiya, T; Kawamura, K; Tokuhiro, A; Takechi, H; Ogata, H

    1997-09-01

    The characteristics of wheelchair cushions used by 218 paraplegic patients who lived independent lives were surveyed to clarify the present state of wheelchair cushioning for pressure sore prevention in Japan. Out of 586 cushions surveyed, 91.0% were ready-made and the rest were custom-made. The outstanding popularity of polyurethane foam ready-made cushions (76.3%) suggested that insufficient consideration was taken in the selection of cushions. Custom-made cushions displayed unique modifications to relieve contact pressure or to stabilize sitting posture, which should be systematically provided for all patients. The variety of cushion types and the frequent dissatisfaction with cushions seen in patients with current pressure sores suggested a strong demand for the effective prescription of cushions. Furthermore, 30% of all cushions had had an excessively prolonged use, indicating insufficient follow-up. A medical system including deliberate prescription and regular follow-up of wheelchair cushions should be established for the effective prevention of pressure sores.

  4. Design and mechanical analysis of a 3D-printed biodegradable biomimetic micro air vehicle wing

    Science.gov (United States)

    Salami, E.; Ganesan, P. B.; Ward, T. A.; Viyapuri, R.; Romli, F. I.

    2016-10-01

    The biomimetic micro air vehicles (BMAV) are unmanned, micro-scaled aircraft that are bio-inspired from flying organisms to achieve the lift and thrust by flapping their wings. There are still many technological challenges involved with designing the BMAV. One of these is designing the ultra-lightweight materials and structures for the wings that have enough mechanical strength to withstand continuous flapping at high frequencies. Insects achieve this by having chitin-based, wing frame structures that encompass a thin, film membrane. The main objectives of this study are to design a biodegradable BMAV wing (inspired from the dragonfly) and analyze its mechanical properties. The dragonfly-like wing frame structure was bio-mimicked and fabricated using a 3D printer. A chitosan nanocomposite film membrane was applied to the BMAV wing frames through casting method. Its mechanical performance was analyzed using universal testing machine (UTM). This analysis indicates that the tensile strength and Young's modulus of the wing with a membrane is nearly double that of the wing without a membrane, which allow higher wing beat frequencies and deflections that in turn enable a greater lifting performance.

  5. Fixed membrane wings for micro air vehicles: Experimental characterization, numerical modeling, and tailoring

    Science.gov (United States)

    Stanford, Bret; Ifju, Peter; Albertani, Roberto; Shyy, Wei

    2008-05-01

    Fixed wing micro air vehicles (wingspan between 10 and 15 cm) are aerodynamically challenging due to the low Reynolds number regime (10 4-10 5) they operate in. The low aspect ratio wings (typically used to maximize area under a size constraint) promote strong tip vortices, and are susceptible to rolling instabilities. Wind gusts can be of the same order of magnitude as the flight speed (10-15 m/s). Standard control surfaces on an empennage must be eliminated for size considerations and drag reduction, and the range of stable center of gravity locations is only a few millimeters long. Membrane aeroelasticity has been identified as a tenable method to alleviate these issues: flexible wing structures with geometric twist (adaptive washout for gust rejection, delayed stall) and aerodynamic twist (adaptive inflation for high lift, larger stability margins) are both considered here. Recent investigations in static aeroelastic characterization, including flight loads, wing deformation, flow structures, aeroelastic-tailoring studies through laminate orientation, as well as unconventional techniques based on membrane pre-tension, are reviewed. Multi-objective optimization aimed at improving lift, drag, and pitching moment considerations is also discussed.

  6. Dynamic stability test results on an 0.024 scale B-1 air vehicle

    Science.gov (United States)

    Beeman, R. R.

    1972-01-01

    Dynamic longitudinal and lateral-directional stability characteristics of the B-1 air vehicle were investigated in three wind tunnels at the Langley Research Center. The main rotary derivatives were obtained for an angle of attack range of -3 degrees to +16 degrees for a Mach number range of 0.2 to 2.16. Damping in roll data could not be obtained at the supersonic Mach numbers. The Langley 7 x 10 foot high speed tunnel, the 8 foot transonic pressure tunnel, and the 4 foot Unitary Plan wind tunnel were the test sites. An 0.024 scale light-weight model was used on a forced oscillation type balance. Test Reynolds number varied from 474,000/ft to 1,550,000/ft. through the Mach number range tested. The results showed that the dynamic stability characteristics of the model in pitch and roll were generally satisfactory up to an angle attack of about +6 degrees. In the wing sweep range from 15 to 25 degrees the positive damping levels in roll deteriorated rapidly above +2 degrees angle of attack. This reduction in roll damping is believed to be due to the onset of separation over the wing as stall is approached.

  7. Roof Modelling Potential of Unmanned Air Vehicle Point Clouds with Respect to Terrestrial Laser Scanning

    Science.gov (United States)

    Karakis, Serkan; Gunes Sefercik, Umut; Atalay, Can

    2016-07-01

    In parallel with the improvement of laser scanning technologies, dense point clouds which provide the detailed description of terrain and non-terrain objects became indispensable for remotely-sensed data users. Owing to the large demand, besides laser scanning, point clouds were started to achieve using photogrammetric images. Unmanned air vehicle (UAV) images are one of the most preferred data for creating dense point clouds by the advantage of low cost, rapid and periodically gain. In this study, we tried to assess the roof modelling potential of UAV point clouds by comparing three dimensional (3D) roof models produced from UAV and terrestrial laser scanning (TLS) point clouds. In the study, very popular low cost action camera SJ4000 and Faro Laser Scanner Focus3D X 330 were used to provide point clouds and the roof of Bulent Ecevit University Civil Aviation Academy building was utilized. For the validation of horizontal and vertical geolocation accuracies, standard deviation was used as the main indicator. The visual results demonstrated that UAV roof model is almost coherent with TLS roof model after the filtering-based refinement on noisy pixels and systematic bias correction. Moreover, the horizontal geolocation accuracy is approx. |5cm| both in X and Y directions and bias corrected vertical geolocation accuracy is approx. 17cm for zero roof slope.

  8. 4D metrology of flapping-wing micro air vehicle based on fringe projection

    Science.gov (United States)

    Zhang, Qican; Huang, Lei; Chin, Yao-Wei; Keong, Lau-Gih; Asundi, Anand

    2013-06-01

    Inspired by dominant flight of the natural flyers and driven by civilian and military purposes, micro air vehicle (MAV) has been developed so far by passive wing control but still pales in aerodynamic performance. Better understanding of flapping wing flight mechanism is eager to improve MAV's flight performance. In this paper, a simple and effective 4D metrology technique to measure full-field deformation of flapping membrane wing is presented. Based on fringe projection and 3D Fourier analysis, the fast and complex dynamic deformation, including wing rotation and wing stroke, of a flapping wing during its flight can be accurately reconstructed from the deformed fringe patterns recorded by a highspeed camera. An experiment was carried on a flapping-wing MAV with 5-cm span membrane wing beating at 30 Hz, and the results show that this method is effective and will be useful to the aerodynamicist or micro aircraft designer for visualizing high-speed complex wing deformation and consequently aid the design of flapping wing mechanism to enhanced aerodynamic performance.

  9. Moss cushions facilitate water and nutrient supply for plant species on bare limestone pavements

    DEFF Research Database (Denmark)

    Jensen, Kaj Sand; Hammer, Kathrine

    2012-01-01

    Dense moss cushions of different size are distributed across the bare limestone pavements on Øland, SE Sweden. Increasing cushion size is predicted to physically protect and improve performance and colonization by vascular plants. Therefore, we tested water balance, phosphorus supply, and species...... richness, and evaluated duration of plant activity during desiccation as a function of ground area, for a large collection of moss cushions. We found that lower evaporation and higher water storage contributed equally to extending the desiccation period with increasing cushion size. Evaporation rates...... under stagnant conditions. One moss species was added to the species pool for every nine-fold increase in cushion area. Vascular plants were absent from the smallest cushions, whereas one or two species, on average, appeared in 375- and 8,500-cm(2) cushions with water available for 6 and 10 days during...

  10. Dual rotor single- stator axial air gap PMSM motor/generator drive for high torque vehicles applications

    Science.gov (United States)

    Tutelea, L. N.; Deaconu, S. I.; Boldea, I.; Popa, G. N.

    2014-03-01

    The actual e - continuously variable transmission (e-CVT) solution for the parallel Hybrid Electric Vehicle (HEV) requires two electric machines, two inverters, and a planetary gear. A distinct electric generator and a propulsion electric motor, both with full power converters, are typical for a series HEV. In an effort to simplify the planetary-geared e-CVT for the parallel HEV or the series HEV we hereby propose to replace the basically two electric machines and their two power converters by a single, axial-air-gap, electric machine central stator, fed from a single PWM converter with dual frequency voltage output and two independent PM rotors, destined for hybrid electric vehicles (HEV) and military vehicles applications. The proposed topologies and the magneto-motive force analysis are the core of the paper.

  11. Utilization Assessment of Target Electrification Vehicles at Naval Air Station Whidbey Island: Task 3

    Energy Technology Data Exchange (ETDEWEB)

    Schey, Steve [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-05-01

    Several U.S. Department of Defense based studies have been conducted to identify potential U.S. Department of Defense transportation systems that are strong candidates for introduction or expansion of plug-in electric vehicles (PEVs). Task 2 involved identifying daily operational characteristics of select vehicles and initiating data logging of vehicle movements in order to characterize the vehicle’s mission. Individual observations of these selected vehicles provide the basis for recommendations related to PEV adoption and whether a battery electric vehicle or plug-in hybrid electric vehicle (collectively referred to as PEVs) can fulfill the mission requirements and provide observations related to placement of PEV charging infrastructure. This report provides the results of the data analysis and observations related to replacement of current vehicles with PEVs. This fulfills part of the Task 3 requirements. Task 3 also includes an assessment of the charging infrastructure required to support this replacement, which is the subject of a separate report.

  12. Performance evaluation of a stack cooling system using CO{sub 2} air conditioner in fuel cell vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Chul; Won, Jong Phil [Thermal Management Research Center, Korea Automotive Technology Institute, Chungnam 330-912 (Korea); Park, Yong Sun; Lim, Tae Won [Corporate Research and Development Division, Hyundai-Kia Motors, Gyeonggi 449-912 (Korea); Kim, Min Soo [School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-744 (Korea)

    2009-01-15

    A relation between the heat release from a fuel cell stack and an air conditioning system's performance was investigated. The air conditioning system installed in a fuel cell vehicle can be used for stack cooling when additional stack heat release is required over a fixed radiator capacity during high vehicle power generation. This study investigated the performance of a stack cooling system using CO{sub 2} air conditioner at various operating conditions. Also, the heat releasing effectiveness and mutual interference were analyzed and compared with those for the conventional radiator cooling system with/without cabin cooling. When the radiator coolant inlet temperature and flow rate were 65 C and 80 L/min, respectively, for the outdoor air inlet speed of 5 m/s, the heat release of the stack cooling system with the aid of CO{sub 2} air conditioner increased up to 36% more than that of the conventional radiator cooling system with cabin cooling. Furthermore, this increased by 7% versus the case without cabin cooling. (author)

  13. GPS navigation algorithms for Autonomous Airborne Refueling of Unmanned Air Vehicles

    Science.gov (United States)

    Khanafseh, Samer Mahmoud

    Unmanned Air Vehicles (UAVs) have recently generated great interest because of their potential to perform hazardous missions without risking loss of life. If autonomous airborne refueling is possible for UAVs, mission range and endurance will be greatly enhanced. However, concerns about UAV-tanker proximity, dynamic mobility and safety demand that the relative navigation system meets stringent requirements on accuracy, integrity, and continuity. In response, this research focuses on developing high-performance GPS-based navigation architectures for Autonomous Airborne Refueling (AAR) of UAVs. The AAR mission is unique because of the potentially severe sky blockage introduced by the tanker. To address this issue, a high-fidelity dynamic sky blockage model was developed and experimentally validated. In addition, robust carrier phase differential GPS navigation algorithms were derived, including a new method for high-integrity reacquisition of carrier cycle ambiguities for recently-blocked satellites. In order to evaluate navigation performance, world-wide global availability and sensitivity covariance analyses were conducted. The new navigation algorithms were shown to be sufficient for turn-free scenarios, but improvement in performance was necessary to meet the difficult requirements for a general refueling mission with banked turns. Therefore, several innovative methods were pursued to enhance navigation performance. First, a new theoretical approach was developed to quantify the position-domain integrity risk in cycle ambiguity resolution problems. A mechanism to implement this method with partially-fixed cycle ambiguity vectors was derived, and it was used to define tight upper bounds on AAR navigation integrity risk. A second method, where a new algorithm for optimal fusion of measurements from multiple antennas was developed, was used to improve satellite coverage in poor visibility environments such as in AAR. Finally, methods for using data-link extracted

  14. Air coditioning of passenger cars VII. Air conditioning of electrically powered vehicles and hybrid electrical-powered vehicles. Concepts, efficiency topics, methods of development, implementation of alternative refrigerants; PKW-Klimatisierung VII. Klimatisierung von E- und Hybridfahrzeugen. Konzepte, Effizienzthemen, Entwicklungsmethoden, Einfuehrung alternativer Kaeltemittel

    Energy Technology Data Exchange (ETDEWEB)

    Mager, Robert (ed.)

    2012-07-01

    The book under consideration reports on technical solutions, trends and current research results in terms of air conditioning for passenger cars. One topic of this book is the simulation of air conditioning of electrical-powered vehicles as well as hybrid electrical-powered vehicles. Furthermore, the tendency of development of electrical-powered vehicles and the conversion of the refrigerant R134a to R1234yf will be discussed.

  15. Optimization of Air Vehicle Operations Using Mixed-Integer Linear Programming

    Science.gov (United States)

    2006-01-01

    heuristic and suboptimal. Tabu search can be used to solve difficult combinatorial optimization problems, e.g., the vehicle routing problem with...the mission. The method presented here can also accommodate fixed time windows, as in the Vehicle Routing Problem (VRP) (Toth et al, 2002...critical timing constraints, which set this problem apart from the classical Vehicle Routing Problem (VRP) (Toth et al, 2002). In the latter, rigid

  16. Analysis and Modeling of Motor Vehicle Crashes Involving Air Force Military Personnel

    Science.gov (United States)

    2009-09-01

    protection systems are safety belts and airbags for four-wheeled vehicle users, and crash helmets for two-wheeled vehicle users. Almost all of the studies...in a recall of the product if it is necessary for public safety (GAO, 03-436: 27). The owner or operator of the vehicle is accountable for...frequently are: - re-experiencing, in which it is difficult for the MVCs’ victims to forget the traumatic experience because they recall

  17. The Role of Design-of-Experiments in Managing Flow in Compact Air Vehicle Inlets

    Science.gov (United States)

    Anderson, Bernhard H.; Miller, Daniel N.; Gridley, Marvin C.; Agrell, Johan

    2003-01-01

    It is the purpose of this study to demonstrate the viability and economy of Design-of-Experiments methodologies to arrive at microscale secondary flow control array designs that maintain optimal inlet performance over a wide range of the mission variables and to explore how these statistical methods provide a better understanding of the management of flow in compact air vehicle inlets. These statistical design concepts were used to investigate the robustness properties of low unit strength micro-effector arrays. Low unit strength micro-effectors are micro-vanes set at very low angles-of-incidence with very long chord lengths. They were designed to influence the near wall inlet flow over an extended streamwise distance, and their advantage lies in low total pressure loss and high effectiveness in managing engine face distortion. The term robustness is used in this paper in the same sense as it is used in the industrial problem solving community. It refers to minimizing the effects of the hard-to-control factors that influence the development of a product or process. In Robustness Engineering, the effects of the hard-to-control factors are often called noise , and the hard-to-control factors themselves are referred to as the environmental variables or sometimes as the Taguchi noise variables. Hence Robust Optimization refers to minimizing the effects of the environmental or noise variables on the development (design) of a product or process. In the management of flow in compact inlets, the environmental or noise variables can be identified with the mission variables. Therefore this paper formulates a statistical design methodology that minimizes the impact of variations in the mission variables on inlet performance and demonstrates that these statistical design concepts can lead to simpler inlet flow management systems.

  18. Evaluation of some significant issues affecting trajectory and control management for air-breathing hypersonic vehicles

    Science.gov (United States)

    Hattis, Philip D.; Malchow, Harvey L.

    1992-01-01

    Horizontal takeoff airbreathing-propulsion launch vehicles require near-optimal guidance and control which takes into account performance sensitivities to atmospheric characteristics while satisfying physically-derived operational constraints. A generic trajectory/control analysis tool that deepens insight into these considerations has been applied to two versions of a winged-cone vehicle model. Information that is critical to the design and trajectory of these vehicles is derived, and several unusual characteristics of the airbreathing propulsion model are shown to have potentially substantial effects on vehicle dynamics.

  19. High-resolution simulation of link-level vehicle emissions and concentrations for air pollutants in a traffic-populated eastern Asian city

    Science.gov (United States)

    Zhang, Shaojun; Wu, Ye; Huang, Ruikun; Wang, Jiandong; Yan, Han; Zheng, Yali; Hao, Jiming

    2016-08-01

    Vehicle emissions containing air pollutants created substantial environmental impacts on air quality for many traffic-populated cities in eastern Asia. A high-resolution emission inventory is a useful tool compared with traditional tools (e.g. registration data-based approach) to accurately evaluate real-world traffic dynamics and their environmental burden. In this study, Macau, one of the most populated cities in the world, is selected to demonstrate a high-resolution simulation of vehicular emissions and their contribution to air pollutant concentrations by coupling multimodels. First, traffic volumes by vehicle category on 47 typical roads were investigated during weekdays in 2010 and further applied in a networking demand simulation with the TransCAD model to establish hourly profiles of link-level vehicle counts. Local vehicle driving speed and vehicle age distribution data were also collected in Macau. Second, based on a localized vehicle emission model (e.g. the emission factor model for the Beijing vehicle fleet - Macau, EMBEV-Macau), this study established a link-based vehicle emission inventory in Macau with high resolution meshed in a temporal and spatial framework. Furthermore, we employed the AERMOD (AMS/EPA Regulatory Model) model to map concentrations of CO and primary PM2.5 contributed by local vehicle emissions during weekdays in November 2010. This study has discerned the strong impact of traffic flow dynamics on the temporal and spatial patterns of vehicle emissions, such as a geographic discrepancy of spatial allocation up to 26 % between THC and PM2.5 emissions owing to spatially heterogeneous vehicle-use intensity between motorcycles and diesel fleets. We also identified that the estimated CO2 emissions from gasoline vehicles agreed well with the statistical fuel consumption in Macau. Therefore, this paper provides a case study and a solid framework for developing high-resolution environment assessment tools for other vehicle-populated cities

  20. SESAME Equations of State for Stress Cushion and Related Materials

    Energy Technology Data Exchange (ETDEWEB)

    Coe, Joshua Damon [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-02-12

    I examine LANL equations of state (EOS) for stress cushion and related materials, namely S5370, SX358, and Sylgard 184. In the the rst two cases, the SESAME library contains entries for both the inert (unreacted) and decomposition products. I compare inert EOS results with ambient property measurements to the extent possible, then I check the compositions used to build the products tables. I plot the predicted Hugoniots alongside the available shock data, then draw some conclusions.

  1. Short communication: Genetic characterization of digital cushion thickness.

    Science.gov (United States)

    Oikonomou, G; Banos, G; Machado, V; Caixeta, L; Bicalho, R C

    2014-01-01

    Dairy cow lameness is a serious animal welfare issue. It is also a significant cause of economic losses, reducing reproductive efficiency and milk production and increasing culling rates. The digital cushion is a complex structure composed mostly of adipose tissue located underneath the distal phalanx and has recently been phenotypically associated with incidence of claw horn disruption lesions (CHDL); namely, sole ulcers and white line disease. The objective of this study was to characterize digital cushion thickness genetically and to investigate its association with body condition score (BCS), locomotion score (LOCO), CHDL, and milk production. Data were collected from 1 large closely monitored commercial dairy farm located in upstate New York; 923 dairy cows were used. Before trimming, the following data were collected by a member of the research team: BCS, cow height measurement, and LOCO. Presence or not of CHDL (sole ulcer or white line disease, or both) was recorded at trimming. Immediately after the cows were hoof trimmed, they underwent digital sonographic B-mode examination for the measurement of digital cushion thickness. Factors such as parity number, stage of lactation, calving date, mature-equivalent 305-d milk yield (ME305MY), and pedigree information were obtained from the farm's dairy management software (DairyCOMP 305; Valley Agricultural Software, Tulare, CA). Univariate animal models were used to obtain variance component estimations for each studied trait (CHDL, BCS, digital cushion thickness average, LOCO, height, and ME305MY) and a 6-variate analysis was conducted to estimate the genetic, residual, and phenotypic correlations between the studied traits. The heritability estimate of DCTA was 0.33±0.09, whereas a statistically significant genetic correlation was estimated between DCTA and CHDL (-0.60±0.29). Of the other genetic correlations, significant estimates were derived for BCS with LOCO (-0.49±0.19) and ME305MY (-0.48±0.20). Digital

  2. The structure of the cushions in the feet of African elephants (Loxodonta africana).

    Science.gov (United States)

    Weissengruber, G E; Egger, G F; Hutchinson, J R; Groenewald, H B; Elsässer, L; Famini, D; Forstenpointner, G

    2006-12-01

    The uniquely designed limbs of the African elephant, Loxodonta africana, support the weight of the largest terrestrial animal. Besides other morphological peculiarities, the feet are equipped with large subcutaneous cushions which play an important role in distributing forces during weight bearing and in storing or absorbing mechanical forces. Although the cushions have been discussed in the literature and captive elephants, in particular, are frequently affected by foot disorders, precise morphological data are sparse. The cushions in the feet of African elephants were examined by means of standard anatomical and histological techniques, computed tomography (CT) and magnetic resonance imaging (MRI). In both the forelimb and the hindlimb a 6th ray, the prepollex or prehallux, is present. These cartilaginous rods support the metacarpal or metatarsal compartment of the cushions. None of the rays touches the ground directly. The cushions consist of sheets or strands of fibrous connective tissue forming larger metacarpal/metatarsal and digital compartments and smaller chambers which were filled with adipose tissue. The compartments are situated between tarsal, metatarsal, metacarpal bones, proximal phalanges or other structures of the locomotor apparatus covering the bones palmarly/plantarly and the thick sole skin. Within the cushions, collagen, reticulin and elastic fibres are found. In the main parts, vascular supply is good and numerous nerves course within the entire cushion. Vater-Pacinian corpuscles are embedded within the collagenous tissue of the cushions and within the dermis. Meissner corpuscles are found in the dermal papillae of the foot skin. The micromorphology of elephant feet cushions resembles that of digital cushions in cattle or of the foot pads in humans but not that of digital cushions in horses. Besides their important mechanical properties, foot cushions in elephants seem to be very sensitive structures.

  3. 压力控制型防压疮垫的减压性能测试分析%Evaluation of Pressure Reduction of Pressure-control Ulcer Cushion

    Institute of Scientific and Technical Information of China (English)

    云晓; 郭欢

    2015-01-01

    Objective To evaluate the decompression performance of anti pressure ulcer cushions with different materials and structures. Methods The common cotton cushion, sponge cushion, 3D fabric cushion, and upper 3D fabric and lower sponge cushion were analyzed by XSensor pressure sensor testing system. The pressure distribution, the pressure peak and the average pressure were analyzed to compare the decompression performance and the comfortable capability. Results and Conclusion The upper 3D fabric and lower sponge cushion can en-sure the decompression performance with excellent permeability. Both decompression and air comfort permeability should be the future di-rection of ulcer cushions research and production.%目的:测试分析几种不同材质结构的防压疮垫的减压性能。方法使用XSensor压力传感器测试系统,测试试验者使用普通棉质床垫、海绵防压疮垫、3D织物防压疮垫和上层3D织物下层海绵防压疮垫4种防压疮垫的压力情况。从压力分布图、压力峰值、压力平均值几个角度进行评价,对比各种防压疮垫减压性能及使用舒适性。结果和结论上层3D织物下层海绵防压疮垫的组合方式既可保证减压性能效果又具备优良的透气性。兼顾减压及透气舒适性应是今后防压疮产品的生产研究方向。

  4. Impact of the Air-Conditioning System on the Power Consumption of an Electric Vehicle Powered by Lithium-Ion Battery

    Directory of Open Access Journals (Sweden)

    Brahim Mebarki

    2013-01-01

    Full Text Available The car occupies the daily universe of our society; however, noise pollution, global warming gas emissions, and increased fuel consumption are constantly increasing. The electric vehicle is one of the recommended solutions by the raison of its zero emission. Heating and air-conditioning (HVAC system is a part of the power system of the vehicle when the purpose is to provide complete thermal comfort for its occupants, however it requires far more energy than any other car accessory. Electric vehicles have a low-energy storage capacity, and HVAC may consume a substantial amount of the total energy stored, considerably reducing the vehicle range, which is one of the most important parameters for EV acceptability. The basic goal of this paper is to simulate the air-conditioning system impact on the power energy source of an electric vehicle powered by a lithium-ion battery.

  5. Aggregated GPS tracking of vehicles and its use as a proxy of traffic-related air pollution emissions

    Science.gov (United States)

    Chen, Shimon; Bekhor, Shlomo; Yuval; Broday, David M.

    2016-10-01

    Most air quality models use traffic-related variables as an input. Previous studies estimated nearby vehicular activity through sporadic traffic counts or via traffic assignment models. Both methods have previously produced poor or no data for nights, weekends and holidays. Emerging technologies allow the estimation of traffic through passive monitoring of location-aware devices. Examples of such devices are GPS transceivers installed in vehicles. In this work, we studied traffic volumes that were derived from such data. Additionally, we used these data for estimating ambient nitrogen dioxide concentrations, using a non-linear optimisation model that includes basic dispersion properties. The GPS-derived data show great potential for use as a proxy for pollutant emissions from motor-vehicles.

  6. 77 FR 50969 - Approval and Promulgation of Air Quality Implementation Plans; Maryland; Low Emission Vehicle...

    Science.gov (United States)

    2012-08-23

    ... means as the former 1-hour ozone standard) albeit with slightly different area names and classifications..., purchase, lease, rent, acquire, or receive a motor vehicle for titling or registration in Maryland....

  7. Drag Identification & Reduction Technology (DIRECT) for Elastically Shaped Air Vehicles Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA and Boeing Phantom Works have been working on the Elastically Shaped Future Vehicle Concept (ESFVC) and have shown that aircraft with elastically shaped wings...

  8. Development of a high temporal-spatial resolution vehicle emission inventory based on NRT traffic data and its impact on air pollution in Beijing – Part 1: Development and evaluation of vehicle emission inventory

    Directory of Open Access Journals (Sweden)

    B. Y. Jing

    2015-10-01

    Full Text Available As the ownership of vehicles and frequency of utilization increase, vehicle emissions have become an important source of air pollution in Chinese cities. An accurate emission inventory for on-road vehicles is necessary for numerical air quality simulation and the assessment of implementation strategies. This paper presents a bottom-up methodology based on the local emission factors, complemented with the widely used emission factors of Computer Programme to Calculate Emissions from Road Transport (COPERT model and near real time (NRT traffic data on road segments to develop a high temporal-spatial resolution vehicle emission inventory (HTSVE for the urban Beijing area. To simulate real-world vehicle emissions accurately, the road has been divided into segments according to the driving cycle (traffic speed on this road segment. The results show that the vehicle emissions of NOx, CO, HC and PM were 10.54 × 104, 42.51 × 104 and 2.13 × 104 and 0.41 × 104 Mg, respectively. The vehicle emissions and fuel consumption estimated by the model were compared with the China Vehicle Emission Control Annual Report and fuel sales thereafter. The grid-based emissions were also compared with the vehicular emission inventory developed by the macro-scale approach. This method indicates that the bottom-up approach better estimates the levels and spatial distribution of vehicle emissions than the macro-scale method, which relies on more information. Additionally, the on-road vehicle emission inventory model and control effect assessment system in Beijing, a vehicle emission inventory model, was established based on this study in a companion paper (He et al., 2015.

  9. Development of a high temporal-spatial resolution vehicle emission inventory based on NRT traffic data and its impact on air pollution in Beijing - Part 1: Development and evaluation of vehicle emission inventory

    Science.gov (United States)

    Jing, B. Y.; Wu, L.; Mao, H. J.; Gong, S. L.; He, J. J.; Zou, C.; Song, G. H.; Li, X. Y.; Wu, Z.

    2015-10-01

    As the ownership of vehicles and frequency of utilization increase, vehicle emissions have become an important source of air pollution in Chinese cities. An accurate emission inventory for on-road vehicles is necessary for numerical air quality simulation and the assessment of implementation strategies. This paper presents a bottom-up methodology based on the local emission factors, complemented with the widely used emission factors of Computer Programme to Calculate Emissions from Road Transport (COPERT) model and near real time (NRT) traffic data on road segments to develop a high temporal-spatial resolution vehicle emission inventory (HTSVE) for the urban Beijing area. To simulate real-world vehicle emissions accurately, the road has been divided into segments according to the driving cycle (traffic speed) on this road segment. The results show that the vehicle emissions of NOx, CO, HC and PM were 10.54 × 104, 42.51 × 104 and 2.13 × 104 and 0.41 × 104 Mg, respectively. The vehicle emissions and fuel consumption estimated by the model were compared with the China Vehicle Emission Control Annual Report and fuel sales thereafter. The grid-based emissions were also compared with the vehicular emission inventory developed by the macro-scale approach. This method indicates that the bottom-up approach better estimates the levels and spatial distribution of vehicle emissions than the macro-scale method, which relies on more information. Additionally, the on-road vehicle emission inventory model and control effect assessment system in Beijing, a vehicle emission inventory model, was established based on this study in a companion paper (He et al., 2015).

  10. The Air Force’s Evolved Expendable Launch Vehicle Competitive Procurement

    Science.gov (United States)

    2014-03-04

    with ULA, committing the government to buy 35 launch vehicle booster cores over a five-year period, and the associated capability to launch them.2...EELV programmatic forecast dated June 2012. 2 The booster core is the main body of a launch vehicle. In the EELV program, common booster cores are...contributors to this report were Art Gallegos, Assistant Director; Peter Anderson, Claire Buck , Raj Chitikila, Desiree Cunningham, Laura Hook, John

  11. Estimation of the ability to use a mass of air from a moving vehicle in wind turbine propulsion

    Directory of Open Access Journals (Sweden)

    Adam BAWORSKI

    2015-09-01

    Full Text Available This work presents division and classification of wind turbines according to the location of the axis of rotation and generated power. The work introduces applications of the wind turbines in electric energy generation with their direct development. The paper discusses indicators and exploitation parameters that characterize particular types of wind rotators. Dimension and construction factors, as well as work parameters, have been analyzed in order to choose the optimal rotator in the road infrastructure application. The aim of the analysis was to conduct further investigation to restore a mass of air from passing vehicles.

  12. Cooperative Electronic Attack for Groups of Unmanned Air Vehicles based on Multi-agent Simulation and Evaluation

    Directory of Open Access Journals (Sweden)

    Yee Ming Chen

    2012-03-01

    Full Text Available In this paper, the issue of path planning is addressed for unmanned air vehicles (UAVs cooperative joint-forces electronic attack operating in a hostile environment. Specifically, the objective is to plan path to a target location in a way that minimizes exposure to threats while keeping fuel usage at acceptable levels. We consider a scenario where a group of UAVs flies in a close formation and cooperates in their use of jamming resources to prevent being tracked by Surface-to-Air Missile (SAM tracking radars. The main goal of this research effort is develop cooperating UAVs within multi-agent simulation environment. Simulations were generated to test the path planning and control strategies given UAVs/SAM tracking radar network scenarios, and overall UAVs cooperative electronic attack performance in each simulation was analyzed.

  13. Cabin air temperature of parked vehicles in summer conditions: life-threatening environment for children and pets calculated by a dynamic model

    Science.gov (United States)

    Horak, Johannes; Schmerold, Ivo; Wimmer, Kurt; Schauberger, Günther

    2016-07-01

    In vehicles that are parked, no ventilation and/or air conditioning takes place. If a vehicle is exposed to direct solar radiation, an immediate temperature rise occurs. The high cabin air temperature can threaten children and animals that are left unattended in vehicles. In the USA, lethal heat strokes cause a mean death rate of 37 children per year. In addition, temperature-sensitive goods (e.g. drugs in ambulances and veterinary vehicles) can be adversely affected by high temperatures. To calculate the rise of the cabin air temperature, a dynamic model was developed that is driven by only three parameters, available at standard meteorological stations: air temperature, global radiation and wind velocity. The transition from the initial temperature to the constant equilibrium temperature depends strongly on the configuration of the vehicle, more specifically on insulation, window area and transmission of the glass, as well as on the meteorological conditions. The comparison of the model with empirical data showed good agreement. The model output can be applied to assess the heat load of children and animals as well as temperature-sensitive goods, which are transported and/or stored in a vehicle.

  14. 新型非导向防撞垫开发%Development and Research on a New Type Non-re-directive Crash Cushion

    Institute of Scientific and Technical Information of China (English)

    闫书明

    2012-01-01

    为降低车辆碰撞护栏端部事故严重度,参考国内外相关标准,依据我国交通流特性,提出非导向防撞垫碰撞试验条件与评价标准,采用理论分析和实车碰撞试验相结合的技术手段,开发出一种新型非导向防撞垫.结果表明,开发的防撞垫能够防护1.5t小型车辆60 km/h正面碰撞,碰撞后车辆姿态良好,车体重心X.Y,Z三方向加速度最大值分别为18.9g,4.2g,6.1g,防撞垫最大动态变形为1 234 mm.非导向防撞垫满足评价标准要求,可弥补护栏端部安全漏洞.%In order to reduce accident severity caused by accident vehicles impact to barrier terminal, impact test condition and evaluation specification for non-re-directive crash cushion were brought out referring to correlative documents in and out of China, a new type of non-re-directive crash cushion which met the evaluation specification by conducting theoretic analysis and full-scale impact tests was invented. The results indicate that the non-re-directive crash cushion able to absorb kinetic energy of a 1. 5 ton car with 60km/h speed. The vehicle performs well after impact, the maximum acceleration at the position of vehicle gravity center is 18. 9g, 4. 2g, 6.1g in three directions, and the maximum dynamic deformation of crash cushion is 1234mm. The performances of the non-re-directive crash cushion meets the acceptance criteria and can make up the security dead angle of barrier terminal.

  15. Numerical modeling of aerodynamics of airfoils of micro air vehicles in gusty environment

    Science.gov (United States)

    Gopalan, Harish

    The superior flight characteristics exhibited by birds and insects can be taken as a prototype of the most perfect form of flying machine ever created. The design of Micro Air Vehicles (MAV) which tries mimic the flight of birds and insects has generated a great deal of interest as the MAVs can be utilized for a number of commercial and military operations which is usually not easily accessible by manned motion. The size and speed of operation of a MAV results in low Reynolds number flight, way below the flying conditions of a conventional aircraft. The insensitivity to wind shear and gust is one of the required factors to be considered in the design of airfoil for MAVs. The stability of flight under wind shear is successfully accomplished in the flight of birds and insects, through the flapping motion of their wings. Numerous studies which attempt to model the flapping motion of the birds and insects have neglected the effect of wind gust on the stability of the motion. Also sudden change in flight conditions makes it important to have the ability to have an instantaneous change of the lift force without disturbing the stability of the MAV. In the current study, two dimensional rigid airfoil, undergoing flapping motion is studied numerically using a compressible Navier-Stokes solver discretized using high-order finite difference schemes. The high-order schemes in space and in time are needed to keep the numerical solution economic in terms of computer resources and to prevent vortices from smearing. The numerical grid required for the computations are generated using an inverse panel method for the streamfunction and potential function. This grid generating algorithm allows the creation of single-block orthogonal H-grids with ease of clustering anywhere in the domain and the easy resolution of boundary layers. The developed numerical algorithm has been validated successfully against benchmark problems in computational aeroacoustics (CAA), and unsteady viscous

  16. Variable Speed CMG Control of a Dual-Spin Stabilized Unconventional VTOL Air Vehicle

    Science.gov (United States)

    Lim, Kyong B.; Moerder, Daniel D.; Shin, J-Y.

    2004-01-01

    This paper describes an approach based on using both bias momentum and multiple control moment gyros for controlling the attitude of statically unstable thrust-levitated vehicles in hover or slow translation. The stabilization approach described in this paper uses these internal angular momentum transfer devices for stability, augmented by thrust vectoring for trim and other outer loop control functions, including CMG stabilization/ desaturation under persistent external disturbances. Simulation results show the feasibility of (1) improved vehicle performance beyond bias momentum assisted vector thrusting control, and (2) using control moment gyros to significantly reduce the external torque required from the vector thrusting machinery.

  17. Maglev vehicles and superconductor technology: Integration of high-speed ground transportation into the air travel system

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, L.R.; Rote, D.M.; Hull, J.R.; Coffey, H.T.; Daley, J.G.; Giese, R.F.

    1989-04-01

    This study was undertaken to (1) evaluate the potential contribution of high-temperature superconductors (HTSCs) to the technical and economic feasibility of magnetically levitated (maglev) vehicles, (2) determine the status of maglev transportation research in the United States and abroad, (3) identify the likelihood of a significant transportation market for high-speed maglev vehicles, and (4) provide a preliminary assessment of the potential energy and economic benefits of maglev systems. HTSCs should be considered as an enhancing, rather than an enabling, development for maglev transportation because they should improve reliability and reduce energy and maintenance costs. Superconducting maglev transportation technologies were developed in the United States in the late 1960s and early 1970s. Federal support was withdrawn in 1975, but major maglev transportation programs were continued in Japan and West Germany, where full-scale prototypes now carry passengers at speeds of 250 mi/h in demonstration runs. Maglev systems are generally viewed as very-high-speed train systems, but this study shows that the potential market for maglev technology as a train system, e.g., from one downtown to another, is limited. Rather, aircraft and maglev vehicles should be seen as complementing rather than competing transportation systems. If maglev systems were integrated into major hub airport operations, they could become economical in many relatively high-density US corridors. Air traffic congestion and associated noise and pollutant emissions around airports would also be reduced. 68 refs., 26 figs., 16 tabs.

  18. ENGINEERING DESIGN: EICOSANE MICROCAPSULES SYNTHESIS AND APPLICATION IN POLYURETHANE FOAMS AIMING TO DIMINISH WHEELCHAIR CUSHION EFFECT ON SKIN TEMPERATURE

    Directory of Open Access Journals (Sweden)

    ELISA M. BERETTA

    2016-12-01

    Full Text Available Thermal comfort of wheelchairs still requires improvements, since users remain on the chair for as long as 12 h a day. Increased sweating makes the skin more susceptible to colonization by fungi and bacteria, and may cause pressure ulcers. In this sense, the microencapsulation of Phase-Change Materials (PCMs may help to enhance wheelchair cushion comfort by regulating heat exchange. This study describes the production of PCM microcapsules and their application in flexible polyurethane foams after expansion, and assesses improvements in heat exchange. Microcapsules with eicosane core coated with melamine-formaldehyde were produced. Eicosane is a thermoregulation agent whose phase-change temperature is near that of the human body’s. Microcapsules were characterized by thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy, and Fourier transform infrared spectroscopy. Then, microcapsules were applied on polyurethane foams by vacuum filtration and high-pressure air gun. Samples were exposed to a heat source and analysed by infrared thermography. The results indicate that thermal load increased in samples treated with microcapsules, especially by pressure air gun, and show that it is possible to enhance thermal comfort in wheelchair seats. Thereby, this study contributes to enhance quality of life for wheelchair users, focusing on thermal comfort provided by cushion seats made from PU foam.

  19. Determination of the volatile fraction of phosphorus flame retardants in cushioning foam of upholstered furniture: towards respiratory exposure assessment.

    Science.gov (United States)

    Ghislain, Mylène; Beigbeder, Joana; Dumazert, Loïc; Lopez-Cuesta, José-Marie; Lounis, Mohammed; Leconte, Stéphane; Desauziers, Valérie

    2016-10-01

    The purpose of this paper was to highlight potential exposure in indoor air to phosphorus flame retardants (PFRs) due to their use in upholstered furniture. For that, an analytical method of PFRs by headspace coupled to solid-phase micro-extraction (HS-SPME) was developed on cushioning foams in order to determine the PFRs' volatile fraction in the material. Tests on model foams proved the feasibility of the method. The average repeatability (RSD) is 6.3 % and the limits of detection range from 0.33 to 1.29 μg g(-1) of foam, depending on the PFRs. Results showed that some PFRs can actually be emitted in air, leading to a potential risk of exposure by inhalation. The volatile fraction can be high (up to 98 % of the total PFRs amount) and depends on the physicochemical properties of flame retardants, on the textural characteristics of the materials and on the temperature. The methodology developed for cushioning foams could be further applied to other types of materials and can be used to rate them according to their potential releases of phosphorus flame retardants.

  20. 78 FR 24373 - Approval and Promulgation of Air Quality Implementation Plans; Wisconsin; Amendments to Vehicle...

    Science.gov (United States)

    2013-04-25

    ... IRON, LLC 241006370 12/31/08 53.50 31.29 DELPHI ENERGY & CHASSIS SYSTEMS 241045750 06/10/10 0.76 19.73... ``anonymous access'' system, which means EPA will not know your identity or contact information unless you... vehicle's computerized second generation on-board diagnostic (OBDII) systems. EPA fully approved...

  1. 78 FR 68378 - Approval and Promulgation of Air Quality Implementation Plans; Illinois; Amendments to Vehicle...

    Science.gov (United States)

    2013-11-14

    ... SIP on February 22, 1999, (64 FR 8517) including the program's legal authority and administrative... testing entirely and inspected all vehicles by scanning the on-board diagnostics (OBD) systems. This... announced the release of MOVES2010 in March 2010 (75 FR 9411). EPA subsequently released two minor...

  2. Characteristic Evaluation on the Cooling Performance of an Electrical Air Conditioning System Using R744 for a Fuel Cell Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Moo-Yeon Lee

    2012-05-01

    Full Text Available The objective of this study was to investigate the cooling performance characteristics of an electrical air conditioning system using R744 as an alternative of R-134a for a fuel cell electric vehicle. In order to analyze the cooling performance characteristics of the air conditioning system using R744 for a fuel cell electric vehicle, an electrical air conditioning system using R744 was developed and tested under various operating conditions according to both inlet air conditions of the gas cooler and evaporator and compressor speed. The cooling capacity and coefficient of performance (COP forcooling of the tested air conditioning system were up to 6.4 kW and 2.5, respectively. In addition, the electrical air conditioning system with R744 using an inverter driven compressor showed better performance than the conventional air conditioning system with R-134a under the same operating conditions. The observed cooling performance of the developed electrical air conditioning system was found to be sufficient for cooling loads under various real driving conditions for a fuel cell electric vehicle.

  3. Simulation research on carbon dioxide as cushion gas in gas underground reservoirs

    Institute of Scientific and Technical Information of China (English)

    TAN Yu-fei; LIN Tao

    2009-01-01

    Aimed at the problem of mixing working gas and cushion gas in carbon sequestration technology, the feasibility of using cation dioxide as the cushion gas in reservoirs is discussed firstly. At the usual condition of reservoirs, carbon dioxide is a kind of supercritieal fluid with high condensability, high viscosity and high density. Secondly, this article studies the laws of formation and development of mixing zone by numerical simulation and analyses the impact on mixing zone brought by different injection modes and rational ratios of cushion gas in reservoirs. It is proposed that the appropriate injection ratio of cushion gas is 20% - 30%. Using carbon dioxide as cushion gas in gas reservoirs is able to make the running of natural gas reservoirs economical and efficient.

  4. 49 CFR 571.208a - Optional test procedures for vehicles manufactured between January 27, 2004 and August 31, 2004.

    Science.gov (United States)

    2010-10-01

    ... plane” refers to a vertical plane parallel to the vehicle's longitudinal centerline. S16.3.1.5 The term “vertical plane” refers to a vertical plane, not necessarily parallel to the vehicle's longitudinal... part of the seat cushion. Measure perpendicular to the longitudinal centerline of the vehicle....

  5. 车内空气污染特点及改善措施%The Characters of air Pollution in Vehicles and Related Strategies for Improvement ,

    Institute of Scientific and Technical Information of China (English)

    夏建伟; 林忠平; 吴昌甫

    2012-01-01

    综述了我国目前汽车车内空气污染状况和各种污染物对人体健康的危害;通过对室内空气污染和车内空气污染对比,认为车内空气污染与室内空气污染的差异较大,应区别对待j根据汽车污染的特点,提出了适用于汽车的新风风量。通过对不同通风方式和过滤器效率车内污染物浓度的讨论,提出了改进的适合汽车的空调送风方案,即司机与乘客分开送风,根据车外污染浓度控制新风量、回风量。%The situation of air pollution in vehicles and the related health effects were reviewed. It is considered that the air pollution in vehicles be different from those indoors. The fresh air requirement applicable in vehicles is suggested based on the characteristics the air quality in vehicles. The relationship of the air pollutant concentration and ventilation modes and cabin air filters with different efficiency was analyzed. An optimized ventilation strategy was proposed, with different proportion of fresh air and return air to driver and passengers respectively according to the concentration of pollutants out of vehicle.

  6. Multi-Agent Management System (MAMS) for Air-Launched, Unmanned Vehicles Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The main goal of this work is to design, implement, and demonstrate a guidance and mission planning toolbox for air-launched, unmanned systems, such as guided...

  7. Method and system for estimating and predicting airflow around air vehicles

    KAUST Repository

    Claudel, Christian G.

    2015-12-31

    A method, system, and sensor for air flow sensing. The system can include a cantilever, a transducer, and a processing module. The method can include measuring beam deflections of one or more cantilevers, extracting information about air flow, and determining one or more of an airspeed, an angle of attack, and a sideslip, based on extracted information. The system and method can exploit nonlinearities in the behavior of the cantilever in fluid flow.

  8. Purwarupa Air Data, Attitude, dan Heading Reference System untuk Unmanned Aerial Vehicle

    OpenAIRE

    Manggala, Adrianus Prima; Sumiharto, Raden; Wibowo, Setyawan Bekti

    2012-01-01

    AbstrakADAHRS  (air data, attitude, and heading reference system )merupakan gabungan dari sensor air data (AD) dan sistem referensi attitude and heading (AHRS). Sistem ini memiliki peran penting dalam memberikan data parameter-parameter penerbangan yang akan digunakan oleh modul lain dalam UAV. Parameter penerbangan yssang dibaca oleh ADAHRS adalah sudut yaw, sudut pitch, sudut roll, serta data ketinggian, kecepatan, suhu, tekanan, dan koordinat GPS yang akan digunakan sebagai referensi dalam...

  9. Rigid-body kinematics versus flapping kinematics of a flapping wing micro air vehicle

    OpenAIRE

    Caetano, J.V.; Weehuizen, M.B.; De Visser, C.C.; De Croon, G.C.H.E.; de Mulder, M.

    2015-01-01

    Several formulations have been proposed to model the dynamics of ornithopters, with inconclusive results regarding the need for complex kinematic formulations. Furthermore, the impact of assumptions made in the collected results was never assessed by comparing simulations with real flight data. In this study two dynamic models of a Flapping Wing Micro Aerial Vehicle (FWMAV) were derived and compared: a) single rigid body aircraft equations of motion and b) Virtual Work Principle derivation fo...

  10. Net air emissions from electric vehicles: the effect of carbon price and charging strategies.

    Science.gov (United States)

    Peterson, Scott B; Whitacre, J F; Apt, Jay

    2011-03-01

    Plug-in hybrid electric vehicles (PHEVs) may become part of the transportation fleet on time scales of a decade or two. We calculate the electric grid load increase and emissions due to vehicle battery charging in PJM and NYISO with the current generation mix, the current mix with a $50/tonne CO(2) price, and this case but with existing coal generators retrofitted with 80% CO(2) capture. We also examine all new generation being natural gas or wind+gas. PHEV fleet percentages between 0.4 and 50% are examined. Vehicles with small (4 kWh) and large (16 kWh) batteries are modeled with driving patterns from the National Household Transportation Survey. Three charging strategies and three scenarios for future electric generation are considered. When compared to 2020 CAFE standards, net CO(2) emissions in New York are reduced by switching from gasoline to electricity; coal-heavy PJM shows somewhat smaller benefits unless coal units are fitted with CCS or replaced with lower CO(2) generation. NO(X) is reduced in both RTOs, but there is upward pressure on SO(2) emissions or allowance prices under a cap.

  11. An air launched, highly responsive military transatmospheric vehicle (TAV), based on existing aerospace systems

    Science.gov (United States)

    Hampsten, Kenneth R.

    1996-03-01

    A novel vehicle design is presented that minimizes Research Development Test and Evaluation (RDT&E) cost. The proposed TAV can satisfy a broad range of military mission applications for the 21st century. TAV deployment is provided by a Rockwell B-1B bomber. Pre-launch orientation of the vehicle is centerline, underneath the B-1B forward weapon bays. Launch occurs at 30,000 ft, Mach 0.90, and at a flight path angle of 15-20 degrees. The TAV is a Two-Stage-To-Orbit (TSTO) vehicle utilizing Liquid Oxygen (LOX) and RP-1 (kerosene) propellants. The reusable upper stage, or TAV, incorporates a 130 cubic foot payload bay for mission specific equipment. The booster can either be expended, or potentially recovered for reuse. TAV reentry relies on a biconic aeroshell for the hypersonic flight phase and a parafoil for the subsonic, terminal recovery phase. Nominal mission performance is between 1,150-1,800 lbs of payload into a 100 nmi circular orbit.

  12. Presentation of an innovative and efficient air conditioning system for electrical powered vehicles; Vorstellung eines innovativen und effizienten Klimasystems fuer elektrisch angetriebene Fahrzeuge

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, Oleg [IAV GmbH, Muenchen (Germany); Ackermann, Jan; Fang, Fang [IAV GmbH, Gifhorn (Germany)

    2012-11-01

    An air-conditioning system for battery electric vehicles requires an efficient approach to provide heat and cool during operation in winter and summer. The required energy expenditure to ensure comfort and safety is enormous especially during the winter. The heat input into the cabin amounts up to 10 kW and above when considering conventional vehicles with an internal combustion engine. In this context IAV is developing an efficient overall air conditioning system. The combination of new system components, such as surface heaters and a heat pump with improved components such as a PTC-heater, can solve the discrepancy between acceptable range and the aspects of comfort and safety. (orig.)

  13. Operational Modes and Capability Requirements for Cooperative Air Combat of Manned Vehicle and Unmanned Vehicle%有人/无人战斗机协同空战模式及能力需求分析

    Institute of Scientific and Technical Information of China (English)

    付昭旺; 寇英信; 于雷; 李战武

    2012-01-01

    针对未来空战的特点对有人/无人战斗机协同空战的作战模式及能力需求进行了研究.从信息链到武器链时空过渡的角度分析了有人/无人机协同空战的作战优势;提出了两种典型的有人/无人机协同空战方式,并给出了作战过程描述及功能结构分析;基于“观测-评估-决策-执行”指挥控制环分析了有人/无人机协同空战的指挥控制流程;基于协同空战的任务需求提出各参与平台的能力需求.此研究对有人/无人机协同空战的发展具有一定的指导意义.%Cooperative modes and capability requirements for cooperative air combat of manned vehicle and unmanned vehicle are proposed based on the characteristics of the future air combat. Firstly, the operational advantage of manned vehicle and unmanned vehicle cooperative air combat is deeply analyzed based on the information transformation style, then, two cooperative combat mode are proposed and the combat process and functional structure are analyzed separately. Third, the command and control problem is searched based on the Observe-Orient-Decide-Act command and control circle. At last the capability requirements for each platform of cooperative combat system are analyzed. This research will be certain significance for the development of cooperative air combat of manned vehicle and unmanned vehicle.

  14. Development of a vehicle emission inventory with high temporal-spatial resolution based on NRT traffic data and its impact on air pollution in Beijing - Part 1: Development and evaluation of vehicle emission inventory

    Science.gov (United States)

    Jing, Boyu; Wu, Lin; Mao, Hongjun; Gong, Sunning; He, Jianjun; Zou, Chao; Song, Guohua; Li, Xiaoyu; Wu, Zhong

    2016-03-01

    This paper presents a bottom-up methodology based on the local emission factors, complemented with the widely used emission factors of Computer Programme to Calculate Emissions from Road Transport (COPERT) model and near-real-time traffic data on road segments to develop a vehicle emission inventory with high temporal-spatial resolution (HTSVE) for the Beijing urban area. To simulate real-world vehicle emissions accurately, the road has been divided into segments according to the driving cycle (traffic speed) on this road segment. The results show that the vehicle emissions of NOx, CO, HC and PM were 10.54 × 104, 42.51 × 104 and 2.13 × 104 and 0.41 × 104 Mg respectively. The vehicle emissions and fuel consumption estimated by the model were compared with the China Vehicle Emission Control Annual Report and fuel sales thereafter. The grid-based emissions were also compared with the vehicular emission inventory developed by the macro-scale approach. This method indicates that the bottom-up approach better estimates the levels and spatial distribution of vehicle emissions than the macro-scale method, which relies on more information. Based on the results of this study, improved air quality simulation and the contribution of vehicle emissions to ambient pollutant concentration in Beijing have been investigated in a companion paper (He et al., 2016).

  15. The Development Status and Key Technologies of Solar Powered Unmanned Air Vehicle

    Science.gov (United States)

    Sai, Li; Wei, Zhou; Xueren, Wang

    2017-03-01

    By analyzing the development status of several typical solar powered unmanned aerial vehicles (UAV) at home and abroad, the key technologies involved in the design and manufacture of solar powered UAV and the technical difficulties need to be solved at present are obtained. It is pointed out that with the improvement of energy system efficiency, advanced aerodynamic configuration design, realization of high applicability flight stability and control system, breakthrough of efficient propulsion system, the application prospect of solar powered UAV will be more extensive.

  16. Experimental analysis of artificial dragonfly wings using black graphite and fiberglass for use in Biomimetic Micro Air Vehicles (BMAVs

    Directory of Open Access Journals (Sweden)

    Nair Praveena

    2015-01-01

    Full Text Available This article examines the suitability of two different materials which are black graphite carbon fiber and red pre-impregnated fiberglass from which to fabricate artificial dragonfly wing frames. These wings could be of use in Biomimetic Micro Aerial Vehicles (BMAV. BMAV are a new class of unmanned micro-sized air vehicles that mimic flying biological organisms. Insects, such as dragonflies, possess corrugated and complex vein structures that are difficult to mimic. Simplified dragonfly wing frames were fabricated from these materials and then a nano-composite film was adhered to them, which mimics the membrane of an actual dragonfly. Experimental analysis of these results showed that although black graphite carbon fiber and red pre-impregnated fiberglass offer some structural advantages, red pre-impregnated fiberglass was a less preferred option due to its warpage and shrinking effects. Black graphite carbon fiber with its high load bearing capability is a more suitable choice for consideration in future BMAV applications.

  17. A systematic review of the recent ecological literature on cushion plants: champions of plant facilitation

    Directory of Open Access Journals (Sweden)

    A. M. Reid

    2010-09-01

    Full Text Available Cushion-forming plant species are found in alpine and polar environments around the world. They modify the microclimate, thereby facilitating other plant species. Similar to the effectiveness of shrubs as a means to study facilitation in arid and semi-arid environments, we explore the potential for cushion plant species to expand the generality of research on this contemporary ecological interaction. A systematic review was conducted to determine the number of publications and citation frequency on relevant ecological topics whilst using shrub literature as a baseline to assess relative importance of cushions as a focal point for future ecological research. Although there are forty times more shrub articles, mean citations per paper is comparable between cushion and shrub literature. Furthermore, the scope of ecological research topics studied using cushions is broad including facilitation, competition, environmental gradients, life history, genetics, reproduction, community, ecosystem and evolution. The preliminary ecological evidence to date also strongly suggests that cushion plants can be keystone species in their ecosystems. Hence, ecological research on net interactions including facilitation and patterns of diversity can be successfully examined using cushion plants, and this is particularly timely given expectations associated with a changing climate in these regions.

  18. BMP-2 induces versican and hyaluronan that contribute to post-EMT AV cushion cell migration.

    Directory of Open Access Journals (Sweden)

    Kei Inai

    Full Text Available Distal outgrowth and maturation of mesenchymalized endocardial cushions are critical morphogenetic events during post-EMT atrioventricular (AV valvuloseptal morphogenesis. We explored the role of BMP-2 in the regulation of valvulogenic extracellular matrix (ECM components, versican and hyaluronan (HA, and cell migration during post-EMT AV cushion distal outgrowth/expansion. We observed intense staining of versican and HA in AV cushion mesenchyme from the early cushion expansion stage, Hamburger and Hamilton (HH stage-17 to the cushion maturation stage, HH stage-29 in the chick. Based on this expression pattern we examined the role of BMP-2 in regulating versican and HA using 3D AV cushion mesenchymal cell (CMC aggregate cultures on hydrated collagen gels. BMP-2 induced versican expression and HA deposition as well as mRNA expression of versican and Has2 by CMCs in a dose dependent manner. Noggin, an antagonist of BMP, abolished BMP-2-induced versican and HA as well as mRNA expression of versican and Has2. We further examined whether BMP-2-promoted cell migration was associated with expression of versican and HA. BMP-2- promoted cell migration was significantly impaired by treatments with versican siRNA and HA oligomer. In conclusion, we provide evidence that BMP-2 induces expression of versican and HA by AV CMCs and that these ECM components contribute to BMP-2-induced CMC migration, indicating critical roles for BMP-2 in distal outgrowth/expansion of mesenchymalized AV cushions.

  19. A Common Communications, Navigation and Surveillance Infrastructure for Accommodating Space Vehicles in the Next Generation Air Transportation System

    Science.gov (United States)

    VanSuetendael, RIchard; Hayes, Alan; Birr, Richard

    2008-01-01

    Suborbital space flight and space tourism are new potential markets that could significantly impact the National Airspace System (NAS). Numerous private companies are developing space flight capabilities to capture a piece of an emerging commercial space transportation market. These entrepreneurs share a common vision that sees commercial space flight as a profitable venture. Additionally, U.S. space exploration policy and national defense will impose significant additional demands on the NAS. Air traffic service providers must allow all users fair access to limited airspace, while ensuring that the highest levels of safety, security, and efficiency are maintained. The FAA's Next Generation Air Transportation System (NextGen) will need to accommodate spacecraft transitioning to and from space through the NAS. To accomplish this, space and air traffic operations will need to be seamlessly integrated under some common communications, navigation and surveillance (CNS) infrastructure. As part of NextGen, the FAA has been developing the Automatic Dependent Surveillance Broadcast (ADS-B) which utilizes the Global Positioning System (GPS) to track and separate aircraft. Another key component of NextGen, System-Wide Information Management/ Network Enabled Operations (SWIM/NEO), is an open architecture network that will provide NAS data to various customers, system tools and applications. NASA and DoD are currently developing a space-based range (SBR) concept that also utilizes GPS, communications satellites and other CNS assets. The future SBR will have very similar utility for space operations as ADS-B and SWIM has for air traffic. Perhaps the FAA, NASA, and DoD should consider developing a common space-based CNS infrastructure to support both aviation and space transportation operations. This paper suggests specific areas of research for developing a CNS infrastructure that can accommodate spacecraft and other new types of vehicles as an integrated part of NextGen.

  20. Conceptual Design Tool to Analyze Electrochemically-Powered Micro Air Vehicles

    Science.gov (United States)

    2011-03-01

    battery chemistries include the lithium thionyl chloride battery (Li/SOCl2), the zinc-air... battery , and the lithium -ion polymer battery . Compared to other lithium anode batteries , a lithium thionyl chloride system has the highest energy...40Staniewicz, R.J., “ Lithium Thionyl Chloride Cells and Batteries Technical Predictions Versus 1994 Realities,” Journal of Power Sources, Vol. 54,

  1. Computational Sensitivity Analysis for the Aerodynamic Design of Supersonic and Hypersonic Air Vehicles

    Science.gov (United States)

    2015-05-18

    USNA-1531-2 This document has been approved for public release and sale ; its distribution is limited. U.S.N.A. --- Trident...towards meaningful results. 3 Contents Nomenclature ...46 4 Nomenclature AFRL Air Force Research Laboratory a∞ Freestream speed of sound, a RT b Wing span c

  2. An audit of cushioned diabetic footwear: relation to patient compliance.

    Science.gov (United States)

    Chantelau, E; Haage, P

    1994-01-01

    The recurrence rate of neuropathic foot ulcers is reported in 51 diabetic patients regularly attending a diabetic foot clinic. All of the patients were provided with protective footwear reducing peak plantar pressure at the forefoot area by 50% (versus normal shoes), and were followed up for up to 4 years. Compliance with this footwear was recorded by assessing the daily time of wearing protective or normal shoes, and compliance with foot care was recorded from the entries in the patients charts. The results of this observational study demonstrate that wearing protective shoes for > 60% of the daytime significantly (p = 0.0002) reduced the ulcer relapse rate by > 50% in comparison with shorter wearing times for these shoes. In addition, patients without ulcer relapses had foot care significantly more frequently than patients with relapse (p < 0.05). It is concluded that cushioned protective footwear in association with frequent foot care is essential in the prevention of neuropathic diabetic foot ulcer recurrence.

  3. Study of distribution and characteristics of the time average of pressure of a water cushion pool

    Science.gov (United States)

    Guo, Y. H.; Fu, J. F.

    2016-08-01

    When a dam discharges flood water, the plunging flow with greater kinetic energy, will scour the riverbed, resulting in erosion damage. In order to improve the anti-erosion capacity of a riverbed, the cushion pool created. This paper is based on turbulent jet theoryto deduce the semi-empirical formula of the time average of pressure in the impinging portion of the cushion pool. Additionally, MATLAB numerical is used to conduct a simulation analysis according to turbulent jet energy and watercushion depth when water floods into the water cushion pool, to determine the regularities of distribution and related characteristics.

  4. Control of air pollution from new motor vehicles and new motor vehicle engines. Federal certification test results for 1993 model year

    Energy Technology Data Exchange (ETDEWEB)

    1993-01-01

    The regulations that apply to the control of emissions from vehicles and engines, appearing in 40 CFR Part 86, set maximum allowable limits on exhaust and evaporative emission levels. The exhaust limits are applicable to gasoline-fueled and diesel light-duty vehicles (passenger cars), light-duty trucks, and heavy-duty engines, and to gasoline-fueled motorcycles. The evaporative limits are applicable to gasoline-fueled light-duty vehicles, light-duty trucks, and heavy-duty vehicles. The report contains all of the individual tests that were required by the certification procedures.

  5. Energy-Based Design of Reconfigurable Micro Air Vehicle (MAV) Flight Structures

    Science.gov (United States)

    2014-02-01

    wingspan, taper ratio, and sweep angle are free to vary independently of each other. Clearly, a wing capable of telescoping , chord extension, and...that can substantially change shape to adapt to changing mission environments. Morphing wings with planform capabilities of telescoping , chord...This report was cleared for public release by the USAF 88th Air Base Wing (88 ABW) Public Affairs Office (PAO) and is available to the general

  6. Passivity-Based Control for a Micro Air Vehicle Using Unit Quaternions

    Directory of Open Access Journals (Sweden)

    Maria Eusebia Guerrero-Sanchez

    2016-12-01

    Full Text Available In this paper the development and practical implementation of a Passivity-Based Control (PBC algorithm to stabilize an Unmanned Aerial Vehicle (UAV described with unit quaternions are presented. First, a mathematical model based on Euler-Lagrange formulation using a logarithmic mapping in the quaternion space is introduced. Then, a new methodology: a quaternion-passivity-based control is derived, which does not compute excessive and complex Partial Differential Equations (PDEs for synthesizing the control law, making a significant advantage in comparison with other methodologies. Therefore, the control design to a system as the quad-rotor is easily solved by the proposed methodology. Another advantage is the possibility to stabilize quad-rotor full dynamics which may not be possible with classical PBC techniques. Experimental results and numerical simulations to validate our proposed scheme are presented.

  7. a Vibrational Model of Open Celled Polyurethane Foam Automotive Seat Cushions

    Science.gov (United States)

    Patten, W. N.; Sha, S.; Mo, C.

    1998-10-01

    A mechanistic model of a seat cushion is developed. The work relates the kinematic motion of the seat to the geometric and constitutive properties of the cellular foam used in the seat. The model includes the influence of pneumatic damping caused by friction between the gas within the open-celled foam and matrix polymer. A continuous shape function is introduced to characterize the piecewise continuous stress-strain characteristic of flexible open-celled foam. After some simplification, a non-linear dynamic automotive seat cushion model is derived, which relies explicitly on the constitutive properties of polyurethane foams and on the geometry of the seat cushion. Experimental and analytical models of the two automotive seats are compared to verify the model. The comparisons indicate that the new model is able to predict the dynamic performance of an automotive seat cushion with fidelity.

  8. Inertial attitude control of a bat-like morphing-wing air vehicle.

    Science.gov (United States)

    Colorado, J; Barrientos, A; Rossi, C; Parra, C

    2013-03-01

    This paper presents a novel bat-like unmanned aerial vehicle inspired by the morphing-wing mechanism of bats. The goal of this paper is twofold. Firstly, a modelling framework is introduced for analysing how the robot should manoeuvre by means of changing wing morphology. This allows the definition of requirements for achieving forward and turning flight according to the kinematics of the wing modulation. Secondly, an attitude controller named backstepping+DAF is proposed. Motivated by biological evidence about the influence of wing inertia on the production of body accelerations, the attitude control law incorporates wing inertia information to produce desired roll (ϕ) and pitch (θ) acceleration commands (desired angular acceleration function (DAF)). This novel control approach is aimed at incrementing net body forces (F(net)) that generate propulsion. Simulations and wind-tunnel experimental results have shown an increase of about 23% in net body force production during the wingbeat cycle when the wings are modulated using the DAF as a part of the backstepping control law. Results also confirm accurate attitude tracking in spite of high external disturbances generated by aerodynamic loads at airspeeds up to 5 ms⁻¹.

  9. A multimodal micro air vehicle for autonomous flight in near-earth environments

    Science.gov (United States)

    Green, William Edward

    Reconnaissance, surveillance, and search-and-rescue missions in near-Earth environments such as caves, forests, and urban areas pose many new challenges to command and control (C2) teams. Of great significance is how to acquire situational awareness when access to the scene is blocked by enemy fire, rubble, or other occlusions. Small bird-sized aerial robots are expendable and can fly over obstacles and through small openings to assist in the acquisition and distribution of intelligence. However, limited flying space and densely populated obstacle fields requires a vehicle that is capable of hovering, but also maneuverable. A secondary flight mode was incorporated into a fixed-wing aircraft to preserve its maneuverability while adding the capability of hovering. An inertial measurement sensor and onboard flight control system were interfaced and used to transition the hybrid prototype from cruise to hover flight and sustain a hover autonomously. Furthermore, the hovering flight mode can be used to maneuver the aircraft through small openings such as doorways. An ultrasonic and infrared sensor suite was designed to follow exterior building walls until an ingress route was detected. Reactive control was then used to traverse the doorway and gather reconnaissance. Entering a dangerous environment to gather intelligence autonomously will provide an invaluable resource to any C2 team. The holistic approach of platform development, sensor suite design, and control serves as the philosophy of this work.

  10. Assessment of Charging Infrastructure for Plug-in Electric Vehicles at Naval Air Station Whidbey Island: Task 3

    Energy Technology Data Exchange (ETDEWEB)

    Schey, Steve [Idaho National Lab. (INL), Idaho Falls, ID (United States); Francfort, Jim [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-07-01

    Several U.S. Department of Defense base studies have been conducted to identify potential U.S. Department of Defense transportation systems that are strong candidates for introduction or expansion of plug-in electric vehicles (PEVs). Task 1 consisted of a survey of the non-tactical fleet of vehicles at NASWI to begin the review of vehicle mission assignments and types of vehicles in service. Task 2 selected vehicles for further monitoring and involved identifying daily operational characteristics of these select vehicles. Data logging of vehicle movements was initiated in order to characterize the vehicle’s mission. The Task 3 Vehicle Utilization report provided the results of the data analysis and observations related to the replacement of current vehicles with PEVs. This report provides an assessment of charging infrastructure required to support the suggested PEV replacements.

  11. Air-fuel ratio and speed control for low emission vehicles based on sliding mode techniques

    Energy Technology Data Exchange (ETDEWEB)

    Puleston, P.F. [UNLP, La Plata (Argentina). Departamento de Electrotecnia, CONICET and LEICI; Monsees, G. [Delft University of Technology (Netherlands). Faculty of Information, Technology and Systems, Control Laboratory; Spurgeon, S.K. [University of Leicester (United Kingdom). Department of Engineering, Control and Instrumentation Group

    2002-05-01

    This paper deals with the combined air-fuel ratio (AFR) and speed control of automotive engines. The robust controller is developed using dynamic sliding mode (SM) control design methods. The proposed controller set-up is tested under realistic operating conditions by means of computer simulation using a comprehensive non-linear model of a four-stroke engine, specifically provided by the automotive industry for these purposes. This accurate industrial model comprises extensive dynamics description and numerous look-up tables representing parameter characteristics obtained from experimental data. The SM controller set-up proves to be robust to model uncertainties and unknown disturbances, regulating effectively the engine speed for a wide range of set-points while maintaining the AFR at the stoichiometric value. (author)

  12. Design, fabrication, and characterization of multifunctional wings to harvest solar energy in flapping wing air vehicles

    Science.gov (United States)

    Perez-Rosado, Ariel; Gehlhar, Rachel D.; Nolen, Savannah; Gupta, Satyandra K.; Bruck, Hugh A.

    2015-06-01

    Currently, flapping wing unmanned aerial vehicles (a.k.a., ornithopters or robotic birds) sustain very short duration flight due to limited on-board energy storage capacity. Therefore, energy harvesting elements, such as flexible solar cells, need to be used as materials in critical components, such as wing structures, to increase operational performance. In this paper, we describe a layered fabrication method that was developed for realizing multifunctional composite wings for a unique robotic bird we developed, known as Robo Raven, by creating compliant wing structure from flexible solar cells. The deformed wing shape and aerodynamic lift/thrust loads were characterized throughout the flapping cycle to understand wing mechanics. A multifunctional performance analysis was developed to understand how integration of solar cells into the wings influences flight performance under two different operating conditions: (1) directly powering wings to increase operation time, and (2) recharging batteries to eliminate need for external charging sources. The experimental data is then used in the analysis to identify a performance index for assessing benefits of multifunctional compliant wing structures. The resulting platform, Robo Raven III, was the first demonstration of a robotic bird that flew using energy harvested from solar cells. We developed three different versions of the wing design to validate the multifunctional performance analysis. It was also determined that residual thrust correlated to shear deformation of the wing induced by torsional twist, while biaxial strain related to change in aerodynamic shape correlated to lift. It was also found that shear deformation of the solar cells induced changes in power output directly correlating to thrust generation associated with torsional deformation. Thus, it was determined that multifunctional solar cell wings may be capable of three functions: (1) lightweight and flexible structure to generate aerodynamic forces, (2

  13. An Improved Evolvable Oscillator and Basis Function Set for Control of an Insect-Scale Flapping-Wing Micro Air Vehicle

    Institute of Scientific and Technical Information of China (English)

    John C.Gallagher; Michael W.Oppenheimer

    2012-01-01

    This paper introduces an improved evolvable and adaptive hardware oscillator design capable of supporting adaptation intended to restore control precision in damaged or imperfectly manufactured insect-scale flapping-wing micro air vehicles.It will also present preliminary experimental results demonstrating that previously used basis function sets may have been too large and that significantly improved learning times may be achieved by judiciously culling the oscillator search space.The paper will conclude with a discussion of the application of this adaptive,evolvable oscillator to full vehicle control as well as the consideration of longer term goals and requirements.

  14. Interior heating of hybrid electric-powered vehicles. Requirement on the air conditioning of vehicles; Fahrzeug-Innenraumheizung von Hybrid- und Elektrofahrzeugen. Anforderungen an die Fahrzeugklimatisierung

    Energy Technology Data Exchange (ETDEWEB)

    Wawzyniak, Markus [Behr GmbH and Co. KG, Stuttgart (Germany)

    2011-08-15

    From the electrification of a powertrain new demands on the climate result as the energy demand of the climate system (cooling and heating) directly impacts vehicle range. The climate comfort and driving safety must not fall.

  15. Using thermal infrared imagery produced by unmanned air vehicles to evaluate locations of ecological road structures

    Directory of Open Access Journals (Sweden)

    Sercan Gülci

    2016-07-01

    Full Text Available The aerial photos and satellite images are widely used and cost efficient data for monitoring and analysis of large areas in forestry activities. Nowadays, accurate and high resolution remote sensing data can be generated for large areas by using Unmanned Aerial Vehicles (UAV integrated with sensors working in various spectral bands. Besides, the UAV systems (UAVs have been used in interdisciplinary studies to produce data of large scale forested areas for desired time periods (i.e. in different seasons or different times of a day. In recent years, it has become more important to conduct studies on determination of wildlife corridors for controlling and planning of habitat fragmentation of wild animals that need vast living areas. The wildlife corridors are a very important base for the determination of a road network planning and placement of ecological road structures (passages, as well as for the assessment of special and sensitive areas such as riparian zones within the forest. It is possible to evaluate wildlife corridors for large areas within a shorter time by using data produced by ground measurements, and remote sensing and viewer systems (i.e. photo-trap, radar and etc., as well as by using remote sensing data generated by UAVs. Ecological behaviors and activities (i.e. sheltering, feeding, mating, etc. of wild animals vary spatially and temporally. Some species are active in their habitats at day time, while some species are active during the night time. One of the most effective methods for evaluation of night time animals is utilizing heat sensitive thermal cameras that can be used to collect thermal infrared images with the night vision feature. When the weather conditions are suitable for a flight, UAVs assist for determining location of corridors effectively and accurately for moving wild animals at any time of the day. Then, the most suitable locations for ecological road structures can be determined based on wildlife corridor

  16. Effects on Air Pollution and Regional Climate of Producing and Using Hydrogen in Fuel Cells in all U.S. OnroadVehicles

    Science.gov (United States)

    Jacobson, M. Z.; Colella, W. G.; Golden, D. M.

    2004-12-01

    The purpose of this study was to examine the potential effects on U.S. air pollution and regional climate of switching the current U.S. fleet of onroad motor vehicles to hydrogen fuel-cell vehicles, where hydrogen was produced by (1) steam-reforming of methane, (2) wind energy, or (3) coal gasification. An additional scenario in which the U.S. fleet was switched to gasoline-electric hybrid vehicles was also examined. The model used was GATOR-GCMOM, a global-through-urban-scale nested and parallelized gas, aerosol, transport, radiation, general-circulation, mesoscale, and ocean model. U.S. emission data for the baseline case were obtained from the U.S. National Emission Inventory, which considers 370,000 stack and fugitive sources, 250,000 area sources, and 1700 categories of onroad and nonroad vehicular sources (including motorcycles, passenger vehicles, trucks, recreational vehicles, construction vehicles, farm vehicles, industrial vehicles, etc.). Emission inventories for each of the three hydrogen scenarios were prepared following a process chain analysis that accounted for energy inputs and pollution outputs during all stages of hydrogen and fossil-fuel production, distribution, storage, and end-use. Emitted pollutants accounted for included CO, CO2, H2, H2O, CH4, speciated ROGs, NOx, NH3, SOx, and speciated particulate matter. Results from the first scenario suggest that switching vehicles in the U.S. to hydrogen produced by steam-reforming of methane may reduce emission of NOx, reactive hydrocarbons, CO, CO2, BC, NO3-, and NH4+, but increase CH4, H2, and SO2 (slightly).The switch may also decrease O3 over most of the U.S. but short-term near-surfaces increases may occur over low-vegetated cities (e.g., in Los Angeles and along the Boston-Washington corridor) due to loss of NOx that otherwise titrates O3. The switch is also estimated to decrease PAN, HCHO, and several other pollutants formed in the atmosphere. Isoprene may increase since fewer oxidants (OH, O3

  17. Non-fragile switching tracking control for a flexible air-breathing hypersonic vehicle based on polytopic LPV model

    Institute of Scientific and Technical Information of China (English)

    Huang Yiqing; Sun Changyin; Qian Chengshan; Wang Li

    2013-01-01

    This article proposes a linear parameter varying (LPV) switching tracking control scheme for a flexible air-breathing hypersonic vehicle (FAHV).First,a polytopic LPV model is constructed to represent the complex nonlinear longitudinal model of the FAHV by using Jacobian linearization and tensor-product (T-P) model transformation approach.Second,for less conservative controller design purpose,the flight envelope is divided into four sub-regions and a non-fragile LPV controller is designed for each parameter sub-region.These non-fragile LPV controllers are then switched in order to guarantee the closed-loop FAHV system to be asymptotically stable and satisfy a specified performance criterion.The desired non-fragile LPV switching controller is found by solving a convex constraint problem which can be efficiently solved using available linear matrix inequality (LMI) techniques,and robust stability analysis of the closed-loop FAHV system is verified based on multiple Lypapunov functions (MLFs).Finally,numerical simulations have demonstrated the effectiveness of the proposed approach.

  18. SIG: Multiple Views on Safety-Critical Automation: Aircraft, Autonomous Vehicles, Air Traffic Management and Satellite Ground Segments Perspectives

    Science.gov (United States)

    Feary, Michael; Palanque, Philippe; Martinie, Célia; Tscheligi, Manfred

    2016-01-01

    This SIG focuses on the engineering of automation in interactive critical systems. Automation has already been studied in a number of (sub-) disciplines and application fields: design, human factors, psychology, (software) engineering, aviation, health care, games. One distinguishing feature of the area we are focusing on is that in the field of interactive critical systems properties such as reliability, dependability, fault tolerance are as important as usability, user experience or overall acceptance issues. The SIG targets at two problem areas: first the engineering of the user interaction with (partly-) autonomous systems: how to design, build and assess autonomous behavior, especially in cases where there is a need to represent on the user interface both autonomous and interactive objects. An example of such integration is the representation of an unmanned aerial vehicle (UAV) (where no direct interaction is possible), together with aircrafts (that have to be instructed by an air traffic controller to avoid the UAV). Second the design and engineering of user interaction in general for autonomous objects/systems (for example a cruise control in a car or an autopilot in an aircraft). The goal of the SIG is to raise interest in the CHI community on the general aspects of automation and to identify a community of researchers and practitioners interested in those increasingly prominent issues of interfaces towards (semi)-autonomous systems. The expected audience should be interested in addressing the issues of integration of mainly unconnected research domains to formulate a new joint research agenda.

  19. Multiple Views on Safety-Critical Automation: Aircraft, Autonomous Vehicles, Air Traffic Management and Satellite Ground Segments Perspectives

    Science.gov (United States)

    Feary, Michael S.; Palanque, Philippe Andre Rolan; Martinie, De Almeida; Tscheligi, Manfred

    2016-01-01

    This SIG focuses on the engineering of automation in interactive critical systems. Automation has already been studied in a number of (sub-) disciplines and application fields: design, human factors, psychology, (software) engineering, aviation, health care, games. One distinguishing feature of the area we are focusing on is that in the field of interactive critical systems properties such as reliability, dependability, fault-tolerance are as important as usability, user experience or overall acceptance issues. The SIG targets at two problem areas: first the engineering of the user interaction with (partly-) autonomous systems: how to design, build and assess autonomous behavior, especially in cases where there is a need to represent on the user interface both autonomous and interactive objects. An example of such integration is the representation of an unmanned aerial vehicle (UAV) (where no direct interaction is possible), together with aircrafts (that have to be instructed by an air traffic controller to avoid the UAV). Second the design and engineering of user interaction in general for autonomous objects systems (for example a cruise control in a car or an autopilot in an aircraft). The goal of the SIG is to raise interest in the CHI community on the general aspects of automation and to identify a community of researchers and practitioners interested in those increasingly prominent issues of interfaces towards (semi)-autonomous systems. The expected audience should be interested in addressing the issues of integration of mainly unconnected research domains to formulate a new joint research agenda.

  20. Plume aerodynamic effects of cushion engine in lunar landing

    Institute of Scientific and Technical Information of China (English)

    He Bijiao; He Xiaoying; Zhang Mingxing; Cai Guobiao

    2013-01-01

    During the second period of China “Tanyue” Project,the explorer will softland on the moon.The cushion engines are used to decelerate the explorer and reduce the impact on the lunar ground.It is necessary to study its plume effects on the explorer component.The self-developed PWS (Plume WorkStation) software based on direct simulation Monte Carlo (DSMC) method is used to simulate the plume effects of two 150 N engines.Due to the complex structure of the explorer,PWS uses a decoupling method to treat the boundary mesh,which mainly interacts with simulation particles,and has no relation with the computational grids.After the analytical expressions of plane surfaces and curved surfaces of each boundary block are given,the particle position within or without the boundary blocks can be easily determined.Finally the 3D plume field of two 150 N engines is simulated.The pressure,temperature and velocity distributions of plume field are clearly presented by three characteristic slices.The aerodynamic effects on the explorer bottom,the landfall legs and antenna are separately shown.The compression influence on the plume flow of four landfall legs can be observed.

  1. The best for the guest: high Andean nurse cushions of Azorella madreporica enhance arbuscular mycorrhizal status in associated plant species.

    Science.gov (United States)

    Casanova-Katny, M Angélica; Torres-Mellado, Gustavo Adolfo; Palfner, Goetz; Cavieres, Lohengrin A

    2011-10-01

    Positive interactions between cushion plant and associated plants species in the high Andes of central Chile should also include the effects of fungal root symbionts. We hypothesized that higher colonization by arbuscular mycorrhizal (AM) fungi exists in cushion-associated (nursling) plants compared with conspecific individuals growing on bare ground. We assessed the AM status of Andean plants at two sites at different altitudes (3,200 and 3,600 ma.s.l.) in 23 species, particularly in cushions of Azorella madreporica and five associated plants; additionally, AM fungal spores were retrieved from soil outside and beneath cushions. 18 of the 23 examined plant species presented diagnostic structures of arbuscular mycorrhiza; most of them were also colonized by dark-septate endophytes. Mycorrhization of A. madreporica cushions showed differences between both sites (68% and 32%, respectively). In the native species Hordeum comosum, Nastanthus agglomeratus, and Phacelia secunda associated to A. madreporica, mycorrhization was six times higher than in the same species growing dispersed on bare ground at 3,600 ma.s.l., but mycorrhiza development was less cushion dependent in the alien plants Cerastium arvense and Taraxacum officinale at both sites. The ratio of AM fungal spores beneath versus outside cushions was also 6:1. The common and abundant presence of AM in cushion communities at high altitudes emphasizes the importance of the fungal root symbionts in such situations where plant species benefit from the microclimatic conditions generated by the cushion and also from well-developed mycorrhizal networks.

  2. Theoretical and experimental validation study on automotive air-conditioning based on heat pipe and LNG cold energy for LNG-fueled heavy vehicles

    Science.gov (United States)

    Deng, Dong; Cheng, Jiang-ping; Zhang, Sheng-chang; Ge, Fang-gen

    2017-03-01

    As a clean fuel, LNG has been used in heavy vehicles widely in China. Before reaching the engine for combustion, LNG store in a high vacuum multi-layer thermal insulation tank and need to be evaporated from its cryogenic state to natural gas. During the evaporation, the available cold energy of LNG has been calculated. The concept has been proposed that the separated type heat pipe technology is employed to utilize the available cold energy for automotive air-conditioning. The experiment has been conducted to validate the proposal. It is found that it is feasible to use the separated type heat pipe to convey the cold energy from LNG to automotive air-conditioning. And the cooling capacity of the automotive air-conditioning increase with the LNG consumption and air flow rate increasing.

  3. Numerical analysis of air flow past the 2415-3S airfoil for an unmanned aerial vehicle with internal propulsion system

    OpenAIRE

    Velázquez-Araque, L.; Mendoza Perez, Luis Daniel; Casanova Kindelán, Jesús; Nozicka, J.

    2013-01-01

    This paper deals with the prediction of pressure and velocity fields on the 2415-3S airfoil which will be used for and unmanned aerial vehicle with internal propulsion system and in this way analyze the air flow through an internal duct of the airfoil using computational fluid dynamics. The main objective is to evaluate the effect of the internal air flow past the airfoil and how this affects the aerodynamic performance by means of lift and drag forces. For this purpose, three different desig...

  4. Analysis of Air Flow Past and through the 2415-3S Airfoil for an Unmanned Aerial Vehicle with Internal Propulsion System

    OpenAIRE

    Luis D. Mendoza; Jiří Nožička

    2014-01-01

    This paper deals with the prediction of velocity fields on the 2415-3S airfoil which will be used for an unmanned aerial vehicle with internal propulsion system and in this way analyze the air flow through an internal duct of the airfoil using computational fluid dynamics. The main objective is to evaluate the effect of the internal air flow past the airfoil and how this affects the aerodynamic performance by means of lift and drag forces. For this purpose, three different designs of the inte...

  5. Analysis of air flow past and through the 2415-3S airfoil for an unmanned aerial vehicle with internal propulsion system

    OpenAIRE

    Velázquez-Araque, L.; Mendoza Pérez, Luis Daniel; J. Nožička

    2014-01-01

    This paper deals with the prediction of velocity fields on the 2415-3S airfoil which will be used for an unmanned aerial vehicle with internal propulsion system and in this way analyze the air flow through an internal duct of the airfoil using computational fluid dynamics. The main objective is to evaluate the effect of the internal air flow past the airfoil and how this affects the aerodynamic performance by means of lift and drag forces. For this purpose, three different designs of the inte...

  6. Development status of zinc air power battery for electric vehicles%汽车用锌空气动力电池研究现状

    Institute of Scientific and Technical Information of China (English)

    景义军; 郭际; 孟宪玲; 武彩霞

    2011-01-01

    锌空气电池具有高比能量、低成本、无污染、不燃爆、可循环利用等优势,适宜用作城市电动汽车的动力电源.目前国内外电动汽车用锌空气动力电池主要采用机械充电式锌空气电池和锌膏循环式锌空气电池两种结构,这两种结构都是通过更换锌负极使电池连续工作.论述了锌空气动力电池还需要解决一些问题,并分析了其发展前景.%Zinc air battery can be an alternative power source for urban electric vehicles due to its high specific energy, low cost, non-pollution, non-explosion and recycle. Now, zinc air battery structures for electric vehicles mainly include mechanically rechargeable zinc air battery and zinc air battery with zinc slurry cycle system. The batteries with both structures continuously work by replacing the discharged zinc electrode with the new zinc electrode or the zinc slurry. The problems of zinc air power battery needed to be solved further were discussed, and its development prospect was analyzed.

  7. Life-cycle assessment of greenhouse gas and air emissions of electric vehicles: A comparison between China and the U.S.

    Science.gov (United States)

    Huo, Hong; Cai, Hao; Zhang, Qiang; Liu, Fei; He, Kebin

    2015-05-01

    We evaluated the fuel-cycle emissions of greenhouse gases (GHGs) and air pollutants (NOx, SO2, PM10, and PM2.5) of electric vehicles (EVs) in China and the United States (U.S.), two of the largest potential markets for EVs in the world. Six of the most economically developed and populated regions in China and the U.S. were selected. The results showed that EV fuel-cycle emissions depend substantially on the carbon intensity and cleanness of the electricity mix, and vary significantly across the regions studied. In those regions with a low share of coal-based electricity (e.g., California), EVs can reduce GHG and air pollutant emissions (except for PM) significantly compared with conventional vehicles. However, in the Chinese regions and selected U.S. Midwestern states where coal dominates in the generation mix, EVs can reduce GHG emissions but increase the total and urban emissions of air pollutants. In 2025, EVs will offer greater reductions in GHG and air pollutant emissions because emissions from power plants will be better controlled; EVs in the Chinese regions examined, however, may still increase SO2 and PM emissions. Reductions of 60-85% in GHGs and air pollutants could be achieved were EVs charged with 80% renewable electricity or the electricity generated from the best available technologies of coal-fired power plants, which are futuristic power generation scenarios.

  8. Endocardial cushion defect associated with cor triatriatum sinistrum or supravalve mitral ring.

    Science.gov (United States)

    Thilenius, O G; Vitullo, D; Bharati, S; Luken, J; Lamberti, J J; Tatooles, C; Lev, M; Carr, I; Arcilla, R A

    1979-12-01

    Clinical and angiographic or autopsy data, or both, on three children with a subdivided left atrium (cor triatriatum) and an associated endocardial cushion defect are reviewed. (One child had ostium primum defect, and two had complete atrioventricular [A-V] canal.) A fourth patient demonstrates the difficulties in differentiating subdivided left atrium from supravalve mitral stenosis in the presence of an endocardial cushion defect. The clinical findings are greatly influenced by the endocardial cushion defect. A pressure gradient between the pulmonary wedge and (left or right) ventricular end-diastolic pressures in patients with an endocardial cushion defect indicates pulmonary venous obstruction and should alert one to the possibility of these combined lesions. The exact diagnosis is made with injections of angiographic contrast medium into the proximal and distal left atrial chambers, to documented the respective relations of the pulmonary veins, left atrial appendage and A-V valves to these atrial chambers. All three patients with an endocardial cushion defect and a subdivided left atrium had an associated patent ductus arteriosus. The common association of subdivided left atrium with intracardiac, pulmonary venous and aortic anomalies is again demonstrated.

  9. Ingredient of Biomass Packaging Material and Compare Study on Cushion Properties

    Directory of Open Access Journals (Sweden)

    Fangyi Li

    2014-01-01

    Full Text Available In order to reduce the white pollution caused by nondegradable waste plastic packaging materials, the biomass cushion packaging material with straw fiber and starch as the main raw materials had been synthesized. The orthogonal experiment was used to study the impact of mass ratio of fiber to starch, content of plasticizer, active agent, and foaming agent on the compressive strength of cushion material. Infrared spectrometer and theory of water’s bridge-connection were used to study the hydroxyl groups among the fiber and starch. The results were demonstrated as follows: the mass ratio of fiber to starch had the most significant impact on compressive strength. When the contents of the plasticizer, the foaming agent, and the active agent were, respectively, 12%, 0.1%, and 0.3% and the mass ratio of fiber to starch was 2 : 5, the compressive strength was the best up to 0.94 MPa. Meanwhile, with the plasticizer content and the mass ratio of fiber to starch increasing, the cushioning coefficient of the material decreased first and then increased. Comparing the cushion and rebound performance of this material with others, the biomass cushion packaging material could be an ideal substitute of plastic packaging materials such as EPS and EPE.

  10. Numerical simulation on the seismic absorption effect of the cushion in rigid-pile composite foundation

    Science.gov (United States)

    Han, Xiaolei; Li, Yaokun; Ji, Jing; Ying, Junhao; Li, Weichen; Dai, Baicheng

    2016-06-01

    In order to quantitatively study the seismic absorption effect of the cushion on a superstructure, a numerical simulation and parametric study are carried out on the overall FEA model of a rigid-pile composite foundation in ABAQUS. A simulation of a shaking table test on a rigid mass block is first completed with ABAQUS and EERA, and the effectiveness of the Drucker-Prager constitutive model and the finite-infinite element coupling method is proved. Dynamic time-history analysis of the overall model under frequent and rare earthquakes is carried out using seismic waves from the El Centro, Kobe, and Bonds earthquakes. The different responses of rigid-pile composite foundations and pile-raft foundations are discussed. Furthermore, the influence of thickness and modulus of cushion, and ground acceleration on the seismic absorption effect of the cushion are analyzed. The results show that: 1) the seismic absorption effect of a cushion is good under rare earthquakes, with an absorption ratio of about 0.85; and 2) the seismic absorption effect is strongly affected by cushion thickness and ground acceleration.

  11. Patterns of correlation between vehicle occupant seat pressure and anthropometry.

    Science.gov (United States)

    Paul, Gunther; Daniell, Nathan; Fraysse, François

    2012-01-01

    Seat pressure is known as a major factor of seat comfort in vehicles. In passenger vehicles, there is lacking research into the seat comfort of rear seat occupants. As accurate seat pressure measurement requires significant effort, simulation of seat pressure is evolving as a preferred method. However, analytic methods are based on complex finite element modeling and therefore are time consuming and involve high investment. Based on accurate anthropometric measurements of 64 male subjects and outboard rear seat pressure measurements in three different passenger vehicles, this study investigates if a set of parameters derived from seat pressure mapping are sensitive enough to differentiate between different seats and whether they correlate with anthropometry in linear models. In addition to the pressure map analysis, H-Points were measured with a coordinate measurement system based on palpated body landmarks and the range of H-Point locations in the three seats is provided. It was found that for the cushion, cushion contact area and cushion front area/force could be modeled by subject anthropometry, while only seatback contact area could be modeled based on anthropometry for all three vehicles. Major differences were found between the vehicles for other parameters.

  12. 微型旋翼无人机的磁操纵研究%Magnetic Operation of Rotor Micro Air Vehicle

    Institute of Scientific and Technical Information of China (English)

    富立; 王浩明; 杨丹迪

    2012-01-01

    磁操纵是微型无人机领域的一种新型控制方式,通过外界磁场的改变控制无人机的稳定。本文设计了一种磁动力控制微型旋翼飞行器,采用方形Helmholtz线圈产生匀强磁场来控制该飞行器的稳定,采用方形Maxwell线圈产生均匀梯度的磁场来控制飞行器的运动。在此基础上设计了框架式的磁场生成系统,该飞行器在框架之中飞行。经过理论计算及仿真,设计的磁场生成系统可以产生满足要求的磁场控制该飞行器使其稳定,进而沿水平方向运动。%Magnetic operation is a new kind of control method of micro air vehicle(MAV),which is to control its stability by changing the external magnetic field.In this thesis,we designed a new magnetic-controlling single rotor-wing MAV.We intended to use two square-Helmholtz coils to control the attitude of MAV by generating uniform magnetic field while two square-Maxwell coils to control the moving by generating magnetic gradient field.All the square coils are mountable on a cubic frame that has an opening to accommodate the MAV.In theory,the attitude of MAV can be controlled and the MAV can move horizontally through simulation.

  13. Air Vehicle Mission Control and Management, The Guidance and Control Panel Symposium (53rd) Held in Amsterdam, The Netherlands on 22-25 October 1991 ((La Gestion et le Controle des Missions des Vehicules Aeriens)

    Science.gov (United States)

    1992-03-01

    actif au pistago - amilioration des performances, notamment passif . riduction dos dun~es d’initialisation, ditettion rapido des evolutions des vihicuies...i C AGARD CONFERENCE PROCEEDINGS 504 Air Vehicle Mission Control and Management (La Gestion et le Contr6le des Missions des Whicules Ariens) cf...Aee.•I, a For Air Vehicle Mission Control J-"- a d and Management (La Gestion et le Contr6le des Missions Dt t ri,,t ion/ des Whicules AMriens) AV

  14. Size class structure, growth rates, and orientation of the central Andean cushion Azorella compacta

    Directory of Open Access Journals (Sweden)

    Catherine Kleier

    2015-03-01

    Full Text Available Azorella compacta (llareta; Apiaceae forms dense, woody, cushions and characterizes the high elevation rocky slopes of the central Andean Altiplano. Field studies of an elevational gradient of A. compacta within Lauca National Park in northern Chile found a reverse J-shape distribution of size classes of individuals with abundant small plants at all elevations. A new elevational limit for A. compacta was established at 5,250 m. A series of cushions marked 14 years earlier showed either slight shrinkage or small degrees of growth up to 2.2 cm yr−1. Despite their irregularity in growth, cushions of A. compacta show a strong orientation, centered on a north-facing aspect and angle of about 20° from horizontal. This exposure to maximize solar irradiance closely matches previous observations of a population favoring north-facing slopes at a similar angle. Populations of A. compacta appear to be stable, or even expanding, with young plants abundant.

  15. Examples of the application of the cause-effect ergonomic evaluation model to the wheelchair cushions.

    Science.gov (United States)

    Barberà-Guillem, Ricard; Page, Álvaro; Laparra, José; Durà, Juan V

    2015-01-01

    This article highlights the potential of the application of the cause-effect model for the ergonomic evaluation in the field of cushions. User involvement in the prescription and development of assistive devices have been identified a key aspect for positive interventions, although the reality is that we lack of systematic approaches and examples of best practices. The potential benefits are identified for the development of new products and in the prescription process. Additional research would be necessary to better link the characteristics of the cushions and users with the biomechanical and physiological performance of the interface cushion-user and the consequences measured in health, user perception and activity performance. This article shows examples of the relationship in this three levels from the point of view of the user perception.

  16. Impact Responses of Composite Cushioning System considering Critical Component with Simply Supported Beam Type

    Directory of Open Access Journals (Sweden)

    Fu-de Lu

    2014-04-01

    Full Text Available In some microelectronic products, one or several components can be idealized as simply supported beam type and viewed as vulnerable elements or critical component due to the fact that they are destroyed easily under impact loadings. The composite cushioning structure made of expanded polyethylene (EPE, and expanded polystyrene (EPS was utilized to protect the vulnerable elements against impact loadings during transportation. The vibration equations of composite cushioning system were deducted and virtual mass method was applied to predict impact behavior of critical component. Numerical results indicate that virtual mass method is appropriate for computing impact response of composite cushioning system with vulnerable element of simply supported beam type, which is affirmed by the fact that the impact responses of structure element in terms of velocity- and displacement-time curves are almost unchanged when virtual mass is smaller than a certain value. The results in this paper make it possible for installation of packaging optimization design.

  17. Size class structure, growth rates, and orientation of the central Andean cushion Azorella compacta

    Science.gov (United States)

    Trenary, Tim; Graham, Eric A.; Stenzel, William; Rundel, Philip W.

    2015-01-01

    Azorella compacta (llareta; Apiaceae) forms dense, woody, cushions and characterizes the high elevation rocky slopes of the central Andean Altiplano. Field studies of an elevational gradient of A. compacta within Lauca National Park in northern Chile found a reverse J-shape distribution of size classes of individuals with abundant small plants at all elevations. A new elevational limit for A. compacta was established at 5,250 m. A series of cushions marked 14 years earlier showed either slight shrinkage or small degrees of growth up to 2.2 cm yr−1. Despite their irregularity in growth, cushions of A. compacta show a strong orientation, centered on a north-facing aspect and angle of about 20° from horizontal. This exposure to maximize solar irradiance closely matches previous observations of a population favoring north-facing slopes at a similar angle. Populations of A. compacta appear to be stable, or even expanding, with young plants abundant. PMID:25802811

  18. Applying ISO 16840–2 Standard to differentiate impact force dissipation characteristics of selection of commercial wheelchair cushions

    Directory of Open Access Journals (Sweden)

    Martin Ferguson-Pell, PhD

    2015-04-01

    Full Text Available Results from applying the International Organization for Standardization (ISO 16840–2 test method for determining the impact damping characteristics of 35 wheelchair cushions plus a high resilience (HR70 polyurethane reference foam sample are reported. The generation of impact forces when a wheelchair user either transfers onto a cushion or the wheelchair encounters rough terrain or bumps down a step can endanger the viability of tissues, especially if these forces occur repeatedly. The results demonstrate significant differences in the impact force dissipation characteristics of different cushion products but do not reliably identify differences in performance that can be attributed to descriptive information about cushion composition alone. Instead, these results demonstrate that the materials, proprietary design, and construction features of wheelchair cushions in combination dictate impact force dissipation properties. The results of a cluster analysis are used to generate a model that can be used to compare the impact damping properties obtained from the ISO 16840–2 test method with those of a range of cushions and the reference cushion. Manufacturers will therefore be able to provide users and clinicians with information about the impact force dissipation properties of the cushions that will enable them to make more informed product choices for achieving improved comfort and to protect skin integrity.

  19. Air Vehicle Path Planning

    Science.gov (United States)

    2007-11-02

    me a much needed creative outlet. Thanks also to Maj Jon Anderson, Maj Jim Rogers, Capt John Erickson , Capt Dave Laird, Capt Kevin LaRochelle, Capt...Mathematical Functions with Formulas, Graphs, and Mathematical Tables, (Ninth Edition) edited by Milton Abramowitz and Irene A. Stegun, Washington DC: U.S...Handbook of Mathematical Func- tions with Formulas, Graphs, and Mathematical Tables, (Ninth Edition) edited by BIB-2 Milton Abramowitz and Irene A. Stegun

  20. Clean Cities ozone air quality attainment and maintenance strategies that employ alternative fuel vehicles, with special emphasis on natural gas and propane

    Energy Technology Data Exchange (ETDEWEB)

    Santini, D.J.; Saricks, C.L.

    1998-08-04

    Air quality administrators across the nation are coming under greater pressure to find new strategies for further reducing automotive generated non-methane hydrocarbon (NMHC) and nitrogen oxide (NOx) emissions. The US Environmental Protection Agency (EPA) has established stringent emission reduction requirements for ozone non-attainment areas that have driven the vehicle industry to engineer vehicles meeting dramatically tightened standards. This paper describes an interim method for including alternative-fueled vehicles (AFVs) in the mix of strategies to achieve local and regional improvements in ozone air quality. This method could be used until EPA can develop the Mobile series of emissions estimation models to include AFVs and until such time that detailed work on AFV emissions totals by air quality planners and emissions inventory builders is warranted. The paper first describes the challenges confronting almost every effort to include AFVs in targeted emissions reduction programs, but points out that within these challenges resides an opportunity. Next, it discusses some basic relationships in the formation of ambient ozone from precursor emissions. It then describes several of the salient provisions of EPA`s new voluntary emissions initiative, which is called the Voluntary Mobile Source Emissions Reduction Program (VMEP). Recent emissions test data comparing gaseous-fuel light-duty AFVs with their gasoline-fueled counterparts is examined to estimate percent emissions reductions achievable with CNG and LPG vehicles. Examples of calculated MOBILE5b emission rates that would be used for summer ozone season planning purposes by an individual Air Quality Control Region (AQCR) are provided. A method is suggested for employing these data to compute appropriate voluntary emission reduction credits where such (lighter) AFVs would be acquired. It also points out, but does not quantify, the substantial reduction credits potentially achievable by substituting gaseous

  1. KCP Activities Supporting the W76LEP Stress Cushions and LK3626 RTV Replacement Material Development

    Energy Technology Data Exchange (ETDEWEB)

    J. W. Schneider

    2009-10-01

    The S-5370 RTV blown foam previously produced by Dow Corning is no longer commercially available. The S-5370 material has been used on all of Los Alamos National Laboratory (LANL) programs to manufacture Stress Cushions up through the W88. The Kansas City Plant (KCP) did not have a sufficient supply of S-5370 material to cover the schedule requirements for the Program. This report provides information on the numerous activities conducted at KCP involving the development of the Program Stress Cushion and replacement RTV material.

  2. Ultra-structure of adipocytes in the digital cushion of ostrich (Stuthio Camelus foot pad

    Directory of Open Access Journals (Sweden)

    Amira Eid Derbalah

    2012-02-01

    Full Text Available The ultra-structural examination of adipocytes in the digital cushion of ostrich foot pad was performed to reveal the structural adaptation of adipocytes and elastic fibers of digital cushion to accommodate with fast movement of this unique bird. Two types of adipocytes were found, the first type was typical signet ring cells which had large fat droplets whose dimension dwarfed the cell organelles. The second type was diffused form with oval shaped adipocytes. Microfibillar aggregates of elastic fibers were closely packed and appeared to bead in a regular fashion. Some of this microfibrillar was reshaping adipocytes by making invagination of their plasma membrane.

  3. An experimental and simulative investigation of vehicle air conditioning systems with secondary circuits; Experimentelle und simulative Untersuchung von Pkw-Klimaanlagensystemen mit Sekundaerkreislaeufen

    Energy Technology Data Exchange (ETDEWEB)

    Lemke, Julia; Lemke, Nicholas; Koehler, Juergen [Technische Univ. Braunschweig (Germany). Inst. fuer Thermodynamik

    2012-07-01

    Different concepts for the redesign of thermal systems in the vehicle are investigated in the framework of the EU project TIFFE (Thermal Systems For Fuel Economy). This is intended to improve the vehicle thermal management along with fuel savings. The background of these investigations provides new propulsion concepts such as concepts with start-stop automatic system. These propulsion concepts also require a restructuring of the vehicle air conditioning system within the overall vehicle thermal management. Thus, within the project framework the mode of operation and influence of compact refrigeration units with secondary circuits for indirect heat uptake and release at different temperature levels are investigated. The authors of the contribution under consideration report on the experimental setup of an indirect system consisting of compact refrigeration units and three secondary circuits. Furthermore, the operation and performance of the presented system are discussed on the basis of experimental results. In addition to the experimental studies, a model of the overall system and simulation results are presented. The overall system is created using the object-oriented modeling language Modelica and the component library TIL Suite.

  4. Safety analysis of railway vehicle in leakage process of air spring%车辆系统空气弹簧失气安全性分析

    Institute of Scientific and Technical Information of China (English)

    高浩; 罗仁; 池茂儒; 戴焕云

    2012-01-01

    The leakage model of air spring with stiffness decay characteristics and the nonlinear stick-slip contact model were established. The dynamic process in loss of gas and the state of emergency after loss of gas were simulated by combining the two models with vehicle system dynamics. The stability of vehicle system with air spring failure was analyzed. The impact of air spring's sudden leakage on the dynamics performance of vehicle was simulated. The running safeties of vehicle under different times of loss of gas, different speeds and curve negotiation conditions were studied. Analysis result shows that the critical speed of vehicle system with air spring failure significantly decreases from 623 km ·h^-1 to 351 km ·h^-1. Because of air spring's sudden leakage, wheel-rail vertical force decreases and reduction rate of wheel load increases. The shorter the leakage process is, the greater reduction rate of wheel load is. It reaches 0. 651 when the leakage time is 0.2 s. The influence of speed on reduction rate of wheel load and wheelrail force is not obvious when vehicle speed is less than 300 km ·h^-1. But, when it is greater than 300 km ·h^-1 , reduction rate of wheel load increases rapidly with speed increase. Leakage occuring on circular curve is most dangerous when vehicle runs, and the maximum of reduction rate of wheel load is 0. 652. 2 tabs, 12 figs, 15 refs.%建立了具有刚度衰变特性的空气弹簧失气模型和非线性粘滑接触模型,结合车辆系统动力学,模拟空气弹簧失气动态过程与失气后的应急状态,分析了空气弹簧失气后车辆系统的稳定性与空气弹簧突然失气对车辆动力学性能的影响,研究了不同失气过程时长、运行速度与曲线通过工况下空气弹簧失气车辆的安全性。计算结果表明:空气弹簧失气后车辆临界速度由623km.h-1大幅降低为351km.h-1。空气弹簧突然失气导致轮轨垂向力减小,轮重减载率增大,且失气过程越短,

  5. Demonstration of zinc/air fuel battery to enhance the range and mission of fleet electric vehicles: Preliminary results in the refueling of a multicell module

    Science.gov (United States)

    Cooper, J. F.; Fleming, D.; Keene, L.; Maimoni, A.; Peterman, K.; Koopman, R.

    1994-08-01

    We report progress in an effort to develop and demonstrate a refuelable zinc/air battery for fleet electric vehicle applications. A refuelable module consisting of twelve bipolar cells with internal flow system has been refueled at rates of nearly 4 cells per minute, indicating a refueling time of 10 minutes for a 15 kW, 55 kWh battery. The module is refueled by entrainment of 0.5-mm particles in rapidly flowing electrolyte, which delivers the particles into hoppers above each cell in a parallel-flow hydraulic circuit. The concept of user-recovery is presented as an alternative to centralized service infrastructure during market entry.

  6. Experiment on Performance of Air Supply Orifice in Rail Vehicle%轨道车辆孔板送风特性的试验研究

    Institute of Scientific and Technical Information of China (English)

    臧建彬; 王亚伟; 陈佳; 高乃平; 史意

    2011-01-01

    Air distribution inside rail vehicles directly affects comfort of passengers. Air supply orificeds in static pressure boxes are characterize by simple structure,well-distributed air temperatures and velocities,so they are suitable for the place of strict requirements for space temperature spans and wind speeds. But the limited space of rail vehicles imposes restrictions on the plenum space of the static pressure boxes,which easily causes nonu-niform static pressures in the static pressure boxes and hinders uniform distribution of orifice air supply;since there are certain sealting areas on both sides of the roof, uniformity of distribution of orifice air supply is affected to some extent in the direction of the width. In this paper,the 1: 1 scale model tests were made. The kind of orifices used in the maglev train was chosen for the tests. The orifice air supply law was studied under the isothermal conditions. The resistance characteristics, static pressure distribution above the orifice and orifice air supply distribution uniformity were investigated.%轨道车辆客室内的气流组织直接影响乘客乘坐的舒适性.静压箱孔板送风具有结构简单、送风温度和速度均匀等优点,适用于区域温差和工作区风速要求严格的场所.但是由于轨道车辆空间有限,静压箱稳压层的高度受限,容易造成静压箱内静压不均匀,影响孔板送风的均匀性;而顶棚两侧由于存在一定的密封区域,对宽度方向上的送风均匀性也有一定的影响.本文采用1:1等比例模型试验的方法,针对一种运用在磁悬浮列车上的孔板,在等温条件下,对轨道车辆孔板送风规律进行研究,考察其阻力特性、孔板上方静压分布及孔板送风均匀性.

  7. Low-cost multi-vehicle air temperature measurements for heat load assessment in local-scale climate applications

    Science.gov (United States)

    Zuvela-Aloise, Maja; Weyss, Gernot; Aloise, Giulliano; Mifka, Boris; Löffelmann, Philemon; Hollosi, Brigitta; Nemec, Johana; Vucetic, Visnja

    2014-05-01

    In the recent years there has been a strong interest in exploring the potential of low-cost measurement devices as alternative source of meteorological monitoring data, especially in the urban areas where high-density observations become crucial for appropriate heat load assessment. One of the simple, but efficient approaches for gathering large amount of spatial data is through mobile measurement campaigns in which the sensors are attached to driving vehicles. However, non-standardized data collecting procedure, instrument quality, their response-time and design, variable device ventilation and radiation protection influence the reliability of the gathered data. We investigate what accuracy can be expected from the data collected through low-cost mobile measurements and whether the achieved quality of the data is sufficient for validation of the state-of-the-art local-scale climate models. We tested 5 types of temperature sensors and data loggers: Maxim iButton, Lascar EL-USB-2-LCD+ and Onset HOBO UX100-003 as market available devices and self-designed solar powered Arduino-based data loggers combined with the AOSONG AM2315 and Sensirion SHT21 temperature and humidity sensors. The devices were calibrated and tested in stationary mode at the Austrian Weather Service showing accuracy between 0.1°C and 0.8°C, which was mostly within the device specification range. In mobile mode, the best response-time was found for self-designed device with Arduino-based data logger and Sensirion SHT21 sensor. However, the device lacks the mechanical robustness and should be further improved for broad-range applications. We organized 4 measurement tours: two taking place in urban environment (Vienna, Austria in July 2011 and July 2013) and two in countryside with complex terrain of Mid-Adriatic islands (Hvar and Korcula, Croatia in August 2013). Measurements were taken on clear-sky, dry and hot days. We combined multiple devices attached to bicycle and cars with different

  8. A Noise-Insensitive Semi-Active Air Suspension for Heavy-Duty Vehicles with an Integrated Fuzzy-Wheelbase Preview Control

    Directory of Open Access Journals (Sweden)

    Zhengchao Xie

    2013-01-01

    Full Text Available Semi-active air suspension is increasingly used on heavy-duty vehicles due to its capabilities of consuming less power and low cost and providing better ride quality. In this study, a new low cost but effective approach, fuzzy-wheelbase preview controller with wavelet denoising filter (FPW, is developed for semi-active air suspension system. A semi-active suspension system with a rolling lobe air spring is firstly modeled and a novel front axle vertical acceleration-based road prediction model is constructed. By adopting a sensor on the front axle, the road prediction model can predict more reliable road information for the rear wheel. After filtering useless signal noise, the proposed FPW can generate a noise-insensitive control damping force. Simulation results show that the ride quality, the road holding, the handling capability, the road friendliness, and the comprehensive performance of the semi-active air suspension with FPW outperform those with the traditional active suspension with PID-wheelbase preview controller (APP. It can also be seen that, with the addition of the wavelet filter, the impact of sensor noise on the suspension performance can be minimized.

  9. Using co-operative vehicle-infrastructure systems to reduce traffic emissions and improve air quality at signalized urban intersections

    NARCIS (Netherlands)

    Mahmod, Mohamed Kamil Morsi

    2011-01-01

    Road transport has expanded the scope of human mobility, increasing the distances people travel. However, the recent increase in the number of vehicles has resulted in many adverse consequences in terms of safety, efficiency and the environment. Traffic emissions are known to be the main source of a

  10. Modeling and Implementation of a 1 kW, Air Cooled HTPEM Fuel Cell in a Hybrid Electrical Vehicle

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Ashworth, Leanne; Remón, Ian Natanael

    2008-01-01

    , was implemented in a small electrical vehicle. A dynamic model was developed using Matlab-Simulink to describe the system characteristics, select operating conditions and to size system components. Preheating of the fuel cell stack with electrical resistors was investigated and found to be an unrealistic approach...

  11. Mobile air quality studies (MAQS in inner cities: particulate matter PM10 levels related to different vehicle driving modes and integration of data into a geographical information program

    Directory of Open Access Journals (Sweden)

    Uibel Stefanie

    2012-10-01

    Full Text Available Abstract Background Particulate matter (PM is assumed to exert a major burden on public health. Most studies that address levels of PM use stationary measure systems. By contrast, only few studies measure PM concentrations under mobile conditions to analyze individual exposure situations. Methods By combining spatial-temporal analysis with a novel vehicle-mounted sensor system, the present Mobile Air Quality Study (MAQS aimed to analyse effects of different driving conditions in a convertible vehicle. PM10 was continuously monitored in a convertible car, driven with roof open, roof closed, but windows open, or windows closed. Results PM10 values inside the car were nearly always higher with open roof than with roof and windows closed, whereas no difference was seen with open or closed windows. During the day PM10 values varied with high values before noon, and occasional high median values or standard deviation values due to individual factors. Vehicle speed in itself did not influence the mean value of PM10; however, at traffic speed (10 – 50 km/h the standard deviation was large. No systematic difference was seen between PM10 values in stationary and mobile cars, nor was any PM10 difference observed between driving within or outside an environmental (low emission zone. Conclusions The present study has shown the feasibility of mobile PM analysis in vehicles. Individual exposure of the occupants varies depending on factors like time of day as well as ventilation of the car; other specific factors are clearly identifiably and may relate to specific PM10 sources. This system may be used to monitor individual exposure ranges and provide recommendations for preventive measurements. Although differences in PM10 levels were found under certain ventilation conditions, these differences are likely not of concern for the safety and health of passengers.

  12. Application of multivariate statistics in model experimental analysis of air cushion towing of 4-suction anchor platform%多元统计在四筒吸力锚平台气浮拖航模型试验中的应用

    Institute of Scientific and Technical Information of China (English)

    乐丛欢; 丁红岩; 董国海

    2011-01-01

    以四筒吸力锚平台结构为对象,就波浪方向、波高、波周期、航速、吃水深度、系缆点、拖缆长度、后倾角度的不同组合采用1∶20的模型进行拖航试验,测定了不同拖航试验组合下吸力锚平台运动加速度、筒内气压力、筒底水压力以及拖缆力,利用谱系聚类分析,对拖航组合进行分类,将拖航方式的优劣组合划分到不同的类。对测试参数进行因子分析,首先得到参数间的相关矩阵,相关矩阵反映了参数间的相互关系。通过因子分析提取占总方差85%的前6个因子,得到各方案组合的因子得分,找出最危险拖航组合和决定最危险组合的特征力学参数,为实际工程中的拖航提供参考。%This paper coducts model tests on a 1∶20 scaled model of four-suction anchor platform.The acceleration,the internal air pressure,the bottom water pressure of the suction anchors and towing force of the suction anchor platform are determined in series of towing combinations with different wave direction,wave velocity,wave period,towing velocity,towing points,towline length and tilt angle.Cluster analyses are used to classify the combinations of towing and factor analyses one used to analyze the mechanical characters.The correlative matrix is obtained which can reflect the correlation of mechanical characters.The factor analysis results show that 85% the total variance is attributed to the former six factors,and the factor scores of the towing combinations was obtained to find the most disadvantageous combinations and the mechanical characters which can lead to the disadvantageous results.The analysis results can be used for consulting the practical application.

  13. Remote Operated Vehicle geophysical surveys on land (underground), air and submarine archaeology: General peculiarities of processing and interpretation

    Science.gov (United States)

    Eppelbaum, Lev

    2016-04-01

    The last Remote Operation Vehicles (ROV) generation - small and maneuvering vehicles with different geophysical sensors - can fly at levels of a few meters (and even tens of centimeters) over the earth's surface, to move on the earth's surface and in the inaccessible underground areas and to explore in underwater investigations (e.g., Mindel and Bingham, 2001; Rowlands and Sarris, 2006; Wilson et al., 2006; Rigaud, 2007; Eppelbaum, 2008; Patterson and Brescia, 2008; Sarris, 2008; Wang et al., 2009; Wu and Tian, 2010; Stall, 2011; Tezkan et al., 2011; Winn et al., 2012; El-Nahhas, 2013; Hadjimitsis et al., 2013; Hajiyev and Vural, 2013; Hugenholtz et al., 2013; Petzke et al., 2013; Pourier et al., 2013; Casana et al., 2014; Silverberg and Bieber, 2014). Such geophysical investigations should have an extremely low exploitation cost and can observe surface practically inaccessible archaeological sites (swampy areas, dense vegetation, rugged relief, over the areas of world recognized religious and cultural artifacts (Eppelbaum, 2010), etc.). Finally, measurements of geophysical fields at different observation levels could provide a new unique geological-geophysical information (Eppelbaum and Mishne, 2011). Let's consider ROV airborne magnetic measurements as example. The modern magnetometric equipment enables to carry out magnetic measurements with a frequency of 50 times per second (and more) that taking into account the low ROV flight speed provides a necessary density of observations. For instance, frequency of observation of 50 times per second by ROV velocity of 40 km/hour gives density of observation about 0.2 m. It is obvious that the calculated step between observation points is more than sufficient one. Such observations will allow not only reduce the influence of some small artificial sources of noise, but also to obtain some additional data necessary for quantitative analysis (some interpretation methodologies need to have observations at two levels; upward

  14. Air Vehicle Technology Integration Program (AVTIP). Delivery Order 0033: Advanced Sol-Gel Adhesion Processes - Transition Support

    Science.gov (United States)

    2005-07-01

    or without an additional acid desmut. The use of an open air plasma process may improve the surface cleanliness, but the results were not conclusive...from PlasmaTreat -North America was used to clean and activate the surface of the aluminum alloy. This process blasts the surface of an object on the...conditioner with or without an additional acid desmut. The use of an open air plasma process may improve the surface cleanliness, but the results

  15. Design/Development of Mini/Micro Air Vehicles through Modelling and Simulation: Case of an Autonomous Quadrotor

    Directory of Open Access Journals (Sweden)

    Nitin K. Gupta

    2011-07-01

    Full Text Available Normal 0 MicrosoftInternetExplorer4 Design and development of an autonomous quadrotor micro aerial vehicle is undertaken following a systematic approach. A fairly detailed model was constructed and simulations were then carried out with the purpose of refining the baseline design, building a controller, and testing the flying qualities of the vehicle on a ground-based flight simulator. Following this, a smooth transition to rig and flight testing has been enabled in a cost- and time-effective manner, meeting all the design requirements.Defence Science Journal, 2011, 61(4, pp.337-345, DOI:http://dx.doi.org/10.14429/dsj.61.1086

  16. The alpine cushion plant Silene acaulis as foundation species: a bug's-eye view to facilitation and microclimate.

    Directory of Open Access Journals (Sweden)

    Olivia Molenda

    Full Text Available Alpine ecosystems are important globally with high levels of endemic and rare species. Given that they will be highly impacted by climate change, understanding biotic factors that maintain diversity is critical. Silene acaulis is a common alpine nurse plant shown to positively influence the diversity and abundance of organisms--predominantly other plant species. The hypothesis that cushion or nurse plants in general are important to multiple trophic levels has been proposed but rarely tested. Alpine arthropod diversity is also largely understudied worldwide, and the plant-arthropod interactions reported are mostly negative, that is,. herbivory. Plant and arthropod diversity and abundance were sampled on S. acaulis and at paired adjacent microsites with other non-cushion forming vegetation present on Whistler Mountain, B.C., Canada to examine the relative trophic effects of cushion plants. Plant species richness and abundance but not Simpson's diversity index was higher on cushion microsites relative to other vegetation. Arthropod richness, abundance, and diversity were all higher on cushion microsites relative to other vegetated sites. On a microclimatic scale, S. acaulis ameliorated stressful conditions for plants and invertebrates living inside it, but the highest levels of arthropod diversity were observed on cushions with tall plant growth. Hence, alpine cushion plants can be foundation species not only for other plant species but other trophic levels, and these impacts are expressed through both direct and indirect effects associated with altered environmental conditions and localized productivity. Whilst this case study tests a limited subset of the membership of alpine animal communities, it clearly demonstrates that cushion-forming plant species are an important consideration in understanding resilience to global changes for many organisms in addition to other plants.

  17. Influence of mobile air-conditioning on vehicle emissions and fuel consumption: a model approach for modern gasoline cars used in Europe.

    Science.gov (United States)

    Weilenmann, Martin F; Vasic, Ana-Marija; Stettler, Peter; Novak, Philippe

    2005-12-15

    The influence of air-conditioning activity on the emissions and fuel consumption of passenger cars is an important issue, since fleet penetration and use of these systems have reached a high level. Apart from the MOBILE6 study in the United States, little data is available on the impact of air-conditioning devices (A/Cs). Since weather conditions and A/C technologies both differ from those in the U. S., a test series was designed for the European setting. A fleet of six modern gasoline passenger cars was tested in different weather conditions. Separate test series were carried out for the initial cooldown and for the stationary situation of keeping the interior of the vehicle cool. As assumed, CO2 emissions and fuel consumption rise with the thermal load. This also causes a notable rise in CO and hydrocarbons (HCs). Moreover, A/Cs do not stop automatically at low ambient temperatures; if necessary, they produce dry air to demist the windscreen. A model is proposed that shows a constant load for lower temperatures and a linear trend for higher temperatures. The initial cooldown tests highlight significant differences among cars but show that A/C operation for the initial cooling of an overheated passenger compartment does not result in any extra emissions for the fleet as a whole.

  18. Use of weight-bearing MRI for evaluating wheelchair cushions based on internal soft-tissue deformations under ischial tuberosities

    Directory of Open Access Journals (Sweden)

    Amit Gefen, PhD

    2010-03-01

    Full Text Available Deep tissue injury (DTI is a severe type of pressure ulcer, in which damage initiates under intact skin, in soft tissues that are mechanically deformed by load-bearing bony prominences. Sitting-acquired DTI typically occurs in the gluteus muscles that could sustain deformations by the weight-bearing ischial tuberosities (ITs. No clinical method currently exists for measuring internal tissue deformations; so design and selection of wheelchair cushions are based mostly on meas-uring sitting pressures. Our objective was to evaluate the influence of different commercial cushions on internal soft-tissue deformations under the ITs, using weight-bearing magnetic resonance imaging (MRI. We specifically compared muscle, superficial fat, and effective (muscle and fat together tissue deformations while subjects (n = 10 sat on four cushions (two viscoelastic and two foam and directly on a rigid support. Deformations were maximal in muscle tissue (mean ~70%, twice more the amount than in fat (~30%. Effective soft-tissue deformations were ~50% to ~60%. Although cushions mildly reduced muscle deformations in the order of 10%, theoretically, our interpretation suggests that this deformation level adds safe sitting time. This study demonstrated that weight-bearing MRI is applicable for evaluating wheelchair cushions and, in the future, may be a tool to systematically support cushion design and selection.

  19. 基于网格模型的无人机航路规划仿真%Path Planning Simulation for Unmanned Air Vehicles Based on Mesh Model Method

    Institute of Scientific and Technical Information of China (English)

    任博; 吕雪燕; 董彦斌

    2011-01-01

    In order to research on autonomous path planning for unmanned air vehicles searching uncertain environment with prior information, a mesh model method was proposed for path planning. Firstly, mission area was divided into weighted meshes considering the existence probability of targets. Secondly, a control model was built according to a path decision set and sensor sweep model was proposed to describe coverage area of a prospecting apparatus carried by unmanned air vehicles. Thirdly, control model and sensor sweep model were applied to calculate the path value of next limited steps. Then an optimum path decision was carried out through solving a dynamic programming. Lastly, a simulation testing for unmanned air vehicles searching uncertain environment was designed, and the simulation results proved the effectiveness of the method.%关于优化无人机覆盖路径规划,应便于实时调整航路.实施战场游弋侦察的无人机要搜索含有先验信息的任务区域,并且没有确定的目标点.针对战场环境瞬息万变,提出了网格模型的航路规划方法.首先,将无人机的任务环境区域划分为若干网格单元,并根据存在目标的概率赋予网格单元权值.接着,依据航路决策集合建立了控制模型,根据探测区域对环境网格的覆盖情况建立了探测模型,采用控制和探测模型计算有限步长内的航路价值,通过求解一个动态规划得到当前状态下的最优航路决策.最后通过对一架和多架无人机侦察给定区域的仿真,验证了方法的有效性,为设计航路提供了科学参考.

  20. 新型可导向防撞垫开发%Development and Research of a New Type of Re-directive Crash Cushion

    Institute of Scientific and Technical Information of China (English)

    闫书明; 白书锋; 吕国仁

    2011-01-01

    In order to reduce accident severity caused by crashes between vehides and barrier terminals, impact test condition and evaluation specification of re-directive crash cushion are brought out based on accident performance and referred to correlative documents in and out of China, and a new type of re-directive crash cushion which meet the evaluation specification is invented by conducting finite element analysis and full-scale impact tests. The results indicate that the re-directive crash cushion is able to absorb kinetic energy of a 1.5 ton car with 60 km/h speed in frontal impact and with 100 km/h speed in side impact. The maximum acceleration direction is 10.7 g in frontal impact and 16.1 g in side impact, and passengers are protected, and the vehicle performance keeps well after crash; The simulation result is coincident with that of test and the error between them is with in 10%.%为降低车辆碰撞护栏端部事故严重程度,根据事故形态和国内外相关标准,提出可导向防撞垫的碰撞试验条件与评价标准,采用有限元仿真和碰撞试验相结合的技术手段,开发出一种新型可导向防撞垫结构.结果表明,开发的防撞垫能防护1.5t的小型车辆以60km/h速度正面碰撞和100km/h速度侧面碰撞,车体碰撞方向加速度最大值分别为10.7g和16.1g,车辆姿态良好,对乘员形成安全保护;仿真结果和试验结果一致,误差在10%以内.

  1. BMPER Promotes Epithelial-Mesenchymal Transition in the Developing Cardiac Cushions.

    Directory of Open Access Journals (Sweden)

    Laura Dyer

    Full Text Available Formation of the cardiac valves is an essential component of cardiovascular development. Consistent with the role of the bone morphogenetic protein (BMP signaling pathway in cardiac valve formation, embryos that are deficient for the BMP regulator BMPER (BMP-binding endothelial regulator display the cardiac valve anomaly mitral valve prolapse. However, how BMPER deficiency leads to this defect is unknown. Based on its expression pattern in the developing cardiac cushions, we hypothesized that BMPER regulates BMP2-mediated signaling, leading to fine-tuned epithelial-mesenchymal transition (EMT and extracellular matrix deposition. In the BMPER-/- embryo, EMT is dysregulated in the atrioventricular and outflow tract cushions compared with their wild-type counterparts, as indicated by a significant increase of Sox9-positive cells during cushion formation. However, proliferation is not impaired in the developing BMPER-/- valves. In vitro data show that BMPER directly binds BMP2. In cultured endothelial cells, BMPER blocks BMP2-induced Smad activation in a dose-dependent manner. In addition, BMP2 increases the Sox9 protein level, and this increase is inhibited by co-treatment with BMPER. Consistently, in the BMPER-/- embryos, semi-quantitative analysis of Smad activation shows that the canonical BMP pathway is significantly more active in the atrioventricular cushions during EMT. These results indicate that BMPER negatively regulates BMP-induced Smad and Sox9 activity during valve development. Together, these results identify BMPER as a regulator of BMP2-induced cardiac valve development and will contribute to our understanding of valvular defects.

  2. Wax beads as cushioning agents during the compression of coated diltiazem pellets.

    Science.gov (United States)

    Vergote, G J; Kiekens, F; Vervaet, C; Remon, J P

    2002-11-01

    Placebo particles were mixed with film-coated diltiazem pellets to evaluate them as cushioning agents during tabletting in order to protect the film coat from damage. The cushioning properties of alpha-lactose monohydrate granules, microcrystalline cellulose pellets and wax/starch beads were evaluated by comparing the dissolution profile of the coated pellets before and after compression (compression force 10 kN). Only the tablet formulations containing wax/starch beads provided protection to the film coat. However, the dissolution rate of tablets formulated with waxy maltodextrin/paraffinic wax placebo beads was too slow as the tablets did not disintegrate. Adding 50% (w/w) drum-dried corn starch/Explotab/paraffinic wax beads to the formulation was the optimal amount of cushioning beads to provide sufficient protection for the film coat and yield disintegrating tablets. Using a compression simulator, the effect of precompression force and compression time on the dissolution rate was found to be insignificant. The diametral crushing strength of tablets containing 50% (w/w) drum-dried corn starch/Explotab/paraffinic wax beads was about 25.0 N (+/-0.3 N), with a friability of 0.4% (+/-0.04%). This study demonstrates that adding deformable wax pellets minimizes the damage to film-coated pellets during compression.

  3. Volatile organic chemical emissions from carpet cushions: Screening measurements. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hodgson, A.T.; Phan, T.A.

    1994-05-01

    The US Consumer Product Safety Commission (CPSC) has received complaints from consumers regarding the occurrence of adverse health effects following the installation of new carpeting (Schachter, 1990). Carpet systems are suspected of emitting chemicals which may be the cause of these complaints, as well as objectionable odors. Carpets themselves have been shown to emit a variety of volatile organic compounds (VOCs). The objective of this study was to screen the representative samples of carpet cushions for emissions of individual VOCS, total VOCs (TVOC), formaldehyde, and, for the two types of polyurethane cushions, isomers of toluene diisocyanate (TDI). The measurements of VOCS, TVOC and formaldehyde were made over six-hour periods using small-volume (4-L) dynamic chambers. Sensitive gas chromatography-mass spectrometry (GC-MS) techniques were used to identify many of the VOCs emitted by the cushion samples and to obtain quantitative estimates of the emission rates of selected compounds. Separate screening measurements were conducted for TDI. The data from the screening measurements were used by the CPSC`s Health Sciences Laboratory to help design and conduct week-long measurements of emission rates of selected compounds.

  4. A comparative sudy of two pressure relieving techniques on three different wheelchair cushions

    Directory of Open Access Journals (Sweden)

    C. Eksteen

    2006-02-01

    Full Text Available Introduction: Pressure relief done by a spinal cordinjured patient is of utmost importance in order to prevent pressuresore formation. Some pressure-relieving techniques are describedin previous literature, but their effectivity has not yet been deter-mined on different wheelchair cushions.Null Hypothesis (H0: The null hypothesis (H0 stated for thistudy is that there is no difference in the effectivity of forwardleaning and forward leaning towards the left as pressure relievingtechniques for quadriplegic wheelchair users over the differenwheelchair cushions.Design: An analytical experimental study design using a convenient sample group of ten complete lesion quadriplegics (C6 to T1 was performed at the Physiotherapy Department,University of Pretoria.Method: Interface pressure (in mmHg over the ischial tuberosities and upper thigh areas was measured using theTalley Oxford Pressure Monitor MKII with a 12-way matrix cell system.Results and Conclusion: The Friedman test for associated observations indicated statistically that the leaning  diagonally forward pressure relieving technique is more effective for all three wheelchair cushions used in this study.

  5. Effects of insoles and additional shock absorption foam on the cushioning properties of sport shoes.

    Science.gov (United States)

    Chiu, Hung-Ta; Shiang, Tzyy-Yuang

    2007-05-01

    The purpose of this study was to investigate the effects of insoles and additional shock absorption foam on the cushioning properties of various sport shoes with an impact testing method. Three commercial sport shoes were used in this study, and shock absorption foam (TPE5020; Vers Tech Science Co. Ltd., Taiwan) with 2-mm thickness was placed below the insole in the heel region for each shoe. Eight total impacts with potential energy ranged from 1.82 to 6.08 J were performed onto the heel region of the shoe. The order of testing conditions was first without insole, then with insole, and finally interposing the shock absorption foam for each shoe. Peak deceleration of the striker was measured with an accelerometer attached to the striker during impact. The results of this study seemed to show that the insole or additional shock absorption foam could perform its shock absorption effect well for the shoes with limited midsole cushioning. Further, our findings showed that insoles absorbed more, even up to 24-32% of impact energy under low impact energy. It seemed to indicate that insoles play a more important role in cushioning properties of sport shoes under a low impact energy condition.

  6. Advanced computer technology - An aspect of the Terminal Configured Vehicle program. [air transportation capacity, productivity, all-weather reliability and noise reduction improvements

    Science.gov (United States)

    Berkstresser, B. K.

    1975-01-01

    NASA is conducting a Terminal Configured Vehicle program to provide improvements in the air transportation system such as increased system capacity and productivity, increased all-weather reliability, and reduced noise. A typical jet transport has been equipped with highly flexible digital display and automatic control equipment to study operational techniques for conventional takeoff and landing aircraft. The present airborne computer capability of this aircraft employs a multiple computer simple redundancy concept. The next step is to proceed from this concept to a reconfigurable computer system which can degrade gracefully in the event of a failure, adjust critical computations to remaining capacity, and reorder itself, in the case of transients, to the highest order of redundancy and reliability.

  7. Modeling and simulation of vehicle active cab air suspension%汽车驾驶室主动空气悬置的建模仿真分析

    Institute of Scientific and Technical Information of China (English)

    潘公宇; 张树

    2014-01-01

    为改善车辆平顺性,在考虑汽车驾驶室的实际位置、半浮式和全浮式驾驶室悬置的特点后,选取了全浮式空气悬置作为研究对象,并通过弹簧特性试验研究了空气弹簧静、动特性曲线;运用Matlab/Simulink建立了八自由度驾驶室空气悬置模型,以滤波白噪声生成路面输入,仿真分析了汽车在B级路面下车速20 m/s、25 m/s及路面有凸块的三种行驶状况的振动;进而设计了模糊控制器,对驾驶室前后空气悬置采取主动控制后的状况进行了仿真分析;以驾驶员、驾驶室的振动响应及悬置动挠度为指标,评价车辆平顺性的变化程度,以此来研究主动空气悬置在改善车辆平顺性方面的效果。三种行驶状况的仿真结果表明,对驾驶室前后空气悬置采取主动控制后,驾驶员加速度均方根值分别减小了8.39%、9.32%、8.55%,驾驶室质心加速度均方根值分别减小了9.64%、11.85%、9.78%,驾驶室俯仰角加速度均方根值分别减小了20.15%、10.14%、20.11%,提高了乘坐的舒适性。%In order to improve the ride comfort of a vehicle, the full floating air suspension was a-dopted by considering the actual location of cab in commercial vehicle and the characteristics of semi and full floating suspension.The stiffness characteristic test was done to study the static and dynamic characteristic curve of air spring.A cab air suspension with 8 freedoms is established in Matlab/Simulink.And filter white noise is taken as road excitation to simulate the vibration of commercial vehicle driving in B grade road.Two fuzzy controllers to control the front and rear cab suspension was designed to simulate passive and active suspension.The vibration response of driver and cab and the suspension dynamic deflection were chosen as targets to evaluate the ride comfort of vehicle in active system has been improved or not when compared to passive system

  8. Environmental Assessment for Establishment of an Off-Highway Vehicle (OHV) Program at Arnold Air Force Base, Tennessee

    Science.gov (United States)

    2010-05-01

    potential to disturb soil stability and increase the susceptibility of soil particles to suspension and transport by wind and water. To avoid potential...motor scooters is prohil>ited on Eielson AFB except on maintained roads to access designated-use areas (areas not llsted in paragraph 9). 10.1.2...Motorcycle h•iotor Scooter X X x’ ATV 4 Wheelers X X X x’ Snowmobiles X X X X 1. Must be registered as a street vehicle or under a separate local system

  9. Aerothermodynamic Testing of Protuberances and Penetrations on the NASA Crew Exploration Vehicle Heat Shield in the NASA Langley 20-Inch Mach 6 Air Tunnel

    Science.gov (United States)

    Liechty, Derek S.

    2008-01-01

    An experimental wind tunnel program is being conducted in support of an Agency wide effort to develop a replacement for the Space Shuttle and to support the NASA s long-term objective of returning to the moon and then on to Mars. This paper documents experimental measurements made on several scaled ceramic heat transfer models of the proposed Crew Exploration Vehicle. Global heat transfer images and heat transfer distributions obtained using phosphor thermography were used to infer interference heating on the Crew Exploration Vehicle Cycle 1 heat shield from local protuberances and penetrations for both laminar and turbulent heating conditions. Test parametrics included free stream Reynolds numbers of 1.0x10(exp 6)/ft to 7.25x10(exp 6)/ft in Mach 6 air at a fixed angle-of-attack. Single arrays of discrete boundary layer trips were used to trip the boundary layer approaching the protuberances/penetrations to a turbulent state. Also, the effects of three compression pad diameters, two radial locations of compression pad/tension tie location, compression pad geometry, and rotational position of compression pad/tension tie were examined. The experimental data highlighted in this paper are to be used to validate CFD tools that will be used to generate the flight aerothermodynamic database. Heat transfer measurements will also assist in the determination of the most appropriate engineering methods that will be used to assess local flight environments associated with protuberances/penetrations of the CEV thermal protection system.

  10. Formation flight control for unmanned air vehicle during aerial refueling%无人机空中加油过程中编队飞行控制

    Institute of Scientific and Technical Information of China (English)

    黄红建; 袁锁中; 戴文正

    2014-01-01

    针对空中加油中无人机位置保持问题,进行了时变质量UAV的动力学建模与非线性控制设计。综合考虑了燃油传输对UAV的质量、惯性矩阵和质心位置的影响,基于相对于惯性系的状态变量,推导了UAV时变质量动力学方程。分析燃油传输带来的动力学影响,并设计神经网络动态逆控制律来实现UAV的位置保持,通过非线性仿真验证了控制律的有效性。%To keep the position of an unmanned air vehicle (UAV) during autonomous aerial refueling, we develop the dynamic model and put forward a nonlinear controller for the UAV with time-varying mass. By comprehensively considering the effect of fuel transfer on the UAV mass, the inertia matrix and the center of mass, we derive the time-varying mass dynamic equations of UAV based on state variables relative to inertial reference frame. Through analyzing the dynamic characteristic effect of fuel transfer, we design neural network dynamic inversion control law to keep the position of unmanned air vehicle, and nonlinear simulation demonstrates the effectiveness of the flight control law.

  11. Determination of turnover and cushion gas volume of a prospected gas storage reservoir under uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Gubik, A. [RAG-AG Wien (Austria); Baffoe, J.; Schulze-Riegert, R. [SPT Group GmbH, Hamburg (Germany)

    2013-08-01

    Gas storages define a key contribution for building a reliable gas supply chain from production to consumers. In a competitive gas market with short reaction times to seasonal and other gas injection and extraction requirements, gas storages also receive a strong focus on availability and precise prediction estimates for future operation scenarios. Reservoir management workflows are increasingly built on reservoir simulation support for optimizing production schemes and estimating the impact of subsurface uncertainties on field development scenarios. Simulation models for gas storages are calibrated to geological data and accurate reproduction of historical production data are defined as a prerequisite for reliable production and performance forecasts. The underlying model validation process is called history matching, which potentially generates alternative simulation models due to prevailing geological uncertainties. In the past, a single basecase reference model was used to predict production capacities of a gas storage. The working gas volume was precisely defined over a contracted plateau delivery and the required cushion gas volume maintains the reservoir pressure during the operation. Cushion and working gas Volume are strongly dependent on reservoir parameters. In this work an existing depleted gas reservoir and the operation target as a gas storage is described. Key input data to the reservoir model description and simulation is reviewed including production history and geological uncertainties based on large well spacing, limited core and well data and a limited seismic resolution. Target delivery scenarios of the prospected gas storage are evaluated under uncertainty. As one key objective, optimal working gas and cushion gas volumes are described in a probabilistic context reflecting geological uncertainties. Several work steps are defined and included in an integrated workflow design. Equiprobable geological models are generated and evaluated based on

  12. Electric vehicle - near or far

    Energy Technology Data Exchange (ETDEWEB)

    Laiho, Y.

    1997-11-01

    Traffic is rapidly becoming the number one environmental problem, especially in metropolitan areas. Electric vehicles have many important advantages to offer. Air quality would be improved, since electric vehicles do not pollute the environment. The improvement obtained might be equated with that resulting from the introduction of district heat for the heating of residential buildings. Electric vehicles also present considerable potential for energy conservation

  13. Air Vehicle Integration and Technology Research (AVIATR). Delivery Order 0013: Nonlinear, Low-Order/Reduced-Order Modeling Applications and Demonstration

    Science.gov (United States)

    2011-12-01

    scientific and technical information exchange, and its publication does not constitute the Government’s approval or disapproval of its ideas or findings...instrumentation potting on the Outer Mold-Line (OML) surface or due to air flow. The surface potting material used was Room Temperature Vulcanizing (RTV) silicone...identification-guided basis selection for reduced- order nonlinear response analysis," Journal of Sound and Vibration, Vol. 315, No. 3, 2008, pp. 467

  14. Design and simulation of ex-range gliding wing of high altitude air-launched autonomous underwater vehicles based on SIMULINK

    Institute of Scientific and Technical Information of China (English)

    Pan Changjun; Guo Yingqing

    2013-01-01

    High altitude air-launched autonomous underwater vehicle (AL-AUV) is a new anti-submarine field,which is designed on the Lockheed Martin's high altitude anti-submarine warfare weapons concept (HAAWC) and conducts the basic aerodynamic feasibility in a series of wind tunnel trials.The AL-AUV is composed of a traditional torpedo-like AUV,an additional ex-range gliding wings unit and a descending parachute unit.In order to accurately and conveniently investigate the dynamic and static characteristic of high altitude AL-AUV,a simulation platform is established based on MATLAB/SIMULINK and an AUV 6DOF (Degree of Freedom) dynamic model.Executing the simulation platform for different wing's parameters and initial fixing angle,a set of AUV gliding data is generated.Analyzing the recorded simulation result,the velocity and pitch characteristics of AL-AUV deployed at varying wing areas and initial setting angle,the optimal wing area is selected for specific AUV model.Then the comparative simulations of AL-AUV with the selected wings are completed,which simulate the AUV gliding through idealized windless air environment and gliding with Dryden wind influence.The result indicates that the method of wing design and simulation with the simulation platform based on SIMULINK is accurately effective and suitable to be widely employed.

  15. Performance study on three-stage power system of compressed air vehicle based on single-screw expander

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A new compressed-air engine system based on three-stage single screw expander was proposed to improve the performance of power system.Three different structure styles were presented,and the studies on the power performance and the distribution of expansion ratios between stages were carried out by programming and mathematical modeling of each style.Research results indicated that the best matches of expansion ratios with equal heat temperature for the air tank of pressure 30 MPa were seven-five-three for"first-stage heating"style,eight-five-three for"two-stage heating"style and five-five-four for"three-stage heating"style,respectively.Results also showed that heating up inlet air or increasing the expander efficiency might improve the power performance.The output power of the"two-stage heating"style is far higher than that of"first-stage heating"style and is a little lower than that of"three-stage heating"style.The new system showed good structure and power performances.

  16. Seat-integrated localized ventilation for exposure reduction to air pollutants in indoor environments

    DEFF Research Database (Denmark)

    Bivolarova, Mariya Petrova; Rezgals, Lauris; Melikov, Arsen Krikor

    2016-01-01

    generated before they disperse around a room. The polluted near the body air is exhausted into the cushion and it is removed from the room by a separate exhaust system. The performance of the method was studied in series of experiments. Full-scale room and a dressed thermal manikin sitting in front...... of a desk were used to simulate one person office. The chair on which the thermal manikin was sitting had the ventilated cushion (VC). Tracer gases, carbon dioxide (CO2) and nitrous oxide (N2O), were used to simulate bioeffluents emitted by the manikin’s armpits and groin region respectively...... from the cushion at 1.5, 3 and 5 L/s were performed. The pollution removal efficiency was assessed by measuring the pollution concentration in the breathing zone of the manikin and at several other locations in the room bulk air. Exhausting air through the VC decreased the concentration of the tracer...

  17. Crystallization Behavior of M97 Series Silicone Cushions

    Energy Technology Data Exchange (ETDEWEB)

    Chien, A.; DeTeresa, S.; Cohenour, R.; Schnieder, J.; LeMay, J.; Balazs, B.

    2000-09-07

    M97 series siloxanes are poly(dimethyl-diphenyl) siloxanes that are reinforced through a mixture of precipitated and fumed silica fillers which are blended in through the addition of a short chain polydimethylsiloxane processing aid. M97 silicones exhibit crystallization at -80.25 C by thermal (modulated differential scanning calorimetry) and mechanical (dynamic mechanical analysis) techniques. Isothermal dynamic mechanical analysis experiments illustrated that crystallization occurred over a 1.8 hour period in silica-filled systems and 2.8 hours in unfilled systems. The onset of crystallization typically occurred after a 30 minute incubation/nucleation period. {gamma}-radiation caused the crystallization rate to decrease proportionally with dosage, but did not decrease the amount of crystallization that ultimately occurred. Irradiation in vacuum resulted in slower overall crystallization rates compared to air irradiation due to increased crosslinking of the polymer matrix under vacuum. Modulated differential scanning calorimetry contrasted the crystallization and melting behavior of pure PDMS versus the M97 base polymer and helped determine which component of the composite was the origin of the crystallization phenomena.

  18. Analysis of Air Flow Past and through the 2415-3S Airfoil for an Unmanned Aerial Vehicle with Internal Propulsion System

    Directory of Open Access Journals (Sweden)

    Luis D. Mendoza

    2014-08-01

    Full Text Available This paper deals with the prediction of velocity fields on the 2415-3S airfoil which will be used for an unmanned aerial vehicle with internal propulsion system and in this way analyze the air flow through an internal duct of the airfoil using computational fluid dynamics. The main objective is to evaluate the effect of the internal air flow past the airfoil and how this affects the aerodynamic performance by means of lift and drag forces. For this purpose, three different designs of the internal duct were studied; starting from the base 2415-3S airfoil developed in previous investigation, basing on the hypothesis of decreasing the flow separation produced when the propulsive airflow merges the external flow, and in this way obtaining the best configuration. For that purpose, an exhaustive study of the mesh sensitivity was performed. It was used a non-structured mesh since the computational domain is three-dimensional and complex. The selected mesh contains approximately 12.5 million elements. Both the computational domain and the numerical solution were made with commercial CAD and CFD software, respectively. Air, incompressible and steady was analyzed. The boundary conditions are in concordance with experimental setup in the AF 6109 wind tunnel. The k-ε model is utilized to describe the turbulent flow process as followed in references. Results allowed obtaining velocity contours as well as lift and drag coefficients and also the location of separation and reattachment regions in some cases for zero degrees of angle of attack on the internal and external surfaces of the airfoil. Finally, the selection of the configuration with the best aerodynamic performance was made, selecting the option without curved baffles.

  19. N-acetyl-S-(n-propyl)-l-cysteine in urine from workers exposed to 1-bromopropane in foam cushion spray adhesives.

    Science.gov (United States)

    Hanley, Kevin W; Petersen, Martin R; Cheever, Kenneth L; Luo, Lian

    2009-10-01

    1-Bromopropane (1-BP) has been marketed as an alternative for ozone depleting and other solvents; it is used in aerosol products, adhesives, metal, precision, and electronics cleaning solvents. Mechanisms of toxicity of 1-BP are not fully understood, but it may be a neurological and reproductive toxicant. Sparse exposure information prompted this study using 1-BP air sampling and urinary metabolites. Mercapturic acid conjugates are excreted in urine from 1-BP metabolism involving debromination. Research objectives were to evaluate the utility of urinary N-acetyl-S-(n-propyl)-L-cysteine (AcPrCys) for assessing exposure to 1-BP and compare it to urinary bromide [Br((-))] previously reported for these workers. Forty-eight-hour urine specimens were obtained from 30 workers at two factories where 1-BP spray adhesives were used to construct polyurethane foam seat cushions. Urine specimens were also obtained from 21 unexposed control subjects. All the workers' urine was collected into composite samples representing three time intervals: at work, after work but before bedtime, and upon awakening. Time-weighted average (TWA) geometric mean breathing zone concentrations were 92.4 and 10.5 p.p.m. for spraying and non-spraying jobs, respectively. Urinary AcPrCys showed the same trend as TWA exposures to 1-BP: higher levels were observed for sprayers. Associations of AcPrCys concentrations, adjusted for creatinine, with 1-BP TWA exposure were statistically significant for both sprayers (P < 0.05) and non-sprayers (P < 0.01). Spearman correlation coefficients for AcPrCys and Br((-)) analyses determined from the same urine specimens were highly correlated (P < 0.0001). This study confirms that urinary AcPrCys is an important 1-BP metabolite and an effective biomarker for highly exposed foam cushion workers.

  20. Kinematics and shoulder belt position of child rear seat passengers during vehicle maneuvers.

    Science.gov (United States)

    Bohman, Katarina; Stockman, Isabelle; Jakobsson, Lotta; Osvalder, Anna-Lisa; Bostrom, Ola; Arbogast, Kristy B

    2011-01-01

    Head impact to the seat back has been identified as one important injury causation scenario for seat belt restrained, head-injured children and previous research highlighted vehicle maneuvers prior to impact as possible contributing factors. The aim was to quantify kinematics of child occupants during swerving maneuvers focusing on the child's lateral movement and seat belt position relative to the child's shoulder. A study was conducted on a closed-circuit test track with 16 children aged 4-12, restrained in the rear seat of a modern passenger vehicle. A professional driving instructor drove at 50 km/h making sharp turns in a repeatable fashion, resulting in inboard motion of the children. The children were exposed to two turns in each of two restraint systems. Shorter children were on a booster or highback booster cushion. The taller children were seated on a booster cushion or with only a lap and shoulder seat belt. Four film cameras were fixed in the vehicle monitoring the child. Vehicle data were also collected. The seat belt slipped off the shoulder in 1 of 5 turns, varying by age and restraint type. Among shorter children, the belt slipped off in a majority of turns when seated on a booster cushion while the belt remained on the shoulder when seated on the highback booster cushion. Among taller children, the shoulder belt moved far laterally on the shoulder in half of the turns. This data provides valuable knowledge on possible pre-impact postures of children as a result of vehicle swerving maneuvers for a variety of restraint systems.

  1. Floating air riding seal for a turbine

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, Todd A

    2016-08-16

    A floating air riding seal for a gas turbine engine with a rotor and a stator, an annular piston chamber with an axial moveable annular piston assembly within the annular piston chamber formed in the stator, an annular cavity formed on the annular piston assembly that faces a seal surface on the rotor, where the axial moveable annular piston includes an inlet scoop on a side opposite to the annular cavity that scoops up the swirling cooling air and directs the cooling air to the annular cavity to form an air cushion with the seal surface of the rotor.

  2. Modeling of In-vehicle Magnetic refrigeration

    DEFF Research Database (Denmark)

    Olsen, Ulrik Lund; Bahl, Christian; Engelbrecht, Kurt;

    2012-01-01

    A high-performance magnetic refrigeration device is considered as a potential technology for in-vehicle air conditioners in electric vehicles. The high power consumption of a conventional air conditioner in an electric vehicle has considerable impacts on cruising distance. For this purpose...

  3. Effectiveness of Disc 'O' Sit cushions on attention to task in second-grade students with attention difficulties.

    Science.gov (United States)

    Pfeiffer, Beth; Henry, Amy; Miller, Stephanie; Witherell, Suzie

    2008-01-01

    This study investigated the effectiveness of a type of dynamic seating system, the Disc 'O' Sit cushion (Gymnic, Osoppo, Italy), for improving attention to task among second-grade students with attention difficulties. Sixty-three second-grade students participated in the study. Using a randomized controlled trial design, 31 students were assigned to a treatment group, and 32 were assigned to a control group. Treatment group participants used Disc 'O' Sit cushions throughout the school day for a 2-week period. The teachers completed the Behavior Rating Inventory of Executive Functioning (Gioia, Isquith, Guy, & Kenworthy, 1996) for each participant before and after the intervention. An analysis of variance identified a statistically significant difference in the attention to task before and after the intervention for the treatment group. The results of the study provide preliminary evidence for the use of the Disc 'O' Sit cushion as an occupational therapy intervention to improve attention in the school setting.

  4. Impact of Heavy-Duty Diesel Vehicles on Air Quality and Control of Their Emissions%重型柴油车对空气质量的影响及其排放的控制

    Institute of Scientific and Technical Information of China (English)

    周磊; 王伯光; 汤大钢

    2011-01-01

    Through an analysis of the characteristics of diesel vehicle emissions and motor vehicle emissions inventories,this paper examines the impact of heavy-duty diesel vehicles on air quality in China as well as issues related to the control of their emissions.Heavy-duty diesel vehicles emit large amounts of nitrogen oxides and particulate matter.Nitrogen oxides is one of the important precursors for the formation of secondary particles and ozone in the atmosphere,causing regional haze.Diesel particulate matter is a major toxic air pollutant with adverse effect on human health,and in particular,the ultrafine particles in 30-100 nm size range can pose great health risks because of its extremely small sizes.Motor vehicles have become a major source of air pollution in many metropolitan areas and city cluster in China,and among them the heavy-duty diesel vehicles are a dominant contributor of nitrogen oxides and particulate matter emissions.Hence,controlling heavy-duty diesel vehicle emissions should be a key component of an effective air quality management plan,and a number of issues related to heavy-duty diesel vehicle emissions need to be addressed.%通过对柴油车污染物排放的特征和机动车排放清单的分析,探讨了重型柴油车对我国城市空气质量的影响及其排放的控制.重型柴油车排放大量的氮氧化物和颗粒物,其中氮氧化物为大气中产生二次细粒子以及臭氧的重要前体物之一,导致区域性灰霾的形成,而柴油颗粒物是影响健康的一个主要有毒空气污染物,尤其是其中粒径为30~100 nm的超细粒子,由于其粒径非常微小,对人体健康有极大的危害性.目前机动车已成为我国很多大城市和城市群地区的重要空气污染源,而其中的重型柴油车则排放了很大部分的氮氧化物和细颗粒物.因此,控制重型柴油车的排放

  5. Force generation and wing deformation characteristics of a flapping-wing micro air vehicle 'DelFly II' in hovering flight.

    Science.gov (United States)

    Percin, M; van Oudheusden, B W; de Croon, G C H E; Remes, B

    2016-05-19

    The study investigates the aerodynamic performance and the relation between wing deformation and unsteady force generation of a flapping-wing micro air vehicle in hovering flight configuration. Different experiments were performed where fluid forces were acquired with a force sensor, while the three-dimensional wing deformation was measured with a stereo-vision system. In these measurements, time-resolved power consumption and flapping-wing kinematics were also obtained under both in-air and in-vacuum conditions. Comparison of the results for different flapping frequencies reveals different wing kinematics and deformation characteristics. The high flapping frequency case produces higher forces throughout the complete flapping cycle. Moreover, a phase difference occurs in the variation of the forces, such that the low flapping frequency case precedes the high frequency case. A similar phase lag is observed in the temporal evolution of the wing deformation characteristics, suggesting that there is a direct link between the two phenomena. A considerable camber formation occurs during stroke reversals, which is mainly determined by the stiffener orientation. The wing with the thinner surface membrane displays very similar characteristics to the baseline wing, which implies the dominance of the stiffeners in terms of providing rigidity to the wing. Wing span has a significant effect on the aerodynamic efficiency such that increasing the span length by 4 cm results in a 6% enhancement in the cycle-averaged X-force to power consumption ratio compared to the standard DelFly II wings with a span length of 28 cm.

  6. Tracking control of a class of non-linear systems with applications to cruise control of air-breathing hypersonic vehicles

    Science.gov (United States)

    Sun, Hongfei; Yang, Zhiling; Meng, Bin

    2015-05-01

    A new tracking-control method for general non-linear systems is proposed. A virtual controller and some command references are introduced to asymptotically stabilise the system of the tracking error dynamics. Then, the actual controller and command references are derived by solving a system of linear algebraic equations. Compared with other tracking-control methods in the literature, the tracking-controller design in this paper is simple because it needs only to solve a system of linear algebraic equations. The boundedness of the tracking controller and command references is guaranteed by the solvability of the terminal value problem (TVP) of an ordinary differential equation. For non-linear systems with minimum-phase properties, the TVP is automatically solvable. A numerical example shows that the tracking-control method is still available for some systems with non-minimum-phase properties. To enhance the robustness of the tracking controller, a non-linear disturbance observer (NDO) is introduced to estimate the disturbance. The combination of the tracking controller and the NDO is applied to the tracking control of an air-breathing hypersonic vehicle.

  7. 四旋翼无人直升机鲁棒飞行控制%Robust Flight Control of Quadrotor Unmanned Air Vehicles

    Institute of Scientific and Technical Information of China (English)

    白永强; 刘昊; 石宗英; 钟宜生

    2012-01-01

    For quadrotor unmanned air vehicles (UAVs) flight control problem, a robust controller design approach is presented. The controller consists of two parts: an inner-loop attitude controller and an outer-loop position controller. The attitude controller is designed with robust control based on signal compensation. The position controller is realized with classical PD method. It is applied to a quadrotor UAV developed in our laboratory to realize indoor hovering. Experimental results demonstrate the effectiveness of this control approach.%讨论了四旋翼无人直升机的飞行控制问题,提出了一种鲁棒控制器设计方法.该控制器由内环姿态控制器和外环位置控制器两部分组成,姿态控制器采用基于信号补偿的鲁棒控制方法,位置控制器由经典的PD控制实现.将该控制器用于实验室自主研制的四旋翼无人直升机系统,实现了室内悬停飞行.实验结果验证了该控制方法的有效性.

  8. The effect of cushioning insoles on back and lower extremity pain in an industrial setting.

    Science.gov (United States)

    Jefferson, John R

    2013-10-01

    The purpose of this study was to examine the relationship between low back pain and lower extremity pain in a group of factory workers and determine the effect of cushioning insoles on low back pain and lower extremity pain. Data were gathered via questionnaire from 306 employees of an aircraft engine assembly factory. A subset of 40 workers who had reported significant levels of back or lower extremity pain were sampled for four consecutive 12-hour shifts wearing their normal footwear and then a week later for four consecutive shifts wearing cushioning insoles. High levels of low back pain and lower extremity pain were reported by workers on the plant floor, but low back pain was poorly correlated to lower extremity pain (r = 0.371). The effect of insoles on the subset of 40 workers was to lower low back pain by 38%, foot pain by 37%, and knee pain by 38% (p < .001). The reduction in low back pain, however, was not correlated to the reduction in lower extremity pain; workers reporting a decrease in low back pain differed from those reporting less lower extremity pain.

  9. Vehicle to Vehicle Services

    DEFF Research Database (Denmark)

    Brønsted, Jeppe Rørbæk

    2008-01-01

    , mobility, and availability of services. The dissertation consists of two parts. Part I gives an overview of service oriented architecture for pervasive computing systems and describes the contributions of the publications listed in part II. We investigate architecture for vehicular technology applications......As computing devices, sensors, and actuators pervade our surroundings, new applications emerge with accompanying research challenges. In the transportation domain vehicles are being linked by wireless communication and equipped with an array of sensors and actuators that make is possible to provide...... location aware infotainment, increase safety, and lessen environmental strain. This dissertation is about service oriented architecture for pervasive computing with an emphasis on vehicle to vehicle applications. If devices are exposed as services, applications can be created by composing a set of services...

  10. 青岛海湾大桥承台混凝土寒季养护技术%Cold Weather Curing of Cushion Cap Concrete in Qingdao Bay Bridge

    Institute of Scientific and Technical Information of China (English)

    郭保林; 刘征涯; 胡孝展

    2011-01-01

    青岛海湾大桥位于海水含盐度高且存在较严重自然冻融循环的胶州湾海域,施工环境与服役环境都比较恶劣.非通航孔桥承台位于潮差区与浪溅区,为了保证施工期及运营期的混凝土耐久性,采用低水胶比、大掺量矿物掺和料、适量引气的混凝土配制技术,并利用外部围水设施实现海上干法施工.在冬季,为了降低施工期外界环境对混凝土性能的不利影响,将围水设施顶部用帆布覆盖,内部空间布置加热水箱,承台侧面利用蓄水型模板衬里提供不间断的保湿养护.自浇筑至14d养护龄期内,承台侧面及顶面温度始终高于15℃,相对湿度高于95%,模板衬里内积蓄的水量高于混凝土养护所需要的水量,采取该养护方案实现了承台混凝土的持续保温保湿养护,保证了承台混凝土的各项性能健康发展.%The saline concentration of seawater is comparatively high and there are 50 times of freezing and thawing cycles in Kiaochow bay where the Qingdao Bay Bridge is located, moreover, the construction and service environment are very severe for reinforced concrete structure.The cushion caps of approach bridge are all among tidal zone and splash zone.Low water-cement-ratio, high volume mineral admixtures, and air entraining are the main technology to prepare cushion cap concrete.Some cofferdams are utilized to make the construction environment seawater free.In winter, the top of cofferdams are covered with canvas, the space between cushion cap and canvas are heated by several boiling water tanks, and the lateral surface of cushion cap are curing by controlled permeability formwork liner in order to reduce the disadvantage influence of construction factor to concrete.During the first 14 days curing,the environment temperature around the cushion cap are kept above 15℃ , and the RH is above 95%.The free water contained among controlled permeability formwork liner is more than the need of concrete

  11. 单片机在微型飞行器增稳系统中的应用%Applications of Single Chip Micyoco in Mini Air Vehicle's Stability Augmentation System

    Institute of Scientific and Technical Information of China (English)

    陈皓生; 李疆

    2001-01-01

    The stability augmentation system(SAS) is important in mini air vehicle's control system. Mini air vehicle's SAS should be small and light.The digital SAS can meet this request.The component of digital SAS are Single Chip Micyoco(SCM) and assistant circuit,but the most simple digital SAS can be realized by a single SCM.So it is very important to mini air vehicle's SAS design.%增稳系统在微型飞行器的控制系统中起到非常重要的作用。微型飞行器的增稳系统除了要实现增稳算法外,还要求系统的体积小、重量轻。数字式的增稳系统能很好地满足这些要求。数字式增稳系统的构成主要是单片机和外围电路,而最简单的数字控制系统可以只用一片单片机实现,这将极大地减小数字系统的体积和重量,而且便于增稳系统算法的选择和调试,对于微型飞行器的设计有极其重要的意义。

  12. The efficacy of a removable vacuum-cushioned cast replacement system in reducing plantar forefoot pressures in diabetic patients

    NARCIS (Netherlands)

    S.A. Bus; R. Waaijman; M. Arts; H. Manning

    2009-01-01

    Background: The purpose of this study was to determine the plantar forefoot offloading efficacy of a new prefabricated vacuum-cushioned cast replacement system designed for foot ulcer treatment in neuropathic diabetic patients. Methods: Fifteen diabetic subjects with peripheral neuropathy underwent

  13. Error analysis and assessment of unsteady forces acting on a flapping wing micro air vehicle: free flight versus wind-tunnel experimental methods.

    Science.gov (United States)

    Caetano, J V; Percin, M; van Oudheusden, B W; Remes, B; de Wagter, C; de Croon, G C H E; de Visser, C C

    2015-08-20

    An accurate knowledge of the unsteady aerodynamic forces acting on a bio-inspired, flapping-wing micro air vehicle (FWMAV) is crucial in the design development and optimization cycle. Two different types of experimental approaches are often used: determination of forces from position data obtained from external optical tracking during free flight, or direct measurements of forces by attaching the FWMAV to a force transducer in a wind-tunnel. This study compares the quality of the forces obtained from both methods as applied to a 17.4 gram FWMAV capable of controlled flight. A comprehensive analysis of various error sources is performed. The effects of different factors, e.g., measurement errors, error propagation, numerical differentiation, filtering frequency selection, and structural eigenmode interference, are assessed. For the forces obtained from free flight experiments it is shown that a data acquisition frequency below 200 Hz and an accuracy in the position measurements lower than ± 0.2 mm may considerably hinder determination of the unsteady forces. In general, the force component parallel to the fuselage determined by the two methods compares well for identical flight conditions; however, a significant difference was observed for the forces along the stroke plane of the wings. This was found to originate from the restrictions applied by the clamp to the dynamic oscillations observed in free flight and from the structural resonance of the clamped FWMAV structure, which generates loads that cannot be distinguished from the external forces. Furthermore, the clamping position was found to have a pronounced influence on the eigenmodes of the structure, and this effect should be taken into account for accurate force measurements.

  14. Research on Auto Flight Path Planning Algorithm of Multiple Unmanned Air Vehicles%多无人机飞行路径自动规划算法研究

    Institute of Scientific and Technical Information of China (English)

    马传焱

    2015-01-01

    The path planning plays an important role in the reconnaissance task of unmanned air vehicle(UAV).Aiming at auto flight path planning algorithm of multi⁃UAV,this paper analyzes the key technologies of modeling and algorithm design.The algorithm uses Voronoi diagram for path planning. Based on the constructed battlefield environment V diagram, the Dijkstra algorithm in graph theory is used for initial path search and optimization.The simulation results show that this algorithm can be used to plan flight path for a typical multi⁃UAV flight task,and adapt to multiple constraint conditions.At last,it is shown that reasonable results of path planning are obtained.%路径规划对无人机完成其侦察作战任务具有重要意义。针对多无人机飞行路径自动规划算法,从模型建立和算法设计2个方面对规划过程中的关键技术进行了详细分析。算法采用构造Voronoi多边形图的方法来进行路径规划。基于构建的战场环境V图,采用图论中的Dijkstra 算法,对V图进行搜索得到初始航路并进行优化。经过分析仿真结果证明,该算法能对典型的多无人机飞行任务进行路径规划,并能满足多种约束条件,获取合理的规划结果。

  15. 重叠结构缓冲材料缓冲性能分析%Analysis of Cushioning Properties for Cushioning Materials with Overlapping Structures of EPE and EPS Via Finite Element Method

    Institute of Scientific and Technical Information of China (English)

    宋晓利; 刘全校; 张改梅; 孟繁珺; 生雪莹

    2016-01-01

    为了研究EPE厚度的变化对重叠结构缓冲材料缓冲性能的影响,发泡聚乙烯( Expanded Polyethylene,EPE)及发泡聚丙烯( Expanded Polystyrene,EPS)所组成的重叠结构的缓冲材料缓冲性能变化情况,采用有限元法对 EPE 及EPS所组成的重叠结构的缓冲材料的缓冲性能进行了分析。结果表明:随着EPE厚度的增加,最大加速度及最小动态缓冲系数呈下降趋势,但不呈线性关系,且缓冲系数的变化幅度不大。当EPE的厚度达到总厚度的75%时,重叠结构缓冲材料的最大加速度及最小动态缓冲系数最小;随着EPE厚度的增加,最小缓冲系数的静应力会逐渐向右移动,缓冲材料的抗压强度越来越好。%In order to study the effect of EPE’s thickness on the cushioning properties of the cushioning materials which were made of Expanded Polyethylene ( EPE ) and Expanded Polystyrene ( EPS) ,the cushioning properties of the cushioning materials are analyzed based on the finite element method. The results show that with the increase of EPE’s thickness, the maximum acceleration and static stress are not proportional and decreasing. The change of the buffer coefficient is not very large. When the thickness of EPE is 75%, the maximum ac-celeration and minimum dynamic buffer coefficient of the cushioning materials is minimum. With the increase of EPE’s thickness, the static stress of the minimum buffer coefficient will move to the right. The compressive strength of the cushioning materials is better and better.

  16. Lighter-Than-Air Vehicles

    Science.gov (United States)

    2012-01-01

    retrieval sight. The PRV is operated as a UAS glider on its return flight. Balloons capable of operating in near space (upper stratosphere) come in two...airship is at first a flaccid balloon when it takes off. Then, once at a proper altitude, it becomes an airship with a hanging SRV (Figure 63) hanging

  17. Multiple environment unmanned vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Hobart, Clinton G.; Morse, William D.; Bickerstaff, Robert James

    2017-02-28

    A MEUV that is able to navigate aerial, aquatic, and terrestrial environments through the use of different mission mobility attachments is disclosed. The attachments allow the MEUV to be deployed from the air or through the water prior to any terrestrial navigation. The mobility attachments can be removed or detached by and from the vehicle during a mission.

  18. DBD Plasma Actuators for Flow Control in Air Vehicles and Jet Engines - Simulation of Flight Conditions in Test Chambers by Density Matching

    Science.gov (United States)

    Ashpis, David E.; Thurman, Douglas R.

    2011-01-01

    Dielectric Barrier Discharge (DBD) Plasma actuators for active flow control in aircraft and jet engines need to be tested in the laboratory to characterize their performance at flight operating conditions. DBD plasma actuators generate a wall-jet electronically by creating weakly ionized plasma, therefore their performance is affected by gas discharge properties, which, in turn, depend on the pressure and temperature at the actuator placement location. Characterization of actuators is initially performed in a laboratory chamber without external flow. The pressure and temperature at the actuator flight operation conditions need to be simultaneously set in the chamber. A simplified approach is desired. It is assumed that the plasma discharge depends only on the gas density, while other temperature effects are assumed to be negligible. Therefore, tests can be performed at room temperature with chamber pressure set to yield the same density as in operating flight conditions. The needed chamber pressures are shown for altitude flight of an air vehicle and for jet engines at sea-level takeoff and altitude cruise conditions. Atmospheric flight conditions are calculated from standard atmosphere with and without shock waves. The engine data was obtained from four generic engine models; 300-, 150-, and 50-passenger (PAX) aircraft engines, and a military jet-fighter engine. The static and total pressure, temperature, and density distributions along the engine were calculated for sea-level takeoff and for altitude cruise conditions. The corresponding chamber pressures needed to test the actuators were calculated. The results show that, to simulate engine component flows at in-flight conditions, plasma actuator should be tested over a wide range of pressures. For the four model engines the range is from 12.4 to 0.03 atm, depending on the placement of the actuator in the engine. For example, if a DBD plasma actuator is to be placed at the compressor exit of a 300 PAX engine, it

  19. Testing the stress-gradient hypothesis at the roof of the world: effects of the cushion plant Thylacospermum caespitosum on species assemblages.

    Directory of Open Access Journals (Sweden)

    Miroslav Dvorský

    Full Text Available Many cushion plants ameliorate the harsh environment they inhabit in alpine ecosystems and act as nurse plants, with significantly more species growing within their canopy than outside. These facilitative interactions seem to increase with the abiotic stress, thus supporting the stress-gradient hypothesis. We tested this prediction by exploring the association pattern of vascular plants with the dominant cushion plant Thylacospermum caespitosum (Caryophyllaceae in the arid Trans-Himalaya, where vascular plants occur at one of the highest worldwide elevational limits. We compared plant composition between 1112 pair-plots placed both inside cushions and in surrounding open areas, in communities from cold steppes to subnival zones along two elevational gradients (East Karakoram: 4850-5250 m and Little Tibet: 5350-5850 m. We used PERMANOVA to assess differences in species composition, Friedman-based permutation tests to determine individual species habitat preferences, species-area curves to assess whether interactions are size-dependent and competitive intensity and importance indices to evaluate plant-plant interactions. No indications for net facilitation were found along the elevation gradients. The open areas were not only richer in species, but not a single species preferred to grow exclusively inside cushions, while 39-60% of 56 species detected had a significant preference for the habitat outside cushions. Across the entire elevation range of T. caespitosum, the number and abundance of species were greater outside cushions, suggesting that competitive rather than facilitative interactions prevail. This was supported by lower soil nutrient contents inside cushions, indicating a resource preemption, and little thermal amelioration at the extreme end of the elevational gradient. We attribute the negative associations to competition for limited resources, a strong environmental filter in arid high-mountain environment selecting the stress

  20. 考虑推进和气动弹性影响的高超飞行器的建模与控制%Modeling and Robust Coupled Control of Air-Breathing Hypersonic Vehicle Considering Propulsion and Aeroelastic Effects

    Institute of Scientific and Technical Information of China (English)

    曲鑫; 李菁菁; 宋勋; 任章

    2011-01-01

    针对高超声速飞行器飞行的速度和高度跨度大、变化快,飞行动力学特性复杂;模型具有非线性,强耦合及不确定性的特点,建立了考虑推进及弹性影响的纵向模型,并提出了纵向模型的鲁棒协调控制器设计方法.该方法在典型高超声速飞行器几何结构基础上,针对机体/发动机一体化设计布局,结合高超声速气动力学和气动弹性有关理论,建立非线性纵向模型;通过分析模型的不确定性来源,对刚体-弹性耦合系统设计了基于线性二次型调节器的隐式模型跟随鲁棒协调控制器,从而保证飞行器在不确定干扰情况下的闭环系统稳定性.仿真结果表明,本方法所设计的控制器在给定的不确定性范围内具有良好的鲁棒性.%Considering intricate coupling between engine and flight dynamics and complex interaction between flexible and rigid modes, a longitudinal dynamic model for a flexible air-breathing hypersonic vehicle is developed. Unlike conventional aircraft, air-breathing hypersonic vehicles require the propulsion system to be bighly integrated into the airframe.Furthermore, full-scale hypersonic vehicles tend to have very lightweight and flexible structures with low natural frequencies. Therefore, the bending modes are important and affect the amount of airflow entering into the engine, thus influencing the performance of the propulsion system. The equations of motion for the flexible vehicle are derived by using Lagrange ' s equations and capture effect between the pitch and normal accelerations of the vehicle and the structural dynamics. And then, the uneertainties of the longitudinal model are analyzed and a robust coupled controller based on LQR is designed by using implicit model-following method with respect to variations in the vehicle dynamics resulted from fuel consumption. Finally, the simulation results show that the method introduced in this paper is feasible.

  1. Motion analysis of wheelchair propulsion movements in hemiplegic patients: effect of a wheelchair cushion on suppressing posterior pelvic tilt.

    Science.gov (United States)

    Kawada, Kyohei; Matsuda, Tadamitsu; Takanashi, Akira; Miyazima, Shigeki; Yamamoto, Sumiko

    2015-03-01

    [Purpose] This study sought to ascertain whether, in hemiplegic patients, the effect of a wheelchair cushion to suppress pelvic posterior tilt when initiating wheelchair propulsion would continue in subsequent propulsions. [Subjects] Eighteen hemiplegic patients who were able to propel a wheelchair in a seated position participated in this study. [Methods] An adjustable wheelchair was fitted with a cushion that had an anchoring function, and a thigh pad on the propulsion side was removed. Propulsion movements from the seated position without moving through three propulsion cycles were measured using a three-dimensional motion analysis system, and electromyography was used to determine the angle of pelvic posterior tilt, muscle activity of the biceps femoris long head, and propulsion speed. [Results] Pelvic posterior tilt could be suppressed through the three propulsion cycles, which served to increase propulsion speed. Muscle activity of the biceps femoris long head was highest when initiating propulsion and decreased thereafter. [Conclusion] The effect of the wheelchair cushion on suppressing pelvic posterior tilt continued through three propulsion cycles.

  2. 单片机控制的冷暖坐垫%Cushion Controlled By Single-Chip

    Institute of Scientific and Technical Information of China (English)

    林建春

    2011-01-01

    介绍了一种利用ATmega8单片机控制帕尔贴半导体组件制冷、制热的坐垫。坐垫内置水管与外部水箱连通。根据帕尔贴原理,对水箱内的水制冷或加热,并通过微型泵进行水循环,使坐垫的温度与水箱温度保持一致。%This paper introduces the cushion controlled by Peltier to cool or heat by ATmega8 Single-Chip.The cushion has built-in water pipes,with water pipes connected with the external tank.According to the principle of Peltier,water in the tank is cooled or heated,and water circulation is realized by the micro-pump,keeping temperature of the cushion the same with the water temperature.

  3. Experimental investigation of the optimization of stilling basin with shallow- water cushion used for low Froude number energy dissipation

    Institute of Scientific and Technical Information of China (English)

    李连侠; 廖华胜; 刘达; 蒋胜银

    2015-01-01

    Energy dissipations induced by the hydraulic jump and the trajectory jet are the most widely known as the two dissipation modes at the downstream of flood discharging structures, which are often considered quite different even contradictory. However, such two energy dissipators can be used jointly and harmonically. In this paper, a new type of stilling basin with a shallow-water cushion and a triangular bottom deflector is proposed based on two different scale physical model tests of the flood discharging tunnel No.2 of Luding hydropower project. The experimental results show that the flow regime of the hydraulic jump in the presented stilling basin with bottom deflector enjoys a good and stable performance within a large range of flow rates and the energy dissipation rate is considerably high as compared to the conventional stilling basin even at a low Froude number. The results also indicate that the stilling basin with triangular bottom deflector has a better performance in improving the potential cavitation erosion according to the analysis of the pressure and the cavitation number compared to the trapezoidal one. The proposed new type of shallow-cushion stilling basin with a shallow-water cushion can be applied in similar energy dissipation projects with low Froude number and large range of flow rates.

  4. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Air brake system and air-over-hydraulic brake... STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.57 Air brake system and air-over-hydraulic brake subsystem. The following requirements apply to vehicles with air brake and...

  5. 空气悬架系统车身高度和水平控制原理%The Principle of height and level control of the vehicle body with air suspension system

    Institute of Scientific and Technical Information of China (English)

    朱春红; 梁时光; 李婕; 宋建桐

    2015-01-01

    空气悬架系统较其他悬架使汽车具有更好的舒适性和操作稳定性,近年来在高档轿车上应用越来越广泛。本文以奔驰CLS350型汽车为例,对空气悬架系统的高度和水平控制进行简要分析。%air suspension system makes the vehicle has better comfort and operation stability than other suspension. It is used more and more widely in high-grade cars in recent years . In this paper, the Mercedes Benz CLS350 car as an example, height and level control of air suspension system are analyzed.

  6. Use of pressure reducing seats and cushions in a community setting.

    Science.gov (United States)

    Collins, Fiona

    2002-01-01

    It is generally accepted that sitting for long periods of time without frequent repositioning or provision of appropriate cushions or chairs can lead to pressure ulcer development in people who are elderly, frail, immobile or neurologically impaired. When sitting, in comparison to lying, only a small surface area of the body is providing support, predominantly the buttocks and thighs, and the feet. Therefore, interface pressures are much greater in sitting than lying. Sitting for long periods of time can result in the person adopting poor posture, which in turn can lead to the development of pressure ulcers, particularly on the buttocks, sacrum, greater trochanter and heels. Assessment and provision of appropriate seating equipment for people at risk is often difficult for clinicians working in the community. This article aims to describe the problems experienced by people who sit for long periods of time, to discuss where people should go in order to obtain help with seating needs, and outline some of the potential solutions to poor seating which are available to community staff.

  7. Metal-Organic Frameworks (MOFs) as Sandwich Coating Cushion for Silicon Anode in Lithium Ion Batteries.

    Science.gov (United States)

    Han, Yuzhen; Qi, Pengfei; Zhou, Junwen; Feng, Xiao; Li, Siwu; Fu, Xiaotao; Zhao, Jingshu; Yu, Danni; Wang, Bo

    2015-12-09

    A novel metal-organic framework (MOF) sandwich coating method (denoted as MOF-SC) is developed for hybrid Li ion battery electrode preparation, in which the MOF films are casted on the surface of a silicon layer and sandwiched between the active silicon and the separator. The obtained electrodes show improved cycling performance. The areal capacity of the cheap and readily available microsized Si treated with MOF-SC can reach 1700 μAh cm(-2) at 265 μA cm(-2) and maintain at 850 μAh cm(-2) after 50 cycles. Beyond the above, the commercial nanosized Si treated by MOF-SC also shows greatly enhanced areal capacity and outstanding cycle stability, 600 μAh cm(-2) for 100 cycles without any apparent fading. By virtue of the novel structure prepared by the MOFs, this new MOF-SC structure serves as an efficient protection cushion for the drastic volume change of silicon during charge/discharge cycles. Furthermore, this MOF layer, with large pore volume and high surface area, can adsorb electrolyte and allow faster diffusion of Li(+) as evidenced by decreased impedance and improved rate performance.

  8. A nanometric cushion for enhancing scratch and wear resistance of hard films.

    Science.gov (United States)

    Gotlib-Vainshtein, Katya; Girshevitz, Olga; Sukenik, Chaim N; Barlam, David; Cohen, Sidney R

    2014-01-01

    Scratch resistance and friction are core properties which define the tribological characteristics of materials. Attempts to optimize these quantities at solid surfaces are the subject of intense technological interest. The capability to modulate these surface properties while preserving both the bulk properties of the materials and a well-defined, constant chemical composition of the surface is particularly attractive. We report herein the use of a soft, flexible underlayer to control the scratch resistance of oxide surfaces. Titania films of several nm thickness are coated onto substrates of silicon, kapton, polycarbonate, and polydimethylsiloxane (PDMS). The scratch resistance measured by scanning force microscopy is found to be substrate dependent, diminishing in the order PDMS, kapton/polycarbonate, Si/SiO2. Furthermore, when PDMS is applied as an intermediate layer between a harder substrate and titania, marked improvement in the scratch resistance is achieved. This is shown by quantitative wear tests for silicon or kapton, by coating these substrates with PDMS which is subsequently capped by a titania layer, resulting in enhanced scratch/wear resistance. The physical basis of this effect is explored by means of Finite Element Analysis, and we suggest a model for friction reduction based on the "cushioning effect" of a soft intermediate layer.

  9. Wear rate evaluation of a novel polycarbonate-urethane cushion form bearing for artificial hip joints.

    Science.gov (United States)

    Elsner, Jonathan J; Mezape, Yoav; Hakshur, Keren; Shemesh, Maoz; Linder-Ganz, Eran; Shterling, Avi; Eliaz, Noam

    2010-12-01

    There is growing interest in the use of compliant materials as an alternative to hard bearing materials such as polyethylene, metal and ceramics in artificial joints. Cushion form bearings based on polycarbonate-urethane (PCU) mimic the natural synovial joint more closely by promoting fluid-film lubrication. In the current study, we used a physiological simulator to evaluate the wear characteristics of a compliant PCU acetabular buffer, coupled against a cobalt-chrome femoral head. The wear rate was evaluated over 8 million cycles gravimetrically, as well as by wear particle isolation using filtration and bio-ferrography (BF). The gravimetric and BF methods showed a wear rate of 9.9-12.5mg per million cycles, whereas filtration resulted in a lower wear rate of 5.8mg per million cycles. Bio-ferrography was proven to be an effective method for the determination of wear characteristics of the PCU acetabular buffer. Specifically, it was found to be more sensitive towards the detection of wear particles compared to the conventional filtration method, and less prone to environmental fluctuations than the gravimetric method. PCU demonstrated a low particle generation rate (1-5×10⁶ particles per million cycles), with the majority (96.6%) of wear particle mass lying above the biologically active range, 0.2-10μm. Thus, PCU offers a substantial advantage over traditional bearing materials, not only in its low wear rate, but also in its osteolytic potential.

  10. Wettability-independent bouncing on flat surfaces mediated by thin air films

    Science.gov (United States)

    de Ruiter, Jolet; Lagraauw, Rudy; van den Ende, Dirk; Mugele, Frieder

    2015-01-01

    The impingement of drops onto solid surfaces plays a crucial role in a variety of processes, including inkjet printing, fog harvesting, anti-icing, dropwise condensation and spray coating. Recent efforts in understanding and controlling drop impact behaviour focused on superhydrophobic surfaces with specific surface structures enabling drop bouncing with reduced contact time. Here, we report a different universal bouncing mechanism that occurs on both wetting and non-wetting flat surfaces for both high and low surface tension liquids. Using high-speed multiple-wavelength interferometry, we show that this bouncing mechanism is based on the continuous presence of an air film for moderate drop impact velocities. This submicrometre `air cushion' slows down the incoming drop and reverses its momentum. Viscous forces in the air film play a key role in this process: they provide transient stability of the air cushion against squeeze-out, mediate momentum transfer, and contribute a substantial part of the energy dissipation during bouncing.

  11. Electric vehicles

    Science.gov (United States)

    1990-03-01

    Quiet, clean, and efficient, electric vehicles (EVs) may someday become a practical mode of transportation for the general public. Electric vehicles can provide many advantages for the nation's environment and energy supply because they run on electricity, which can be produced from many sources of energy such as coal, natural gas, uranium, and hydropower. These vehicles offer fuel versatility to the transportation sector, which depends almost solely on oil for its energy needs. Electric vehicles are any mode of transportation operated by a motor that receives electricity from a battery or fuel cell. EVs come in all shapes and sizes and may be used for different tasks. Some EVs are small and simple, such as golf carts and electric wheel chairs. Others are larger and more complex, such as automobile and vans. Some EVs, such as fork lifts, are used in industries. In this fact sheet, we will discuss mostly automobiles and vans. There are also variations on electric vehicles, such as hybrid vehicles and solar-powered vehicles. Hybrid vehicles use electricity as their primary source of energy, however, they also use a backup source of energy, such as gasoline, methanol or ethanol. Solar-powered vehicles are electric vehicles that use photovoltaic cells (cells that convert solar energy to electricity) rather than utility-supplied electricity to recharge the batteries. These concepts are discussed.

  12. 桩帽垫层对锤击沉桩的影响数值分析%Numerical Analysis of Influence of Pile Cap Cushion on Driving Pile

    Institute of Scientific and Technical Information of China (English)

    王继成; 倪占东; 柳爱; 周向阳

    2011-01-01

    Elastic pile cap cushion and hardwood cushion are simulated by ABAQUS, the famous finite element software, in order to study the influence of pile cap cushion on driving pile in this paper. It is discovered that elastic cushion can reduce the stress of the driven pile evidently during the driving process,but the capacity of reducing the pile stress of hardwood is poor. The penetration can be increased greatly with suitable thickness and stiffness of the cushion. There is certain relationship among hammering energy, thickness and stiffness of the cushion. A certain stiffness corresponds to an optimal thickness, the optimal thickness and the range of optimal thickness is enlarged with the increase of stiffness. Much better effectiveness of driving pile with thicker and suitable pile cap cushion can be obtained.%为了研究桩帽垫层对锤击沉桩效果的影响,采用有限元软件ABAQUS对弹性桩帽垫层和硬木垫层进行了模拟,发现弹性垫层在锤击过程中可显著降低桩身应力,而硬木板降低桩身应力的能力有限.采用合适厚度、刚度的垫层时,可显著增加贯人度.锤击能、垫层厚度、垫层刚度之间存在一定关系.对于某一垫层刚度,存在一最优垫层厚度,垫层刚度增加,最优垫层厚度范围也增加了.厚度较厚、刚度稍大的垫层能取得较好的沉桩效果.

  13. 40 CFR 85.1703 - Definition of motor vehicle.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Definition of motor vehicle. 85.1703... (CONTINUED) CONTROL OF AIR POLLUTION FROM MOBILE SOURCES Exclusion and Exemption of Motor Vehicles and Motor Vehicle Engines § 85.1703 Definition of motor vehicle. (a) For the purpose of determining...

  14. Thermal management optimization of an air-cooled Li-ion battery module using pin-fin heat sinks for hybrid electric vehicles

    Science.gov (United States)

    Mohammadian, Shahabeddin K.; Zhang, Yuwen

    2015-01-01

    Three dimensional transient thermal analysis of an air-cooled module that contains prismatic Li-ion cells next to a special kind of aluminum pin fin heat sink whose heights of pin fins increase linearly through the width of the channel in air flow direction was studied for thermal management of Lithium-ion battery pack. The effects of pin fins arrangements, discharge rates, inlet air flow velocities, and inlet air temperatures on the battery were investigated. The results showed that despite of heat sinks with uniform pin fin heights that increase the standard deviation of the temperature field, using this kind of pin fin heat sink compare to the heat sink without pin fins not only decreases the bulk temperature inside the battery, but also decreases the standard deviation of the temperature field inside the battery as well. Increasing the inlet air temperature leads to decreasing the standard deviation of the temperature field while increases the maximum temperature of the battery. Furthermore, increasing the inlet air velocity first increases the standard deviation of the temperature field till reaches to the maximum point, and after that decreases. Also, increasing the inlet air velocity leads to decrease in the maximum temperature of the battery.

  15. A new mulinane diterpenoid from the cushion shrub Azorella compacta growing in Perú

    Science.gov (United States)

    Salgado, Francisco; Areche, Carlos; Sepúlveda, Beatriz; Simirgiotis, Mario J.; Cáceres, Fátima; Quispe, Cristina; Quispe, Lina; Cano, Teresa

    2014-01-01

    Background: Azorella compacta is a rare yellow-green compact resinous cushion shrub growing from the high Andes of southern Perú to northwestern Argentina, and which is a producer of biologically active and unique diterpenoids. Objective: This study investigated the secondary metabolites present in a Peruvian sample of Azorella compacta and the evaluation of gastroprotective activity of the isolated compounds in a gastric- induced ulcer model in mice. Material and Methods: Six secondary metabolites (diterpenoids 1-6) present in the dichloromethane (DCM) extract of A. compacta growing in Perú were isolated by a combination of Sephadex LH-20 permeation and silica gel chromatography and their chemical structures were elucidated by spectroscopic methods (NMR) and molecular modeling. The gastroprotective activity of the new compound 1 was evaluated on the HCl/EtOH-induced gastric lesion model in mice and compared to the activity showed by the known compounds. Results: A new mulinane diterpene along with five known diterpenoids have been isolated from a Peruvian sample of A. compacta and the gastroprotective results show that compound 1 is less active than the other known mulinane diterpenoids isolated. Conclusions: A. compacta growing in Perú showed the presence of the new mulinane 1, which was poorly active in the HCl/EtOH-induced gastric lesion model in mice. Indeed, the activity was lower than other diterpenoids (2-6) showing an oxygenated function at C-16 or/and C-20, which confirm the role of an oxygenated group (OH or carboxylic acid) for the gastroprotective activity of mulinane compounds. PMID:25298672

  16. Retinoic Acid Signaling Is Essential for Valvulogenesis by Affecting Endocardial Cushions Formation in Zebrafish Embryos.

    Science.gov (United States)

    Li, Junbo; Yue, Yunyun; Zhao, Qingshun

    2016-02-01

    Retinoic acid (RA) plays important roles in many stages of heart morphogenesis. Zebrafish embryos treated with exogenous RA display defective atrio-ventricular canal (AVC) specification. However, whether endogenous RA signaling takes part in cardiac valve formation remains unknown. Herein, we investigated the role of RA signaling in cardiac valve development by knocking down aldh1a2, the gene encoding an enzyme that is mainly responsible for RA synthesis during early development, in zebrafish embryos. The results showed that partially knocking down aldh1a2 caused defective formation of primitive cardiac valve leaflets at 108 hpf (hour post-fertilization). Inhibiting endogenous RA signaling by 4-diethylaminobenzal-dehyde revealed that 16-26 hpf was a key time window when RA signaling affects the valvulogenesis. The aldh1a2 morphants had defective formation of endocardial cushion (EC) at 76 hpf though they had almost normal hemodynamics and cardiac chamber specification at early development. Examining the expression patterns of AVC marker genes including bmp4, bmp2b, nppa, notch1b, and has2, we found the morphants displayed abnormal development of endocardial AVC but almost normal development of myocardial AVC at 50 hpf. Being consistent with the reduced expression of notch1b in endocardial AVC, the VE-cadherin gene cdh5, the downstream gene of Notch signaling, was ectopically expressed in AVC of aldh1a2 morphants at 50 hpf, and overexpression of cdh5 greatly affected the formation of EC in the embryos at 76 hpf. Taken together, our results suggest that RA signaling plays essential roles in zebrafish cardiac valvulogenesis.

  17. Evolved Expendable Launch Vehicle: The Air Force Needs to Adopt an Incremental Approach to Future Acquisition Planning to Enable Incorporation of Lessons Learned

    Science.gov (United States)

    2015-08-01

    Acquisitions, Technology, and Logistics directed the Air Force to introduce a competitive procurement environment for up to 14 launches.11... competition in the launch industry is a high priority for the service, and not requiring DOD-approved business systems is a key advantage of...program is the primary provider launches for military and intelligence satellites. The Air Force is working to introduce competition into the program

  18. Calculation of Manpower Requirements for Vehicle Maintenance at U.S. Army Installation Directorates of Engineering and Housing, Based on Air Force, Navy and Army Reserves Staffing Techniques

    Science.gov (United States)

    1988-10-01

    request; maintains suspense files; inspects and maintains tools; schedules precision measurement equipment (PME); performs tool crib inventory. 3...assets. 12. Tool Crib. Issues and receives tools upon request; maintains suspense file; inspects and maintains tools; schedules precision measurement...MOTORCYCLE, PACKAGE DELIVERY, 3-WHEEL WITH SIDE CAR (ALSO SERVICE VEHICLE) 0905 Z SCOOT PK 3-4WRL SCOOTER , MOTOR, PKG DELIVERY, 3-4 WHEEL WITH SIDE CAR 0907 Z

  19. 无人机溢油监视监测系统方案构想%roject concept on unmanned air vehicle oil spill monitoring system

    Institute of Scientific and Technical Information of China (English)

    舒迟

    2015-01-01

    The paper introduces the functions and system components of the oil spill surveillance and monitor system using unmanned aerial vehicles (UAV) and analyzes its advantage of application in oil spill surveillance and monitor.%文中介绍了无人机溢油监视监测系统的功能和系统组成,并分析了其在溢油监视监测领域中的应用优势。

  20. Subjective valuation of cushioning in a human drop landing task as quantified by trade-offs in mechanical work.

    Science.gov (United States)

    Skinner, Nathaniel E; Zelik, Karl E; Kuo, Arthur D

    2015-07-16

    Humans can perform motor tasks in a variety of ways, yet often favor a particular strategy. Some factors governing the preferred strategy may be objective and quantifiable, (e.g. metabolic energy or mechanical work) while others may be more subjective and less measurable, (e.g. discomfort, pain, or mental effort). Subjectivity can make it challenging to explain or predict preferred movement strategies. We propose that subjective factors might nevertheless be characterized indirectly by their trade-offs against more objective measures such as work. Here we investigated whether subjective costs that influence human movement during drop landings could be indirectly assessed by quantifying mechanical work performed. When landing on rigid ground, humans typically absorb much of the collision actively by bending their knees, perhaps to avoid the discomfort of stiff-legged landings. We measured how work performed by healthy adults (N=8) changed as a function of surface cushioning for drop landings (fixed at about 0.4m) onto varying amounts of foam. Landing on more foam dissipated more energy passively in the surface, thus reducing the net dissipation required of subjects, due to relatively fixed landing energy. However, subjects actually performed even less work in the dissipative collision, as well as in the subsequent active, positive work to return to upright stance (approximately linear decrease of about 1.52 J per 1 cm of foam thickness). As foam thickness increased, there was also a corresponding reduction in center-of-mass vertical displacement after initial impact by up to 43%. Humans appear to subjectively value cushioning, revealed by the extra work they perform landing without it. Cushioning is thus worth more than the energy it dissipates, in an amount that indicates the subjective discomfort of stiff landings.

  1. Air Data Calibration Facility

    Data.gov (United States)

    Federal Laboratory Consortium — This facility is for low altitude subsonic altimeter system calibrations of air vehicles. Mission is a direct support of the AFFTC mission. Postflight data merge is...

  2. 75 FR 18061 - Approval and Promulgation of Air Quality Implementation Plans; Texas; Control of Air Pollution...

    Science.gov (United States)

    2010-04-09

    ... Air Pollution From Motor Vehicles AGENCY: Environmental Protection Agency (EPA). ACTION: Direct final... amend 30 TAC Chapter 114, Control of Air Pollution from Motor Vehicles. These revisions consist of the... to develop air pollution regulations and control strategies to ensure that air quality meets...

  3. Digital Cushion Fatty Acid Composition and Lipid Metabolism Gene Network Expression in Holstein Dairy Cows Fed a High-Energy Diet.

    Directory of Open Access Journals (Sweden)

    Zeeshan Muhammad Iqbal

    Full Text Available The hoof digital cushion is a complex structure composed of adipose tissue beneath the distal phalanx, i.e. axial, middle and abaxial fat pad. The major role of these fat depots is dampening compression of the corium underneath the cushion. The study aimed to determine expression of target genes and fatty acid profiles in the hoof of non-pregnant dry Holstein cows fed low (CON or high-energy (OVE diets. The middle fat pad of the hoof digital cushion was collected soon after slaughter. Despite the lack of effect on expression of the transcription regulators SREBF1 and PPARG, the expression of the lipogenic enzymes ACACA, FASN, SCD, and DGAT2 was upregulated with OVE. Along with the upregulation of G6PD and IDH1, important for NADPH synthesis during lipogenesis, and the basal glucose transporter SLC2A1, these data indicated a pro-lipogenic response in the digital cushion with OVE. The expression of the lipid droplet-associated protein PLIN2 was upregulated while expression of lipolytic enzymes (ATGL, ABDH5, and LIPE only tended to be upregulated with OVE. Therefore, OVE induced lipogenesis, lipid droplet formation, and lipolysis, albeit to different extents. Although concentration of monounsaturated fatty acids (MUFA did not differ, among the polyunsaturated fatty acids (PUFA, the concentration of 20:5n3 was lower with OVE. Among the saturated fatty acids, 20:0 concentration was greater with OVE. Although data indicated that the hoof digital cushion metabolic transcriptome is responsive to higher-energy diets, this did not translate into marked differences in the fatty acid composition. The decrease in concentration of PUFA, which could contribute to synthesis of inflammatory molecules, in OVE-fed cows indicated that feeding higher-energy diets might be detrimental for the mediation of inflammation in digital cushion. This effect could be further exacerbated by physiologic and endocrine changes during the peripartal period that favor inflammation.

  4. Air riding seal for a turbine

    Energy Technology Data Exchange (ETDEWEB)

    Mills, Jacob A; Brown, Wesley D; Sexton, Thomas D; Jones, Russell B

    2016-07-19

    An air riding seal between a rotor and a stator in a turbine of a gas turbine engine, where an annular piston is movable in an axial direction within a housing that extends from the stator, and a bellows is secured to the annular piston to form a flexible air passageway from a compressed air inlet through the annular piston and into a cushion cavity that forms an air riding seal between the annular piston and the rotor sealing surface. In another embodiment, a flexible seal secured to and extending from the annular piston forms a sealing surface between the annular piston chamber and the annular piston to provide a seal and allow for axial movement.

  5. Transplantation and Appl ication of MAVLink Micro Unmanned Air Vehicle Communication Protocol Based on DSP%DSP 的 MAVLink 微型无人机通信协议移植与应用

    Institute of Scientific and Technical Information of China (English)

    吕强; 倪佩佩; 王国胜; 刘峰

    2014-01-01

    MAVLink micro unmanned air vehicle communication protocol is widely used in communications between the ground control station and unmanned air vehicle flight control platform such as PIXHAWK,SLUGS and ArduPilot.MAVLink has been proven to work on ARM7,ATmega and STM32 microcontrollers and it can be developed under Windows,Linux and MacOS operating systems. Because of MAVLink'incompatibility with DSP,a method is proposed to transplant MAVLink to DSP and communicate with ground control station software QGroundControl via WiFi.Experimental results show that this method can effectively make MAVLink compati-ble with DSP,reduce CPU consumption via SPI-to-WiFi,improve data transmission rates and reduce data loss.%MAVLink 微型无人机通信协议广泛应用于地面控制站与 PIXHAWK、SLUGS 和 ArduPilot 等无人机飞控平台的通信。MAVLink 已被证明能够工作在 ARM7、ATmega、STM32等微控制器上,并能在 Windows、Linux 和 MacOS 操作系统下开发。由于 MAVLink 与 DSP 不兼容,故本文提出一种将 MAVLink 移植到 DSP,并通过 WiFi 与地面控制站软件 QGroundControl 进行通信的方法。实验证明,该方法能够使 MAVLink 有效兼容 DSP,并且通过 SPI 转 WiFi 连接,减小了 CPU 开销,提高了数据传输速率,减少了数据的丢失情况。

  6. Abandoned vehicles

    CERN Multimedia

    Relations with the Host States Service

    2004-01-01

    The services in charge of managing the CERN site have recently noted an increase in the number of abandoned vehicles. This poses a risk from the point of view of safety and security and, on the eve of several important events in honour of CERN's fiftieth anniversary, is detrimental to the Organization's image. Owners of vehicles that have been left immobile for some time on the CERN site, including on the external car park by the flags, are therefore invited to contact the Reception and Access Control Service (service-parking-longterm@cern.ch) before 1st October 2004 and, where appropriate, move their vehicle to a designated long-term parking area. After this date, any vehicle whose owner has failed to respond to this request and which is without a number plate, has been stationary for several weeks or is out of service, may be impounded at the owner's risk and expense. Relations with the Host States Service Tel. 72848

  7. Influence of Cushioning Variables in the Workplace and in the Family on the Probability of Suffering Stress.

    Science.gov (United States)

    Gonzalo, David Cárdenas

    2016-09-01

    Stress at work and in the family is a very common issue in our society that generates many health-related problems. During recent years, numerous studies have sought to define the term stress, raising many contradictions that various authors have studied. Other authors have attempted to establish some criteria, in subjective and not very quantitative ways, in an attempt to reduce and even to eliminate stressors and their effects at work and in the family context. The purpose of this study was to quantify so-called cushioning variables, such as control, social support, home/work life conciliation, and even sports and leisure activities, with the purpose of, as much as possible, reducing the negative effects of stress, which seriously affects the health of workers. The study employs data from the Fifth European Working Conditions Survey, in which nearly 44,000 interviewees from 34 countries in the European Union participated. We constructed a probabilistic model based on a Bayesian network, using variables from both the workplace and the family, the aforementioned cushioning variables, as well as the variable stress. If action is taken on the above variables, then the probabilities of suffering high levels of stress may be reduced. Such action may improve the quality of life of people at work and in the family.

  8. Mapping sub-antarctic cushion plants using random forests to combine very high resolution satellite imagery and terrain modelling.

    Directory of Open Access Journals (Sweden)

    Phillippa K Bricher

    Full Text Available Monitoring changes in the distribution and density of plant species often requires accurate and high-resolution baseline maps of those species. Detecting such change at the landscape scale is often problematic, particularly in remote areas. We examine a new technique to improve accuracy and objectivity in mapping vegetation, combining species distribution modelling and satellite image classification on a remote sub-Antarctic island. In this study, we combine spectral data from very high resolution WorldView-2 satellite imagery and terrain variables from a high resolution digital elevation model to improve mapping accuracy, in both pixel- and object-based classifications. Random forest classification was used to explore the effectiveness of these approaches on mapping the distribution of the critically endangered cushion plant Azorella macquariensis Orchard (Apiaceae on sub-Antarctic Macquarie Island. Both pixel- and object-based classifications of the distribution of Azorella achieved very high overall validation accuracies (91.6-96.3%, κ = 0.849-0.924. Both two-class and three-class classifications were able to accurately and consistently identify the areas where Azorella was absent, indicating that these maps provide a suitable baseline for monitoring expected change in the distribution of the cushion plants. Detecting such change is critical given the threats this species is currently facing under altering environmental conditions. The method presented here has applications to monitoring a range of species, particularly in remote and isolated environments.

  9. Novel wireless health monitor with acupuncture bio-potentials obtained by using a replaceable salt-water-wetted foam-rubber cushions on RFID-tag.

    Science.gov (United States)

    Lin, Jium-Ming; Lu, Hung-Han; Lin, Cheng-Hung

    2014-01-01

    This paper proposes a bio-potential measurement apparatus including a wireless device for transmitting acupuncture bio-potential information to a remote control station for health conditions analysis and monitor. The key technology of this system is to make replaceable foam-rubber cushions, double-side conducting tapes, chip and antenna on the radio frequency identification (RFID) tag. The foam-rubber cushions can be wetted with salt-water and contact with the acupuncture points to reduce contact resistance. Besides, the double-side conducting tapes are applied to fix foam-rubber cushions. Thus, one can peel the used cushions or tapes away and supply new ones quickly. Since the tag is a flexible plastic substrate, it is easy to deploy on the skin. Besides, the amplifier made by CMOS technology on RFID chip could amplify the signals to improve S/N ratio and impedance matching. Thus, cloud server can wirelessly monitor the health conditions. An example shows that the proposed system can be used as a wireless health condition monitor, the numerical method and the criteria are given to analyze eleven bio-potentials for the important acupunctures of eleven meridians on a person's hands and legs. Then a professional doctor can know the performance of an individual and the cross-linking effects of the organs.

  10. Contact sensitization to calocephalin, a sesquiterpene lactone of the guaianolide type from cushion bush (Leucophyta brownii, Compositae)

    DEFF Research Database (Denmark)

    Paulsen, Evy; Christensen, Lars P; Hindsén, Monica;

    2013-01-01

    Cushion bush [Leucophyta brownii Cass. = Calocephalus brownii (Cass.) F. Muell.] is an Australian Compositae shrub that has been introduced into Scandinavia as a pot plant. The first case of sensitization occurred in a gardener, and the main allergen was identified as the guaianolide calocephalin....

  11. electric vehicle

    Directory of Open Access Journals (Sweden)

    W. R. Lee

    1999-01-01

    Full Text Available A major problem facing battery-powered electric vehicles is in their batteries: weight and charge capacity. Thus, a battery-powered electric vehicle only has a short driving range. To travel for a longer distance, the batteries are required to be recharged frequently. In this paper, we construct a model for a battery-powered electric vehicle, in which driving strategy is to be obtained such that the total travelling time between two locations is minimized. The problem is formulated as an optimization problem with switching times and speed as decision variables. This is an unconventional optimization problem. However, by using the control parametrization enhancing technique (CPET, it is shown that this unconventional optimization is equivalent to a conventional optimal parameter selection problem. Numerical examples are solved using the proposed method.

  12. The Characterization of Material Properties and Structural Dynamics of the Manduca Sexta Forewing for Application to Flapping Wing Micro Air Vehicle Design

    Science.gov (United States)

    O'Hara, Ryan P.

    Collateral damage presents a significant risk during air drops and airstrikes, risking citizens' lives and property, straining the relationship between the United States Air Force and host nations. This dissertation presents a methodology to determine the optimal location for making supply airdrops in order to minimize collateral damage while maintaining a high likelihood of successful recovery. A series of non-linear optimization algorithms are presented along with their relative success in finding the optimal location in the airdrop problem. Additionally, we present a quick algorithm for accurately creating the Pareto frontier in the multi-objective airstrike problem. We demonstrate the effect of differing guidelines, damage functions, and weapon employment selection which significantly alter the location of the optimal aimpoint in this targeting problem. Finally, we have provided a framework for making policy decisions in fast-moving troops-in-contact situations where observers are unsure of the nature of possible enemy forces in both finite and infinite time horizon problems. Through a recursive technique of solving this Markov decision process we have demonstrated the effect of improved intelligence and differing weights in the face of uncertain situations.

  13. Adaptive backstepping control for an air-breathing hypersonic vehicle with input constraints%吸气式高超声速飞行器输入受限自适应反演控制

    Institute of Scientific and Technical Information of China (English)

    时建明; 王洁; 叶继坤; 邵雷

    2012-01-01

    The issues of flight control of an air-breathing hypersonic vehicle with constrained inputs and uncertain aerodynamic coefficients were addressed. Based on backstepping procedure, virtual and actual controllers were designed for linearly parameterized form of the vehicle longitudinal motion model. To deal with uncertain parametric coefficients, on-line adaptive bounding learning scheme was selected. Considering input constraints condition, tracking errors were modified by introducing margin filtering terms of designed controllers and executable inputs. Stability analysis was implemented to prove the effectiveness of the proposed method. Reference trajectory tracking simulation results demonstrate the effectiveness of the control law design under wind disturbance.%针对输入受限和气动与推进参数存在不确定时的吸气式高超声速飞行器飞行控制问题,建立了线性参数化形式的纵向运动模型,通过引入控制量与可执行输入之间的差值滤波环节,修正跟踪误差的定义,设计了使闭环系统稳定的反演鲁棒控制器,给出了气动与推进参数向量的有界自适应估计律.轨迹跟踪仿真结果表明,提出的自适应控制方法能够保证阵风干扰情况下飞行器控制的稳定性.

  14. Experimental Evaluation of the Effect of Angle-of-attack on the External Aerodynamics and Mass Capture of a Symmetric Three-engine Air-breathing Launch Vehicle Configuration at Supersonic Speeds

    Science.gov (United States)

    Kim, Hyun D.; Frate, Franco C.

    2001-01-01

    A subscale aerodynamic model of the GTX air-breathing launch vehicle was tested at NASA Glenn Research Center's 10- by 10-Foot Supersonic Wind Tunnel from Mach 2.0 to 3.5 at various angles-of-attack. The objective of the test was to investigate the effect of angle-of-attack on inlet mass capture, inlet diverter effectiveness, and the flowfield at the cowl lip plane. The flow-through inlets were tested with and without boundary-layer diverters. Quantitative measurements such as inlet mass flow rates and pitot-pressure distributions in the cowl lip plane are presented. At a 3deg angle-of-attack, the flow rates for the top and side inlets were within 8 percent of the zero angle-of-attack value, and little distortion was evident at the cowl lip plane. Surface oil flow patterns showing the shock/boundary-layer interaction caused by the inlet spikes are shown. In addition to inlet data, vehicle forebody static pressure distributions, boundary-layer profiles, and temperature-sensitive paint images to evaluate the boundary-layer transition are presented. Three-dimensional parabolized Navier-Stokes computational fluid dynamics calculations of the forebody flowfield are presented and show good agreement with the experimental static pressure distributions and boundary-layer profiles. With the boundary-layer diverters installed, no adverse aerodynamic phenomena were found that would prevent the inlets from operating at the required angles-of-attack. We recommend that phase 2 of the test program be initiated, where inlet contraction ratio and diverter geometry variations will be tested.

  15. 40 CFR 69.51 - Motor vehicle diesel fuel.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Motor vehicle diesel fuel. 69.51... (CONTINUED) SPECIAL EXEMPTIONS FROM REQUIREMENTS OF THE CLEAN AIR ACT Alaska § 69.51 Motor vehicle diesel... motor vehicle diesel fuel standards and dye provisions under 40 CFR 80.520 and associated...

  16. Numerical simulation of dynamic derivatives for air-breathing hypersonic vehicle%吸气式内外流一体化飞行器动导数数值模拟

    Institute of Scientific and Technical Information of China (English)

    刘绪; 刘伟; 周云龙; 柴振霞

    2015-01-01

    Dynamic derivatives are important parameters for designing aircraft trajectory and attitude control system,and for deciding the divergence behavior of vibration under disturbance. After calibration model validation,the dynamic behavior of an air—breathing hypersonic vehicle, namely WR—A (Wave Rider)is characterized.The unsteady flow field around the under aircraft forced simple harmonic vibration (SHV)condition is simulated using Navier Stokes equation. The direct damping derivatives,acceleration derivatives and rotary derivatives of this air—breathing hypersonic vehicle are obtained.The air inlet performance parameter derivatives are solved using Etkin predictive aerodynamic model.The air inlet performance parameters under large—amplitude vibration are successfully predicted using the dynamic derivative model.This offers a guideline for characterizing the dynamic unsteady internal flow field and predicting air inlet performance variation.The proportion of acceleration derivative,which represents the flow time lag effect,in the direct damping derivative can be as high as forty percent but is opposite to the damping deriv—ative direction in some cases,contributing to dynamic instability adversely.It is reasonable to using this dynamic derivative model to express the aerodynamic behavior of air—breathing hyper—sonic vehicle at large angles of attack according to this WR—A large—amplitude vibration simula—tion.%动导数是飞行器轨道及姿态控制系统设计时的重要参数,对飞行器开环系统受到扰动时振荡的敛散特性起重要作用。在标模验证的基础上开展吸气式内外流一体化飞行器 WR—A 动态特性分析,采用 N—S 方程模拟强迫简谐振动的非定常流场,获得了飞行器的直接阻尼导数、加速度导数和旋转导数,并对 WR—A 外形大振幅振动时的进气道性能参数进行了分析。研究表明,在某些情况下反映流动时滞效应的加速度导数

  17. Dynamic characteristics of peripheral jet ACV. II - Pitching motion

    Science.gov (United States)

    Mori, T.; Maeda, H.

    The dynamic pitching characteristics of peripheral jet ACV (Air Cushion Vehicle) which have a stability curtain are investigated analytically and experimentally. The measured values of moment, lift and cushion pressure are compared with numerical results noting applicability to the pitching motion. The response of ACV to the sinusoidal pitching oscillation of the ground is also studied.

  18. 生物质缓冲包装材料制备及性能实验研究%Preparation and properties of biomass cushion packaging material

    Institute of Scientific and Technical Information of China (English)

    李刚; 李方义; 管凯凯; 刘鹏; 吕禹; 贾秀杰; 李剑峰

    2013-01-01

    To solve the environmental pollution caused by the non-degradable waste of plastic packaging materials,the biomass cushion packaging materials with different ingredients have been synthesized,which are made up of straw fiber and starch as the main raw materials.The orthogonal experiment method is used to study the impact of the mass ratio of fiber and starch,the content of plasticizer,active agent and blowing agent on the compressive strength of biomass cushion packaging material.The results were as follows:the influence order of various factors on compressive strength was:plasticizer >the mass ratio of fiber and starch> foaming agent>active agent.When the contents of the plasticizer,foaming agent,active agent are respectively 12%,0.1%,0.3% with the mass ratio of fiber and starch being 2:5,the compressive strength can reach 0.94MPa.Through research on the impacts of plasticizer content and mass ratio of fiber and starch on the cushion performance,the cushion coefficient of the material decreases firstly and increases subsequently with the two factors rising.When the plasticizer content was 12% and the mass ratio of fiber and starch was 2:5,the smallest cushion coefficient and the best cushion performance of the material are obtained.Compared the cushion and rebound performance with EPS (expanded polystyrene),EPE (expanded polyethylene) and other packaging materials,it indicates that the biomass cushion packaging material can replace the cushion packaging materials such as EPS and EPE.%为解决不可降解的废弃塑料类包装材料对环境造成的污染,以稻草纤维、淀粉为主要原料制备了生物质缓冲包装材料,采用正交实验方法研究了生物质缓冲包装材料纤维与淀粉质量比、塑化剂、活性剂和发泡剂含量等对材料抗压强度的影响,结果表明,各因素对材料抗压强度影响的主次顺序为塑化剂>纤维与淀粉质量比>发泡剂>活性剂.塑化剂含量为12%、

  19. 气垫船兴波破冰问题的数值计算%Numerical computation of broken ice by air-cursion vehicles in wave making

    Institute of Scientific and Technical Information of China (English)

    刘巨斌; 张志宏; 张辽远; 姚俊

    2012-01-01

    将求解船舶兴波问题的Rankine源数值计算方法推广应用到水面边界条件为碎冰面、纯冰面和半冰面-半水面等气垫船破冰中不同类型的兴波问题.对不同类型兴波问题采用统一形式的基本方程,通过面元法与有限差分法相结合的方法对方程进行数值离散.重点对气垫船在全冰面、半冰面-半水面上运动时的兴波进行了数值计算,兴波阻力和波形等计算结果与相关文献符合较好.%Water waves of different type in broken ice by ACV (air-cursion vechice) were computed numerically by a genetic governing equations. The Rankine source panel method which was originally used in marine hydrodynamics was extended to water wave problems in broken ice by ACV with broken ice, infinite or semi-infinite ice sheet on water surface. Wave patterns and wave drags were computed for total ice and semi infinite ice problems. Computed results are in good agreement with the a vailable theoretical ones.

  20. Feasibility of Reducing Incidence of Low Back Pain in Helicopter Pilots Using Improved Crewseat Cushions

    Science.gov (United States)

    1992-12-01

    APPENIX A SAMPLE PILOT SURVEY SLACK HAW CREMSEAT CONFORT A.- 1 BLACK HAWK CRENSEAT CONFORT Simula Inc. under contract to the U.S. Air Force Aerospace...Any other comments: __...... .. _ _ A-4 ,rI, APPEiDIX B SUNNARY OF CONNENTS FPRO CONFORT EVALUATION B-1 Comments from 5th-, 5Oth-, and 95th

  1. STUDY ON SOLAR-ASSISTED HEAT PUMP SYSTEM FOR ELECTRIC VEHICLE AIR CONDITIONING%太阳能辅助电动汽车热泵空调系统的研究

    Institute of Scientific and Technical Information of China (English)

    马国远; 史保新; 陈观生; 吴立志

    2001-01-01

    介绍研制的电动汽车热泵空调系统及其配用的双工作腔滑片压缩机的性能,依据测试样机的试验结果分析了转速对该空调系统制冷量、输入功率及COP等性能的影响。若轿车顶盖全部布满太阳电池,所产生的电能约为225W,可以使空调系统的制冷量增加8%左右,同时还能降低汽车空调冷负荷的峰值。%This paper describes the heat pump system for electric vehicle air conditioning and the sliding vane compressor with double-actions used in the system.According to the experimental results of the sample,the influence of compressor speed on the cooling/heating capacity,power input,and COP of the heat pump system is discussed.The photovoltaic cells,assumed to cover the roof area of a compact car,can only generate about 225W power.This can improve the refrigerating capacity of the heat pump system by about eight percent,which significantly reduces the peak cooling load when the car is parked under the strong sunlight.

  2. Primary Research on the Standard System of Air Vehicle Calibration Models Used in Wind Tunnel Test%飞行器风洞试验标模体系研究初探

    Institute of Scientific and Technical Information of China (English)

    战培国; 罗月培

    2011-01-01

    风洞试验标模是一种评估风洞试验准度和验证CFD算法的通用校准模型.本文归纳分析了北大西洋公约组织AGARD系列、法国ONERAM系列为代表的国外风洞试验标模发展情况,阐述了我国DBM、GBM、HSCM风洞标模系列的发展现状,探讨了建立和完善风洞试验标模体系的一些问题,意在为国内风洞和试验技术发展提供参考.%The standard air vehicle calibration model is a common calibration model used for evaluating wind tunnel test results and validating CFD methods.This paper analyses the development of overseas wind tunnel calibration models,typically,NATO AGARD series and ONERA M series in France,introduces state of the art domestic calibration models,such as DBM,CBM and HSCM series,discusses some problems about setting up and consummating the system of calibration models.The purpose is to provide thoughts and references for the development of domestic wind tunnel techniques.

  3. Principle Analysis & Numerical Simulation to New Type NC Hydraulic Cushion System%新型数控液压垫系统原理分析及数字仿真

    Institute of Scientific and Technical Information of China (English)

    蔡喜; 陈刚

    2016-01-01

    The paper introduces a new type NC hydraulic cushion system. The numerical simulation to the cushion system was performed with matlab simulink to provide the basis for the optimization. The cushion system with high stability and dynamic response meets the requirement of customers in actual application and replaces abroad branded NC hydraulic cushion systems.%介绍一种新型数控液压垫系统,利用matlab simulink对该液压垫系统做数字仿真分析,为优化系统参数提供依据。该系统具有很好的稳定性和动态响应,能够满足用户实际使用需要,可以替代国外品牌的数控液压垫。

  4. 燃料电池汽车空辅系统噪声有源控制技术%Active Noise Control Technology of Air Auxiliary System in Fuel Cell Vehicles

    Institute of Scientific and Technical Information of China (English)

    胡佳杰; 左曙光; 何吕昌; 张孟浩

    2013-01-01

      燃料电池汽车(FCV)的动力系统及噪声特性与传统汽车相比有着很大差异,其中空气辅助系统已成为主要的噪声源。虽然有源噪声控制(ANC)是近年来的研究热点;但是,由于噪声源与环境的时变性,对空辅系统的中低频段噪声更有效的对策是使用自适应有源噪声控制技术(AANC)。在归纳总结有源噪声控制技术的发展进程及基本原理的基础上,阐述近年来有源噪声控制的研究现状,并重点分析关注自适应算法的研究进展;由此对自适应有源噪声控制在燃料电池汽车空辅系统减振降噪方面的应用前景进行预测和展望。%The power system and its noise characteristic of Fuel Cell Vehicle (FCV) are quite different from those of traditional cars. In FCV, the air auxiliary system becomes one of the main noise sources. In recent years, active noise control (ANC) has become a research focus. It has advantages for the traditional passive noise control in middle-and low-frequency range. However, because of the time-variation property of noise sources and environments, it is necessary to use adaptive active noise control (AANC) in middle-and low-frequency noise control of the air auxiliary system in FCV. In this paper, the development progress of ANC technology was summarized, and the research of ANC in recent years was expatiated. Analysis was focused on the research progress of adaptive algorithm. Finally, the prospect of the ANNC application in the field of vibration and noise reduction of the air auxiliary system in FCV was forecasted.

  5. Guaianolides and a seco-Eudesmane from the Resinous Exudates of Cushion Bush (Leucophyta brownii) and Evaluation of Their Cytostatic and Anti-inflammatory Activity

    DEFF Research Database (Denmark)

    Hyldgaard, Mette G; Purup, Stig; Bond, Andrew D

    2015-01-01

    A detailed phytochemical investigation of a dichloromethane extract of the resinous exudates of the cushion bush plant (Leucophyta brownii) resulted in the isolation of the new 8,12-guaianolides leucophytalins A (5) and B (6), the new 1,10-seco-eudesmane leucophytalin C (10), six rare 8,12-guaian......A detailed phytochemical investigation of a dichloromethane extract of the resinous exudates of the cushion bush plant (Leucophyta brownii) resulted in the isolation of the new 8,12-guaianolides leucophytalins A (5) and B (6), the new 1,10-seco-eudesmane leucophytalin C (10), six rare 8......,12-guaianolides (1–4, 7, and 8), and the xanthanolide tomentosin (9). The structures of all isolated compounds were elucidated on the basis of spectroscopic and spectrometric analyses. The structures of compounds isolated in crystalline form, including leucophytalins A and C, were further confirmed by X...

  6. Study of Cushion Airbag Material for Precision Airdrop%精确空投缓冲气囊材料研究

    Institute of Scientific and Technical Information of China (English)

    黄刚; 李良春

    2011-01-01

    介绍了精确空投着陆缓冲的作用原理以及对气囊材料的要求,分析了聚酰胺、聚酯纤维2种气囊织物材料和氯丁橡胶、硅酮2种涂层材料的结构性能及发展,总结了当前主要的新材料技术,提出了着陆缓冲气囊材料的发展趋势.%The cushion principle of precision airdrop landing and its requirements for airbag material were introduced. The structure, performance, and development of two airbag fabric materials polyamide (PA) and polyester and two coat materials neoprene and silicone were analyzed. Several main new material technologies were summarized and the development trend of the landing cushion airbag material technology was put forward.

  7. Rain erosion of wind turbine blade coatings using discrete water jets: Effects of water cushioning, substrate geometry, impact distance, and coating properties

    DEFF Research Database (Denmark)

    Zhang, Shizhong; Dam-Johansen, Kim; Bernad, Pablo L.

    2015-01-01

    Rapid and reliable rain erosion screening of blade coatings for wind turbines is a strong need in the coatings industry. One possibility in this direction is the use of discrete water jets, where so-called jet slugs are impacted on a coating surface. Previous investigations have mapped...... the influence of water jet slug velocity and impact frequency. In the present work, the effects on coating erosion of water cushioning, substrate curvature, and water nozzle-coating distance were explored. The investigations showed that in some cases water cushioning (the presence of a liquid film...... on the coating surface prior to impact) influences the erosion. Contrary to this, substrate curvature and the water nozzle-coating distance (coatings, including tensile strength, flexibility...

  8. 吸气式高超声速飞行器纵向运动反演控制器设计%Design of Backstepping Controller for Longitudinal Motion of an Air-Breathing Hypersonic Vehicle

    Institute of Scientific and Technical Information of China (English)

    时建明; 王洁; 王琨; 邵雷

    2013-01-01

    针对气动/推进/结构耦合的吸气式高超声速飞行器纵向平面飞行控制问题,提出了基于反演的鲁棒控制器设计方法.利用曲线拟合模型将控制系统表示为反馈形式,采用反演方法设计虚拟和实际控制器,并引入鲁棒微分器估计虚拟控制量的导数,解决了虚拟控制量求导运算复杂的问题.为增强控制器应对不确定项的鲁棒性,设计了超扭曲滑模干扰观测器,实现了对系统模型不确定项的估计和补偿.对吸气式高超声速飞行器一体化原理模型的速度和高度指令跟踪仿真表明,该控制器对拟合误差和外加干扰等系统不确定项具有鲁棒性,系统状态量能够在指令跟踪过程中趋于平衡状态,从而验证了所提方案的有效性.%A robust controller based on backstepping design procedure is proposed for an air-breathing hypersonic vehicle with aerodynamic, propulsion and structural couplings. Expressing the control system as strict feedback form via the curve-fitted model, virtual and actual controllers are constructed for the velocity and altitude subsystems. To omit analytic calculation of the virtual control law derivatives, which is very difficult to evaluate in the traditional backstepping control, robust differentiators are introduced. Super-twisting sliding mode disturbance observers are designed to compensate uncertainties in the system dynamics. Trajectory tracking simulation performed on the first principle model of the vehicle's longitudinal dynamics shows that the designed controllers are robust to model fitting errors and outside disturbances, and the system states reach trimmed condition asymptotically.

  9. A high-resolution vehicle emission inventory for China

    Science.gov (United States)

    Zheng, B.; Zhang, Q.; He, K.; Huo, H.; Yao, Z.; Wang, X.

    2012-12-01

    Developing high resolution emission inventory is an essential task for air quality modeling and management. However, current vehicle emission inventories in China are usually developed at provincial level and then allocated to grids based on various spatial surrogates, which is difficult to get high spatial resolution. In this work, we developed a new approach to construct a high-resolution vehicle emission inventory for China. First, vehicle population at county level were estimated by using the relationship between per-capita GDP and vehicle ownership. Then the Weather Research and Forecasting (WRF) model were used to drive the International Vehicle Emission (IVE) model to get monthly emission factors for each county. Finally, vehicle emissions by county were allocated to grids with 5-km horizon resolution by using high-resolution road network data. This work provides a better understanding of spatial representation of vehicle emissions in China and can benefit both air quality modeling and management with improved spatial accuracy.

  10. Electric and Hybrid Vehicle Technology: TOPTEC

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    Today, growing awareness of environmental and energy issues associated with the automobile has resulted in renewed interest in the electric vehicle. In recognition of this, the Society of Automotive Engineers has added a TOPTEC on electric vehicles to the series of technical symposia focused on key issues currently facing industry and government. This workshop on the Electric and Hybrid Vehicle provides an opportunity to learn about recent progress in these rapidly changing technologies. Research and development of both the vehicle and battery system has accelerated sharply and in fact, the improved technologies of the powertrain system make the performance of today's electric vehicle quite comparable to the equivalent gasoline vehicle, with the exception of driving range between refueling'' stops. Also, since there is no tailpipe emission, the electric vehicle meets the definition of Zero Emission Vehicle: embodied in recent air quality regulations. The discussion forum will include a review of the advantages and limitations of electric vehicles, where the technologies are today and where they need to be in order to get to production level vehicles, and the service and maintenance requirements once they get to the road. There will be a major focus on the status of battery technologies, the various approaches to recharge of the battery systems and the activities currently underway for developing standards throughout the vehicle and infrastructure system. Intermingled in all of this technology discussion will be a view of the new relationships emerging between the auto industry, the utilities, and government. Since the electric vehicle and its support system will be the most radical change ever introduced into the private vehicle sector of the transportation system, success in the market requires an understanding of the role of all of the partners, as well as the new technologies involved.

  11. Electric and Hybrid Vehicle Technology: TOPTEC

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-01

    Today, growing awareness of environmental and energy issues associated with the automobile has resulted in renewed interest in the electric vehicle. In recognition of this, the Society of Automotive Engineers has added a TOPTEC on electric vehicles to the series of technical symposia focused on key issues currently facing industry and government. This workshop on the Electric and Hybrid Vehicle provides an opportunity to learn about recent progress in these rapidly changing technologies. Research and development of both the vehicle and battery system has accelerated sharply and in fact, the improved technologies of the powertrain system make the performance of today`s electric vehicle quite comparable to the equivalent gasoline vehicle, with the exception of driving range between ``refueling`` stops. Also, since there is no tailpipe emission, the electric vehicle meets the definition of ``Zero Emission Vehicle: embodied in recent air quality regulations. The discussion forum will include a review of the advantages and limitations of electric vehicles, where the technologies are today and where they need to be in order to get to production level vehicles, and the service and maintenance requirements once they get to the road. There will be a major focus on the status of battery technologies, the various approaches to recharge of the battery systems and the activities currently underway for developing standards throughout the vehicle and infrastructure system. Intermingled in all of this technology discussion will be a view of the new relationships emerging between the auto industry, the utilities, and government. Since the electric vehicle and its support system will be the most radical change ever introduced into the private vehicle sector of the transportation system, success in the market requires an understanding of the role of all of the partners, as well as the new technologies involved.

  12. 基于单目视觉的室内微型飞行器位姿估计与环境构建%Monocular Vision Based Motion Estimation of Indoor Micro Air Vehicles and Structure Recovery

    Institute of Scientific and Technical Information of China (English)

    郭力; 昂海松; 郑祥明

    2012-01-01

    Micro air vehicles (MAVs) need reliable attitude and position information in indoor environment. The measurements of onboard inertial measurement unit (IMU) sensors such as gyros and acce-larometers are corrupted by large accumulated errors, and GPS signal is unavailable in such situation. Therefore, a monocular vision based indoor MAV motion estimation and structure recovery method is presented. Firstly, the features are tracked by biological vision based matching algorithm through the image sequence, and the motion of camra is estimated by the five-point algorithm. In the indoor enviro-ment, the planar relationship is used to reduce the feature point dimentions from three to two. Then, these parameters are optimized by an local strategy to improve the motion estimation and structure recovery accuracy. The measurements of IMU sensors and vision module are fused with extended Kalman fileter. The attitude and position information of MAVs is estimated. The experiment shows that the method can reliably estimate the indoor motion of MAV in real-time, and the recovered enviroment information can be used for navigation of MAVs.%针对微型飞行嚣(Micro air vehicle,MAV)在室内飞行过程中无法获得GPS信号,而微型惯性单元(Inertial measurement unit,IMU)的陀螺仪和加速度计随机漂移误差较大,提出一种利用单目视觉估计微型飞行嚣位姿并构建室内环境的方法.在机载单目摄像机拍摄的序列图像中引入一种基于生物视觉的方法获得匹配特征点,并由五点算法获得帧间摄像机运动参数和特征点位置参数的初始解;利用平面关系将特征点的位置信息由三维降低到二维,给出一种局部优化方法求解摄像机运动参数和特征点位置参数的最大似然估计,提高位姿估计和环境构建的精度.最后通过扩展卡尔曼滤波方法融合IMU传感器和单目视觉测量信息解算出微型飞行器的位姿.实验结果表明,该方法能够实时可

  13. SVD Algorithm for Multiple Unmanned Combat Air Vehicles Emergent Task Allocation%多架无人作战飞机紧急任务分配奇异值分解算法

    Institute of Scientific and Technical Information of China (English)

    陈琛

    2016-01-01

    A stable algorithm for multiple Unmanned Combat Air Vehicles(UCAV)dynamic emergent task allocation with the practical battlefield requirement was proposed.We extracted the task related parameters to be a multi-dimensional feature vector and constructed UCAV parameters matrix in the whole control range,and then calculated the cosine between different multi-dimensional feature vector and the right singular matrix to allocate emergent task.At last,we verified the applicability and analyzed the complexity of the algorithm.The algorithm is concise which is in line with the operational flow requirement of stability and rapidly.%从战场实际需求出发,在动态条件下对多无人机紧急任务分配问题提出了一种可行稳健算法;将无人机与任务相关的状态参数提取为多维特征向量,构造控制单元范围内所有无人机状态参数矩阵,通过计算特征向量方向余弦值并利用矩阵奇异值分解后的右奇异值矩阵优选分配紧急任务,进行了算例验证并分析了算法复杂度。算法简洁、计算耗时少,符合作战流程中对该问题求解的可靠性、迅速性要求。

  14. Mmp15 is a direct target of Snai1 during endothelial to mesenchymal transformation and endocardial cushion development.

    Science.gov (United States)

    Tao, Ge; Levay, Agata K; Gridley, Thomas; Lincoln, Joy

    2011-11-15

    Cardiac valves originate from endocardial cushions (EC) formed by endothelial-to-mesenchymal transformation (EMT) during embryogenesis. The zinc-finger transcription factor Snai1 has previously been reported to be important for EMT during organogenesis, yet its role in early valve development has not been directly examined. In this study we show that Snai1 is highly expressed in endothelial, and newly transformed mesenchyme cells during EC development. Mice with targeted snai1 knockdown display hypocellular ECs at E10.5 associated with decreased expression of mesenchyme cell markers and downregulation of the matrix metalloproteinase (mmp) family member, mmp15. Snai1 overexpression studies in atrioventricular canal collagen I gel explants indicate that Snai1 is sufficient to promote mmp15 expression, cell transformation, and mesenchymal cell migration and invasion. However, treatment with the catalytically active form of MMP15 promotes cell motility, and not transformation. Further, we show that Snai1-mediated cell migration requires MMP activity, and caMMP15 treatment rescues attenuated migration defects observed in murine ECs following snai1 knockdown. Together, findings from this study reveal previously unappreciated mechanisms of Snai1 for the direct regulation of MMPs during EC development.

  15. In-vehicle nitrogen dioxide concentrations in road tunnels

    Science.gov (United States)

    Martin, Ashley N.; Boulter, Paul G.; Roddis, Damon; McDonough, Liza; Patterson, Michael; Rodriguez del Barco, Marina; Mattes, Andrew; Knibbs, Luke D.

    2016-11-01

    There is a lack of knowledge regarding in-vehicle concentrations of nitrogen dioxide (NO2) during transit through road tunnels in urban environments. Furthermore, previous studies have tended to involve a single vehicle and the range of in-vehicle NO2 concentrations that vehicle occupants may be exposed to is not well defined. This study describes simultaneous measurements of in-vehicle and outside-vehicle NO2 concentrations on a route through Sydney, Australia that included several major tunnels, minor tunnels and busy surface roads. Tests were conducted on nine passenger vehicles to assess how vehicle characteristics and ventilation settings affected in-vehicle NO2 concentrations and the in-vehicle-to-outside vehicle (I/O) concentration ratio. NO2 was measured directly using a cavity attenuated phase shift (CAPS) technique that gave a high temporal and spatial resolution. In the major tunnels, transit-average in-vehicle NO2 concentrations were lower than outside-vehicle concentrations for all vehicles with cabin air recirculation either on or off. However, markedly lower I/O ratios were obtained with recirculation on (0.08-0.36), suggesting that vehicle occupants can significantly lower their exposure to NO2 in tunnels by switching recirculation on. The highest mean I/O ratios for NO2 were measured in older vehicles (0.35-0.36), which is attributed to older vehicles having higher air exchange rates. The results from this study can be used to inform the design and operation of future road tunnels and modelling of personal exposure to NO2.

  16. Electric-vehicle batteries

    Science.gov (United States)

    Oman, Henry; Gross, Sid

    1995-02-01

    Electric vehicles that can't reach trolley wires need batteries. In the early 1900's electric cars disappeared when owners found that replacing the car's worn-out lead-acid battery costs more than a new gasoline-powered car. Most of today's electric cars are still propelled by lead-acid batteries. General Motors in their prototype Impact, for example, used starting-lighting-ignition batteries, which deliver lots of power for demonstrations, but have a life of less than 100 deep discharges. Now promising alternative technology has challenged the world-wide lead miners, refiners, and battery makers into forming a consortium that sponsors research into making better lead-acid batteries. Horizon's new bipolar battery delivered 50 watt-hours per kg (Wh/kg), compared with 20 for ordinary transport-vehicle batteries. The alternatives are delivering from 80 Wh/kg (nickel-metal hydride) up to 200 Wh/kg (zinc-bromine). A Fiat Panda traveled 260 km on a single charge of its zinc-bromine battery. A German 3.5-ton postal truck traveled 300 km with a single charge in its 650-kg (146 Wh/kg) zinc-air battery. Its top speed was 110 km per hour.

  17. Canadair CL-227 Remotely Piloted Vehicle

    Science.gov (United States)

    Clark, Andrew S.

    1983-08-01

    The Canadair CL-227 is a rotary winged Remotely Piloted Vehicle (RPV) intended initially as the air-vehicle for a medium range battlefield surveillance and target acquisition system. The concept on which this vehicle is based brings together in-house expertise as a designer and manufacturer of surveillance drones (AN-USD-50l -MIDGE-) with experience in rigid rotor technology from the CL-84 tilt wing VTOL program. The vehicle is essentially modular in design with a power module containing the engine, fuel and related systems, a rotor module containing the two counter-rotating rotors and control actuators, and a control module containing the autopilot, data link and sensor system. The vehicle is a true RPV (as opposed to a drone) as it is flown in real time by an operator on the ground and requires relatively little skill to pilot.

  18. Vehicle Development Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Supports the development of prototype deployment platform vehicles for offboard countermeasure systems. DESCRIPTION: The Vehicle Development Laboratory is...

  19. Vehicle Development Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Supports the development of prototype deployment platform vehicles for offboard countermeasure systems.DESCRIPTION: The Vehicle Development Laboratory is...

  20. Compressed natural gas vehicles motoring towards a green Beijing

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ming; Kraft-Oliver, T. [International Institute for Energy Conservation (IIEC) - Asia, Bangkok (Thailand); Guo Xiao Yan [China North Vehicle Research Institute (CNVRI), Beijing (China)

    1996-12-31

    This paper first describes the state-of-the-art of compressed natural gas (CNG) technologies and evaluates the market prospects for CNG vehicles in Beijing. An analysis of the natural gas resource supply for fleet vehicles follows. The costs and benefits of establishing natural gas filling stations and promoting the development of vehicle technology are evaluated. The quantity of GHG reduction is calculated. The objective of the paper is to provide information of transfer niche of CNG vehicle and equipment production in Beijing. This paper argues that the development of CNG vehicles is a cost-effective strategy for mitigating both air pollution and GHG.

  1. Advanced Composites for Air and Ground Vehicles

    Science.gov (United States)

    2015-08-01

    Characterization of Flexural Behavior of Vacuum-Assisted Resin Transfer Molding ( VARTM )-Infused Composite Sandwich Structures 105 9.1.1 Summary 105 9.1.2...the unit cell ......101 Fig. 9.1.1 Layup for the VARTM process .........................................................107 Fig. 9.1.2 a) 3...126 Fig. 9.2.3 VARTM setup ...................................................................................126 Fig. 9.2.4 RTM setup

  2. Scaling Flight Tests of Unmanned Air Vehicles

    Science.gov (United States)

    2006-09-01

    historical perspective, the concept of scaling goes back to 1638, when Galileo first introduced “scaling” and “physics” in his treatise Disclosures...Vertical Field of View,VFOV (degrees):5.16897 103 Bibliography 1. G. Galilei , Disclosure and Mathematic Demonstrations Concerning Two Sciences

  3. Advanced Metallic Air Vehicle Structure Program

    Science.gov (United States)

    1974-06-01

    At-. . S REMOE LMINATORIS YO HIC4rMESS .9Q!Oe L4aD 1A7 TOKMS Fit% VOID SEQO TO VILL VOID o tFILVD i- ---I -SICRM 45 SAO 4 PLAC S I.LtLOIS RIF 572Z5902...creating a heavy globular underbead and severe underfill on the face of the weld. Weld parameters that were investigated include variations of voltage

  4. Enabling Technologies for Nano Air Vehicles

    Science.gov (United States)

    2009-02-10

    minimum drag where fart is the forcing frequency of the actuator, D is the chord length and Uoo is the freestream velocity. It was also concluded that the...performance. Since Ellington’s6 research showed that quasi-steady analysis underpredicts the forces Fart II Page 1 generated in flapping flight, a

  5. Center for Micro Air Vehicle Studies

    Science.gov (United States)

    2013-02-01

    SUPPLEMENTARY NOTES PA Case Number: 88ABW-2013-1337; Clearance Date: 20 Mar 2013. Report contains color. 14. ABSTRACT This report summarizes the...shown in Figure 32 contains a costa, subcosta, radius and cubitus. The radius contains two branches that spread out to cover the surface area of the...were considered; the cone, disk, toroidal , and magnetic CVTs. The cone CVT was selected for further development based on the openness of its

  6. Unmanned air vehicle: autonomous takeoff and landing

    Science.gov (United States)

    Lim, K. L.; Gitano-Briggs, Horizon Walker

    2010-03-01

    UAVs are increasing in popularity and sophistication due to the demonstrated performance which cannot be attained by manned aircraft1. These developments have been made possible by development of sensors, instrumentation, telemetry and controls during the last few decades. UAVs are now common in areas such as aerial observation and as communication relays3. Most UAVs, however, are still flown by a human pilot via remote control from a ground station. Even the existing autonomous UAVs often require a human pilot to handle the most difficult tasks of take off and landing2 (TOL). This is mainly because the navigation of the airplane requires observation, constant situational assessment and hours of experience from the pilot himself4. Therefore, an autonomous takeoff and landing system (TLS) for UAVs using a few practical design rules with various sensors, instrumentation, etc has been developed. This paper details the design and modeling of the UAV TLS. The model indicates that the UAV's TLS shows promising stability.

  7. Cooperative Electronic Attack using Unmanned Air Vehicles

    Science.gov (United States)

    2006-01-01

    Proceedings of the American Control Conference , pp. 1917–1922, 2002. [8] V...Gazi and K. M. Passino, “Stability analysis of swarms in an environment with an attractant/repellent profile,” Proceedings of the American Control Conference , pp...ference on Networking, Sensing and Control, March 2005. [12] D. Maithripala and S. Jayasuriya, “Radar deception through phantom track generation,” Proceedings of the American

  8. Modal analysis of PATHFINDER unmanned air vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Woehrle, T.G.; Costerus, B.W.; Lee, C.L.

    1994-10-19

    An experimental modal analysis was performed on PATHFINDER, a 450-lb, 100-ft wing span, flying-wing-design aircraft powered by solar/electric motors. The aircraft was softly suspended and then excited using random input from a long-stroke shaker. Modal data was taken from 92 measurement locations on the aircraft using newly designed, lightweight, tri-axial accelerometers. A conventional PC-based data acquisition system provided data handling. Modal parameters were calculated, and animated mode shapes were produced using SMS STARStruct{trademark} Modal Analysis System software. The modal parameters will be used for validation of finite element models, optimum placement of onboard accelerometers during flight testing, and vibration isolation design of sensor platforms.

  9. Demonstration of a Wingless Electromagnetic Air Vehicle

    Science.gov (United States)

    2011-12-20

    PET 127 No Polyester film (one sided silicone) 69 No Silicone (one sided) paper 63 No Silicone rubber (high-purity) 127, 254 Yes, No Teflon (PTFE...voltage. The supply voltage typically is connected to ground via a large capacitor to prevent any RF signals leaking into the supply. The class-E...amplifier adds a Ct ( capacitor ) between the transistors and uses a transformer/impedance matching network to step up the input voltage. • Switched

  10. Site Monitoring and Analysis on Differential Settlement of Subgrade Adjusted with Gravel Cushion%碎石垫层调整路基差异沉降的现场监测与分析

    Institute of Scientific and Technical Information of China (English)

    叶勇

    2014-01-01

    我国对水泥混凝土路面下碎石垫层的研究很不充分,对碎石垫层调整路基差异沉降的机理研究较少,缺乏对碎石垫层调整路基差异沉降的现场监测研究。依托广东省阳江~阳春高速公路进行了碎石垫层调整路基差异沉降的现场监测研究,研究成果对于完善水泥路面碎石垫层的设计方法具有重要作用。%As there is not sufficient researches on the gravel cushion under cement concrete pavement in our country, there is less researches on mechanism of subgrade differential settlement adjusted by gravel cushion,there is also short-age of researches on on-site monitoring for subgrade differential settlement adjusted by gravel cushion.In this article, being based on practice of Yangjiang-Yangchun Expressway in Guangdong Province,study on on-site monitoring for subgrade differential settlement adjusted by gravel cushion has been carried out,and the study findings have an impor-tant role on the design method improvement for gravel cushion for cement pavement.

  11. How important is vehicle safety in the new vehicle purchase process?

    Science.gov (United States)

    Koppel, Sjaanie; Charlton, Judith; Fildes, Brian; Fitzharris, Michael

    2008-05-01

    Whilst there has been a significant increase in the amount of consumer interest in the safety performance of privately owned vehicles, the role that it plays in consumers' purchase decisions is poorly understood. The aims of the current study were to determine: how important vehicle safety is in the new vehicle purchase process; what importance consumers place on safety options/features relative to other convenience and comfort features, and how consumers conceptualise vehicle safety. In addition, the study aimed to investigate the key parameters associated with ranking 'vehicle safety' as the most important consideration in the new vehicle purchase. Participants recruited in Sweden and Spain completed a questionnaire about their new vehicle purchase. The findings from the questionnaire indicated that participants ranked safety-related factors (e.g., EuroNCAP (or other) safety ratings) as more important in the new vehicle purchase process than other vehicle factors (e.g., price, reliability etc.). Similarly, participants ranked safety-related features (e.g., advanced braking systems, front passenger airbags etc.) as more important than non-safety-related features (e.g., route navigation systems, air-conditioning etc.). Consistent with previous research, most participants equated vehicle safety with the presence of specific vehicle safety features or technologies rather than vehicle crash safety/test results or crashworthiness. The key parameters associated with ranking 'vehicle safety' as the most important consideration in the new vehicle purchase were: use of EuroNCAP, gender and education level, age, drivers' concern about crash involvement, first vehicle purchase, annual driving distance, person for whom the vehicle was purchased, and traffic infringement history. The findings from this study are important for policy makers, manufacturers and other stakeholders to assist in setting priorities with regard to the promotion and publicity of vehicle safety features

  12. Aerodynamic Characteristics Simulation Study of Air-launched Launch Vehicle in the Process of Rocket Separating from Plane%空射火箭箭机分离过程气动特性仿真

    Institute of Scientific and Technical Information of China (English)

    屈亮; 张登成; 张艳华; 胡孟权; 李达

    2013-01-01

    为研究内装式空中发射运载火箭在箭机分离过程中的气动特性尤其是大迎角情况下的气动变化规律,应用计算流体力学(CFD)软件中的k-w模型对火箭气动特性进行了仿真研究,得到火箭气动特性随马赫数和迎角的变化规律,同时对改进后的火箭模型进行气动特性分析.仿真结果表明:发现火箭尾部改进成收敛-扩张型喷管可使火箭下落初期有一个抬头力矩,有利于运载火箭初期快速调整姿态;当快到达预期点火姿态时,由于气动力作用点后移产生的与角速度方向相反的力矩,可迫使运载火箭稳定,从而更容易地捕捉到点火角度,并保证点火时的姿态稳定.%For studying the aerodynamic characteristics of rocket in the process of the rocket separating from the plane internally carried air-launched launch vehicle,especially when the rocket is at high angle of attack,CFD is applied to the simulation of rocket aerodynamic characteristics.Based on the improvement of rocket shape,the rocket aerodynamic characteristics with Mach number and angle of attack can be obtained.The analysis of the aerodynamic characteristics of the improved rocket model shows that the rocket tail improved into a convergent nozzle is of great benefit to the attitude adjustment.These analyses provide a theoretical foundation for the further research on rocket attitude stabilization and track design.

  13. Application of unmanned air vehicle remote sensing system in land and resources law enforcement and supervision%无人机遥感系统在国土资源执法监察中的应用研究

    Institute of Scientific and Technical Information of China (English)

    杨晓红

    2013-01-01

    无人机遥感系统是一种新型的高分辨率影像数据快速获取方式,具有高效快速、精细准确、作业成本低等特点。本文介绍了无人机遥感系统的组成、特点,设计了无人机遥感系统在国土资源执法监察中应用的技术流程,并以芜湖县湾沚镇为航摄区域进行实例验证分析。通过遥感影像的几何校正、空三加密、图像拼接和数据精度分析等数据预处理,套合比对2011年度的卫星影像数据和第二次土地调查的土地利用现状数据库,对国土资源执法监察区域的土地利用变化情况进行了初步评价,取得了较好的效果。%Unmanned air vehicle (UAV) remote sensing system is a new way of rapid acquisition of high resolution im-age data. It is efficient,quick,accurate and economic. This paper introduced the composition and characteristics of UAV remote sensing system,designed a technical process for application of UAV remote sensing system in land and re-sources law enforcement and supervision,and made a testing analysis with the town of Wanzhi,Wuhu County as the aerophotographic area. After remote sensing image pretreatment,such as geometric correction,aerial triangulation en-cryption,image mosaicking and data precision analysis,and registration with landsat image data of 2011 and the second land survey’s land utilization status database,it made an initial assessment of the land use change in the area under su-pervision and proved good in the result.

  14. Cooperative Search and Path Planning of Multi-unmanned Air Vehicles in Uncertain Environment%不确定环境下的多无人机协同搜索航路规划

    Institute of Scientific and Technical Information of China (English)

    吴文超; 黄长强; 宋磊; 唐上钦; 白壬潮

    2011-01-01

    In order to resolve the cooperative search problem of multiple unmanned air vehicles ( UAV) in a uncertain environment, this paper presents a basic framework for it first, and then gives the search environment and UAV models. Based on them, a cooperative search path decision for UAV to satisfy the maximum turn radius restriction and communication delay is proposed. According to prior knowledge, the environment can be divided as unknown regions, known regions and prohibited areas, and an award function can be designed for a team of UAVs to search the unknown regions and avoid the known regions. By using an avoidance decision, UAV can get rid of the prohibited area ultimately. Finally, these ideas are simulated and compared with the uncooperative search patterns. The simulation results demonstrate the efficiency of the proposed cooperative approach.%为解决多架无人机(UAV)在不确定环境中搜索目标的问题,根据多UAV协同搜索的基本原则,建立了多UAV协同搜索的环境模型和UAV运动模型,提出了一种满足UAV机动限制和适应数据通讯延迟的协同路径决策算法.根据先验知识将环境分为未知环境,已知环境和禁飞区,设计了搜索回报函数,引导UAV对未知环境进行搜索,对已知环境进行规避;提出了禁飞区回避决策,实现了UAV对禁飞区的完全回避.最后进行了仿真实验,并与2种非协同搜索算法的仿真结果进行了比较,结果表明,本文提出的协同搜索算法的有效性.

  15. 自主空中加油时变质量无人作战飞机非线性控制%Nonlinear control for unmanned combat air vehicle with time-varying mass in autonomous aerial refueling

    Institute of Scientific and Technical Information of China (English)

    郭军; 董新民; 王龙

    2012-01-01

    To keep the position of an unmanned combat air vehicle (UCAV) during autonomous aerial refueling, we develop the dynamic model and put forward a nonlinear controller for the UCAV with time-varying mass. By comprehen- sively considering the effect of fuel transfer on the UCAV mass, the inertia matrix and the center of mass, we derive the time-varying mass dynamic equations of UCAV based on state variables relative to inertial reference frame. By introducing the spectral radius, we apply the command filtered backstepping (CFBS) method based on localized adaptive bounds to control the UCAV in a desired position. The unknown model uncertainties are approximated online by using approxima- tors. Localized adaptive bounds are used to compensate inherent approximation errors and external disturbances. Using CFBS, we design four feedback control loops for the relative position, airspeed, attitude angle, and angular rate to guarantee the stability of the UCAV. Nonlinear simulation demonstrates the effectiveness of the nonlinear flight control law in three different refueling cases.%针对自主空中加油中无人作战飞机(UCAV)位置保持问题,进行了时变质量UCAV的动力学建模与非线性控制设计.综合考虑了燃油传输对UCAV的质量、惯性矩阵和质心位置的影响,基于相对于惯性系的状态变量,推导了uCAV时变质量动力学方程.通过引入谱半径,将局部化自适应边界指令滤波反推方法应用于UCAV的位置保持控制.使用逼近器对未知模型不确定性进行在线逼近.对于固有逼近误差和外部扰动,采用局部化自适应边界进行补偿.通过指令滤波反推,设计了相对位置、速度、姿态角和角速度四个反馈回路来保证UCAV的稳定性.最后,三种不同加油方案下的非线性仿真验证了非线性飞行控制律的有效性.

  16. In-vehicle vibration study of child safety seats.

    Science.gov (United States)

    Giacomin, J; Gallo, S

    2003-12-15

    This paper reports experimental measurements of the in-vehicle vibrational behaviour of stage 0&1 child safety seats. Road tests were performed for eight combinations of child, child seat and automobile. Four accelerometers were installed in the vehicles and orientated to measure as closely as possible in the vertical direction; two were attached to the floor and two located at the human interfaces. An SAE pad was placed under the ischial tuberosities of the driver at the seat cushion and a child pad, designed for the purpose of this study, was placed under the child. Four test runs were made over a pave' (cobblestone) surface for the driver's seat and four for the child seat at both 20 km h(-1) and 40 km h(-1). Power spectral densities were determined for all measurement points and acceleration transmissibility functions (ATFs) were estimated from the floor of the vehicle to the human interfaces. The system composed of automobile seat, child seat and child was found to transmit greater vibration than the system composed of automobile seat and driver. The ensemble mean transmissibility in the frequency range from 1 to 60 Hz was found to be 77% for the child seats systems as opposed to 61% for the driver's seats. The acceleration transmissibility for the child seat system was found to be higher than that of the driver's seat at most frequencies above 10 Hz for all eight systems tested. The measured ATFs suggest that the principal whole-body vibration resonance of the children occurred at a mean frequency of 8.5, rather than the 3.5 to 5.0 Hz typically found in the case of seated adults. It can be concluded that current belt-fastened child seats are less effective than the vehicle primary seating systems in attenuating vibrational disturbances. The results also suggest the potential inability of evaluating child comfort by means of existing whole-body vibration standards.

  17. Comparative costs and benefits of hydrogen vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Berry, G.D. [Lawrence Livermore National Lab., CA (United States)

    1996-10-01

    The costs and benefits of hydrogen as a vehicle fuel are compared to gasoline, natural gas, and battery-powered vehicles. Costs, energy, efficiency, and tail-pipe and full fuel cycle emissions of air pollutants and greenhouse gases were estimated for hydrogen from a broad range of delivery pathways and scales: from individual vehicle refueling systems to large stations refueling 300 cars/day. Hydrogen production from natural gas, methanol, and ammonia, as well as water electrolysis based on alkaline or polymer electrolytes and steam electrolysis using solid oxide electrolytes are considered. These estimates were compared to estimates for competing fuels and vehicles, and used to construct oil use, air pollutant, and greenhouse gas emission scenarios for the U.S. passenger car fleet from 2005-2050. Fuel costs need not be an overriding concern in evaluating the suitability of hydrogen as a fuel for passenger vehicles. The combined emissions and oil import reduction benefits of hydrogen cars are estimated to be significant, valued at up to {approximately}$400/yr for each hydrogen car when primarily clean energy sources are used for hydrogen production. These benefits alone, however, become tenuous as the basis supporting a compelling rationale for hydrogen fueled vehicles, if efficient, advanced fossil-fuel hybrid electric vehicles (HEV`s) can achieve actual on-road emissions at or below ULEV standards in the 2005-2015 timeframe. It appears a robust rationale for hydrogen fuel and vehicles will need to also consider unique, strategic, and long-range benefits of hydrogen vehicles which can be achieved through the use of production, storage, delivery, and utilization methods for hydrogen which are unique among fuels: efficient use of intermittent renewable energy sources, (e,g, wind, solar), small-scale feasibility, fuel production at or near the point of use, electrolytic production, diverse storage technologies, and electrochemical conversion to electricity.

  18. Anal cushion lifting method is a novel radical management strategy for hemorrhoids that does not involve excision or cause postoperative anal complications

    Institute of Scientific and Technical Information of China (English)

    Gentaro; Ishiyama; Toshihiko; Nishidate; Yuji; Ishiyama; Akihiko; Nishio; Ken; Tarumi; Maiko; Kawamura; Kenji; Okita; Toru; Mizuguchi; Mineko; Fujimiya; Koichi; Hirata

    2015-01-01

    AIM: To describe the anal cushion lifting(ACL) method with preliminary clinical results. METHODS: Between January to September 2007, 127 patients who received ACL method for hemorrhoid was investigated with informed consent. In this study, three surgeons who specialized in anorectal surgery performed the procedures. Patients with grade two or more severe hemorrhoids according to Goligher’s classification were considered to be indicated for surgery. The patients were given the choice to undergo either the ACL method or theligation and excision method. ACL method is an original technique for managing hemorrhoids without excision. After dissecting the anal cushion from the internal sphincter muscle, the anal cushion was lifted to oral side and ligated at the proper position. Clinical characteristics and outcomes of patients were recorded including complications after surgery. RESULTS: A total of 127 patients were enrolled. Their median age was 42(19-84) years, and 74.8% were female. In addition, more than 99% of the patients had grade 3 or worse hemorrhoids. The median followup period was 26(0-88) mo, and the median operative time was 15(4-30) min. After surgery, analgesics were used for a median period of three days(0-21). Pain control was achieved using extra-oral analgesic drugs, although some patients required intravenous injections of analgesic drugs. The median duration of the patients’ postoperative hospital stay was 7(2-13) d. A total of 10 complications(7.9%) occurred. Bleeding was observed in one patient and was successfully controlled with manual compression. Urinary retention occurred in 6 patients, but it disappeared spontaneously in all cases. Recurrent hemorrhoids developed in 3 patients after 36, 47, and 61 mo, respectively. No anal stenosis or persistent anal pain occurred. CONCLUSION: We consider that the ACL method might be better than all other current methods for managing hemorrhoids.

  19. Estimation and Prediction of Unmanned Aerial Vehicle Trajectories Project

    Data.gov (United States)

    National Aeronautics and Space Administration — There is serious concern about the introduction of Unmanned Aerial Vehicles (UAV) in the National Air Space (NAS) because of their potential to increase the risk of...

  20. Revolutionary Performance For Ultra Low Reynolds Number Vehicles Project

    Data.gov (United States)

    National Aeronautics and Space Administration — An important mission for NASA is the development of revolutionary flight concepts and technology. The development of Micro unmanned air vehicles (Micro-UAVs) and...

  1. Seamless Mode Switching for Shared Control of Semiautonomous Vehicles Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Whether it be a crew station, the Shuttle Remote Manipulator System (SRMS), an unmanned ground rover (UGV) or air vehicle (UAV), or teams thereof, the controllers...

  2. Settlement Calculation and Analysis of Replacement Cushion Foundation in Angola%安哥拉换填垫层地基的沉降计算分析

    Institute of Scientific and Technical Information of China (English)

    彭友君; 杨铮; 彭博

    2015-01-01

    安哥拉浅部棕红色砂Quelo地层具有湿陷性特征,采用换填垫层进行地基处理后,沉降计算是岩土工程研究最重要的课题。分别对换填垫层、压实地基、天然地基浸水后,通过勘探和原位测试给出了土的物理力学指标,建立锥头阻力与地基反力系数的回归方程,完善随深度变化的沉降计算参数,按照英国标准规定的公式和算例进行沉降计算,假定条形基础与换填垫层组成整体基础并对其可靠性进行验算,从而简化了沉降计算方法,将沉降计算结果与实测沉降量对比分析后,说明沉降计算结果可信并满足设计要求,实体楼的浸水试验也得到了印证,安哥拉砂土地基采用换填垫层法进行地基处理是合理的。%The shallow red brown sand Quelo stratum in Angola has the characteristic of collapsibility, and the most important subject of geotechnical engineering research is settlement calculation after foundation treatment by adopting replacement cushion. After immersion of the replacement cushion, compacted foundation and natural foundation, the physical and mechanical indicators of the soil are given through exploration and in⁃situ test, the regression equation of the cone resistance and foundation reaction force coefficient is established, and the settlement calculation parameters changed with depth are perfected. Settlement calculation is conducted according to the formula and example specified in British Standards. It is assumed that the strip foundation and the replacement cushion constitute the overall foundation, and reliability is checked, so as to simplify the settlement calculation method. Through contrastive analysis of the settlement calculation results and measured settlement amount, it indicates that the settlement calculation results are reliable, and can meet design requirements. The water immersion test of the entity building is also proved, and it is reasonable to

  3. Decentralized Receding Horizon Control and Coordination of Autonomous Vehicle Formations

    NARCIS (Netherlands)

    Keviczky, T.; Borelli, F.; Fregene, K.; Godbole, D.; Bals, G.J.

    2008-01-01

    This paper describes the application of a novel methodology for high-level control and coordination of autonomous vehicle teams and its demonstration on high-fidelity models of the organic air vehicle developed at Honeywell Laboratories. The scheme employs decentralized receding horizon controllers

  4. Air and metal hydride battery

    Energy Technology Data Exchange (ETDEWEB)

    Lampinen, M.; Noponen, T. [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Applied Thermodynamics

    1998-12-31

    The main goal of the air and metal hydride battery project was to enhance the performance and manufacturing technology of both electrodes to such a degree that an air-metal hydride battery could become a commercially and technically competitive power source for electric vehicles. By the end of the project it was possible to demonstrate the very first prototype of the air-metal hydride battery at EV scale, achieving all the required design parameters. (orig.)

  5. 带回热器的整车空调系统性能实验研究及系统匹配法则%Experimental Study and System Matching Principles for the Performance of Vehicle Air Conditioning System with Internal Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    钱锐; 韩晓波; 孟祥军

    2014-01-01

    The matching mechanisms for the application of internal heat exchanger (IHX) in the vehicle air conditioning system were analyzed, and the matching principles for the rest air conditioner components and the system after adding IHX were proposed. The effect of IHX on the vehicle performance under the conditions of different vehicle speeds and modes was investigated through the automotive air conditioning environment experiment. The research results show that, the reasonably matched IHX system may decrease the average discharge temperature by 1.5 °C than the original system, and reduce the system power consumption under the condition of the same system refrigeration performance.%本文分析了回热器(IHX)在汽车空调系统匹配中的匹配机制,提出了加入回热器以后其余汽车空调部件以及系统的一些应用法则。利用汽车空调环模试验,研究了回热器在不同车速和模式下对汽车整车性能的影响。研究结果表明,经过合理匹配的IHX系统可以使得空调系统出风口平均温度比原系统降低约1.5℃,在获得同样的系统制冷性能情况下,系统能耗可以降低约10%。

  6. Application of UGNX NC Programming Technology in Lebuss Drum Cushion Block's Processing%UGNX数控编程技术在Lebus卷筒导向垫块加工中的应用

    Institute of Scientific and Technical Information of China (English)

    邓玉聪; 徐长生

    2011-01-01

    针对Lebuss卷筒导向垫块在设计和制造上存在的困难,建立卷筒和垫块的三维模型,利用UG的数控加工自动编程功能生成垫块的数控加工程序来对垫块进行精确加工.%Based on the difficulties in designing and manufacturing of lebuss drum cushion block, 3D models of drum and cushion block are established directly,and using UG CNC automatic programming function the NC machining process of cushion block is generated to process it precisely.This pape's method has Practical application value on Lebuss drum design and manufacturing.

  7. Side skirt for a pulled vehicle

    NARCIS (Netherlands)

    Van Raemdonck, G.M.R.

    2009-01-01

    The present invention relates to a device for minimizing the aerodynamic drag that results when tractors, trailers, rigid trucks, lorries, and other vehicles are moving through air. In particular the invention relates to a plate-shaped flow conductor (31) having a front edge, a lower edge, a rear ed

  8. Innovative control systems for tracked vehicle platforms

    CERN Document Server

    2014-01-01

     This book has been motivated by an urgent need for designing and implementation of innovative control algorithms and systems for tracked vehicles. Nowadays the unmanned vehicles are becoming more and more common. Therefore there is a need for innovative mechanical constructions capable of adapting to various applications regardless the ground, air or water/underwater environment. There are multiple various activities connected with tracked vehicles. They can be distributed among three main groups: design and control algorithms, sensoric and vision based in-formation, construction and testing mechanical parts of unmanned vehicles. Scientists and researchers involved in mechanics, control algorithms, image processing, computer vision, data fusion, or IC will find this book useful.

  9. Adaptability Research on Micro-channel Heat Exchanger Applied to Heat Pump Air Conditioning System for Electrical Vehicle%电动汽车热泵空调系统微通道换热器适应性研究

    Institute of Scientific and Technical Information of China (English)

    巫江虹; 谢方; 刘超鹏; 欧阳光

    2012-01-01

    One enhanced and baseline heat pump air conditioning system(HPACS) for electrical vehicle(EV) are established including the new multi-flow micro-channel heat exchangers(HE) and the traditional fin-and-tube heat exchangers(HE), respectively. Is order to provide theoretical guidance to the follow-up research of EV HPACS based on novel micro-channel design and frosting control, the performance differences are discussed between the two systems, the refrigeration and heating characteristics of both systems are compared under variable test conditions and the results show that volume of the indoor and outdoor heat exchangers decrease by 57.6% and 62.5%, respectively, effectively reduce air conditioner's weight which contributes to the increase of EV's Life mileage; at the same time, the enhanced system with compact HE could reduce air conditioner system's charge by 26.5% which benefits to reduce the greenhouse effect The cooling capacity and refrigeration coefficient of performance of the enhanced system reduce by 4.1%-10.7% and 1.7%-4.8%, respectively. It indicates that there are still some technical barriers require to be managed in case of multi-flow micro-channel HE applied in HPACS, for example, the flow path design of micro-channel HE, flow distribution and pressure drop in micro-channel HE. The heating capacity and heating performance coefficient of the enhanced system reduce by l%-5% and 4.2%-9.7%, but the heating capacity per unit area increase by 16.7%-21.0%. The outdoor micro-channel HE will be frost when the outdoor temperature below 7 ℃, it immensely affects the heating capacity and the heating performance coefficient of enhanced system and demands to improve the frosting control strategy.%探讨管翅式换热器和多流程微通道换热器在同一电动汽车热泵空调系统中的性能差异,为电动汽车热泵空调系统中微通道设计和结霜控制的后续研究提供依据.试验比较在不同测试工况下采用微通道换热器和

  10. Numerical Simulation and Analysis of Migration Law of Gas Mixture Using Carbon Dioxide as Cushion Gas in Underground Gas Storage Reservoir

    Institute of Scientific and Technical Information of China (English)

    ChuanKai Niu; YuFei Tan

    2014-01-01

    One of the major technical challenges in using carbon dioxide ( CO2 ) as part of the cushion gas of the underground gas storage reservoir ( UGSR) is the mixture of CO2 and natural gas. To decrease the mixing extent and manage the migration of the mixed zone, an understanding of the mechanism of CO2 and natural gas mixing and the diffusion of the mixed gas in aquifer is necessary. In this paper, a numerical model based on the three dimensional gas-water two-phase flow theory and gas diffusion theory is developed to understand this mechanism. This model is validated by the actual operational data in Dazhangtuo UGSR in Tianjin City, China. Using the validated model, the mixed characteristic of CO2 and natural gas and the migration mechanism of the mixed zone in an underground porous reservoir is further studied. Particularly, the impacts of the following factors on the migration mechanism are studied:the ratio of CO2 injection, the reservoir porosity and the initial operating pressure. Based on the results, the optimal CO2 injection ratio and an optimal control strategy to manage the migration of the mixed zone are obtained. These results provide technical guides for using CO2 as cushion gas for UGSR in real projects.

  11. Effect of the Research Advances of Anal Cushions on the Treatment of Hemorrhoids%肛垫的研究进展对痔治疗的影响

    Institute of Scientific and Technical Information of China (English)

    高枫

    2003-01-01

    @@ 肛垫(anal cushions,vascular cushions)是一个解剖学概念,最早见于Thomson 1975年发表的论文(The nature of haemorrhoids),也称肛门海绵体(corpus cavernosum recti),是指齿状线上方宽约1.5 cm呈环状增厚的直肠柱区,借"Y"形沟分割成右前、右后和左中三块,由血管、平滑肌(Treitz肌)、弹力纤维和结缔组织所构成.肛垫早在胚胎期就已存在,属于人体正常结构的一部分.与直肠粘膜、粘膜下层、肌层比较,主要表现为肛管内局部增厚的粘膜下组织.

  12. Co-occurrence of pathogenic and non-pathogenic Fusarium decemcellulare and Lasiodiplodia theobromae isolates in cushion galls disease of cacao (Theobroma cacao L.

    Directory of Open Access Journals (Sweden)

    Castillo Daynet Sosa del

    2016-04-01

    Full Text Available Flowery cushion gall of cacao is a disease complex with six types. Fusarium decemcellulare have been isolated from both flowery and green point galls and recognized as the etiological agent of the disease. In the present work we: i identified by ITS-rDNA sequencing and/or taxonomy the cultivable fungal species or Operative Taxonomic Units (OTUs associated with the five symptoms of cushion galls in cacao from Venezuela, and ii determined the gall inducing capacity on cacao peeled seeds after 45 days of inoculation with suspensions of mycelia/ spores from distinct isolate types. The whole isolate collection rendered an abundance of 113 isolates with a richness of 39 OTUs (27 and eight identified at the species or genera levels, respectively, and in unidentified fungi. The dominant recovered species (≈36% were F. decemcellulare and Lasiodiplodia theobromae. Some isolates of F. decemcellulare, L. theobromae, F. equiseti, Fusarium spp., F. solani, F. incarnatum, Rhizocthonia solani and Penicillium sp. were pathogenic. Some other isolates of the first six mentioned taxa behave as non-pathogenic. Furthermore, pathogenic and non-pathogenic isolates can also co-occur within a single plant and gall type. Moreover, 2-5 species within a single gall symptom in a single tree were identified (not necessarily at the same point in the tree, indicating a broad diversity of co-occurring taxa.

  13. Modeling Languages Refine Vehicle Design

    Science.gov (United States)

    2009-01-01

    Cincinnati, Ohio s TechnoSoft Inc. is a leading provider of object-oriented modeling and simulation technology used for commercial and defense applications. With funding from Small Business Innovation Research (SBIR) contracts issued by Langley Research Center, the company continued development on its adaptive modeling language, or AML, originally created for the U.S. Air Force. TechnoSoft then created what is now known as its Integrated Design and Engineering Analysis Environment, or IDEA, which can be used to design a variety of vehicles and machinery. IDEA's customers include clients in green industries, such as designers for power plant exhaust filtration systems and wind turbines.

  14. 40 CFR 80.532 - How are motor vehicle diesel fuel credits used and transferred?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false How are motor vehicle diesel fuel... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Motor Vehicle Diesel....532 How are motor vehicle diesel fuel credits used and transferred? (a) Credit use stipulations....

  15. 40 CFR 80.531 - How are motor vehicle diesel fuel credits generated?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false How are motor vehicle diesel fuel... (CONTINUED) AIR PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Motor Vehicle Diesel Fuel... are motor vehicle diesel fuel credits generated? (a) Generation of credits from June 1, 2006...

  16. 40 CFR 88.308-94 - Programmatic requirements for clean-fuel fleet vehicles.

    Science.gov (United States)

    2010-07-01

    ...-fuel fleet vehicles. 88.308-94 Section 88.308-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CLEAN-FUEL VEHICLES Clean-Fuel Fleet Program § 88.308-94 Programmatic requirements for clean-fuel fleet vehicles. (a) Multi-State nonattainment areas. The...

  17. Engineering Design of Driving System for Flapping-Wing Micro Air Vehicles%微型扑翼飞行器驱动系统工程设计方法

    Institute of Scientific and Technical Information of China (English)

    王利光; 宋笔锋; 付鹏; 安伟刚

    2013-01-01

    以微型扑翼飞行器研制为背景,从系统的角度提出了一种仿生扑翼驱动系统的工程设计方法.根据仿生尺度率原理,对微型扑翼飞行器的总体参数进行了初步设计,提出了驱动系统的设计目标.进行了扑动翼风洞实验,以实际能达到的飞行状态为标准对实验数据进行分析处理,获得了扑动参数的可行范围和功耗需求.对微型无刷电机进行了工作特性测试,得到了电机转速、转矩、输出功率、效率等的拟合关系.综合考虑扑动参数可行范围、功耗需求和电机特性等多个因素,对驱动系统的减速比分配、减速器优化和四连杆扑动机构计算等方面进行了设计,得到了具有良好系统匹配性能的微型扑翼驱动系统,并通过样机研制和飞行实验证明了设计方法的有效性与可行性.所得研究结论对微型扑翼飞行器的工程设计和研制有一定指导意义.%For developing an efficient flapping-wing micro air vehicle (FMAV),an engineering design method for flappingwing driving system is systematically proposed.According to the principle of bionic scale law,the initial design of FMAV is carried out and the goal of flapping-wing driving system design is specified.The feasible flutter parameters and power requirements of the flapping-wing are demonstrated by the wind tunnel experiments which are processed submitting to the practical flying status.After carrying out another test,the micro brushless motor's operating characteristics of angular speed,torque,power output and efficiency are achieved.Then the feasible flutter parameters,power requirements and motor's operating characteristics are comprehensively considered,which make the assignation of the reduction ratio,optimization of the reduction gear and design of the four-link mechanism concordant.The mechanism prototype's flying tests verify the effectiveness and feasibility of this design approach.The results of this research are

  18. Moving target geolocation for micro air vehicles based on monocular vision%基于单目视觉的微型飞行器移动目标定位方法

    Institute of Scientific and Technical Information of China (English)

    郭力; 昂海松; 郑祥明

    2012-01-01

    针对目标在地形高度未知环境中移动的情况,给出一种利用微型飞行器机载单目摄像机进行目标定位的方法.首先,借助光流直方图从当前图像帧中提取出移动目标局部区域内的背景特征点;然后,结合机载微机电系统(micro electro mechanical system,MEMS)/全球定位系统(global positioning system,GPS)传感器测量的飞行器位姿和空间平面点成像的单应变换关系,在期望值最大化算法中将背景特征点分类为辅助平面点和非辅助平面点,并估计辅助平面到摄像机光心的距离参数和法矢量参数,从而确定移动目标所处辅助平面的空间平面方程;最后,联立求解目标视线方程和辅助平面方程获得交点坐标,转换到惯性系下完成移动目标的地理定位.实验结果表明,当微型飞行器飞行高度为100 m时,操作人员单次点击移动目标的定位误差在15 m以内.%Aiming at the movement of the targets in unknown altitude terrain, a monocular camera based target geolocation method for micro air vehicles (MAV) is presented. Firstly, the optical flow histgram algorithm extracts background features in the target's local region. Secondly, these features are clustered into two possible classes including aided plane features and non-aided plane features by the expectation maximization algorithm, in which the homography relationship between MAV's flight status measured by onboard micro electro mechanical systems (MEMS)/ global positioning system (GPS) sensors and planar is used. Meanwile, the normal vector of aided plane and the distance between the camera and the plane are estimated. Then the aided plane equation can be establised. Finally, the moving taregt can be geolocated by calculating the intersection of target's sight line and aided plane in inertial frame. Experimental results show that this method can instantaneously geolocate the moving target by operator's single click and the error can reach less than

  19. Electric Vehicle Charging Modeling

    OpenAIRE

    Grahn, Pia

    2014-01-01

    With an electrified passenger transportation fleet, carbon dioxide emissions could be reduced significantly depending on the electric power production mix. Increased electric power consumption due to electric vehicle charging demands of electric vehicle fleets may be met by increased amount of renewable power production in the electrical systems. With electric vehicle fleets in the transportation system there is a need for establishing an electric vehicle charging infrastructure that distribu...

  20. Propane vehicles : status, challenges, and opportunities.

    Energy Technology Data Exchange (ETDEWEB)

    Rood Werpy, M.; Burnham, A.; Bertram, K.; Energy Systems

    2010-06-17

    Propane as an auto fuel has a high octane value and has key properties required for spark-ignited internal combustion engines. To operate a vehicle on propane as either a dedicated fuel or bi-fuel (i.e., switching between gasoline and propane) vehicle, only a few modifications must be made to the engine. Until recently propane vehicles have commonly used a vapor pressure system that was somewhat similar to a carburetion system, wherein the propane would be vaporized and mixed with combustion air in the intake plenum of the engine. This leads to lower efficiency as more air, rather than fuel, is inducted into the cylinder for combustion (Myers 2009). A newer liquid injection system has become available that injects propane directly into the cylinder, resulting in no mixing penalty because air is not diluted with the gaseous fuel in the intake manifold. Use of a direct propane injection system will improve engine efficiency (Gupta 2009). Other systems include the sequential multi-port fuel injection system and a bi-fuel 'hybrid' sequential propane injection system. Carbureted systems remain in use but mostly for non-road applications. In the United States a closed-loop system is used in after-market conversions. This system incorporates an electronic sensor that provides constant feedback to the fuel controller to allow it to measure precisely the proper air/fuel ratio. A complete conversion system includes a fuel controller, pressure regulator valves, fuel injectors, electronics, fuel tank, and software. A slight power loss is expected in conversion to a vapor pressure system, but power can still be optimized with vehicle modifications of such items as the air/fuel mixture and compression ratios. Cold start issues are eliminated for vapor pressure systems since the air/fuel mixture is gaseous. In light-duty propane vehicles, the fuel tank is typically mounted in the trunk; for medium- and heavy-duty vans and trucks, the tank is located under the body of