Achieving better cooling of turbine blades using numerical simulation methods

Science.gov (United States)

Inozemtsev, A. A.; Tikhonov, A. S.; Sendyurev, C. I.; Samokhvalov, N. Yu.

2013-02-01

A new design of the first-stage nozzle vane for the turbine of a prospective gas-turbine engine is considered. The blade's thermal state is numerically simulated in conjugate statement using the ANSYS CFX 13.0 software package. Critical locations in the blade design are determined from the distribution of heat fluxes, and measures aimed at achieving more efficient cooling are analyzed. Essentially lower (by 50-100°C) maximal temperature of metal has been achieved owing to the results of the performed work.

blades

Directory of Open Access Journals (Sweden)

Shashishekara S. Talya

1999-01-01

Full Text Available Design optimization of a gas turbine blade geometry for effective film cooling toreduce the blade temperature has been done using a multiobjective optimization formulation. Three optimization formulations have been used. In the first, the average blade temperature is chosen as the objective function to be minimized. An upper bound constraint has been imposed on the maximum blade temperature. In the second, the maximum blade temperature is chosen as the objective function to be minimized with an upper bound constraint on the average blade temperature. In the third formulation, the blade average and maximum temperatures are chosen as objective functions. Shape optimization is performed using geometric parameters associated with film cooling and blade external shape. A quasi-three-dimensional Navier–Stokes solver for turbomachinery flows is used to solve for the flow field external to the blade with appropriate modifications to incorporate the effect of film cooling. The heat transfer analysis for temperature distribution within the blade is performed by solving the heat diffusion equation using the finite element method. The multiobjective Kreisselmeier–Steinhauser function approach has been used in conjunction with an approximate analysis technique for optimization. The results obtained using both formulations are compared with reference geometry. All three formulations yield significant reductions in blade temperature with the multiobjective formulation yielding largest reduction in blade temperature.

The heat transfer analysis of the first stage blade

International Nuclear Information System (INIS)

Hong, Yong Ju; Choi, Bum Seog; Park, Byung Gyu; Yoon, Eui Soo

2001-01-01

To get higher efficiency of gas turbine, the designer should have more higher Turbine Inlet Temperature(TIT). Today, modern gas turbine having sophisticated cooling scheme has TIT above 1,700 .deg. C. In the Korea, many gas turbine having TIT above 1,300 .deg. C was imported and being operated, but the gas with high TIT above 1,300 .deg. C in the turbine will give damage to liner of combustor, and blade of turbine and etc. So frequently maintenance for parts enduring high temperature was performed. In this study, the heat transfer analysis of cooling air in the internal cooling channel (network analysis) and temperature analysis of the blade (Finite Element Analysis) in the first stage rotor was conducted for development of the optimal cooling passage design procedure. The results of network analysis and FEM analysis of blade show that the high temperature spot are occurred at the leading edge, trailing edge near tip, and platform. So to get more reliable performance of gas turbine, the more efficient cooling method should be applied at the leading edge and tip section and the thermal barrier coating on the blade surface has important role in cooling blade

Blade-to-coolant heat-transfer results and operating data from a natural-convection water-cooled single-stage turbine

Science.gov (United States)

Diaguila, Anthony J; Freche, John C

1951-01-01

Blade-to-coolant heat-transfer data and operating data were obtained with a natural-convection water-cooled turbine over range of turbine speeds and inlet-gas temperatures. The convective coefficients were correlated by the general relation for natural-convection heat transfer. The turbine data were displaced from a theoretical equation for natural convection heat transfer in the turbulent region and from natural-convection data obtained with vertical cylinders and plates; possible disruption of natural convection circulation within the blade coolant passages was thus indicated. Comparison of non dimensional temperature-ratio parameters for the blade leading edge, midchord, and trailing edge indicated that the blade cooling effectiveness is greatest at the midchord and least at the trailing edge.

Film cooling effects on the tip flow characteristics of a gas turbine blade

Directory of Open Access Journals (Sweden)

Jin Wang

2015-03-01

Full Text Available An experimental investigation of the tip flow characteristics between a gas turbine blade tip and the shroud was conducted by a pressure-test system and a particle image velocimetry (PIV system. A three-times scaled profile of the GE-E3 blade with five film cooling holes was used as specimen. The effects on flow characteristics by the rim width and the groove depth of the squealer tip were revealed. The rim widths were (a 0.9%, (b 2.1%, and (c 3.0% of the axial chord, and the groove depths were (a 2.8%, (b 4.8%, and (c 10% of the blade span. Several pressure taps on the top plate above the blades were connected to pressure gauges. By a CCD camera the PIV system recorded the velocity field around the leading edge zone including the five cooling holes. The flow distributions both in the tip clearance and in the passage were revealed, and the influence of the inlet velocity was determined. In this work, the tip flow characteristics with and without film cooling were investigated. The effects of different global blowing ratios of M=0.5, 1.0, 1.3 and 2.5 were established. It was found that decreasing the rim width resulted in a lower mass flow rate of the leakage flow, and the pressure distributions from the leading edge to the trailing edge showed a linearly increasing trend. It was also found that if the inlet velocity was less than 1.5 m/s, the flow field in the passage far away from the suction side appeared as a stagnation zone.

CMC blade with pressurized internal cavity for erosion control

Science.gov (United States)

Garcia-Crespo, Andres; Goike, Jerome Walter

2016-02-02

A ceramic matrix composite blade for use in a gas turbine engine having an airfoil with leading and trailing edges and pressure and suction side surfaces, a blade shank secured to the lower end of each airfoil, one or more interior fluid cavities within the airfoil having inlet flow passages at the lower end which are in fluid communication with the blade shank, one or more passageways in the blade shank corresponding to each one of the interior fluid cavities and a fluid pump (or compressor) that provides pressurized fluid (nominally cool, dry air) to each one of the interior fluid cavities in each airfoil. The fluid (e.g., air) is sufficient in pressure and volume to maintain a minimum fluid flow to each of the interior fluid cavities in the event of a breach due to foreign object damage.

A reverse engineering methodology for nickel alloy turbine blades with internal features

DEFF Research Database (Denmark)

Gameros, A.; De Chiffre, Leonardo; Siller, H.R.

2015-01-01

The scope of this work is to present a reverse engineering (RE) methodology for freeform surfaces, based on a case study of a turbine blade made of Inconel, including the reconstruction of its internal cooling system. The methodology uses an optical scanner and X-ray computed tomography (CT......) equipment. Traceability of the measurements was obtained through the use of a Modular Freeform Gage (MFG). An uncertainty budget is presented for both measuring technologies and results show that the RE methodology presented is promising when comparing uncertainty values against common industrial tolerances....

Performance and internal flow condition of mini centrifugal pump with splitter blades

International Nuclear Information System (INIS)

Shigemitsu, T; Fukutomi, J; Kaji, K; Wada, T

2012-01-01

Mini centrifugal pumps having a diameter smaller than 100mm are employed in many fields. But the design method for the mini centrifugal pump is not established because the internal flow condition for these small-sized fluid machines is not clarified and conventional theory is not suitable for small-sized pumps. Therefore, mini centrifugal pumps with simple structure were investigated by this research. Splitter blades were adopted in this research to improve the performance and the internal flow condition of mini centrifugal pump which had large blade outlet angle. The original impeller without the splitter blades and the impeller with the splitter blades were prepared for an experiment. The performance tests are conducted with these rotors in order to investigate the effect of the splitter blades on performance and internal flow condition of mini centrifugal pump. On the other hand, a three dimensional steady numerical flow analysis is conducted with the commercial code (ANSYS-CFX) to investigate the internal flow condition in detail. It is clarified from the experimental results that the performance of the mini centrifugal pump is improved by the effect of the splitter blades. The blade-to-blade low velocity regions are suppressed in the case with the splitter blades and the total pressure loss regions are decreased. The effects of the splitter blades on the performance and the internal flow condition are discussed in this paper.

TACT1- TRANSIENT THERMAL ANALYSIS OF A COOLED TURBINE BLADE OR VANE EQUIPPED WITH A COOLANT INSERT

Science.gov (United States)

Gaugler, R. E.

1994-01-01

As turbine-engine core operating conditions become more severe, designers must develop more effective means of cooling blades and vanes. In order to design reliable, cooled turbine blades, advanced transient thermal calculation techniques are required. The TACT1 computer program was developed to perform transient and steady-state heat-transfer and coolant-flow analyses for cooled blades, given the outside hot-gas boundary condition, the coolant inlet conditions, the geometry of the blade shell, and the cooling configuration. TACT1 can analyze turbine blades, or vanes, equipped with a central coolant-plenum insert from which coolant-air impinges on the inner surface of the blade shell. Coolant-side heat-transfer coefficients are calculated with the heat transfer mode at each station being user specified as either impingement with crossflow, forced convection channel flow, or forced convection over pin fins. A limited capability to handle film cooling is also available in the program. The TACT1 program solves for the blade temperature distribution using a transient energy equation for each node. The nodal energy balances are linearized, one-dimensional, heat-conduction equations which are applied at the wall-outer-surface node, at the junction of the cladding and the metal node, and at the wall-inner-surface node. At the mid-metal node a linear, three-dimensional, heat-conduction equation is used. Similarly, the coolant pressure distribution is determined by solving the set of transfer momentum equations for the one-dimensional flow between adjacent fluid nodes. In the coolant channel, energy and momentum equations for one-dimensional compressible flow, including friction and heat transfer, are used for the elemental channel length between two coolant nodes. The TACT1 program first obtains a steady-state solution using iterative calculations to obtain convergence of stable temperatures, pressures, coolant-flow split, and overall coolant mass balance. Transient

Multi-scale simulation of single crystal hollow turbine blade manufactured by liquid metal cooling process

Directory of Open Access Journals (Sweden)

Xuewei Yan

2018-02-01

Full Text Available Liquid metal cooling (LMC process as a powerful directional solidification (DS technique is prospectively used to manufacture single crystal (SC turbine blades. An understanding of the temperature distribution and microstructure evolution in LMC process is required in order to improve the properties of the blades. For this reason, a multi-scale model coupling with the temperature field, grain growth and solute diffusion was established. The temperature distribution and mushy zone evolution of the hollow blade was simulated and discussed. According to the simulation results, the mushy zone might be convex and ahead of the ceramic beads at a lower withdrawal rate, while it will be concave and laggard at a higher withdrawal rate, and a uniform and horizontal mushy zone will be formed at a medium withdrawal rate. Grain growth of the blade at different withdrawal rates was also investigated. Single crystal structures were all selected out at three different withdrawal rates. Moreover, mis-orientation of the grains at 8 mm/min reached ~30°, while it was ~5° and ~15° at 10 mm/min and 12 mm/min, respectively. The model for predicting dendritic morphology was verified by corresponding experiment. Large scale for 2D dendritic distribution in the whole sections was investigated by experiment and simulation, and they presented a well agreement with each other. Keywords: Hollow blade, Single crystal, Multi-scale simulation, Liquid metal cooling

Estimation of Efficiency of the Cooling Channel of the Nozzle Blade of Gas-Turbine Engines

Science.gov (United States)

Vikulin, A. V.; Yaroslavtsev, N. L.; Zemlyanaya, V. A.

2018-02-01

The main direction of improvement of gas-turbine plants (GTP) and gas-turbine engines (GTE) is increasing the gas temperature at the turbine inlet. For the solution of this problem, promising systems of intensification of heat exchange in cooled turbine blades are developed. With this purpose, studies of the efficiency of the cooling channel of the nozzle blade in the basic modification and of the channel after constructive measures for improvement of the cooling system by the method of calorimetry in a liquid-metal thermostat were conducted. The combined system of heat-exchange intensification with the complicated scheme of branched channels is developed; it consists of a vortex matrix and three rows of inclined intermittent trip strips. The maximum value of hydraulic resistance ξ is observed at the first row of the trip strips, which is connected with the effect of dynamic impact of airflow on the channel walls, its turbulence, and rotation by 117° at the inlet to the channels formed by the trip strips. These factors explain the high value of hydraulic resistance equal to 3.7-3.4 for the first row of the trip strips. The obtained effect was also confirmed by the results of thermal tests, i.e., the unevenness of heat transfer on the back and on the trough of the blade is observed at the first row of the trip strips, which amounts 8-12%. This unevenness has a fading character; at the second row of the trip strips, it amounts to 3-7%, and it is almost absent at the third row. At the area of vortex matrix, the intensity of heat exchange on the blade back is higher as compared to the trough, which is explained by the different height of the matrix ribs on its opposite sides. The design changes in the nozzle blade of basic modification made it possible to increase the intensity of heat exchange by 20-50% in the area of the vortex matrix and by 15-30% on the section of inclined intermittent trip strips. As a result of research, new criteria dependences for the

Implementation of creep-fatigue model into finite-element code to assess cooled turbine blade.

CSIR Research Space (South Africa)

Dedekind, MO

1994-01-01

Full Text Available Turbine blades which are designed with airfoil cooling are subject to thermo-mechanical fatigue as well as creep damage. These problems arise due to thermal cycling and high operating temperatures in service. An implementation of fatigue and creep...

Influence of internal channel geometry of gas turbine blade on flow structure and heat transfer

Science.gov (United States)

Szwaba, Ryszard; Kaczynski, Piotr; Telega, Janusz; Doerffer, Piotr

2017-12-01

This paper presents the study of the influence of channel geometry on the flow structure and heat transfer, and also their correlations on all the walls of a radial cooling passage model of a gas turbine blade. The investigations focus on the heat transfer and aerodynamic measurements in the channel, which is an accurate representation of the configuration used in aeroengines. Correlations for the heat transfer coefficient and the pressure drop used in the design of internal cooling passages are often developed from simplified models. It is important to note that real engine passages do not have perfect rectangular cross sections, but include a corner fillets, ribs with fillet radii and a special orientation. Therefore, this work provides detailed fluid flow and heat transfer data for a model of radial cooling geometry which has very realistic features.

Determination of blade-to-coolant heat-transfer coefficients on a forced-convection, water-cooled, single-stage turbine

Science.gov (United States)

Freche, John C; Schum, Eugene F

1951-01-01

Blade-to-coolant convective heat-transfer coefficients were obtained on a forced-convection water-cooled single-stage turbine over a large laminar flow range and over a portion of the transition range between laminar and turbulent flow. The convective coefficients were correlated by the general relation for forced-convection heat transfer with laminar flow. Natural-convection heat transfer was negligible for this turbine over the Grashof number range investigated. Comparison of turbine data with stationary tube data for the laminar flow of heated liquids showed good agreement. Calculated average midspan blade temperatures using theoretical gas-to-blade coefficients and blade-to-coolant coefficients from stationary-tube data resulted in close agreement with experimental data.

Optimizing parameters of GTU cycle and design values of air-gas channel in a gas turbine with cooled nozzle and rotor blades

Science.gov (United States)

Kler, A. M.; Zakharov, Yu. B.

2012-09-01

The authors have formulated the problem of joint optimization of pressure and temperature of combustion products before gas turbine, profiles of nozzle and rotor blades of gas turbine, and cooling air flow rates through nozzle and rotor blades. The article offers an original approach to optimization of profiles of gas turbine blades where the optimized profiles are presented as linear combinations of preliminarily formed basic profiles. The given examples relate to optimization of the gas turbine unit on the criterion of power efficiency at preliminary heat removal from air flows supplied for the air-gas channel cooling and without such removal.

Aero-thermal optimization of film cooling flow parameters on the suction surface of a high pressure turbine blade

Science.gov (United States)

El Ayoubi, Carole; Hassan, Ibrahim; Ghaly, Wahid

2012-11-01

This paper aims to optimize film coolant flow parameters on the suction surface of a high-pressure gas turbine blade in order to obtain an optimum compromise between a superior cooling performance and a minimum aerodynamic penalty. An optimization algorithm coupled with three-dimensional Reynolds-averaged Navier Stokes analysis is used to determine the optimum film cooling configuration. The VKI blade with two staggered rows of axially oriented, conically flared, film cooling holes on its suction surface is considered. Two design variables are selected; the coolant to mainstream temperature ratio and total pressure ratio. The optimization objective consists of maximizing the spatially averaged film cooling effectiveness and minimizing the aerodynamic penalty produced by film cooling. The effect of varying the coolant flow parameters on the film cooling effectiveness and the aerodynamic loss is analyzed using an optimization method and three dimensional steady CFD simulations. The optimization process consists of a genetic algorithm and a response surface approximation of the artificial neural network type to provide low-fidelity predictions of the objective function. The CFD simulations are performed using the commercial software CFX. The numerical predictions of the aero-thermal performance is validated against a well-established experimental database.

Rotational effects on turbine blade cooling

Energy Technology Data Exchange (ETDEWEB)

Govatzidakis, G.J.; Guenette, G.R.; Kerrebrock, J.L. [Massachusetts Institute of Technology, Cambridge, MA (United States)

1995-10-01

An experimental investigation of the influence of rotation on the heat transfer in a smooth, rectangular passage rotating in the orthogonal mode is presented. The passage simulates one of the cooling channels found in gas turbine blades. A constant heat flux is imposed on the model with either inward or outward flow. The effects of rotation and buoyancy on the Nusselt number were quantified by systematically varying the Rotation number, Density Ratio, Reynolds number, and Buoyancy parameter. The experiment utilizes a high resolution infrared temperature measurement technique in order to measure the wall temperature distribution. The experimental results show that the rotational effects on the Nusselt number are significant and proper turbine blade design must take into account the effects of rotation, buoyancy, and flow direction. The behavior of the Nusselt number distribution depends strongly on the particular side, axial position, flow direction, and the specific range of the scaling parameters. The results show a strong coupling between buoyancy and Corollas effects throughout the passage. For outward flow, the trailing side Nusselt numbers increase with Rotation number relative to stationary values. On the leading side, the Nusselt numbers tended to decrease with rotation near the inlet and subsequently increased farther downstream in the passage. The Nusselt numbers on the side walls generally increased with rotation. For inward flow, the Nusselt numbers generally improved relative to stationary results, but increases in the Nusselt number were relatively smaller than in the case of outward flow. For outward and inward flows, increasing the density ratio generally tended to decrease Nusselt numbers on the leading and trailing sides, but the exact behavior and magnitude depended on the local axial position and specific range of Buoyancy parameters.

Mesh sensitivity in the thermal analysis of a gas turbine a blade with internal cooling; Sensibilidad de malla en el analisis termico de un alabe de turbina de gas con enfriamiento interno

Energy Technology Data Exchange (ETDEWEB)

Alfaro Ayala, Jorge Arturo; Gallegos Munoz, Armando [Facultad de Ingenieria Mecanica, Electrica y Electronica (FIMEE), Universidad de Guanajuato (Mexico); Campos Amezcua, Alfonso [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2007-11-15

This article presents the methodology to generate the mesh model of the computer model of a blade by means of commands in the software of CFD Fluent, mainly in the fluid zone, since a mesh sensitivity analysis becomes too expensive in terms of human and computer resources. When geometry is too irregular, modifications are required in the mesh to avoid problems such as the divergence, instability in the solution and the dependency on the results of temperature, pressure, velocity, etc. Such is the case of a blade with internal cooling of the first stage of a gas turbine. The results are included of the generated mesh as well as of the thermal analysis of the blade. Additionally the results of temperature, pressure and velocity of the combustion gases and of the cooling air are shown. [Spanish] Este articulo presenta la metodologia para generar el mallado del modelo computacional de un alabe por medio de comandos en el software de CFD Fluent, principalmente en la zona del fluido, ya que un analisis de sensibilidad de malla se vuelve demasiado costoso en terminos de recursos humanos y computacionales. Cuando la geometria es demasiado irregular, se requiere de modificaciones en la malla para evitar problemas como son la divergencia, inestabilidad en la solucion y la dependencia de los resultados de temperatura, presion, velocidad, etc. Tal es el caso de un alabe con enfriamiento interno de la primera etapa de una turbina de gas. Se incluyen los resultados tanto de la malla generada como del analisis termico del alabe. Adicionalmente se muestran los resultados de temperatura, presion y velocidad de los gases de la combustion y del aire de enfriamiento.

Air cooled turbine component having an internal filtration system

Science.gov (United States)

Beeck, Alexander R [Orlando, FL

2012-05-15

A centrifugal particle separator is provided for removing particles such as microscopic dirt or dust particles from the compressed cooling air prior to reaching and cooling the turbine blades or turbine vanes of a turbine engine. The centrifugal particle separator structure has a substantially cylindrical body with an inlet arranged on a periphery of the substantially cylindrical body. Cooling air enters centrifugal particle separator through the separator inlet port having a linear velocity. When the cooling air impinges the substantially cylindrical body, the linear velocity is transformed into a rotational velocity, separating microscopic particles from the cooling air. Microscopic dust particles exit the centrifugal particle separator through a conical outlet and returned to a working medium.

A Numerical Analysis of Heat Transfer and Effectiveness on Film Cooled Turbine Blade Tip Models

Science.gov (United States)

Ameri, A. A.; Rigby, D. L.

1999-01-01

A computational study has been performed to predict the distribution of convective heat transfer coefficient on a simulated blade tip with cooling holes. The purpose of the examination was to assess the ability of a three-dimensional Reynolds-averaged Navier-Stokes solver to predict the rate of tip heat transfer and the distribution of cooling effectiveness. To this end, the simulation of tip clearance flow with blowing of Kim and Metzger was used. The agreement of the computed effectiveness with the data was quite good. The agreement with the heat transfer coefficient was not as good but improved away from the cooling holes. Numerical flow visualization showed that the uniformity of wetting of the surface by the film cooling jet is helped by the reverse flow due to edge separation of the main flow.

Numerical study on film cooling and convective heat transfer characteristics in the cutback region of turbine blade trailing edge

Directory of Open Access Journals (Sweden)

Xie Yong-Hui

2016-01-01

Full Text Available Gas turbine blade trailing edge is easy to burn out under the exposure of high-temperature gas due to its thin shape. The cooling of this area is an important task in gas turbine blade design. The structure design and analysis of trailing edge is critical because of the complexity of geometry, arrangement of cooling channels, design requirement of strength, and the working condition of high heat flux. In the present paper, a 3-D model of the trailing edge cooling channel is constructed and both structures with and without land are numerically investigated at different blowing ratio. The distributions of film cooling effectiveness and convective heat transfer coefficient on cutback and land surface are analyzed, respectively. According to the results, it is obtained that the distributions of film cooling effectiveness and convective heat transfer coefficient both show the symmetrical characteristics as a result of the periodic structure of the trailing edge. The increase of blowing ratio significantly improves the film cooling effectiveness and convective heat transfer coefficient on the cutback surface, which is beneficial to the cooling of trailing edge. It is also found that the land structure is advantageous for enhancing the streamwise film cooling effectiveness of the trailing edge surface while the film cooling effectiveness on the land surface remains at a low level. Convective heat transfer coefficient exhibits a strong dependency with the blowing ratio, which suggests that film cooling effectiveness and convective heat transfer coefficient must be both considered and analyzed in the design of trailing edge cooling structure.

Low pressure cooling seal system for a gas turbine engine

Science.gov (United States)

Marra, John J

2014-04-01

A low pressure cooling system for a turbine engine for directing cooling fluids at low pressure, such as at ambient pressure, through at least one cooling fluid supply channel and into a cooling fluid mixing chamber positioned immediately downstream from a row of turbine blades extending radially outward from a rotor assembly to prevent ingestion of hot gases into internal aspects of the rotor assembly. The low pressure cooling system may also include at least one bleed channel that may extend through the rotor assembly and exhaust cooling fluids into the cooling fluid mixing chamber to seal a gap between rotational turbine blades and a downstream, stationary turbine component. Use of ambient pressure cooling fluids by the low pressure cooling system results in tremendous efficiencies by eliminating the need for pressurized cooling fluids for sealing this gap.

A scaled experimental study of control blade insertion dynamics in Pebble-Bed Fluoride-Salt-Cooled High-Temperature Reactors

Energy Technology Data Exchange (ETDEWEB)

Buster, Grant C., E-mail: grant.buster@gmail.com; Laufer, Michael R.; Peterson, Per F.

2016-07-15

Highlights: • A granular dynamics scaling methodology is discussed. • Control blade insertion in a representative pebble-bed core is experimentally studied. • Control blade insertion forces and pebble displacements are experimentally measured. • X-ray tomography techniques are used to observe pebble displacement distributions. - Abstract: Direct control element insertion into a pebble-bed reactor core is proposed as a viable control system in molten-salt-cooled pebble-bed reactors. Unlike helium-cooled pebble-bed reactors, this reactor type uses spherical fuel elements with near-neutral buoyancy in the molten-salt coolant, thus reducing contact forces on the fuel elements. This study uses the X-ray Pebble Bed Recirculation Experiment facility to measure the force required to insert a control element directly into a scaled pebble-bed. The required control element insertion force, and therefore the contact force on fuel elements, is measured to be well below recommended limits. Additionally, X-ray tomography is used to observe how the direct insertion of a control element physically displaces spherical fuel elements. The tomography results further support the viability of direct control element insertion into molten-salt-cooled pebble-bed reactor cores.

Sand transport in a two pass internal cooling duct with rib turbulators

International Nuclear Information System (INIS)

Singh, Sukhjinder; Tafti, Danesh; Reagle, Colin; Delimont, Jacob; Ng, Wing; Ekkad, Srinath

2014-01-01

Highlights: • Highest particle impingement observed in the bend and first quarter of 2nd pass. • Average particle impingement per pitch is 28% higher in the second pass. • Rib faces are by far the most susceptible to particle impingement. • Particle impingement is sensitive to particle size. • Particle impingement is sensitive to wall collision model used. - Abstract: Jet engines often operate under dirty conditions where large amounts of particulate matter can be ingested, especially, sand, ash and dirt. Particulate matter in different engine components can lead to degradation in performance. The focus of this study is to investigate the sand transport and deposition in the internal cooling passages of turbine blades. A two pass stationary square duct with rib turbulators subjected to sand ingestion is studied using Large Eddy Simulations (LES). Each pass has ribs on two opposite walls and aligned normal to the main flow direction. The rib pitch to rib height (P/e) is 9.28, the rib height to channel hydraulic diameter (e/D h ) is 0.0625 and calculations have been carried out for a bulk Reynolds number of 25,000. Particle sizes in the range 0.5–25 μm are considered, with the same size distribution as found in Arizona Road Dust (medium). Large Eddy Simulation (LES) with a wall-model is used to model the flow and sand particles are modeled using a discrete Lagrangian framework. Results quantify the distribution of particle impingement density on all surfaces. Highest particle impingement density is found in the first quarter section of the second pass after the 180° turn, where the recorded impingement is more than twice that of any other region. It is also found that the average particle impingement per pitch is 28% higher in the second pass than the first pass. Results show lower particle tendency to impact the region immediately behind the rib in the first pass compared to the second pass where particle impingement is more uniform in the region

Numerical simulation on vacuum solution heat treatment and gas quenching process of a low rhenium-containing Ni-based single crystal turbine blade

Directory of Open Access Journals (Sweden)

Zhe-xin Xu

2016-11-01

Full Text Available Numerical heat-transfer and turbulent flow model for an industrial high-pressure gas quenching vacuum furnace was established to simulate the heating, holding and gas fan quenching of a low rhenium-bearing Ni-based single crystal turbine blade. The mesh of simplified furnace model was built using finite volume method and the boundary conditions were set up according to the practical process. Simulation results show that the turbine blade geometry and the mutual shielding among blades have significant influence on the uniformity of the temperature distribution. The temperature distribution at sharp corner, thin wall and corner part is higher than that at thick wall part of blade during heating, and the isotherms show a toroidal line to the center of thick wall. The temperature of sheltered units is lower than that of the remaining part of blade. When there is no shelteration among multiple blades, the temperature distribution for all blades is almost identical. The fluid velocity field, temperature field and cooling curves of the single and multiple turbine blades during gas fan quenching were also simulated. Modeling results indicate that the loading tray, free outlet and the location of turbine blades have important influences on the flow field. The high-speed gas flows out from the nozzle is divided by loading tray, and the free outlet enhanced the two vortex flow at the end of the furnace door. The closer the blade is to the exhaust outlet and the nozzle, the greater the flow velocity is and the more adequate the flow is. The blade geometry has an effect on the cooling for single blade and multiple blades during gas fan quenching, and the effects in double layers differs from that in single layer. For single blade, the cooing rate at thin-walled part is lower than that at thick-walled part, the cooling rate at sharp corner is greater than that at tenon and blade platform, and the temperature at regions close to the internal position is

Film cooling adiabatic effectiveness measurements of pressure side trailing edge cooling configurations

Directory of Open Access Journals (Sweden)

R. Becchi

2015-12-01

Full Text Available Nowadays total inlet temperature of gas turbine is far above the permissible metal temperature; as a consequence, advanced cooling techniques must be applied to protect from thermal stresses, oxidation and corrosion the components located in the high pressure stages, such as the blade trailing edge. A suitable design of the cooling system for the trailing edge has to cope with geometric constraints and aerodynamic demands; state-of-the-art of cooling concepts often use film cooling on blade pressure side: the air taken from last compressor stages is ejected through discrete holes or slots to provide a cold layer between hot mainstream and the blade surface. With the goal of ensuring a satisfactory lifetime of blades, the design of efficient trailing edge film cooling schemes and, moreover, the possibility to check carefully their behavior, are hence necessary to guarantee an appropriate metal temperature distribution. For this purpose an experimental survey was carried out to investigate the film covering performance of different pressure side trailing edge cooling systems for turbine blades. The experimental test section consists of a scaled-up trailing edge model installed in an open loop suction type test rig. Measurements of adiabatic effectiveness distributions were carried out on three trailing edge cooling system configurations. The baseline geometry is composed by inclined slots separated by elongated pedestals; the second geometry shares the same cutback configuration, with an additional row of circular film cooling holes located upstream; the third model is equipped with three rows of in-line film cooling holes. Experiments have been performed at nearly ambient conditions imposing several blowing ratio values and using carbon dioxide as coolant in order to reproduce a density ratio close to the engine conditions (DR=1.52. To extend the validity of the survey a comparison between adiabatic effectiveness measurements and a prediction by

Cooling system with compressor bleed and ambient air for gas turbine engine

Science.gov (United States)

Marsh, Jan H.; Marra, John J.

2017-11-21

A cooling system for a turbine engine for directing cooling fluids from a compressor to a turbine blade cooling fluid supply and from an ambient air source to the turbine blade cooling fluid supply to supply cooling fluids to one or more airfoils of a rotor assembly is disclosed. The cooling system may include a compressor bleed conduit extending from a compressor to the turbine blade cooling fluid supply that provides cooling fluid to at least one turbine blade. The compressor bleed conduit may include an upstream section and a downstream section whereby the upstream section exhausts compressed bleed air through an outlet into the downstream section through which ambient air passes. The outlet of the upstream section may be generally aligned with a flow of ambient air flowing in the downstream section. As such, the compressed air increases the flow of ambient air to the turbine blade cooling fluid supply.

Blade runner. Blade server and virtualization technology can help hospitals save money--but they are far from silver bullets.

Science.gov (United States)

Lawrence, Daphne

2009-03-01

Blade servers and virtualization can reduce infrastructure, maintenance, heating, electric, cooling and equipment costs. Blade server technology is evolving and some elements may become obsolete. There is very little interoperability between blades. Hospitals can virtualize 40 to 60 percent of their servers, and old servers can be reused for testing. Not all applications lend themselves to virtualization--especially those with high memory requirements. CIOs should engage their vendors in virtualization discussions.

Investigation of heat transfer and flow using ribs within gas turbine blade cooling passage: Experimental and hybrid LES/RANS modeling

Science.gov (United States)

Kumar, Sourabh

Gas turbines are extensively used for aircraft propulsion, land based power generation and various industrial applications. Developments in innovative gas turbine cooling technology enhance the efficiency and power output, with an increase in turbine rotor inlet temperatures. These advancements of turbine cooling have allowed engine design to exceed normal material temperature limits. For internal cooling design, techniques for heat extraction from the surfaces exposed to hot stream are based on the increase of heat transfer areas and on promotion of turbulence of the cooling flow. In this study, it is obtained by casting repeated continuous V and broken V shaped ribs on one side of the two pass square channel into the core of blade. Despite extensive research on ribs, only few papers have validated the numerical data with experimental results in two pass channel. In the present study, detailed experimental investigation is carried out for two pass square channels with 180° turn. Detailed heat transfer distribution occurring in the ribbed passage is reported for steady state experiment. Four different combinations of 60° and Broken 60° V ribs in channel are considered. Thermocouples are used to obtain the temperature on the channel surface and local heat transfer coefficients are obtained for various Reynolds numbers, within the turbulent flow regime. Area averaged data are calculated in order to compare the overall performance of the tested ribbed surface and to evaluate the degree of heat transfer enhancement induced by the ribs with. Flow within the channels is characterized by heat transfer enhancing ribs, bends, rotation and buoyancy effects. Computational Fluid Dynamics (CFD) simulations were carried out for the same geometries using different turbulence models such as k-o Shear stress transport (SST) and Reynolds stress model (RSM). These CFD simulations were based on advanced computing in order to improve the accuracy of three dimensional metal

Effects of free-stream turbulence intensity and blowing ratio on film cooling of turbine blade leading edge

International Nuclear Information System (INIS)

Kim, S. M.; Kim, Youn J.; Cho, H. H.

2001-01-01

We used a cylindrical model which simulates turbine blade leading edge to investigate the effects of free-stream turbulence intensity and blowing ratio on film cooling of turbine blade leading edge. Tests are carried out in a low-speed wind tunnel on a cylindrical model with three rows of injection holes. Mainstream Reynolds number based on the cylinder diameter was 7.1x10 4 . Two types of turbulence grid are used to increase a free-stream turbulence intensity. The effect of coolant blowing ratio was studied for various blowing ratios. For each blowing ratios, wall temperatures around the surface of the test model are measured by thermocouples installed inside the model. Results show that blowing ratios have small effect on spanwise-averaged film effectiveness at high free-stream turbulence intensity. However, an increase in free-stream turbulence intensity enhances significantly spanwise-averaged film effectiveness at low blowing ratio

Contrastive experimental study on heat transfer and friction characteristics in steam cooled and air cooled rectangular channels with rib turbulators

Energy Technology Data Exchange (ETDEWEB)

Gong, Jianying; Li, Guojun; Gao, Tieyu [Xian Jiaotong University, Xian (China)

2014-09-15

The present experiment compares the heat transfer and friction characteristics in steam cooled and air cooled rectangular channels (simulating a gas turbine blade cooling passage) with two opposite rib-roughened walls. The Reynolds number (Re) whose length scale is the hydraulic diameter of the passage is set within the range of 10000-60000. The channel length is 1000 mm. The pitch-to-rib height ratio, the channel aspect ratio and the channel blockage ratio is 10, 0.5 and 0.047, respectively. It is found that the average Nu, the average friction coefficient, and the heat transfer performance of both steam and air in the ribbed channels show almost the same change trend with the increase of Re. Under the same test conditions, the average Nu of steam is 30.2% higher than that of air, the average friction coefficient is 18.4% higher, and the heat transfer performances of steam on the ribbed and the smooth walls are 8.4% and 7.3% higher than those of air, respectively. In addition, semi-empirical correlations for the two test channels are developed, which can predict the Nu under the given test condition. The correlations can be used in the design of the internal cooling passage of new generation steam cooled gas turbine blade/vane.

Wind turbine generators having wind assisted cooling systems and cooling methods

Science.gov (United States)

Bagepalli, Bharat [Niskayuna, NY; Barnes, Gary R [Delanson, NY; Gadre, Aniruddha D [Rexford, NY; Jansen, Patrick L [Scotia, NY; Bouchard, Jr., Charles G.; Jarczynski, Emil D [Scotia, NY; Garg, Jivtesh [Cambridge, MA

2008-09-23

A wind generator includes: a nacelle; a hub carried by the nacelle and including at least a pair of wind turbine blades; and an electricity producing generator including a stator and a rotor carried by the nacelle. The rotor is connected to the hub and rotatable in response to wind acting on the blades to rotate the rotor relative to the stator to generate electricity. A cooling system is carried by the nacelle and includes at least one ambient air inlet port opening through a surface of the nacelle downstream of the hub and blades, and a duct for flowing air from the inlet port in a generally upstream direction toward the hub and in cooling relation to the stator.

Analytical Modelling of the Effects of Different Gas Turbine Cooling Techniques on Engine Performance =

Science.gov (United States)

Uysal, Selcuk Can

In this research, MATLAB SimulinkRTM was used to develop a cooled engine model for industrial gas turbines and aero-engines. The model consists of uncooled on-design, mean-line turbomachinery design and a cooled off-design analysis in order to evaluate the engine performance parameters by using operating conditions, polytropic efficiencies, material information and cooling system details. The cooling analysis algorithm involves a 2nd law analysis to calculate losses from the cooling technique applied. The model is used in a sensitivity analysis that evaluates the impacts of variations in metal Biot number, thermal barrier coating Biot number, film cooling effectiveness, internal cooling effectiveness and maximum allowable blade temperature on main engine performance parameters of aero and industrial gas turbine engines. The model is subsequently used to analyze the relative performance impact of employing Anti-Vortex Film Cooling holes (AVH) by means of data obtained for these holes by Detached Eddy Simulation-CFD Techniques that are valid for engine-like turbulence intensity conditions. Cooled blade configurations with AVH and other different external cooling techniques were used in a performance comparison study. (Abstract shortened by ProQuest.).

Prediction of Film Cooling Effectiveness on a Gas Turbine Blade Leading Edge Using ANN and CFD

Science.gov (United States)

Dávalos, J. O.; García, J. C.; Urquiza, G.; Huicochea, A.; De Santiago, O.

2018-05-01

In this work, the area-averaged film cooling effectiveness (AAFCE) on a gas turbine blade leading edge was predicted by employing an artificial neural network (ANN) using as input variables: hole diameter, injection angle, blowing ratio, hole and columns pitch. The database used to train the network was built using computational fluid dynamics (CFD) based on a two level full factorial design of experiments. The CFD numerical model was validated with an experimental rig, where a first stage blade of a gas turbine was represented by a cylindrical specimen. The ANN architecture was composed of three layers with four neurons in hidden layer and Levenberg-Marquardt was selected as ANN optimization algorithm. The AAFCE was successfully predicted by the ANN with a regression coefficient R2<0.99 and a root mean square error RMSE=0.0038. The ANN weight coefficients were used to estimate the relative importance of the input parameters. Blowing ratio was the most influential parameter with relative importance of 40.36 % followed by hole diameter. Additionally, by using the ANN model, the relationship between input parameters was analyzed.

Application of additive laser technologies in the gas turbine blades design process

Science.gov (United States)

Shevchenko, I. V.; Rogalev, A. N.; Osipov, S. K.; Bychkov, N. M.; Komarov, I. I.

2017-11-01

An emergence of modern innovative technologies requires delivering new and modernization existing design and production processes. It is especially relevant for designing the high-temperature turbines of gas turbine engines, development of which is characterized by a transition to higher parameters of working medium in order to improve their efficient performance. A design technique for gas turbine blades based on predictive verification of thermal and hydraulic models of their cooling systems by testing of a blade prototype fabricated using the selective laser melting technology was presented in this article. Technique was proven at the time of development of the first stage blade cooling system for the high-pressure turbine. An experimental procedure for verification of a thermal model of the blades with convective cooling systems based on the comparison of heat-flux density obtained from the numerical simulation data and results of tests in a liquid-metal thermostat was developed. The techniques makes it possible to obtain an experimentally tested blade version and to exclude its experimental adjustment after the start of mass production.

Pink-Beam, Highly-Accurate Compact Water Cooled Slits

International Nuclear Information System (INIS)

Lyndaker, Aaron; Deyhim, Alex; Jayne, Richard; Waterman, Dave; Caletka, Dave; Steadman, Paul; Dhesi, Sarnjeet

2007-01-01

Advanced Design Consulting, Inc. (ADC) has designed accurate compact slits for applications where high precision is required. The system consists of vertical and horizontal slit mechanisms, a vacuum vessel which houses them, water cooling lines with vacuum guards connected to the individual blades, stepper motors with linear encoders, limit (home position) switches and electrical connections including internal wiring for a drain current measurement system. The total slit size is adjustable from 0 to 15 mm both vertically and horizontally. Each of the four blades are individually controlled and motorized. In this paper, a summary of the design and Finite Element Analysis of the system are presented

Hot spot detection system for vanes or blades of a combustion turbine

Science.gov (United States)

Twerdochlib, M.

1999-02-02

This invention includes a detection system that can determine if a turbine component, such as a turbine vane or blade, has exceeded a critical temperature, such as a melting point, along any point along the entire surface of the vane or blade. This system can be employed in a conventional combustion turbine having a compressor, a combustor and a turbine section. Included within this system is a chemical coating disposed along the entire interior surface of a vane or blade and a closed loop cooling system that circulates a coolant through the interior of the vane or blade. If the temperature of the vane or blade exceeds a critical temperature, the chemical coating will be expelled from the vane or blade into the coolant. Since while traversing the closed loop cooling system the coolant passes through a detector, the presence of the chemical coating in the coolant will be sensed by the system. If the chemical coating is detected, this indicates that the vane or blade has exceeded a critical temperature. 5 figs.

Experimental investigation of heat transfer and flow using V and broken V ribs within gas turbine blade cooling passage

Science.gov (United States)

Kumar, Sourabh; Amano, R. S.

2015-05-01

Gas turbines are extensively used for aircraft propulsion, land-based power generation, and various industrial applications. With an increase in turbine rotor inlet temperatures, developments in innovative gas turbine cooling technology enhance the efficiency and power output; these advancements of turbine cooling have allowed engine designs to exceed normal material temperature limits. For internal cooling design, techniques for heat extraction from the surfaces exposed to hot stream of gas are based on an increase in the heat transfer areas and on the promotion of turbulence of the cooling flow. In this study, an improvement in performance is obtained by casting repeated continuous V- and broken V-shaped ribs on one side of the two pass square channels into the core of the blade. A detailed experimental investigation is done for two pass square channels with a 180° turn. Detailed heat transfer distribution occurring in the ribbed passage is reported for a steady state experiment. Four different combinations of 60° V- and broken 60° V-ribs in a channel are considered. A series of thermocouples are used to obtain the temperature on the channel surface and local heat transfer coefficients are obtained for Reynolds numbers 16,000, 56,000 and 85,000 within the turbulent flow regime. Area averaged data are calculated in order to compare the overall performance of the tested ribbed surface and to evaluate the degree of heat transfer enhancement induced by the rib. Flow within the channels is characterized by heat transfer enhancing ribs, bends, rotation and buoyancy effects. A series of experimental measurements is performed to predict the overall performance of the channel. This paper presents an attempt to collect information about the Nusselt number, the pressure drop and the overall performance of the eight different ribbed ducts at the specified Reynolds number. The main contribution of this study is to evaluate the best combination of rib arrangements

Effect of jet nozzle geometry on flow and heat transfer performance of vortex cooling for gas turbine blade leading edge

International Nuclear Information System (INIS)

Du, Changhe; Li, Liang; Wu, Xin; Feng, Zhenping

2016-01-01

Highlights: • We establish a suitable vortex chamber model for gas turbine blade leading edge. • Mechanism of vortex cooling is further discussed and presented. • Influences of jet nozzle geometry on vortex cooling characteristics are researched. • This paper focuses on assessment of flow field and thermal performance for different jet nozzle aspect ratio and area. - Abstract: In this paper, 3D viscous steady Reynolds Averaged Navier–Stokes (RANS) equations are utilized to investigate the influence of jet nozzle geometry on flow and thermal behavior of vortex cooling for gas turbine blades. Comparison between calculation with different turbulence models and the experimental data is conducted, and results show that the standard k-ω model provides the best accuracy. The grid independence analysis is performed to obtain the proper mesh number. First, the mechanism of vortex cooling is further discussed, and the pronounced impact of kinetic turbulence intensity, thin thermal boundary layer, violent radial convection and complex vortices on enhanced heat transfer performance is confirmed. Then, seven jet nozzle aspect ratios and seven jet nozzle to chamber cross section area ratios are selected to research the flow field and thermal characteristics of vortex cooling focusing on the streamline, static pressure ratio, total pressure loss ratio and Nusselt number. It is presented that the jet nozzle aspect ratio and jet nozzle to chamber cross section area ratio both impose a significant effect on the flow and thermal parameters. The averaged Nusselt number decreases at first and then increases with the increasing jet nozzle aspect ratio, reaching highest when aspect ratio equals to 1. The effect of area ratio on averaged Nusselt number is complex. Finally, the heat transfer results in this study are compared with other previous works. Results indicate that good agreement with previous data is achieved, and the enhanced thermal behavior may be acquired by

Lightning transient analysis in wind turbine blades

DEFF Research Database (Denmark)

Candela Garolera, Anna; Holbøll, Joachim; Madsen, Søren Find

2013-01-01

The transient behavior of lightning surges in the lightning protection system of wind turbine blades has been investigated in this paper. The study is based on PSCAD models consisting of electric equivalent circuits with lumped and distributed parameters involving different lightning current...... waveforms. The aim of the PSCAD simulations is to study the voltages induced by the lightning current in the blade that may cause internal arcing. With this purpose, the phenomenon of current reflections in the lightning down conductor of the blade and the electromagnetic coupling between the down conductor...... and other internal conductive elements of the blade is studied. Finally, several methods to prevent internal arcing are discussed in order to improve the lightning protection of the blade....

Heat transfer and friction characteristics in steam cooled rectangular channels with rib turbulators

Energy Technology Data Exchange (ETDEWEB)

Gong, Jianying; Gao, Tieyu; Li, Guojun [Xi' an Jiaotong University, Xi' an (China)

2014-01-15

We studied the heat transfer and friction characteristics in steam-cooled rectangular channels with rib turbulators on W side or H side walls in the Reynolds number (Re) range of 10000-80000. Each of the test channels was welded by four stainless steel plates to simulate the actual geometry and heat transfer structure of blade/vane internal cooling passage. The length of the channel L was 1000 mm, the cross section of the channel was 40 mm X 80 mm, and the pitch-to-rib height ratio p/e was kept at 10. The channel blockage ratio (W/H) was 0.047. Results showed that the Nusselt number (Nu) distributions displayed different trends at the entrance region with the increase of Re for the rib turbulators on the W side walls. The heat transfer performance of the rib turbulators on the H side walls was about 24- 27% higher than that on the W side walls at the same pumping power. In addition, semi-empirical correlations for the two cases, rib turbulators on W side walls and rib turbulators on H side walls, were developed based on the heat transfer results, which could be used in the design of the internal cooling passage of new generation steam-cooled gas turbine blade/vane.

Design of TFTR movable limiter blades for ohmic and neutral-beam-heated plasmas

International Nuclear Information System (INIS)

Doll, D.W.; Ulrickson, M.A.; Cecchi, J.L.; Citrolo, J.C.; Weissenburger, D.; Bialek, J.

1981-10-01

A new set of movable limiter blades has been designed for TFTR that will meet both the requirements of the 4 MW ohmic heated and the 33 MW neutral beam heated plasmas. This is accomplished with three limiter blades each having and elliptical shape along the toroidal direction. Heat flux levels are acceptable for both ohmic heated and pre-strong compression plasmas. The construction consists of graphite tiles attached to cooled backing plates. The tiles have an average thickness of approx. 4.7 cm and are drawn against the backing plate with spring loaded fasteners that are keyed into the graphite. The cooled backing plate provides the structure for resisting disruption and fault induced loads. A set of rollers attached to the top and bottom blades allow them to be expanded and closed in order to vary the plasma surface for scaling experiments. Water cooling lines penetrate only the mid-plane port cover/support plate in such a way as to avoid bolted water connections inside the vacuum boundary and at the same time allow blade movement. Both the upper and lower blades are attached to the mid-plane limiter blade through pivots. Pivot connections are protected against arcing with an alumina coating and a shunt bar strap. Remote handling is considered throughout the design

Distal femoral osteotomy in genovalgum: internal fixation with blade plate versus casting.

Science.gov (United States)

Makhmalbaf, Hadi; Moradi, Ali; Ganji, Saeid

2014-10-01

To compare the results of two different ways of distal femoral osteotomy stabilization in patients suffering from genuvalgum: internal fixation with plate, and casting. In a non-randomized prospective study, after distal femoral osteotomy with the zigzag method, patients were divided into two groups: long leg casting, and internal fixation with blade plate. For all patients, questionnaires were filled to obtain data. Information such as range of motion, tibiofemoral anatomical angle and complications were recorded. 38 knees with valgus deformity underwent distal femoral supracondylar osteotomy. (8 with plaster cast and 30 with internal fixation using a blade plate). Preoperative range of motion was 129±6° and six months later it was 120±14°. The preoperative tibiofemoral angle was 32±6°; postoperative tibiofemoral angles were 3±3°, 6±2°, and 7±3° just after operation, six months, and two years later, respectively. Although this angle was greater among the group stabilized with a cast, this difference was not statistically significant. In postoperative complications, over-correction was found in five, recorvatom deformity in one, knee stiffness in three and superficial wound infection was recorded in three knees. There is no prominent difference in final range of motion and alignment whether fixation is done with casting or internal fixation. However, the complication rate seems higher in the casting method.

Novel casting processes for single-crystal turbine blades of superalloys

Science.gov (United States)

Ma, Dexin

2018-03-01

This paper presents a brief review of the current casting techniques for single-crystal (SC) blades, as well as an analysis of the solidification process in complex turbine blades. A series of novel casting methods based on the Bridgman process were presented to illustrate the development in the production of SC blades from superalloys. The grain continuator and the heat conductor techniques were developed to remove geometry-related grain defects. In these techniques, the heat barrier that hinders lateral SC growth from the blade airfoil into the extremities of the platform is minimized. The parallel heating and cooling system was developed to achieve symmetric thermal conditions for SC solidification in blade clusters, thus considerably decreasing the negative shadow effect and its related defects in the current Bridgman process. The dipping and heaving technique, in which thinshell molds are utilized, was developed to enable the establishment of a high temperature gradient for SC growth and the freckle-free solidification of superalloy castings. Moreover, by applying the targeted cooling and heating technique, a novel concept for the three-dimensional and precise control of SC growth, a proper thermal arrangement may be dynamically established for the microscopic control of SC growth in the critical areas of large industrial gas turbine blades.

Dimensional accuracy of internal cooling channel made by selective laser melting (SLM And direct metal laser sintering (DMLS processes in fabrication of internally cooled cutting tools

Directory of Open Access Journals (Sweden)

Ghani S. A. C.

2017-01-01

Full Text Available Selective laser melting(SLM and direct metal laser sintering(DMLS are preferred additive manufacturing processes in producing complex physical products directly from CAD computer data, nowadays. The advancement of additive manufacturing promotes the design of internally cooled cutting tool for effectively used in removing generated heat in metal machining. Despite the utilisation of SLM and DMLS in a fabrication of internally cooled cutting tool, the level of accuracy of the parts produced remains uncertain. This paper aims at comparing the dimensional accuracy of SLM and DMLS in machining internally cooled cutting tool with a special focus on geometrical dimensions such as hole diameter. The surface roughness produced by the two processes are measured with contact perthometer. To achieve the objectives, geometrical dimensions of identical tool holders for internally cooled cutting tools fabricated by SLM and DMLS have been determined by using digital vernier calliper and various magnification of a portable microscope. In the current study, comparing internally cooled cutting tools made of SLM and DMLS showed that generally the higher degree of accuracy could be obtained with DMLS process. However, the observed differences in surface roughness between SLM and DMLS in this study were not significant. The most obvious finding to emerge from this study is that the additive manufacturing processes selected for fabricating the tool holders for internally cooled cutting tool in this research are capable of producing the desired internal channel shape of internally cooled cutting tool.

International Ventilation Cooling Application Database

DEFF Research Database (Denmark)

Holzer, Peter; Psomas, Theofanis Ch.; OSullivan, Paul

2016-01-01

The currently running International Energy Agency, Energy and Conservation in Buildings, Annex 62 Ventilative Cooling (VC) project, is coordinating research towards extended use of VC. Within this Annex 62 the joint research activity of International VC Application Database has been carried out...... and locations, using VC as a mean of indoor comfort improvement. The building-spreadsheet highlights distributions of technologies and strategies, such as the following. (Numbers in % refer to the sample of the database’s 91 buildings.) It may be concluded that Ventilative Cooling is applied in temporary......, systematically investigating the distribution of technologies and strategies within VC. The database is structured as both a ticking-list-like building-spreadsheet and a collection of building-datasheets. The content of both closely follows Annex 62 State-Of-The- Art-Report. The database has been filled, based...

The effect of internal ribbing on forced convective heat transfer in circular-sectioned tubes

International Nuclear Information System (INIS)

Farhadi Rahmat-Abadi, K.; Morris, W. D.

2003-01-01

This paper presents the results of an experimental examination of the effect of internal circumferential ribs on forced convection in circular-sectioned tubes. The work is relevant to the internal cooling of gas turbine rotor blades. The influence of rib geometry is investigated for three different rib configurations and simple design-type, empirical equations are developed for estimating heat transfer at rib and mid-rib locations. It is demonstrated that heat transfer may be improved by up to three fold in relation to fully developed forced convection in smooth-walled tubes. The geometric parameters which have been used for the experiments are typical of those currently applied to gas turbine blade cooling designs

Report on the achievements in fiscal 1998. Hydrogen utilizing international clean energy system technology (WE-NET). Subtask 8. Development of hydrogen combustion turbine (development of major components such as turbine blades and rotors); 1998 nendo suiso riyo kokusai clean energy system gijutsu (WE-NET). 8. Suiso nensho turbine no kaihatsu (turbine yoku, rotor nado shuyo kosei kiki no kaihatsu)

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

The present research and development is intended to establish the fundamental technologies required to develop a pilot plant, by investigating development of such major component devices as turbine blades and rotors in a hydrogen combustion turbine. In the turbine moving and stator blade cooling technology, it is intended to achieve the power plant efficiency of 60% (based on HHV) as established in the interim evaluation performed in fiscal 1996. Therefore, the necessary element tests, detailed blade design, and partial fabrication were moved forward on the three kinds of the selected blade cooling systems as the cooling systems that can deal with the steam temperature condition as high as 1,700 degrees C. Fiscal 1998 will execute the design and fabrication of test blades and testing devices for blade cooling evaluation tests to be performed at Tashiro Township in Akita Prefecture. At the same time, evaluation and selection will be made on the three kinds of the cooling blades. In the rotor cooling technology, for the purpose of analyzing the rolling-in phenomenon of steam in the main turbine flow, a method will be developed to analyze rotor disk cavity temperatures based on CFD, the basic sealing conditions based thereon will be discussed, and generalization will be made on the rotor cooling technology. (NEDO)

Hydrogen utilization international clean energy system technology (WE-NET). Subtask 8. Development of hydrogen combustion turbines (development of the main component devices such as turbine blades and rotors); Suiso riyo kokusai clean energy system gijutsu (WE-NET). Subtask 8. Suiso nensho turbine no kaihatsu (turbine yoku, rotor nado shuyo kosei kiki no kaihatsu)

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

The paper described the result of the fiscal 1996 development relating to hydrogen combustion turbines, as one of the hydrogen utilization technologies, which have excellent environmentality and are expected of remarkably high efficiency. In the film cooling system of first-stage moving/stationary blades, the smaller the pitch of film pore is, the higher the mean cooling efficiency becomes, indicating 0.7 at maximum. As compared with the conventional shower head type, the metal temperature can be reduced 30-40degC. In the recovery type inner (convection) cooling system, by reducing the blade number, the consumption amount of coolant can be reduced 6% in stationary blade and 13% in moving blade, as compared with the result of the preceding year. In the element test of the hybrid cooling system, film cooling efficiency was actually measured by the porous module test equipment, and the result well agreed with the calculation result. In the water cooling system, studied were water (stationary blade) and vapor (moving blade) of the closed cooling structure for realization of a cycle efficiency of 60%. In rotor/disk cooling, analyses were made of seal characteristic grasp tests and characteristics of the rotor. The effect of deflection in the mainstream was small. Besides, proper value of the seal overlapping amount could be obtained. 6 refs., 368 figs., 55 tabs.

Estimation of internal heat transfer coefficients and detection of rib positions in gas turbine blades from transient surface temperature measurements

International Nuclear Information System (INIS)

Heidrich, P; Wolfersdorf, J v; Schmidt, S; Schnieder, M

2008-01-01

This paper describes a non-invasive, non-destructive, transient inverse measurement technique that allows one to determine internal heat transfer coefficients and rib positions of real gas turbine blades from outer surface temperature measurements after a sudden flow heating. The determination of internal heat transfer coefficients is important during the design process to adjust local heat transfer to spatial thermal load. The detection of rib positions is important during production to fulfill design and quality requirements. For the analysis the one-dimensional transient heat transfer problem inside of the turbine blade's wall was solved. This solution was combined with the Levenberg-Marquardt method to estimate the unknown boundary condition by an inverse technique. The method was tested with artificial data to determine uncertainties with positive results. Then experimental testing with a reference model was carried out. Based on the results, it is concluded that the presented inverse technique could be used to determine internal heat transfer coefficients and to detect rib positions of real turbine blades.

Real-Time Closed Loop Modulated Turbine Cooling

Science.gov (United States)

Shyam, Vikram; Culley, Dennis E.; Eldridge, Jeffrey; Jones, Scott; Woike, Mark; Cuy, Michael

2014-01-01

It has been noted by industry that in addition to dramatic variations of temperature over a given blade surface, blade-to-blade variations also exist despite identical design. These variations result from manufacturing variations, uneven wear and deposition over the life of the part as well as limitations in the uniformity of coolant distribution in the baseline cooling design. It is proposed to combine recent advances in optical sensing, actuation, and film cooling concepts to develop a workable active, closed-loop modulated turbine cooling system to improve by 10 to 20 the turbine thermal state over the flight mission, to improve engine life and to dramatically reduce turbine cooling air usage and aircraft fuel burn. A reduction in oxides of nitrogen (NOx) can also be achieved by using the excess coolant to improve mixing in the combustor especially for rotorcraft engines. Recent patents filed by industry and universities relate to modulating endwall cooling using valves. These schemes are complex, add weight and are limited to the endwalls. The novelty of the proposed approach is twofold 1) Fluidic diverters that have no moving parts are used to modulate cooling and can operate under a wide range of conditions and environments. 2) Real-time optical sensing to map the thermal state of the turbine has never been attempted in realistic engine conditions.

Silent cooling system with a double suction type centrifugal fan with backward blades; Ryosuikomi turbo fan wo mochiita teisoon engine reikyaku system no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Funabashi, S. [Hitachi, Ltd., Tokyo (Japan); Nakamura, K. [Hitachi Construction Machinery Co. Ltd., Tokyo (Japan)

2000-04-25

We have developed a new cooling system for the engine of construction machinery. This system produces two different air flow routes by a double suction type centrifugal fan with backward blades. We first measured aerodynamic performance and sound level of the double suction type fan, which consists of two single suction type fans of different design, and compared these measurements to those of single suction type fans. Next, we installed the fan in a scale model of the new cooling system. The performance of this double suction type fan was different to that of a single suction type. It is considered that the effect of interaction of the exit flows from the two different fans caused this performance change. The test model installed in an engine compartment showed that this cooling system reduced the area of air inlets and outlets around the engine and did not cause re-circulation of cooling air. (author)

Ways of TPP and NPP powerful steam turbine blade erosion decreasing in low flow rate regimes

International Nuclear Information System (INIS)

Khrabrov, P.V.; Khaimov, V.A.; Matveenko, V.A.

1986-01-01

A systematized approach to the problem of efficient cooling of flow passage and exhaust parts of TPP and NPP steam turbines and prevention of erosion wear of inlet and outlet edges of operating blades is presented. Methods for LP casing cooling and sources of erosion-hazard moisture as well as the main technological and design measures to decrease the erosion of blades are determined

Experimental Evaluation of Cermet Turbine Stator Blades for Use at Elevated Gas Temperatures

Science.gov (United States)

Chiarito, Patrick T.; Johnston, James R.

1959-01-01

The suitability of cermets for turbine stator blades of a modified turbojet engine was determined at an average turbine-inlet-gas temperature of 2000 F. Such an increase in temperature would yield a premium in thrust from a service engine. Because the cermet blades require no cooling, all the available compressor bleed air could be used to cool a turbine made from conventional ductile alloys. Cermet blades were first run in 100-hour endurance tests at normal gas temperatures in order to evaluate two methods for mounting them. The elevated gas-temperature test was then run using the method of support considered best for high-temperature operation. After 52 hours at 2000 F, one of the group of four cermet blades fractured probably because of end loads resulting from thermal distortion of the spacer band of the nozzle diaphragm. Improved design of a service engine would preclude this cause of premature failure.

Analytical study on different blade-shape design of HAWT for wasted kinetic energy recovery system (WKERS)

Science.gov (United States)

Goh, J. B.; Jamaludin, Z.; Jafar, F. A.; Mat Ali, M.; Mokhtar, M. N. Ali; Tan, C. H.

2017-06-01

Wasted kinetic energy recovery system (WKERS) is a wind renewable gadget installed above a cooling tower outlet to harvest the discharged wind for electrical regeneration purpose. The previous WKERS is operated by a horizontal axis wind turbine (HAWT) with delta blade design but the performance is still not at the optimum level. Perhaps, a better blade-shape design should be determined to obtain the optimal performance, as it is believed that the blade-shape design plays a critical role in HAWT. Hence, to determine a better blade-shape design for a new generation of WKERS, elliptical blade, swept blade and NREL Phase IV blade are selected for this benchmarking process. NREL Phase IV blade is a modern HAWT’s blade design by National Renewable Energy Laboratory (NREL) research lab. During the process of benchmarking, Computational Fluid Dynamics (CFD) analysis was ran by using SolidWorks design software, where all the designs are simulated with linear flow simulation. The wind speed in the simulation is set at 10.0 m/s, which is compatible with the average wind speed produced by a standard size cooling tower. The result is obtained by flow trajectories of air motion, surface plot and cut plot of the applied blade-shape. Besides, the aspect ratio of each blade is calculated and included as one of the reference in the comparison. Hence, the final selection of the best blade-shape design will bring to the new generation of WKERS.

Reverse Flow Engine Core Having a Ducted Fan with Integrated Secondary Flow Blades

Science.gov (United States)

Kisska, Michael K. (Inventor); Princen, Norman H. (Inventor); Kuehn, Mark S. (Inventor); Cosentino, Gary B. (Inventor)

2014-01-01

Secondary air flow is provided for a ducted fan having a reverse flow turbine engine core driving a fan blisk. The fan blisk incorporates a set of thrust fan blades extending from an outer hub and a set of integral secondary flow blades extending intermediate an inner hub and the outer hub. A nacelle provides an outer flow duct for the thrust fan blades and a secondary flow duct carries flow from the integral secondary flow blades as cooling air for components of the reverse flow turbine engine.

Rotational effects on impingement cooling

Science.gov (United States)

Epstein, A. H.; Kerrebrock, J. L.; Koo, J. J.; Preiser, U. Z.

1987-01-01

The present consideration of rotation effects on heat transfer in a radially exhausted, impingement-cooled turbine blade model gives attention to experimental results for Reynolds and Rossby numbers and blade/coolant temperature ratio values that are representative of small gas turbine engines. On the basis of a model that encompasses the effects of Coriolis force and buoyancy on heat transfer, bouyancy is identified as the cause of an average Nusselt number that is 20-30 percent lower than expected from previous nonrotating data. A heuristic model is proposed which predicts that the impingement jets nearest the blade roots should deflect inward, due to a centripetal force generated by their tangential velocity counter to the blade motion. Potentially serious thermal stresses must be anticipated from rotation effects in the course of blade design.

Cooling Tower Overhaul of Secondary Cooling System in HANARO

Energy Technology Data Exchange (ETDEWEB)

Park, Young Chul; Lee, Young Sub; Jung, Hoan Sung; Lim, In Chul [KAERI, Daejeon (Korea, Republic of)

2007-07-01

HANARO, an open-tank-in-pool type research reactor of 30 MWth power in Korea, has been operating normally since its initial criticality in February, 1995. For the last about ten years, A cooling tower of a secondary cooling system has been operated normally in HANARO. Last year, the cooling tower has been overhauled for preservative maintenance including fills, eliminators, wood support, water distribution system, motors, driving shafts, gear reducers, basements, blades and etc. This paper describes the results of the overhaul. As results, it is confirmed that the cooling tower maintains a good operability through a filed test. And a cooling capability will be tested when a wet bulb temperature is maintained about 28 .deg. C in summer and the reactor is operated with the full power.

Axial Fan Blade Vibration Assessment under Inlet Cross-Flow Conditions Using Laser Scanning Vibrometry

Directory of Open Access Journals (Sweden)

Till Heinemann

2017-08-01

Full Text Available In thermal power plants equipped with air-cooled condensers (ACCs, axial cooling fans operate under the influence of ambient flow fields. Under inlet cross-flow conditions, the resultant asymmetric flow field is known to introduce additional harmonic forces to the fan blades. This effect has previously only been studied numerically or by using blade-mounted strain gauges. For this study, laser scanning vibrometry (LSV was used to assess fan blade vibration under inlet cross-flow conditions in an adapted fan test rig inside a wind tunnel test section. Two co-rotating laser beams scanned a low-pressure axial fan, resulting in spectral, phase-resolved surface vibration patterns of the fan blades. Two distinct operating points with flow coefficients of 0.17 and 0.28 were examined, with and without inlet cross-flow influence. While almost identical fan vibration patterns were found for both reference operating points, the overall blade vibration increased by 100% at the low fan flow rate as a result of cross-flow, and by 20% at the high fan flow rate. While numerically predicted natural frequency modes could be confirmed from experimental data as minor peaks in the vibration amplitude spectrum, they were not excited significantly by cross-flow. Instead, primarily higher rotation-rate harmonics were amplified; that is, a synchronous blade-tip flapping was strongly excited at the blade-pass frequency.

Equipment to separate liquid droplets from the cooling air stream of a liquid cooling tower

International Nuclear Information System (INIS)

Thompson, S.E.; Schwinn, J.M.

1977-01-01

In order to separate off liquid droplets from the air stream of a cooling tower, one uses separator blades that are secured to the supporting construction. An improvement on this is proposed to make the repairs easier. According to the invention, the separator blades should be fabricated from springy material with self-supporting strength and can be fitted onto the supporting construction by means of slits and notches. (RW) [de

Internally cooled V-shape inclined monochromator

Czech Academy of Sciences Publication Activity Database

Oberta, Peter; Áč, V.; Hrdý, Jaromír

2008-01-01

Roč. 15, - (2008), 8-11 ISSN 0909-0495 R&D Projects: GA AV ČR IAA100100716 Grant - others:VEGA(SK) 1/4134/07 Institutional research plan: CEZ:AV0Z10100522 Keywords : inclined monochromator * heat load * internal cooling Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.333, year: 2008

Influence of precooling cooling air on the performance of a gas turbine combined cycle

Energy Technology Data Exchange (ETDEWEB)

Kwon, Ik Hwan; Kang, Do Won; Kang, Soo Young; Kim, Tong Seop [Inha Univ., Incheon (Korea, Republic of)

2012-02-15

Cooling of hot sections, especially the turbine nozzle and rotor blades, has a significant impact on gas turbine performance. In this study, the influence of precooling of the cooling air on the performance of gas turbines and their combined cycle plants was investigated. A state of the art F class gas turbine was selected, and its design performance was deliberately simulated using detailed component models including turbine blade cooling. Off design analysis was used to simulate changes in the operating conditions and performance of the gas turbines due to precooling of the cooling air. Thermodynamic and aerodynamic models were used to simulate the performance of the cooled nozzle and rotor blade. In the combined cycle plant, the heat rejected from the cooling air was recovered at the bottoming steam cycle to optimize the overall plant performance. With a 200K decrease of all cooling air stream, an almost 1.78% power upgrade due to increase in main gas flow and a 0.70 percent point efficiency decrease due to the fuel flow increase to maintain design turbine inlet temperature were predicted.

Experimental determination of average turbulent heat transfer and friction factor in stator internal rib-roughened cooling channels.

Science.gov (United States)

Battisti, L; Baggio, P

2001-05-01

In gas turbine cooling design, techniques for heat extraction from the surfaces exposed to the hot stream are based on the increase of the inner heat transfer areas and on the promotion of the turbulence of the cooling flow. This is currently obtained by casting periodic ribs on one or more sides of the serpentine passages into the core of the blade. Fluid dynamic and thermal behaviour of the cooling flow have been extensively investigated by means of experimental facilities and many papers dealing with this subject have appeared in the latest years. The evaluation of the average value of the heat transfer coefficient most of the time is inferred from local measurements obtained by various experimental techniques. Moreover the great majority of these studies are not concerned with the overall average heat transfer coefficient for the combined ribs and region between them, but do focus just on one of them. This paper presents an attempt to collect information about the average Nusselt number inside a straight ribbed duct. Series of measurements have been performed in steady state eliminating the error sources inherently connected with transient methods. A low speed wind tunnel, operating in steady state flow, has been built to simulate the actual flow condition occurring in a rectilinear blade cooling channel. A straight square channel with 20 transverse ribs on two sides has been tested for Re of about 3 x 10(4), 4.5 x 10(4) and 6 x 10(4). The ribbed wall test section is electrically heated and the heat removed by a stationary flow of known thermal and fluid dynamic characteristics.

Computer simulation of multiple stability regions in an internally cooled superconducting conductor and of helium replenishment in a bath-cooled conductor

International Nuclear Information System (INIS)

Turner, L.R.; Shindler, J.

1984-09-01

For upcoming fusion experiments and future fusion reactors, superconducting magnetic have been chosen or considered which employ cooling by pool-boiling HeI, by HeII, and by internally flowing HeI. The choice of conductor and cooling method should be determined in part by the response of the magnet to sudden localized heat pulses of various magnitudes. The paper describes the successful computer simulation of multiple stability in internally cooled conductors, as observed experimentally, using the computer code SSICC. It also describes the modeling of helium replenishment in the cooling channels of a bath-cooled conductor, using the computer code TASS

Achievement report for fiscal 1993. International clean energy system technology to utilize hydrogen - WE-NET (Sub-task 8. Development of hydrogen burning turbines - Development of main components including turbine blades and rotors); 1993 nendo seika hokokusho. Suiso riyo kokusai clean energy system gijutsu (WE-NET) (Sub tusk 8: Suiso nensho tabin no kaihatsu - tabin yoku rota tou shuyou kosei kiki no kaihatsu)

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-03-01

Among the research and development items in relation with the 'development of hydrogen burning turbines' based on the WE-NET project, surveys have been performed on developing the main components including turbine blades and rotors. The current fiscal year has surveyed the latest trends in the existing gas turbine and rotor cooling technologies, and the technological problems were extracted from the viewpoint of application to the hydrogen fueled turbines. Since the hydrogen fueled turbines have the entrance temperature higher than that of power generation gas turbines, development of the blade cooling technology is important. Main cooling methods available are the film cooling and transpiration cooling, whose technological development is necessary in the advanced forms. Cooling method for the inner side of blades includes the impingement cooling and the pin fin cooling, whereas the V-letter shaped turbulence accelerating rib and the serpentine flow path structure are considered promising. Increasing the anti-heat temperature of blades may be realized by utilizing ceramics. As a technology close to putting it into practical use, application of heat shield coating is promising. (NEDO)

Influence of water–air ratio on the heat transfer and creep life of a high pressure gas turbine blade

International Nuclear Information System (INIS)

Eshati, S.; Abu, A.; Laskaridis, P.; Khan, F.

2013-01-01

An analytical model to investigate the influence of Water–Air Ratio (WAR) on turbine blade heat transfer and cooling processes (and thus the blade creep life) of industrial gas turbines is presented. The effects of WAR are emphasised for the modelling of the gas properties and the subsequent heat transfer process. The approach considers convective/film cooling and includes the influence of a thermal barrier coating. In addition, the approach is based on the thermodynamic outputs of a gas turbine performance simulation, heat transfer model, as well as a method that accounts for the changes in the properties of moist air as a function of WAR. For a given off-design point, the variation of WAR (0.0–0.10) was investigated using the heat transfer model. Results showed that with increasing WAR the blade inlet coolant temperature reduced along the blade span. The blade metal temperature at each section was reduced as WAR increased, which in turn increased the blade creep life. The increase in WAR increased the specific heat of the coolant and increased the heat transfer capacity of the coolant air flow. The model can be implemented by using the thermodynamic cycle of the engine, without knowing the turbine cooling details in the conceptual design stage. Also, this generic method assists the end user to understand the effect of operating conditions and design parameter on the creep life of a high pressure turbine blade. -- Highlights: • The influence of WAR on gas turbine blade heat transfer and creep life is examined. • Coolant specific heat capacity is the key property affected by changes in WAR. • Increase in WAR reduces the coolant and metal temperature along the blade span. • Creep life increases with increase in WAR even if ambient temperature is increased

Effect of Reynolds number, turbulence level and periodic wake flow on heat transfer on low pressure turbine blades.

Science.gov (United States)

Suslov, D; Schulz, A; Wittig, S

2001-05-01

The development of effective cooling methods is of major importance for the design of new gas turbines blades. The conception of optimal cooling schemes requires a detailed knowledge of the heat transfer processes on the blade's surfaces. The thermal load of turbine blades is predominantly determined by convective heat transfer which is described by the local heat transfer coefficient. Heat transfer is closely related to the boundary layer development along the blade surface and hence depends on various flow conditions and geometrical parameters. Particularly Reynolds number, pressures gradient and turbulence level have great impact on the boundary layer development and the according heat transfer. Therefore, in the present study, the influence of Reynolds number, turbulence intensity, and periodic unsteady inflow on the local heat transfer of a typical low pressure turbine airfoil is experimentally examined in a plane cascade.

Advanced multistage turbine blade aerodynamics, performance, cooling, and heat transfer

Energy Technology Data Exchange (ETDEWEB)

Fleeter, S.; Lawless, P.B. [Purdue Univ., West Lafayette, IN (United States)

1995-10-01

The gas turbine has the potential for power production at the highest possible efficiency. The challenge is to ensure that gas turbines operate at the optimum efficiency so as to use the least fuel and produce minimum emissions. A key component to meeting this challenge is the turbine. Turbine performance, both aerodynamics and heat transfer, is one of the barrier advanced gas turbine development technologies. This is a result of the complex, highly three-dimensional and unsteady flow phenomena in the turbine. Improved turbine aerodynamic performance has been achieved with three-dimensional highly-loaded airfoil designs, accomplished utilizing Euler or Navier-Stokes Computational Fluid Dynamics (CFD) codes. These design codes consider steady flow through isolated blade rows. Thus they do not account for unsteady flow effects. However, unsteady flow effects have a significant impact on performance. Also, CFD codes predict the complete flow field. The experimental verification of these codes has traditionally been accomplished with point data - not corresponding plane field measurements. Thus, although advanced CFD predictions of the highly complex and three-dimensional turbine flow fields are available, corresponding data are not. To improve the design capability for high temperature turbines, a detailed understanding of the highly unsteady and three-dimensional flow through multi-stage turbines is necessary. Thus, unique data are required which quantify the unsteady three-dimensional flow through multi-stage turbine blade rows, including the effect of the film coolant flow. This requires experiments in appropriate research facilities in which complete flow field data, not only point measurements, are obtained and analyzed. Also, as design CFD codes do not account for unsteady flow effects, the next logical challenge and the current thrust in CFD code development is multiple-stage analyses that account for the interactions between neighboring blade rows.

Thermo-Elastic Analysis of Internally Cooled Structures Using a Higher Order Theory

Science.gov (United States)

Arnold, Steven M.; Bednarcyk, Brett A.; Aboudi, Jacob

2001-01-01

This paper presents the results of a study on the thermomechanical behavior of internally cooled silicon nitride structures. Silicon nitride is under consideration for elevated temperature aerospace engine applications. and techniques for lowering the operating temperature of structures composed of this material are under development. Lowering the operating temperature provides a large payoff in terms of fatigue life and may be accomplished through the use of thermal barrier coatings (TBC's) and the novel concept of included cooling channels. Herein, an in-depth study is performed on the behavior of a flame-impinged silicon nitride plate with a TBC and internal channels cooled by forced air. The analysis is performed using the higher order theory for functionally graded materials (HOTFGM), which has been developed through NASA Glenn Research Center funding over the past several years. HOTFGM was chosen over the traditional finite element approach as a prelude to an examination of functionally graded silicon nitride structures for which HOTFGM is ideally suited. To accommodate the analysis requirement% of the internally cooled plate problem, two crucial enhancements were made to the two-dimensional Cartesian-based version of HOTFGM. namely, incorporation of internal boundary capabilities and incorporation of convective boundary conditions. Results indicate the viability and large benefits of cooling the plate via forced air through cooling channels. Furthermore, cooling can positively impact the stress and displacement fields present in the plate, yielding an additional payoff in terms of fatigue life. Finally, a spin-off capability resulted from inclusion of internal boundaries within HOTFGM; the ability to simulate the thermo-elastic response of structures with curved surfaces. This new capability is demonstrated, and through comparison with an analytical solution, shown to be viable and accurate.

Coupled calculation of external heat transfer and material temperatures of convection-cooled turbine blades. Final report; Gekoppelte Berechnung des aeusseren Waermeuebergangs und der Materialtemperaturen konvektionsgekuehlter Turbinenschaufeln. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Heselhaus, A.

1997-05-01

In this work a hybrid program system consisting of a 3D finite-volume Navier-Stokes flow solver and a 3D finite-element heat conduction solver has been developed. It enables the coupled calculation of structure temperatures in diabatic solid/fluid configurations. The grids of both the finite element and the finite volume computational domain may be completely independent. The coupled program fully resolves the thermal interaction between heat transfer and the resulting material temperatures. The developed coupling algorithm is numerically stable, conservative and works without the need to define ambient temperatures in the flowfield. This allows for the simulation of any solid/fluid configuration. When simulating combined blade/endwall cooling or filmcooling, only a coupled procedure is capable to completely account for the interaction between all relevant thermal parameters. It is found that the coupled calculation of convective cooling in a realistic guide vane leads locally to 45 K higher and 107 K lower blade temperatures than the uncoupled calculation. This shows that accounting for the thermal interaction between the flow and the structure offers both potential to save cooling air and a lower margin of safety when designing cooling systems close to the thermal limits of the blade material. (orig.) [Deutsch] Im Rahmen der vorliegenden Arbeit wurde ein Verfahren zur Berechnung der Temperaturverteilung in diabat umstroemten Koerpern entwickelt, bei dem ein 3D-Finite Volumen Navier-Stokes Stroemungsloeser und ein 3D-Finite Elemente Waermeleitungsloeser zu einem hybriden Programmsystem gekoppelt werden. Dabei besteht die Moeglichkeit, voellig unabhaengige Rechennetze fuer Stroemung und Struktur zu verwenden. Mit dem gekoppelten Verfahren kann die Wechselwirkung zwischen resultierenden Materialtemperaturen und dem davon rueck-beeinflussten Waermeuebergang beruecksichtigt werden. Weiterhin ist der hier entwickelte, stabile und konservative Kopplungsalgorithmus nicht

Massachusetts Large Blade Test Facility Final Report

Energy Technology Data Exchange (ETDEWEB)

Rahul Yarala; Rob Priore

2011-09-02

Project Objective: The Massachusetts Clean Energy Center (CEC) will design, construct, and ultimately have responsibility for the operation of the Large Wind Turbine Blade Test Facility, which is an advanced blade testing facility capable of testing wind turbine blades up to at least 90 meters in length on three test stands. Background: Wind turbine blade testing is required to meet international design standards, and is a critical factor in maintaining high levels of reliability and mitigating the technical and financial risk of deploying massproduced wind turbine models. Testing is also needed to identify specific blade design issues that may contribute to reduced wind turbine reliability and performance. Testing is also required to optimize aerodynamics, structural performance, encourage new technologies and materials development making wind even more competitive. The objective of this project is to accelerate the design and construction of a large wind blade testing facility capable of testing blades with minimum queue times at a reasonable cost. This testing facility will encourage and provide the opportunity for the U.S wind industry to conduct more rigorous testing of blades to improve wind turbine reliability.

Development of a structure-dependent materials model for complex high-temperature loads: Turbine blades of IN 738 LC

International Nuclear Information System (INIS)

1989-01-01

In the framework of a material research programme of the Federal Ministry for Research and Technology a joint project of 10 institutes has started. It aims at developing new concepts for high-temperature components. A subtask is concerned with the internally cooled turbine blade of IN 738 LC for stationary gas turbines. The envisaged procedure for the development of the design conception and the level of knowledge concerning the influencing parameters of the structure and the mechanical behaviour at high operating temperatures are reported on. (orig.) [de

Experimental investigation of temperature rise in bone drilling with cooling: A comparison between modes of without cooling, internal gas cooling, and external liquid cooling.

Science.gov (United States)

Shakouri, Ehsan; Haghighi Hassanalideh, Hossein; Gholampour, Seifollah

2018-01-01

Bone fracture occurs due to accident, aging, and disease. For the treatment of bone fractures, it is essential that the bones are kept fixed in the right place. In complex fractures, internal fixation or external methods are used to fix the fracture position. In order to immobilize the fracture position and connect the holder equipment to it, bone drilling is required. During the drilling of the bone, the required forces to chip formation could cause an increase in the temperature. If the resulting temperature increases to 47 °C, it causes thermal necrosis of the bone. Thermal necrosis decreases bone strength in the hole and, subsequently, due to incomplete immobilization of bone, fracture repair is not performed correctly. In this study, attempts have been made to compare local temperature increases in different processes of bone drilling. This comparison has been done between drilling without cooling, drilling with gas cooling, and liquid cooling on bovine femur. Drilling tests with gas coolant using direct injection of CO 2 and N 2 gases were carried out by internal coolant drill bit. The results showed that with the use of gas coolant, the elevation of temperature has limited to 6 °C and the thermal necrosis is prevented. Maximum temperature rise reached in drilling without cooling was 56 °C, using gas and liquid coolant, a maximum temperature elevation of 43 °C and 42 °C have been obtained, respectively. This resulted in decreased possibility of thermal necrosis of bone in drilling with gas and liquid cooling. However, the results showed that the values obtained with the drilling method with direct gas cooling are independent of the rotational speed of drill.

Research and development of cooled turbine for aircraft engines. Koku engine yo reikyaku turbine no kenkyu kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Maya, T; Yamawaki, S [Ishikawajima-Harima Heavy Industries, Co. Ltd., Tokyo (Japan)

1994-05-01

For the turbine which is one of the principal elements of aircraft engine, progress in turbine use material development and cooling performance further heightened for the turbine are needed to grapple with the required heightening of turbine inlet temperature. In the present paper based on the turbine inlet temperature designed to be 1600[degree]C as a target, a two-dimensional model used for the turbine cooling performance test was structurally given together with the result of the above test which aimed at confirming the design calculation. As a result of cooling design for the turbine which was about 1600[degree]C in inlet temperature, the highest gas temperature was 1890 and 1470[degree]C on the stator blade and rotor blade, respectively. Both those blades were 0.66 and 0.62, respectively in cooling efficiency. To test the cooling performance, a two-dimensional cascade was tested with a doubly amplified model of cooling blade, the use of which could set its Reynolds number near that of the actual one. As compared with the actual operation, the test was made at low temperatures of 400 to 500[degree]C and low pressures of 0.02 to 0.03MPa. The test agreed with the design calculation in result. 4 refs., 8 figs.

Influence of Thermal Effects During Blade-Casing Contact Experiments

OpenAIRE

Millecamps , Antoine; Brunel , Jean-François; Dufrenoy , Philippe; Garcin , François; Nucci , Marco

2009-01-01

International audience; In rotating machinery, notably in modern high efficiency compressors, a critical requirement for optimal performance consists in minimizing radial clearances between the rotating bladed disk and the casing. This solution significantly increases the risks of contact between rotating bladed disk and casing and may lead in specific conditions to catastrophic behavior (component failure, etc.). The physical phenomena and mechanisms involved in blade-casing contact interact...

Wireless Inductive Power Device Suppresses Blade Vibrations

Science.gov (United States)

Morrison, Carlos R.; Provenza, Andrew J.; Choi, Benjamin B.; Bakhle, Milind A.; Min, James B.; Stefko, George L.; Duffy, Kirsten P.; Fougers, Alan J.

2011-01-01

Vibration in turbomachinery can cause blade failures and leads to the use of heavier, thicker blades that result in lower aerodynamic efficiency and increased noise. Metal and/or composite fatigue in the blades of jet engines has resulted in blade destruction and loss of lives. Techniques for suppressing low-frequency blade vibration, such as gtuned circuit resistive dissipation of vibratory energy, h or simply "passive damping," can require electronics incorporating coils of unwieldy dimensions and adding unwanted weight to the rotor. Other approaches, using vibration-dampening devices or damping material, could add undesirable weight to the blades or hub, making them less efficient. A wireless inductive power device (WIPD) was designed, fabricated, and developed for use in the NASA Glenn's "Dynamic Spin Rig" (DSR) facility. The DSR is used to simulate the functionality of turbomachinery. The relatively small and lightweight device [10 lb (approx.=4.5 kg)] replaces the existing venerable and bulky slip-ring. The goal is the eventual integration of this technology into actual turbomachinery such as jet engines or electric power generators, wherein the device will facilitate the suppression of potentially destructive vibrations in fan blades. This technology obviates slip rings, which require cooling and can prove unreliable or be problematic over time. The WIPD consists of two parts: a remote element, which is positioned on the rotor and provides up to 100 W of electrical power to thin, lightweight piezoelectric patches strategically placed on/in fan blades; and a stationary base unit that wirelessly communicates with the remote unit. The base unit supplies inductive power, and also acts as an input and output corridor for wireless measurement, and active control command to the remote unit. Efficient engine operation necessitates minimal disturbance to the gas flow across the turbine blades in any effort to moderate blade vibration. This innovation makes it

Unsteady, Cooled Turbine Simulation Using a PC-Linux Analysis System

Science.gov (United States)

List, Michael G.; Turner, Mark G.; Chen, Jen-Pimg; Remotigue, Michael G.; Veres, Joseph P.

2004-01-01

The fist stage of the high-pressure turbine (HPT) of the GE90 engine was simulated with a three-dimensional unsteady Navier-Sokes solver, MSU Turbo, which uses source terms to simulate the cooling flows. In addition to the solver, its pre-processor, GUMBO, and a post-processing and visualization tool, Turbomachinery Visual3 (TV3) were run in a Linux environment to carry out the simulation and analysis. The solver was run both with and without cooling. The introduction of cooling flow on the blade surfaces, case, and hub and its effects on both rotor-vane interaction as well the effects on the blades themselves were the principle motivations for this study. The studies of the cooling flow show the large amount of unsteadiness in the turbine and the corresponding hot streak migration phenomenon. This research on the GE90 turbomachinery has also led to a procedure for running unsteady, cooled turbine analysis on commodity PC's running the Linux operating system.

Blade dynamic stress analysis of rotating bladed disks

Directory of Open Access Journals (Sweden)

Kellner J.

2007-10-01

Full Text Available The paper deals with mathematical modelling of steady forced bladed disk vibrations and with dynamic stress calculation of the blades. The blades are considered as 1D kontinuum elastic coupled with three-dimensional elastic disk centrally clamped into rotor rotating with constant angular speed. The steady forced vibrations are generated by the aerodynamic forces acting along the blade length. By using modal synthesis method the mathematical model of the rotating bladed disk is condensed to calculate steady vibrations. Dynamic stress analysis of the blades is based on calculation of the time dependent reduced stress in blade cross-sections by using Hubert-Misses-Hencky stress hypothesis. The presented method is applied to real turbomachinery rotor with blades connected on the top with shroud.

International Energy Agency Solar Heating and Cooling Program

Science.gov (United States)

Brooks, A. J.

This trip was undertaken to participate in and represent the United States Industry at the International Energy Agency (IEA) Solar Heating and Cooling Program (SHCP) Task 14 Workshop. The meeting took place at the A1 Bani Hotel in Rome Italy.

Airfoil, platform, and cooling passage measurements on a rotating transonic high-pressure turbine

Science.gov (United States)

Nickol, Jeremy B.

An experiment was performed at The Ohio State University Gas Turbine Laboratory for a film-cooled high-pressure turbine stage operating at design-corrected conditions, with variable rotor and aft purge cooling flow rates. Several distinct experimental programs are combined into one experiment and their results are presented. Pressure and temperature measurements in the internal cooling passages that feed the airfoil film cooling are used as boundary conditions in a model that calculates cooling flow rates and blowing ratio out of each individual film cooling hole. The cooling holes on the suction side choke at even the lowest levels of film cooling, ejecting more than twice the coolant as the holes on the pressure side. However, the blowing ratios are very close due to the freestream massflux on the suction side also being almost twice as great. The highest local blowing ratios actually occur close to the airfoil stagnation point as a result of the low freestream massflux conditions. The choking of suction side cooling holes also results in the majority of any additional coolant added to the blade flowing out through the leading edge and pressure side rows. A second focus of this dissertation is the heat transfer on the rotor airfoil, which features uncooled blades and blades with three different shapes of film cooling hole: cylindrical, diffusing fan shape, and a new advanced shape. Shaped cooling holes have previously shown immense promise on simpler geometries, but experimental results for a rotating turbine have not previously been published in the open literature. Significant improvement from the uncooled case is observed for all shapes of cooling holes, but the improvement from the round to more advanced shapes is seen to be relatively minor. The reduction in relative effectiveness is likely due to the engine-representative secondary flow field interfering with the cooling flow mechanics in the freestream, and may also be caused by shocks and other

Superconducting solenoids for an international muon cooling experiment

International Nuclear Information System (INIS)

Green, M.A.; Rey, J.M.

2002-01-01

The international muon ionization cooling experiment MICE will consist of two focusing cooling cells and a pair of uniform field solenoids used for particle identification and emittance measurements. The 2.75-meter long cooling cells have a pair of field flip coils and a coupling coil. The 0.52-meter diameter field flip coils surround an absorber that removes transverse and longitudinal momentum from the muons to be cooled. The beam in the absorber is at a minimum beta point so that scattering of the muons is minimized. The 1.7-meter diameter coupling coils are outside of conventional 201.25 MHz RF cavities that accelerate the muons putting longitudinal momentum into the muons without putting back the transverse momentum into the beam. A third set of flip coils helps the muon beam transition from and to the experimental solenoids. The 0.6-meter diameter experimental solenoids have a uniform field region (good to about 1 part in 1000) that is 1.3-meters long. The MICE experiment magnets must operate as a single unit so that the field profile will produce the maximum muon cooling

STATUS OF THE INTERNATIONAL MUON IONIZATION COOLING EXPERIMENT(MICE)

International Nuclear Information System (INIS)

Zisman, Michael S.

2007-01-01

An international experiment to demonstrate muon ionization cooling is scheduled for beam at Rutherford Appleton Laboratory (RAL) in 2007. The experiment comprises one cell of the Study II cooling channel [1], along with upstream and downstream detectors to identify individual muons and measure their initial and final 6D phase-space parameters to a precision of 0.1%. Magnetic design of the beam line and cooling channel are complete and portions are under construction. The experiment will be described, including cooling channel hardware designs, fabrication status, and running plans. Phase 1 of the experiment will prepare the beam line and provide detector systems, including time-of-flight, Cherenkov, scintillating-fiber trackers and their spectrometer solenoids, and an electromagnetic calorimeter. The Phase 2 system will add the cooling channel components, including liquid-hydrogen absorbers embedded in superconducting Focus Coil solenoids, 201-MHz normal-conducting RF cavities, and their surrounding Coupling Coil solenoids. The MICE Collaboration goal is to complete the experiment by 2010; progress toward this is discussed

Thermal stress analysis and thermo-mechanical fatigue for gas turbine blade

International Nuclear Information System (INIS)

Hyun, J. S.; Kim, B. S.; Kang, M. S.; Ha, J. S.; Lee, Y. S.

2002-01-01

The numerical analysis for gas turbine blades were carried out under several conditions by compounding temperature field, velocity field, thermal conduction of blade, and cooling heat transfer. The three types of 1,100 deg. C class 1st-stage gas turbine blades were analyzed. The analysis results are applied to the study on evaluating the remaining life for thermo-mechanical fatigue life. The thermo-mechanical fatigue experiments under out-of-phase and in-phase have been performed. The physical-based life prediction models which considered the contribution of different damage mechanisms have been applied. These models were applied to the temperature and strain rate dependences of isothermal cycling fatigue lives, and the strain-temperature history effect on the thermo-mechanical fatigue lives

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-10-15

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

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

International Nuclear Information System (INIS)

Lim, Tae Gyun; Jeon, Wan Ho; Minorikawa, Gaku

2016-01-01

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

PREFACE: 7th International Conference on Cooling & Heating Technologies (ICCHT 2014)

Science.gov (United States)

2015-09-01

The Kyoto protocol has initiated a pledge from almost all developing and developed countries to be committed to reducing CO2 emissions. Development of new renewable energy technologies are also of interest in this conference. Greenhouse gases have contributed to global warming and other man-made disasters. Cooling and Heating communities also have responsibilities towards the commitment of reducing the greenhouse gas emissions. In addition, depleting natural resources also act as a threat to the Cooling and Heating industries, causing them to develop highly efficient equipment and innovative technologies. The 1st International Conference on Cooling & Heating Technologies was held in Hanoi Vietnam (Jan. 2005). Whereas the 2nd, 3rd, 4th and 5th ICCHT conferences were held in Dalian, China (Jul. 2006), Tokyo, Japan (Jul. 2007), Jinhae, Korea (Oct. 2008) and Bandung, Indonesia (Dec. 2010) respectively. The 6th International Conference on Cooling & Heating Technologies (ICCTH2012) was held in Xi'an in China on November 9-12, 2012. It is our pleasure to welcome you to the 7th International Conference on Cooling & Heating Technologies (ICCTH2014) on 4th - 6th November 2014 at the Grand Dorsett Subang Hotel, Subang Jaya, Selangor Darul Ehsan, Malaysia The Theme of the Conference is ''Sustainability and Innovation in Heating & Cooling Technologies''. The sub-themes are:- • CO2 Reduction and Low Carbon Technologies • HVAC System and Natural Ventilation • Energy & Alternative Energy • Computational Fluid Dynamics • Low Temperature & Refrigeration Engineering In conjunction with the Conference, an Exhibition will be organized as an integral part of the Conference. Project experiences, product solutions, new applications and state-of-the art information will be highlighted.

Status of the International Muon Ionization Cooling Experiment (MICE)

International Nuclear Information System (INIS)

Zisman, Michael S.; Zisman, Michael S.

2007-01-01

An international experiment to demonstrate muon ionization cooling is scheduled for beam at Rutherford Appleton Laboratory (RAL) in 2007. The experiment comprises one cell of the Study II cooling channel [1], along with upstream and downstream detectors to identify individual muons and measure their initial and final 6D phase-space parameters to a precision of 0.1 percent. Magnetic design of the beam line and cooling channel are complete and portions are under construction. The experiment will be described, including cooling channel hardware designs, fabrication status, and running plans. Phase 1 of the experiment will prepare the beam line and provide detector systems, including time-of-flight, Cherenkov, scintillating-fiber trackers and their spectrometer solenoids, and an electromagnetic calorimeter. The Phase 2 system will add the cooling channel components, including liquid-hydrogen absorbers embedded in superconducting Focus Coil solenoids, 201-MHz normal conducting RF cavities, and their surrounding Coupling Coil solenoids. The MICE Collaboration goal is to complete the experiment by 2010; progress toward this is discussed

Experimental and numerical study of near bleed hole heat transfer enhancement in internal turbine blade cooling channels

CSIR Research Space (South Africa)

Scheepers, G

2006-01-01

Full Text Available This paper describes an experimental and numerical study of the heat transfer augmentation near the entrance to a gas turbine film cooling hole at different engine representative suction ratios (Vhole/V). For the experimental component the use...

Research and development of asymmetrical heat transfer augmentation method in radial channels of blades for high temperature gas turbines

Science.gov (United States)

Shevchenko, I. V.; Rogalev, A. N.; Garanin, I. V.; Vegera, A. N.; Kindra, V. O.

2017-11-01

The serpentine-like one and half-pass cooling channel systems are primarily used in blades fabricated by the lost-wax casting process. The heat transfer turbulators like cross-sectional or angled ribs used in channels of the midchord region failed to eliminate the temperature irregularity from the suction and pressure sides, which is reaching 200°C for a first stage blade of the high-pressure turbine for an aircraft engine. This paper presents the results of a numerical and experimental test of an advanced heat transfer augmentation system in radial channels developed for alignment of the temperature field from the suction and pressure sides. A numerical simulation of three-dimensional coolant flow for a wide range of Reynolds numbers was carried out using ANSYS CFX software. Effect of geometrical parameters on the heat removal asymmetry was determined. The test results of a blade with the proposed intensification system conducted in a liquid-metal thermostat confirmed the accuracy of calculations. Based on the experimental data, the dependencies for calculation of heat transfer coefficients to the cooling air in the blade studied were obtained.

Computational Analysis of Droplet Mass and Size Effect on Mist/Air Impingement Cooling Performance

Directory of Open Access Journals (Sweden)

Zhenglei Yu

2013-01-01

Full Text Available Impingement cooling has been widely employed to cool gas turbine hot components such as combustor liners, combustor transition pieces, turbine vanes, and blades. A promising technology is proposed to enhance impingement cooling with water droplets injection. However, previous studies were conducted on blade shower head film cooling, and less attention was given to the transition piece cooling. As a continuous effort to develop a realistic mist impingement cooling scheme, this paper focuses on simulating mist impingement cooling under typical gas turbine operating conditions of high temperature and pressure in a double chamber model. Furthermore, the paper presents the effect of cooling effectiveness by changing the mass and size of the droplets. Based on the heat-mass transfer analogy, the results of these experiments prove that the mass of 3E – 3 kg/s droplets with diameters of 5–35 μm could enhance 90% cooling effectiveness and reduce 122 K of wall temperature. The results of this paper can provide guidance for corresponding experiments and serve as the qualification reference for future more complicated studies with convex surface cooling.

Computational study of a High Pressure Turbine Nozzle/Blade Interaction

Science.gov (United States)

Kopriva, James; Laskowski, Gregory; Sheikhi, Reza

2015-11-01

A downstream high pressure turbine blade has been designed for this study to be coupled with the upstream uncooled nozzle of Arts and Rouvroit [1992]. The computational domain is first held to a pitch-line section that includes no centrifugal forces (linear sliding-mesh). The stage geometry is intended to study the fundamental nozzle/blade interaction in a computationally cost efficient manner. Blade/Nozzle count of 2:1 is designed to maintain computational periodic boundary conditions for the coupled problem. Next the geometry is extended to a fully 3D domain with endwalls to understand the impact of secondary flow structures. A set of systematic computational studies are presented to understand the impact of turbulence on the nozzle and down-stream blade boundary layer development, resulting heat transfer, and downstream wake mixing in the absence of cooling. Doing so will provide a much better understanding of stage mixing losses and wall heat transfer which, in turn, can allow for improved engine performance. Computational studies are performed using WALE (Wale Adapted Local Eddy), IDDES (Improved Delayed Detached Eddy Simulation), SST (Shear Stress Transport) models in Fluent.

Numerical studies on the heat transfer and friction characteristics of the first wall inserted with the screw blade for water cooled ceramic breeder blanket of CFETR

International Nuclear Information System (INIS)

Jiang, Kecheng; Ma, Xuebin; Cheng, Xiaoman; Liu, Songlin

2016-01-01

Highlights: • Enhanced heat transfer and friction characteristics of the FW inserted with screw blade is investigated. • The screw blade structure optimization was done on the screw pitch and diameter. • Decreasing screw pitch and increasing screw diameter could further enhance heat transfer accompanied with increasing flow resistance. • Evaluate the overall enhanced heat performance by using the PEC value. - Abstract: The Water Cooled Ceramic Breeder (WCCB) blanket based on Pressurized Water Reactor (PWR) condition is one of the blanket candidates for Chinese Fusion Engineering Test Reactor (CFETR). The first wall (FW) which plays an important part in the blanket design must remove the high heat flux radiated from plasma and nuclear heat deposition on the structure in any operating conditions. In this paper, the characteristics of enhanced heat transfer and friction for the FW with the inserted screw blade are studied by the numerical method. After the comparison between the numerical and experimental results, the standard k–ε turbulent model is selected to do the numerical calculation. The numerical results show that the peak temperature of RAFM steel could be reduced by decreasing screw pitch or increasing screw diameter, while accompanied with ascending flow resistance. Besides, among all of the chosen calculation cases compared with the smooth channel, the maximum value of temperature reduction is 10 °C under the conditions of heat flux of 0.5 MW/m"2 as well as screw pitch of 18 mm and screw diameter of 6 mm. The maximum increment ratio of the friction factor is 257% under the conditions of screw pitch of 10 mm and screw diameter of 4 mm. Furthermore, screw blade of 74 mm pitch and 4 mm diameter presents the highest overall performance evaluation criterion (PEC) value of 0.93 under Reynolds number of 270 000 conditions, and shows the best overall heat transfer enhancement performance.

Numerical studies on the heat transfer and friction characteristics of the first wall inserted with the screw blade for water cooled ceramic breeder blanket of CFETR

Energy Technology Data Exchange (ETDEWEB)

Jiang, Kecheng [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); University of Science and Technology of China, Hefei, Anhui 230037 (China); Ma, Xuebin; Cheng, Xiaoman [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Liu, Songlin, E-mail: slliu@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China)

2016-03-15

Highlights: • Enhanced heat transfer and friction characteristics of the FW inserted with screw blade is investigated. • The screw blade structure optimization was done on the screw pitch and diameter. • Decreasing screw pitch and increasing screw diameter could further enhance heat transfer accompanied with increasing flow resistance. • Evaluate the overall enhanced heat performance by using the PEC value. - Abstract: The Water Cooled Ceramic Breeder (WCCB) blanket based on Pressurized Water Reactor (PWR) condition is one of the blanket candidates for Chinese Fusion Engineering Test Reactor (CFETR). The first wall (FW) which plays an important part in the blanket design must remove the high heat flux radiated from plasma and nuclear heat deposition on the structure in any operating conditions. In this paper, the characteristics of enhanced heat transfer and friction for the FW with the inserted screw blade are studied by the numerical method. After the comparison between the numerical and experimental results, the standard k–ε turbulent model is selected to do the numerical calculation. The numerical results show that the peak temperature of RAFM steel could be reduced by decreasing screw pitch or increasing screw diameter, while accompanied with ascending flow resistance. Besides, among all of the chosen calculation cases compared with the smooth channel, the maximum value of temperature reduction is 10 °C under the conditions of heat flux of 0.5 MW/m{sup 2} as well as screw pitch of 18 mm and screw diameter of 6 mm. The maximum increment ratio of the friction factor is 257% under the conditions of screw pitch of 10 mm and screw diameter of 4 mm. Furthermore, screw blade of 74 mm pitch and 4 mm diameter presents the highest overall performance evaluation criterion (PEC) value of 0.93 under Reynolds number of 270 000 conditions, and shows the best overall heat transfer enhancement performance.

Internally-cooled centrifugal compressor with cooling jacket formed in the diaphragm

Science.gov (United States)

Moore, James J.; Lerche, Andrew H.; Moreland, Brian S.

2014-08-26

An internally-cooled centrifugal compressor having a shaped casing and a diaphragm disposed within the shaped casing having a gas side and a coolant side so that heat from a gas flowing though the gas side is extracted via the coolant side. An impeller disposed within the diaphragm has a stage inlet on one side and a stage outlet for delivering a pressurized gas to a downstream connection. The coolant side of the diaphragm includes at least one passageway for directing a coolant in a substantially counter-flow direction from the flow of gas through the gas side.

High power cable with internal water cooling 400 kV

Energy Technology Data Exchange (ETDEWEB)

Rasquin, W; Harjes, B

1982-08-01

The project was planned for a duration of 4 years. Afterwards it has been extended over 6 years and finally stopped after 3 1/2 years. Therefore, of course results of field tests with an internally cooled 400 kV cable are not available. Nevertheless, this conductor cooled high power cable has been developed to such an extend, that this manufactured cable could withstand type tests according to IEC/VDE recommendations. Even by missing field tests it is obvious that a high power cable for 400 kV is available.

Characteristics of Vacuum Freeze Drying with Utilization of Internal Cooling and Condenser Waste Heat for Sublimation

Directory of Open Access Journals (Sweden)

Muhammad Alhamid

2013-09-01

Full Text Available Vacuum freeze drying is an excellent drying method, but it is very energy-intensive because a relatively long drying time is required. This research investigates the utilization of condenser waste heat for sublimation as a way of accelerating the drying rate. In addition, it also investigates the effect of internal cooling combined with vacuum cooling in the pressure reduction process. Jelly fish tentacles were used as the specimen, with different configurations for condenser heat waste and internal cooling valve opening. The results show that heating with condenser heat waste can accelerate the drying rate up to 0.0035 kg/m2.s. In addition, pre-freezing by internal cooling prevents evaporation until the mass of the specimen is 0.47 g and promotes transition of the specimen into the solid phase.

Resonant vibration control of wind turbine blades

DEFF Research Database (Denmark)

Svendsen, Martin Nymann; Krenk, Steen; Høgsberg, Jan Becker

2010-01-01

. The efficiency of the resonant controller is demonstrated for a representative turbine blade exposed to turbulent wind loading. It is found that the present explicit tuning procedure yields close to optimal tuning, with very limited modal spill-over and effective reduction of the vibration amplitudes.......The paper deals with introduction of damping to specific vibration modes of wind turbine blades, using a resonant controller with acceleration feedback. The wind turbine blade is represented by three-dimensional, two-node finite elements in a local, rotating frame of reference. The element...... formulation accounts for arbitrary mass density distributions, general elastic crosssection properties and geometric stiffness effects due to internal stresses. A compact, linear formulation for aerodynamic forces with associated stiffness and damping terms is established and added to the structural model...

Plate-fin array cooling using a finger-like piezoelectric fan

International Nuclear Information System (INIS)

Shyu, Jin-Cherng; Syu, Jhih-Zong

2014-01-01

In this study, the heat transfer of a plate-fin array cooled by a vibrating finger-like piezoelectric fan comprising four flexible rectangular blades was investigated. The results indicated that the heat transfer enhancement of the fin array cooled by a vibrating piezoelectric fan at x/L = 0.5 and H = 5 mm ranged between 1.5 and 3.3, regardless of the fin array orientation. However, the heat transfer enhancement caused by a fan being placed at either edge of the fin array yielded a dissimilar result between both of the fin array orientations because of the superimposed effects of the boundary layer development and the air flow induced by the fan. This dissimilarity was especially noticeable when the piezoelectric fan was composed of aluminum blades to accommodate the moderate Reynolds number. In addition to the Reynolds number, the ratio of the fan blade vibration envelope to the source area determined the Nu number of the piezoelectric fan-cooled fin array. This design enhanced the fin array heat transfer and reduced cooler volume by embedding multiple vibrating beams into the fin array. -- Highlights: • Heat transfer of a piezoelectric fan-cooled plate-fin array was investigated. • Effects of fan position, fan height and fan material on heat transfer were examined. • Similar heat transfer enhancement range was shown for both fin array orientations. • Fin heat transfer with a running Al fan at x = 0 was higher than that at x = 0.25L. • Besides fan Reynolds number, the area ratio also determined Nu of the fin array

WhalePower tubercle blade power performance test report

Energy Technology Data Exchange (ETDEWEB)

NONE

2008-07-15

Toronto-based WhalePower Corporation has developed turbine blades that are modeled after humpback whale flippers. The blades, which incorporate tubercles along the leading edge of the blade, have been fitted to a Wenvor 25 kW turbine installed in North Cape, Prince Edward Island at a test site for the Wind Energy Institute of Canada (WEICan). A test was conducted to characterize the power performance of the prototype wind turbine. This report described the wind turbine configuration with particular reference to turbine information, power rating, blade information, tower information, control systems and grid connections. The test site was also described along with test equipment and measurement procedures. Information regarding power output as a function of wind speed was included along with power curves, power coefficient and annual energy production. The results for the power curve and annual energy production contain a level of uncertainty. While measurements for this test were collected and analyzed in accordance with International Electrotechnical Commission (IEC) standards for performance measurements of electricity producing wind turbines (IEC 61400-12-1), the comparative performance data between the prototype WhalePower wind turbine blade and the Wenvor standard blade was not gathered to IEC data standards. Deviations from IEC-61400-12-1 procedures were listed. 6 tabs., 16 figs., 3 appendices.

EB-PVD process management for highly productive zirconia thermal barrier coating of turbine blades

International Nuclear Information System (INIS)

Reinhold, E.; Botzler, P.; Deus, C.

1999-01-01

Zirconia thermal barrier coatings are well used in the turbine manufacturing industry because they ensure extended lifetimes of turbine blades. Compared with other techniques, EB-PVD processes are best suited for the deposition on turbine blades with regard to the layer properties. Therefore EB-PVD coaters for turbine blades are becoming increasingly interesting. The coating costs per component are mainly dependent on a highly productive solution for the deposition task. Thus the EB-PVD process management has to be optimized in order to meet the productivity requirements of the manufacturers. This includes the requirement of high deposition rates, large deposition areas, long time stable production cycles as well as a matched duration of preheating, deposition and cooling down per charge. Modern EB-PVD solutions to be introduced allow deposition rates on blades up to 7 μm/min. The consequences for the technological process management and plant design concerning long time stable coating cycles with high productivity will be discussed. (orig.)

Aerodynamics and Optimal Design of Biplane Wind Turbine Blades

Science.gov (United States)

Chiu, Phillip

extreme conditions. Finally, considering these aerodynamic loads, the blade mass reductions achievable by biplane blades are quantified. The internal structure of the biplane blades are designed using a multi-disciplinary optimization which seeks to minimize mass, subject to constraints which represent realistic design requirements. Using this approach, it is shown that biplane blades can be built more than 45% lighter than a similarly-optimized conventional blade; the reasons for these mass reductions are examined in detail. As blade length is increased, these mass reductions are shown to be even more significant. These large mass reductions are indicative of significant cost of electricity reductions from rotors fitted with biplane blades. Taken together, these results show that biplane blades are a concept which can enable the next generation of larger wind turbine rotors.

Corrosion fatigue in LP steam turbine blading - experiences, causes and appropriate measures; Korrosionsutmattning i aangturbinskovlar - Erfarenheter, inverkande faktorer och moejliga aatgaerder

Energy Technology Data Exchange (ETDEWEB)

Tavast, J [ABB STAL AB, Finspaang (Sweden)

1996-12-01

Corrosion fatigue in LP steam turbine blading was reviewed together with result of tests performed in order to find blade materials with improved resistance against this. According to international experience, corrosion fatigue of 12Cr steam turbine blades in the transition zone between dry and wet steam, is one of the major causes, if not the major cause, for unavailability of steam turbines. Corrosion fatigue in LP blading is a frequent problem also in Swedish and Finnish nuclear power plants, especially in turbines of type D54 in BWR-plants. Corrosion fatigue has also been discovered in at least one type of nuclear turbine. Initiation times have been very long and the varying experiences in different types of turbines may simply reflect differing initiation times. Corrosion fatigue may therefore become more frequent in other types of turbines in the future. The type of water treatment (BWR/PWR) and possibly temperature after reheating seem to influence the risk for corrosion fatigue. Influence of inleakage of cooling water is less clear for these nuclear plants. The long initiation times together with the fact that very few of the cracked blades have actually failed, indicate that the cracks initiate and/or propagate during transients. Extensive laboratory tests show that there are alternative blade materials available with improved resistance against corrosion fatigue, with the most promising being 15/5 PH and A905, together with Ti6Al4V. The Ti alloy shows the best resistance against corrosion fatigue in most environments and is already used in some turbines. Disadvantage is a higher cost and possible need for redesign of the blades. The alternative materials are recommended for use for blades in the transition zone between dry and wet steam in LP turbines. The main disadvantage is a lack of references, even if 15%5 PH has been used to a very limited extent. 40 refs, 24 figs, 12 tabs, 9 appendices

Selection of a turbine cooling system applying multi-disciplinary design considerations.

Science.gov (United States)

Glezer, B

2001-05-01

The presented paper describes a multi-disciplinary cooling selection approach applied to major gas turbine engine hot section components, including turbine nozzles, blades, discs, combustors and support structures, which maintain blade tip clearances. The paper demonstrates benefits of close interaction between participating disciplines starting from early phases of the hot section development. The approach targets advancements in engine performance and cost by optimizing the design process, often requiring compromises within individual disciplines.

Two strategies of lowering surface deformations of internally cooled X-ray optics

International Nuclear Information System (INIS)

Oberta, P.; Áč, V.; Hrdý, J.

2013-01-01

Internally cooled X-ray optics, like X-ray monochromators and reflecting X-ray mirrors, play a crucial role in defining a beamlines resolution, degree of coherence and flux. A great effort is invested in the development of these optical components. An important aspect of the functionality of high heat load optics is its cooling and its influence on surface deformation. The authors present a study of two different geometrical cooling approaches. Its influence on beam inhomogeneity due to the strain from the manufacturing process is presented. X-ray topographic images and FWHM measurements are presented. FEA simulations of cooling efficiency and surface deformations were performed. The best achieved results are under an enlargement of 0.4μrad of the measured rocking curve

Performance of Savonius Blade Waterwheel with Variation of Blade Number

Science.gov (United States)

Sule, L.; Rompas, P. T. D.

2018-02-01

The utilization of water energy source is mainly used as a provider of electrical energy through hydroelectric power. The potential utilization of water flow energy is relatively small. The objective of this study is to know the best blade of Savonius waterwheel with various variables such as water discharge, blade number, and loading. The data used the efficiency of waterwheel, variation of blade number, variable water discharge, and loading in the shaft. The test results have shown that the performances of a top-water mill with the semicircular curve where the variation in the number of blades are 4, 6, and 8 at discharge and loading of 0.01587 m3/s and 1000 grams respectively were 9.945%, 13.929%, and 17.056% respectively. The blades number of 8 obtained the greatest performance. The more number of blades the greater the efficiency of the waterwheel Savonius.

Film Cooling Optimization Using Numerical Computation of the Compressible Viscous Flow Equations and Simplex Algorithm

Directory of Open Access Journals (Sweden)

Ahmed M. Elsayed

2013-01-01

Full Text Available Film cooling is vital to gas turbine blades to protect them from high temperatures and hence high thermal stresses. In the current work, optimization of film cooling parameters on a flat plate is investigated numerically. The effect of film cooling parameters such as inlet velocity direction, lateral and forward diffusion angles, blowing ratio, and streamwise angle on the cooling effectiveness is studied, and optimum cooling parameters are selected. The numerical simulation of the coolant flow through flat plate hole system is carried out using the “CFDRC package” coupled with the optimization algorithm “simplex” to maximize overall film cooling effectiveness. Unstructured finite volume technique is used to solve the steady, three-dimensional and compressible Navier-Stokes equations. The results are compared with the published numerical and experimental data of a cylindrically round-simple hole, and the results show good agreement. In addition, the results indicate that the average overall film cooling effectiveness is enhanced by decreasing the streamwise angle for high blowing ratio and by increasing the lateral and forward diffusion angles. Optimum geometry of the cooling hole on a flat plate is determined. In addition, numerical simulations of film cooling on actual turbine blade are performed using the flat plate optimal hole geometry.

Structural Testing of the Blade Reliability Collaborative Effect of Defect Wind Turbine Blades

Energy Technology Data Exchange (ETDEWEB)

Desmond, M. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hughes, S. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Paquette, J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-06-08

Two 8.3-meter (m) wind turbine blades intentionally constructed with manufacturing flaws were tested to failure at the National Wind Technology Center (NWTC) at the National Renewable Energy Laboratory (NREL) south of Boulder, Colorado. Two blades were tested; one blade was manufactured with a fiberglass spar cap and the second blade was manufactured with a carbon fiber spar cap. Test loading primarily consisted of flap fatigue loading of the blades, with one quasi-static ultimate load case applied to the carbon fiber spar cap blade. Results of the test program were intended to provide the full-scale test data needed for validation of model and coupon test results of the effect of defects in wind turbine blade composite materials. Testing was part of the Blade Reliability Collaborative (BRC) led by Sandia National Laboratories (SNL). The BRC seeks to develop a deeper understanding of the causes of unexpected blade failures (Paquette 2012), and to develop methods to enable blades to survive to their expected operational lifetime. Recent work in the BRC includes examining and characterizing flaws and defects known to exist in wind turbine blades from manufacturing processes (Riddle et al. 2011). Recent results from reliability databases show that wind turbine rotor blades continue to be a leading contributor to turbine downtime (Paquette 2012).

EPB standard EN ISO 52016: calculation of the building’s energy needs for heating and cooling, internal temperatures and heating and cooling load

NARCIS (Netherlands)

Dijk, H.A.L. van; Spiekman, M.E.; Hoes-van Oeffelen, E.C.M.

2016-01-01

EN ISO 52016-1 presents a coherent set of calculation methods at different levels of detail, for the (sensible) energy needs for the space heating and cooling and (latent) energy needs (de)humidification of a building and/or internal temperatures and heating and/or cooling loads, including the

Using internally cooled cutting tools in the machining of difficult-to-cut materials based on Waspaloy

Directory of Open Access Journals (Sweden)

Yahya Isik

2016-05-01

Full Text Available Nickel-based superalloys such as Waspaloy are used for engine components and in the nuclear industry, where considerable strength and corrosion resistance at high operating temperatures are called for. These characteristics of such alloys cause increases in cutting temperature and resultant tool damage, even at low cutting speeds and low feed rates. Thus, they are classified as difficult-to-cut materials. This article presents a cooling method to be used in metal cutting based on a tool holder with a closed internal cooling system with cooling fluid circulating inside. Hence, a green cooling method that does not harm the environment and is efficient in removing heat from the cutting zone was developed. A series of cutting experiments were conducted to investigate the practicality and effectiveness of the internally cooled tool model. The developed system achieved up to 13% better surface quality than with dry machining, and tool life was extended by 12%. The results clearly showed that with the reduced cutting temperature of the internal cooling, it was possible to control the temperature and thus prevent reaching the critical cutting temperature during the turning process, which is vitally important in extending tool life during the processing of Waspaloy.

Technology development for laser-cooled clocks on the International Space Station

Science.gov (United States)

Klipstein, W. M.

2003-01-01

The PARCS experiment will use a laser-cooled cesium atomic clock operating in the microgravity environment aboard the International Space Station to provide both advanced tests of gravitational theory to demonstrate a new cold-atom clock technology for space.

Structural investigation of composite wind turbine blade considering various load cases and fatigue life

International Nuclear Information System (INIS)

Kong, C.; Bang, J.; Sugiyama, Y.

2005-01-01

This study proposes a structural design for developing a medium scale composite wind turbine blade made of E-glass/epoxy for a 750 kW class horizontal axis wind turbine system. The design loads were determined from various load cases specified at the IEC61400-1 international specification and GL regulations for the wind energy conversion system. A specific composite structure configuration, which can effectively endure various loads such as aerodynamic loads and loads due to accumulation of ice, hygro-thermal and mechanical loads, was proposed. To evaluate the proposed composite wind turbine blade, structural analysis was performed by using the finite element method. Parametric studies were carried out to determine an acceptable blade structural design, and the most dominant design parameters were confirmed. In this study, the proposed blade structure was confirmed to be safe and stable under various load conditions, including the extreme load conditions. Moreover, the blade adapted a new blade root joint with insert bolts, and its safety was verified at design loads including fatigue loads. The fatigue life of a blade that has to endure for more than 20 years was estimated by using the well-known S-N linear damage theory, the service load spectrum, and the Spera's empirical equations. With the results obtained from all the structural design and analysis, prototype composite blades were manufactured. A specific construction process including the lay-up molding method was applied to manufacturing blades. Full-scale static structural test was performed with the simulated aerodynamic loads. From the experimental results, it was found that the designed blade had structural integrity. In addition, the measured results of deflections, strains, mass, and radial center of gravity agreed well with the analytical results. The prototype blade was successfully certified by an international certification institute, GL (Germanisher Lloyd) in Germany

Wind Turbine Blade

DEFF Research Database (Denmark)

2010-01-01

The invention relates to a blade for a wind turbine, particularly to a blade that may be produced by an advanced manufacturing process for producing a blade with high quality structural components. Particularly, the structural components, which are preferably manufactured from fibre reinforced...

Bladed disc crack diagnostics using blade passage signals

Science.gov (United States)

Hanachi, Houman; Liu, Jie; Banerjee, Avisekh; Koul, Ashok; Liang, Ming; Alavi, Elham

2012-12-01

One of the major potential faults in a turbo fan engine is the crack initiation and propagation in bladed discs under cyclic loads that could result in the breakdown of the engines if not detected at an early stage. Reliable fault detection techniques are therefore in demand to reduce maintenance cost and prevent catastrophic failures. Although a number of approaches have been reported in the literature, it remains very challenging to develop a reliable technique to accurately estimate the health condition of a rotating bladed disc. Correspondingly, this paper presents a novel technique for bladed disc crack detection through two sequential signal processing stages: (1) signal preprocessing that aims to eliminate the noises in the blade passage signals; (2) signal postprocessing that intends to identify the crack location. In the first stage, physics-based modeling and interpretation are established to help characterize the noises. The crack initiation can be determined based on the calculated health monitoring index derived from the sinusoidal effects. In the second stage, the crack is located through advanced detrended fluctuation analysis of the preprocessed data. The proposed technique is validated using a set of spin rig test data (i.e. tip clearance and time of arrival) that was acquired during a test conducted on a bladed military engine fan disc. The test results have demonstrated that the developed technique is an effective approach for identifying and locating the incipient crack that occurs at the root of a bladed disc.

Intubation of prehospital patients with curved laryngoscope blade is more successful than with straight blade.

Science.gov (United States)

Alter, Scott M; Haim, Eithan D; Sullivan, Alex H; Clayton, Lisa M

2018-02-17

Direct laryngoscopy can be performed using curved or straight blades, and providers usually choose the blade they are most comfortable with. However, curved blades are anecdotally thought of as easier to use than straight blades. We seek to compare intubation success rates of paramedics using curved versus straight blades. Design: retrospective chart review. hospital-based suburban ALS service with 20,000 annual calls. prehospital patients with any direct laryngoscopy intubation attempt over almost 9years. First attempt and overall success rates were calculated for attempts with curved and straight blades. Differences between the groups were calculated. 2299 patients were intubated by direct laryngoscopy. 1865 had attempts with a curved blade, 367 had attempts with a straight blade, and 67 had attempts with both. Baseline characteristics were similar between groups. First attempt success was 86% with a curved blade and 73% with a straight blade: a difference of 13% (95% CI: 9-17). Overall success was 96% with a curved blade and 81% with a straight blade: a difference of 15% (95% CI: 12-18). There was an average of 1.11 intubation attempts per patient with a curved blade and 1.13 attempts per patient with a straight blade (2% difference, 95% CI: -3-7). Our study found a significant difference in intubation success rates between laryngoscope blade types. Curved blades had higher first attempt and overall success rates when compared to straight blades. Paramedics should consider selecting a curved blade as their tool of choice to potentially improve intubation success. Copyright © 2018 Elsevier Inc. All rights reserved.

Turbomachine blade reinforcement

Science.gov (United States)

Garcia Crespo, Andres Jose

2016-09-06

Embodiments of the present disclosure include a system having a turbomachine blade segment including a blade and a mounting segment coupled to the blade, wherein the mounting segment has a plurality of reinforcement pins laterally extending at least partially through a neck of the mounting segment.

Post-recombination early Universe cooling by translation-internal inter-conversion: The role of minor constituents.

Science.gov (United States)

McCaffery, Anthony J

2015-09-14

Little is known of the mechanism by which H and H2, the principal constituents of the post-re-combination early Universe, cooled sufficiently to permit cluster formation, nucleosynthesis, and, eventually, the formation of structured objects. Radiative decay primarily cools the internal modes of H2, as Δj = - 2 jumps accompany quadrupolar emission. This, however, would be a self-limiting mechanism. In this work, a translational energy cooling mechanism based on collision-induced, translation-to-internal mode conversion, is extended, following an earlier study [A. J. McCaffery and R. J. Marsh, J. Chem. Phys. 139, 234310 (2013)] of ensembles comprising H2 in a H atom bath gas. Here, the possible influence of minor species, such as HD, on this cooling mechanism is investigated. Results suggest that the influence of HD is small but not insignificant. Conversion is very rapid and an overall translation-to-internal energy conversion efficiency of some 5% could be expected. This finding may be of use in the further development of models of this complex phase of early Universe evolution. An unexpected finding in this study was that H2 + HD ensembles are capable of very rapid translation-to-internal conversion with efficiencies of >40% and relaxation rates that appear to be relatively slow. This may have potential as an energy storage mechanism.

[Fluid dynamics of supercritical helium within internally cooled cabled superconductors

International Nuclear Information System (INIS)

Van Sciver, S.W.

1995-01-01

The Applied Superconductivity Center of the University of Wisconsin-Madison proposes to conduct research on low temperature helium fluid dynamics as it applies to the cooling of internally cooled cabled superconductors (ICCS). Such conductors are used in fusion reactor designs including most of the coils in ITER. The proposed work is primarily experimental involving measurements of transient and steady state pressure drop in a variety of conductor configurations. Both model and prototype conductors for actual magnet designs will be investigated. The primary goal will be to measure and model the friction factor for these complex geometries. In addition, an effort will be made to study transient processes such as heat transfer and fluid expulsion associated with quench conditions

Steam as turbine blade coolant: Experimental data generation

Energy Technology Data Exchange (ETDEWEB)

Wilmsen, B.; Engeda, A.; Lloyd, J.R. [Michigan State Univ., East Lansing, MI (United States)

1995-10-01

Steam as a coolant is a possible option to cool blades in high temperature gas turbines. However, to quantify steam as a coolant, there exists practically no experimental data. This work deals with an attempt to generate such data and with the design of an experimental setup used for the purpose. Initially, in order to guide the direction of experiments, a preliminary theoretical and empirical prediction of the expected experimental data is performed and is presented here. This initial analysis also compares the coolant properties of steam and air.

Application of internally cooled superconductors to tokamak fusion reactors

International Nuclear Information System (INIS)

Materna, P.A.

1986-01-01

Recent proposals for ignition tokamaks containing superconductors are reviewed. As the funding prospects for the U.S. fusion program have worsened, the proposed designs have been shrinking to smaller machines with less ambitious goals. The most recent proposal, the Tokamak Fusion Core Experiment (TFCX), was based on internally cooled cabled Nb 3 Sn conductors for the options which used superconductors. Internally cooled conductors are particularly advantageous in their electrical insulating properties and in the similarity of their winding procedures to those of conventional copper coils. Epoxy impregnation is possible and is advantageous both structurally and electrically. The allowable current density for this type of conductor was shown to be larger than the current density for more conventional superconducting technology. The TFCX effort identified research and development needed in advance of TFCX or any other large ignition machine. These topics include the metal used for the conduit; nuclear effects on materials; properties of electrical and thermal insulators; extension of superconducting technology to the sizes of coils envisioned and to the field level envisioned; pulsed coil superconducting technology; joints and insulating breaks in conductors; heat removal or flow path length limitations; mechanical behavior of potted conductor bundles; instrumentation; and fault modes and various questions integrated with overall machine design

Experimental investigation of cross-over jets in a rib-roughened trailing-edge cooling channel

Science.gov (United States)

Xue, Fei

Increasing the rotor inlet temperature can dramatically increase the efficiency and power output of the gas turbine engine. However, the melting point of turbine blade material limits the realistic upper bound of the rotor inlet temperature. As a result, the development of high temperature turbine blade material and advanced turbine blade cooling technology determines the future of turbine blade engine. Adding impingement jet holes and rib turbulators in the inner cooling channel of the gas turbine blades are two effective ways to enhance the cooling effects. The purpose of this study is to figure out the influence of different combinations of jet holes and rib turbulators on the heat transfer efficiency. A tabletop scale test model is used in the study to simulate the cooling cavity of trailing edge and its feed channel in a real gas turbine blade. The Dimensional Analysis Theory is used in the study to eliminate the influence of scaling. Two different crossover slots are tested with 5 different rib arrangements, and each of the test geometries is tested for 6 jet Reynolds numbers ranging from 10,000 to 36,000. The two different crossover slots are the crossover slots with 0 and 5 degree tilt angles. The four different rib arrangements are ribs with 0 degree, 45 degree, 90 degree and 135 degree angles of attack with respect to the flow direction. Furthermore, a smooth test section (no ribs) was also tested. The steady state liquid crystal thermography is used to quantify the heat transfer performance of the target areas. The variation of Nusselt number versus Reynolds number is plotted for each of the 10 geometries. Also, the variation of Nusselt number versus Reynolds number are compared for different rib angles of attack with the same crossover slot tilt angle, and between different crossover slots tilt angles with the same rib angle. The results show that, the area-weighted average Nusselt number increases monotonically with the Reynolds number; the target

Turbomachine blade assembly

Science.gov (United States)

Garcia Crespo, Andres Jose

2016-11-01

Embodiments of the present disclosure include a system comprising a turbomachine blade assembly having a blade portion, a shank portion, and a mounting portion, wherein the blade portion, the shank portion, and the mounting portion comprise a first plurality of plies extending from a tip of the airfoil to a base of the dovetail.

Metallurgy of gas turbine blades with integral shroud and its influence on blades performance

International Nuclear Information System (INIS)

Mazur, Z.; Marino, C.; Kubiak, J.

1999-01-01

The influence of the microstructure of the gas turbine blades with integral shroud on the blades performance is presented. The analysis of the solidification process of the gas turbine blades during conventionally casting process (equiaxed grains) with all elements which has influence on the mode of its solidification and variation of the microstructure is carried out. Also, the evaluation of the failure of the gas turbine blade is present. A detailed analysis of the blade tip shroud microstructure (presence of the equiaxed and columnar grains) and its influence on the failure initiation and propagation is carried out. Finally, conclusions and some necessary improvements of the blades casting process to prevent blades failures are presented. (Author) 2 refs

BWR control blade replacement strategies

Energy Technology Data Exchange (ETDEWEB)

Kennard, M W [Stoller Nuclear Fuel, NAC International, Pleasantville, NY (United States); Harbottle, J E [Stoller Nuclear Fuel, NAC International, Thornbury, Bristol (United Kingdom)

2000-02-01

The reactivity control elements in a BWR, the control blades, perform three significant functions: provide shutdown margin during normal and accident operating conditions; provide overall core reactivity control; and provide axial power shaping control. As such, the blades are exposed to the core's neutron flux, resulting in irradiation of blade structural and absorber materials. Since the absorber depletes with time (if B{sub 4}C is used, it also swells) and the structural components undergo various degradation mechanisms (e.g., embrittlement, corrosion), the blades have limits on their operational lifetimes. Consequently, BWR utilities have implemented strategies that aim to maximize blade lifetimes while balancing operational costs, such as extending a refuelling outage to shuffle high exposure blades. This paper examines the blade replacement strategies used by BWR utilities operating in US, Europe and Asia by assembling information related to: the utility's specific blade replacement strategy; the impact the newer blade designs and changes in core operating mode were having on those strategies; the mechanical and nuclear limits that determined those strategies; the methods employed to ensure that lifetime limits were not exceeded during operation; and blade designs used (current and replacement blades). (author)

BWR control blade replacement strategies

International Nuclear Information System (INIS)

Kennard, M.W.; Harbottle, J.E.

2000-01-01

The reactivity control elements in a BWR, the control blades, perform three significant functions: provide shutdown margin during normal and accident operating conditions; provide overall core reactivity control; and provide axial power shaping control. As such, the blades are exposed to the core's neutron flux, resulting in irradiation of blade structural and absorber materials. Since the absorber depletes with time (if B 4 C is used, it also swells) and the structural components undergo various degradation mechanisms (e.g., embrittlement, corrosion), the blades have limits on their operational lifetimes. Consequently, BWR utilities have implemented strategies that aim to maximize blade lifetimes while balancing operational costs, such as extending a refuelling outage to shuffle high exposure blades. This paper examines the blade replacement strategies used by BWR utilities operating in US, Europe and Asia by assembling information related to: the utility's specific blade replacement strategy; the impact the newer blade designs and changes in core operating mode were having on those strategies; the mechanical and nuclear limits that determined those strategies; the methods employed to ensure that lifetime limits were not exceeded during operation; and blade designs used (current and replacement blades). (author)

A zero torsional stiffness twist morphing blade as a wind turbine load alleviation device

Science.gov (United States)

Lachenal, X.; Daynes, S.; Weaver, P. M.

2013-06-01

This paper presents the design, analysis and realization of a zero stiffness twist morphing wind turbine blade. The morphing blade is designed to actively twist as a means of alleviating the gust loads which reduce the fatigue life of wind turbine blades. The morphing structure exploits an elastic strain energy balance within the blade to enable large twisting deformations with modest actuation requirements. While twist is introduced using the warping of the blade skin, internal pre-stressed members ensure that a constant strain energy balance is achieved throughout the deformation, resulting in a zero torsional stiffness structure. The torsional stability of the morphing blade is characterized by analysing the elastic strain energy in the device. Analytical models of the skin, the pre-stressed components and the complete blade are compared to their respective finite element models as well as experimental results. The load alleviation potential of the adaptive structure is quantified using a two-dimensional steady flow aerodynamic model which is experimentally validated with wind tunnel measurements.

Modelling of lightning streamer formation and propagation in wind turbine blades

DEFF Research Database (Denmark)

Candela Garolera, Anna; Holbøll, Joachim; Madsen, Søren Find

2013-01-01

of the air termination in enhancing the electric field and attracting the lightning discharge, thus shielding the blade surface and preventing electrical breakdown of the blade material. However, the number and location of the discrete receptors may be difficult to establish, since their performance....... The present paper presents a method to investigate the origin and propagation of streamers from different conductive elements of the blade when exposed to a high electric field. The calculations are performed using dynamic simulations with the finite element method, and the results have been correlated...... with high voltage tests in the laboratory. The algorithms developed are intended to be a new and improved tool for the design of the blade lightning protection system, in particular to assess the effectiveness of the air termination system and the effects of internal conductive materials. The simulation...

Determination of Remaining Useful Life of Gas Turbine Blade

Directory of Open Access Journals (Sweden)

Meor Said Mior Azman

2016-01-01

Full Text Available The aim of this research is to determine the remaining useful life of gas turbine blade, using service-exposed turbine blades. This task is performed using Stress Rupture Test (SRT under accelerated test conditions where the applied stresses to the specimen is between 400 MPa to 600 MPa and the test temperature is 850°C. The study will focus on the creep behaviour of the 52000 hours service-exposed blades, complemented with creep-rupture modelling using JMatPro software and microstructure examination using optical microscope. The test specimens, made up of Ni-based superalloy of the first stage turbine blades, are machined based on International Standard (ISO 24. The results from the SRT will be analyzed using these two main equations – Larson-Miller Parameter and Life Fraction Rule. Based on the results of the remaining useful life analysis, the 52000h service-exposed blade has the condition to operate in the range of another 4751 hr to 18362 hr. The microstructure examinations shows traces of carbide precipitation that deteriorate the grain boundaries that occurs during creep process. Creep-rupture life modelling using JMatPro software has shown good agreement with the accelerated creep rupture test with minimal error.

Influence of pitch, twist, and taper on a blade`s performance loss due to roughness

Energy Technology Data Exchange (ETDEWEB)

Tangler, J.L. [National Renewable Energy Lab., Golden, CO (United States)

1996-12-31

The purpose of this study was to determine the influence of blade geometric parameters such as pitch, twist, and taper on a blade`s sensitivity to leading edge roughness. The approach began with an evaluation of available test data of performance degradation due to roughness effects for several rotors. In addition to airfoil geometry, this evaluation suggested that a rotor`s sensitivity to roughness was also influenced by the blade geometric parameters. Parametric studies were conducted using the PROP computer code with wind-tunnel airfoil characteristics for smooth and rough surface conditions to quantify the performance loss due to roughness for tapered and twisted blades relative to a constant-chord, non-twisted blade at several blade pitch angles. The results indicate that a constant-chord, non-twisted blade pitched toward stall will have the greatest losses due to roughness. The use of twist, taper, and positive blade pitch angles all help reduce the angle-of-attack distribution along the blade for a given wind speed and the associated performance degradation due to roughness. 8 refs., 6 figs.

Influence of pitch, twist, and taper on a blade`s performance loss due to roughness

Energy Technology Data Exchange (ETDEWEB)

Tangler, J.L. [National Renewable Energy Laboratory, Golden, Colorado (United States)

1997-08-01

The purpose of this study was to determine the influence of blade geometric parameters such as pitch, twist, and taper on a blade`s sensitivity to leading edge roughness. The approach began with an evaluation of available test data of performance degradation due to roughness effects for several rotors. In addition to airfoil geometry, this evaluation suggested that a rotor`s sensitivity to roughness was also influenced by the blade geometric parameters. Parametric studies were conducted using the PROP computer code with wind-tunnel airfoil characteristics for smooth and rough surface conditions to quantify the performance loss due to roughness for tapered and twisted blades relative to a constant-chord, non-twisted blade at several blade pitch angles. The results indicate that a constant-chord, non-twisted blade pitched toward stall will have the greatest losses due to roughness. The use of twist, taper, and positive blade pitch angles all help reduce the angle-of-attack distribution along the blade for a given wind speed and the associated performance degradation due to roughness. (au)

Propagation of internal stresses in composite materials during heating and cooling according to thermal cycles of welding

International Nuclear Information System (INIS)

Gukasyan, L.E.; Belov, V.V.

1977-01-01

Investigations of free thermal expansion of a composite material, of fibre and matrix during welding thermal cycle make it possible to estimate mean internal strain and stress in the composite components, as well as the residual internal stress and strain present in the composite material after manufacturing. The samples investigated consisted of nickel-chromium EhI445 alloy, reinforced by tungsten-rhenium alloy fibres. As the composite material was cooled and heated in course of welding, the stress and strain changed their sign twice, the first time upon heating, the second time upon cooling. After complete cooling of the composite material residual stresses in the fibre stay at the proportionality level, while those in the matrix are lower. Experimental evidence of internal stress and strain appearing in the composite material during heating are fairly consistent with calculations in the elastic region, if account is taken of the temperature of internal residual stress relaxation upon heating

Two strategies of lowering surface deformations of internally cooled X-ray optics

Czech Academy of Sciences Publication Activity Database

Oberta, Peter; Áč, V.; Hrdý, Jaromír

2013-01-01

Roč. 729, NOV (2013), s. 302-306 ISSN 0168-9002 R&D Projects: GA MPO FR-TI1/412 Institutional support: RVO:68378271 Keywords : internal cooling * X-ray optics * monochromator Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.316, year: 2013

Investigation of Water-spray Cooling of Turbine Blades in a Turbojet Engine

Science.gov (United States)

Freche, John C; Stelpflug, William J

1953-01-01

An analytical and experimental investigation was made with a J33-A-9 engine to determine the effectiveness of spray cooling as a means of increasing thrust by permitting engine operation at inlet-gas temperatures and speeds above rated. With the assumption of adequate spray cooling at a coolant-to-gas flow ratio of 3 percent, calculations for the sea-level static condition indicated a thrust may be achieved by engine operation at an inlet-gas temperature of 2000 degrees F and an overspeed of 10 percent. Of the water-injection configurations investigated experimentally, those located in the inner ring of the stator diaphragm provided the best cooling at rated engine speed.

Blade attachment assembly

Science.gov (United States)

Garcia-Crespo, Andres Jose; Delvaux, John McConnell; Miller, Diane Patricia

2016-05-03

An assembly and method for affixing a turbomachine rotor blade to a rotor wheel are disclosed. In an embodiment, an adaptor member is provided disposed between the blade and the rotor wheel, the adaptor member including an adaptor attachment slot that is complementary to the blade attachment member, and an adaptor attachment member that is complementary to the rotor wheel attachment slot. A coverplate is provided, having a coverplate attachment member that is complementary to the rotor wheel attachment slot, and a hook for engaging the adaptor member. When assembled, the coverplate member matingly engages with the adaptor member, and retains the blade in the adaptor member, and the assembly in the rotor wheel.

A zero torsional stiffness twist morphing blade as a wind turbine load alleviation device

International Nuclear Information System (INIS)

Lachenal, X; Daynes, S; Weaver, P M

2013-01-01

This paper presents the design, analysis and realization of a zero stiffness twist morphing wind turbine blade. The morphing blade is designed to actively twist as a means of alleviating the gust loads which reduce the fatigue life of wind turbine blades. The morphing structure exploits an elastic strain energy balance within the blade to enable large twisting deformations with modest actuation requirements. While twist is introduced using the warping of the blade skin, internal pre-stressed members ensure that a constant strain energy balance is achieved throughout the deformation, resulting in a zero torsional stiffness structure. The torsional stability of the morphing blade is characterized by analysing the elastic strain energy in the device. Analytical models of the skin, the pre-stressed components and the complete blade are compared to their respective finite element models as well as experimental results. The load alleviation potential of the adaptive structure is quantified using a two-dimensional steady flow aerodynamic model which is experimentally validated with wind tunnel measurements. (paper)

The effect of internal mould water spray cooling on rotationally moulded polyethylene parts

Science.gov (United States)

McCourt, Mark P.; Kearns, Mark P.; Martin, Peter J.

2018-05-01

The conventional method of cooling during the rotational moulding process is through the use of forced air. During the cooling phase of a typical rotomoulding cycle, large volumes of high velocity room temperature air are forced across the outside of the rotating rotomoulding tool to encourage cooling of the metal mould and molten polymer. Since no cooling is applied to the inside of the mould, the inner surface of the polymer (polyethylene) cools more slowly and will have a tendency to be more crystalline and the polyethylene will have a higher density in this region. The side that cools more quickly (in contact with the inside mould wall) will be less crystalline, and will therefore have a lower density. The major consequence of this difference in crystallinity will be a buildup of internal stresses producing warpage and excessive shrinkage of the part with subsequent increased levels of scrap. Therefore excessive cooling on the outside of the mould should be avoided. One consequence of this effect is that the cooling time for a standard rotationally moulded part can be quite long and this has an effect on the overall economics of the process in terms of part manufacture. A number of devices are currently on the market to enhance the cooling of rotational moulding by introducing a water spray to the inside of the rotomoulding during cooling. This paper reports on one such device 'Rotocooler' which during a series of initial industrial trials has been shown to reduce the cycletime by approximately 12 to 16%, with minimal effect on the mechanical properties, leading to a part which has less warpage and shrinkage than a conventionally cooled part.

Standard practice for examination of fiberglass reinforced plastic fan blades using acoustic emission

CERN Document Server

American Society for Testing and Materials. Philadelphia

2010-01-01

1.1 This practice provides guidelines for acoustic emission (AE) examinations of fiberglass reinforced plastic (FRP) fan blades of the type used in industrial cooling towers and heat exchangers. 1.2 This practice uses simulated service loading to determine structural integrity. 1.3 This practice will detect sources of acoustic emission in areas of sensor coverage that are stressed during the course of the examination. 1.4 This practice applies to examinations of new and in-service fan blades. 1.5 This practice is limited to fan blades of FRP construction, with length (hub centerline to tip) of less than 3 m [10 ft], and with fiberglass content greater than 15 % by weight. 1.6 AE measurements are used to detect emission sources. Other nondestructive examination (NDE) methods may be used to evaluate the significance of AE sources. Procedures for other NDE methods are beyond the scope of this practice. 1.7 Units—The values stated in either SI units or inch-pound units are to be regarded separately as sta...

Cooling of molecular ion beams

International Nuclear Information System (INIS)

Wolf, A.; Krohn, S.; Kreckel, H.; Lammich, L.; Lange, M.; Strasser, D.; Grieser, M.; Schwalm, D.; Zajfman, D.

2004-01-01

An overview of the use of stored ion beams and phase space cooling (electron cooling) is given for the field of molecular physics. Emphasis is given to interactions between molecular ions and electrons studied in the electron cooler: dissociative recombination and, for internally excited molecular ions, electron-induced ro-vibrational cooling. Diagnostic methods for the transverse ion beam properties and for the internal excitation of the molecular ions are discussed, and results for phase space cooling and internal (vibrational) cooling are presented for hydrogen molecular ions

The SNL100-03 Blade: Design Studies with Flatback Airfoils for the Sandia 100-meter Blade.

Energy Technology Data Exchange (ETDEWEB)

Griffith, Daniel; Richards, Phillip William

2014-09-01

A series of design studies were performed to inv estigate the effects of flatback airfoils on blade performance and weight for large blades using the Sandi a 100-meter blade designs as a starting point. As part of the study, the effects of varying the blade slenderness on blade structural performance was investigated. The advantages and disadvantages of blad e slenderness with respect to tip deflection, flap- wise & edge-wise fatigue resistance, panel buckling capacity, flutter speed, manufacturing labor content, blade total weight, and aerodynamic design load magn itude are quantified. Following these design studies, a final blade design (SNL100-03) was prod uced, which was based on a highly slender design using flatback airfoils. The SNL100-03 design with flatback airfoils has weight of 49 tons, which is about 16% decrease from its SNL100-02 predecessor that used conventional sharp trailing edge airfoils. Although not systematically optimized, the SNL100 -03 design study provides an assessment of and insight into the benefits of flatback airfoils for la rge blades as well as insights into the limits or negative consequences of high blade slenderness resulting from a highly slender SNL100-03 planform as was chosen in the final design definition. This docum ent also provides a description of the final SNL100-03 design definition and is intended to be a companion document to the distribution of the NuMAD blade model files for SNL100-03, which are made publicly available. A summary of the major findings of the Sandia 100-meter blade development program, from the initial SNL100-00 baseline blade through the fourth SNL100-03 blade study, is provided. This summary includes the major findings and outcomes of blade d esign studies, pathways to mitigate the identified large blade design drivers, and tool development that were produced over the course of this five-year research program. A summary of large blade tec hnology needs and research opportunities is also presented.

Heat transfer performance comparison of steam and air in gas turbine cooling channels with different rib angles

Science.gov (United States)

Shi, Xiaojun; Gao, Jianmin; Xu, Liang; Li, Fajin

2013-11-01

Using steam as working fluid to replace compressed air is a promising cooling technology for internal cooling passages of blades and vanes. The local heat transfer characteristics and the thermal performance of steam flow in wide aspect ratio channels ( W/ H = 2) with different angled ribs on two opposite walls have been experimentally investigated in this paper. The averaged Nusselt number ratios and the friction factor ratios of steam and air in four ribbed channels were also measured under the same test conditions for comparison. The Reynolds number range is 6,000-70,000. The rib angles are 90°, 60°, 45°, and 30°, respectively. The rib height to hydraulic diameter ratio is 0.047. The pitch-to-rib height ratio is 10. The results show that the Nusselt number ratios of steam are 1.19-1.32 times greater than those of air over the range of Reynolds numbers studied. For wide aspect ratio channels using steam as the coolant, the 60° angled ribs has the best heat transfer performance and is recommended for cooling design.

Effect of linear and non-linear blade modelling techniques on simulated fatigue and extreme loads using Bladed

Science.gov (United States)

Beardsell, Alec; Collier, William; Han, Tao

2016-09-01

There is a trend in the wind industry towards ever larger and more flexible turbine blades. Blade tip deflections in modern blades now commonly exceed 10% of blade length. Historically, the dynamic response of wind turbine blades has been analysed using linear models of blade deflection which include the assumption of small deflections. For modern flexible blades, this assumption is becoming less valid. In order to continue to simulate dynamic turbine performance accurately, routine use of non-linear models of blade deflection may be required. This can be achieved by representing the blade as a connected series of individual flexible linear bodies - referred to in this paper as the multi-part approach. In this paper, Bladed is used to compare load predictions using single-part and multi-part blade models for several turbines. The study examines the impact on fatigue and extreme loads and blade deflection through reduced sets of load calculations based on IEC 61400-1 ed. 3. Damage equivalent load changes of up to 16% and extreme load changes of up to 29% are observed at some turbine load locations. It is found that there is no general pattern in the loading differences observed between single-part and multi-part blade models. Rather, changes in fatigue and extreme loads with a multi-part blade model depend on the characteristics of the individual turbine and blade. Key underlying causes of damage equivalent load change are identified as differences in edgewise- torsional coupling between the multi-part and single-part models, and increased edgewise rotor mode damping in the multi-part model. Similarly, a causal link is identified between torsional blade dynamics and changes in ultimate load results.

Active Blade Pitch Control for Straight Bladed Darrieus Vertical Axis Wind Turbine of New Design

DEFF Research Database (Denmark)

Chougule, Prasad; Nielsen, Søren R.K.; Basu, Biswajit

2013-01-01

in a previous publication. Further, it is well know that the variation of the blade pitch angle during the rotation improves the power efficiency. A blade pitch variation is implemented by active blade pitch control, which operates as per wind speed and position of the blade with respect to the rotor. A double...

Analysis of flavor and perfume using an internally cooled coated fiber device.

Science.gov (United States)

Chen, Yong; Begnaud, Frédéric; Chaintreau, Alain; Pawliszyn, Janusz

2007-05-01

A miniaturized internally cooled coated fiber device was applied for the analysis of flavors and fragrances from various matrices. Its integration with a CTC CombiPAL autosampler enabled high throughput for the analysis of analytes in complex matrices that required simultaneous heating of the matrices and cooling of the fiber coating to achieve high extraction efficiency. It was found that up to ten times increase of extraction efficiencies was observed when the device was used to extract flavor compounds in water, even when limited sample temperatures were used to preserve the integrity of target compounds. The extraction of the flavor compounds in water with the device was reproducible, with RSD not larger than 15%. The lower limits of the linear ranges were in the low ppb range, which was about one order of magnitude smaller than those obtained with the commercialized 100 microm PDMS fibers. Exhaustive extraction of some perfume ingredients from a complex matrix (shampoo) was realized. All achieved recoveries were not less than 80%. The repeatability of the extraction of the perfume compounds from shampoo was better than 10%. The linear ranges were about 1-3000 microg/g, and the LOD was about 0.2-1 microg/g. The automated internally cooled coated fiber device was demonstrated to be a powerful sample preparation tool in flavor and fragrance analysis.

Low-Z internal target from a cryogenically cooled liquid microjet source

Energy Technology Data Exchange (ETDEWEB)

Kuehnel, M.; Petridis, N. [Institut fuer Kernphysik, J.W. Goethe-Universitaet, Max-von-Laue-Str. 1, 60438 Frankfurt (Germany); Winters, D.F.A. [GSI, Planckstr. 1, 64291 (Germany); Physikalisches Institut, Ruprecht-Karls-Universitaet, Philosophenweg 12, 69120 Heidelberg (Germany); Popp, U. [GSI, Planckstr. 1, 64291 (Germany); Doerner, R. [Institut fuer Kernphysik, J.W. Goethe-Universitaet, Max-von-Laue-Str. 1, 60438 Frankfurt a. M. (Germany); Stoehlker, Th. [GSI, Planckstr. 1, 64291 (Germany); Physikalisches Institut, Ruprecht-Karls-Universitaet, Philosophenweg 12, 69120 Heidelberg (Germany); Grisenti, R.E. [Institut fuer Kernphysik, J.W. Goethe-Universitaet, Max-von-Laue-Str. 1, 60438 Frankfurt (Germany); GSI, Planckstr. 1, 64291 (Germany)], E-mail: grisenti@atom.uni-frankfurt.de

2009-04-21

We carried out an extensive investigation on the production of cryogenically cooled liquid hydrogen and helium droplet beams at the experimental storage ring at GSI with the goal to achieve high area densities for these low-Z internal targets. Our results show that an area density of up to 10{sup 14}cm{sup -2} is achieved for both light gases by expanding the liquid through sub-10 {mu}m diameter nozzles. The achieved area density is comparable with the previous results for the hydrogen internal target and represents an improvement by about four orders of magnitude for the helium target.

Low-Z internal target from a cryogenically cooled liquid microjet source

International Nuclear Information System (INIS)

Kuehnel, M.; Petridis, N.; Winters, D.F.A.; Popp, U.; Doerner, R.; Stoehlker, Th.; Grisenti, R.E.

2009-01-01

We carried out an extensive investigation on the production of cryogenically cooled liquid hydrogen and helium droplet beams at the experimental storage ring at GSI with the goal to achieve high area densities for these low-Z internal targets. Our results show that an area density of up to 10 14 cm -2 is achieved for both light gases by expanding the liquid through sub-10 μm diameter nozzles. The achieved area density is comparable with the previous results for the hydrogen internal target and represents an improvement by about four orders of magnitude for the helium target.

High power cable with internal water cooling 400 kV

Science.gov (United States)

Rasquin, W.; Harjes, B.

1982-08-01

Due to the concentration of electricity production in large power plants, the need of higher power transmissions, and the protection of environment, developement of a 400 kV water cooled cable in the power range of 1 to 5 GVA was undertaken. The fabrication and testing of equipment, engineering of cable components, fabrication of a test cable, development of cable terminal laboratory, testing of test cable, field testing of test cable, fabrication of industrial cable laboratory, testing of industrial cable, field testing of industrial cable, and system analysis for optimization were prepared. The field testing was impossible to realize. However, it is proved that a cable consisting of an internal stainless steel water cooled tube, covered by stranded copper profiles, insulated with heavy high quality paper, and protected by an aluminum cover can be produced, withstand tests accordingly to IEC/VDE recommendations, and is able to fulfill all exploitation conditions.

Test Rig for Evaluating Active Turbine Blade Tip Clearance Control Concepts

Science.gov (United States)

Lattime, Scott B.; Steinetz, Bruce M.; Robbie, Malcolm G.

2003-01-01

Improved blade tip sealing in the high pressure compressor and high pressure turbine can provide dramatic improvements in specific fuel consumption, time-on-wing, compressor stall margin and engine efficiency as well as increased payload and mission range capabilities of both military and commercial gas turbine engines. The preliminary design of a mechanically actuated active clearance control (ACC) system for turbine blade tip clearance management is presented along with the design of a bench top test rig in which the system is to be evaluated. The ACC system utilizes mechanically actuated seal carrier segments and clearance measurement feedback to provide fast and precise active clearance control throughout engine operation. The purpose of this active clearance control system is to improve upon current case cooling methods. These systems have relatively slow response and do not use clearance measurement, thereby forcing cold build clearances to set the minimum clearances at extreme operating conditions (e.g., takeoff, re-burst) and not allowing cruise clearances to be minimized due to the possibility of throttle transients (e.g., step change in altitude). The active turbine blade tip clearance control system design presented herein will be evaluated to ensure that proper response and positional accuracy is achievable under simulated high-pressure turbine conditions. The test rig will simulate proper seal carrier pressure and temperature loading as well as the magnitudes and rates of blade tip clearance changes of an actual gas turbine engine. The results of these evaluations will be presented in future works.

Cooling off with physics

Energy Technology Data Exchange (ETDEWEB)

Clarke, Chris [Unilever R and D (United Kingdom)

2003-08-01

You might think of ice cream as a delicious treat to be enjoyed on a sunny summer's day. However, to the ice-cream scientists who recently gathered in Thessaloniki in Greece for the 2nd International Ice Cream Symposium, it is a complex composite material. Ice cream consists of three dispersed phases: ice crystals, which have a mean size of 50 microns, air bubbles with a diameter of about 70 microns, and fat droplets with a size of 1 micron. These phases are held together by what is called the matrix - not a sci-fi film, but a viscous solution of sugars, milk proteins and polysaccharides. The microstructure, and hence the texture that you experience when you eat ice cream, is created in a freezing process that has remained fundamentally unchanged since the first ice-cream maker was patented in the 1840s. The ingredients - water, milk protein, fat, sugar, emulsifiers, stabilizers, flavours and a lot of air - are mixed together before being pasteurized and homogenized. They are then pumped into a cylinder that is cooled from the outside with a refrigerant. As the mixture touches the cylinder wall it freezes and forms ice crystals, which are quickly scraped off by a rotating blade. The blade is attached to a beater that disperses the ice crystals into the mixture. At the same time, air is injected and broken down into small bubbles by the shear that the beater generates. As the mixture passes along the cylinder, the number of ice crystals increases and its temperature drops. As a result, the viscosity of the mixture increases, so that more energy input is needed to rotate the beater. This energy is dissipated as heat, and when the ice cream reaches about -6 deg. C the energy input through the beater equals the energy removed as heat by the refrigerant. The process therefore becomes self-limiting and it is not possible to cool the ice cream any further. However, at -6 deg. C the microstructure is unstable. The ice cream therefore has to be removed from the freezer

The SNL100-01 blade :

Energy Technology Data Exchange (ETDEWEB)

Griffith, Daniel

2013-02-01

A series of design studies to investigate the effect of carbon on blade weight and performance for large blades was performed using the Sandia 100-meter All-glass Baseline Blade design as a starting point. This document provides a description of the final carbon blade design, which is termed as SNL100-01. This report includes a summary of the design modifications applied to the baseline all-glass 100-meter design and a description of the NuMAD model files that are made publicly available. This document is intended primarily to be a companion document to the distribution of the NuMAD blade model files for SNL100-01.

New morphing blade section designs and structural solutions for smart blades

DEFF Research Database (Denmark)

Karakalas, Anargyros A.; Machairas, Theodore; Solomou, Alexandros

2015-01-01

Within INNWIND.EU new concepts are investigated having the ultimate goal to reduce the cost per kilowatt-hour of the produced energy. With increasing size of wind turbines, new approaches to load control are required to reduce the stresses in blades. Experimental and numerical studies in the fields...... of helicopter and wind turbine blade research have shown the potential of shape morphing in reducing blade loads. Morphing technologies, along with other control concepts, are investigated under Task 2.3 of WP “Lightweight Rotor”, against aerodynamic compliance and requirements of the complete wind turbine...... the efforts performed within Task 2.2 “Lightweight structural design” of INNWIND.Eu work-package WP2 “Lightweight Rotor” regarding the structural solutions necessary to accommodate the requirements of smart blades developed within work-package WP2 Task 2.3 “Active and passive loads control and alleviation...

Ceramic blade attachment system

Science.gov (United States)

Frey, G.A.; Jimenez, O.D.

1996-12-03

A turbine blade having a preestablished rate of thermal expansion is attached to a turbine flange having a preestablished rate of thermal expansion being greater than the preestablished rate of thermal expansion of the turbine blade. The turbine flange includes a first upstanding flange and a second upstanding flange having a groove formed between them. The turbine flange further includes a recess. Each of the first and second upstanding flanges have a plurality of bores therein. A turbine blade has a first member and a second member positioned in one of the groove and the recess. Each of the first member and the second member have a plurality of bores therein. A pin is positioned in respective ones of the plurality of bores in the first and second upstanding members and the first and second members and attach the blade to the turbine flange. The pin has a preestablished rate of thermal expansion being substantially equal to the rate of thermal expansion of the blade. 4 figs.

The Internal Stress Evaluation of Pultruded Blades for a Darrieus Wind Turbine

DEFF Research Database (Denmark)

Baran, Ismet; Tutum, Cem Celal; Hattel, Jesper Henri

2013-01-01

This paper investigates the integrated modeling of a pultruded NACA0018 blade profile which is a part of the FP7 EU project DeepWind. The pultrusion process simulation is combined with the preliminary subsequent in-service load scenario. In particular, the process induced residual stresses...

The Internal Stress Evaluation of Pultruded Blades for a Darrieus Wind Turbine

NARCIS (Netherlands)

Baran, Ismet; Tutum, Cem C.; Hattel, Jesper Henri

2013-01-01

This paper investigates the integrated modeling of a pultruded NACA0018 blade profile which is a part of the FP7 EU project DeepWind. The pultrusion process simulation is combined with the preliminary subsequent in-service load scenario. In particular, the process induced residual stresses and

Failure analysis of gas turbine blades in a gas turbine engine used ...

African Journals Online (AJOL)

PROMOTING ACCESS TO AFRICAN RESEARCH. AFRICAN ... International Journal of Engineering, Science and Technology ... examination reveals that there was no micro-structural damage due to blade operation at elevated temperatures.

Flapping inertia for selected rotor blades

Science.gov (United States)

Berry, John D.; May, Matthew J.

1991-01-01

Aerodynamics of helicopter rotor systems cannot be investigated without consideration for the dynamics of the rotor. One of the principal properties of the rotor which affects the rotor dynamics is the inertia of the rotor blade about its root attachment. Previous aerodynamic investigation have been performed on rotor blades with a variety of planforms to determine the performance differences due to blade planform. The blades tested for this investigation have been tested on the U.S. Army 2 meter rotor test system (2MRTS) in the NASA Langley 14 by 22 foot subsonic tunnel for hover performance. This investigation was intended to provide fundamental information on the flapping inertia of five rotor blades with differing planforms. The inertia of the bare cuff and the cuff with a blade extension were also measured for comparison with the inertia of the blades. Inertia was determined using a swing testing technique, using the period of oscillation to determine the effective flapping inertia. The effect of damping in the swing test was measured and described. A comparison of the flapping inertials for rectangular and tapered planform blades of approximately the same mass showed the tapered blades to have a lower inertia, as expected.

New blades shape up for dozers

Energy Technology Data Exchange (ETDEWEB)

Chironis, N.P.

1985-05-01

This article discusses the design of blades used on dozers for the reclamation work following surface mining. Two blades are described which have led to a 50% reduction in reclamation costs and a 20% reduction in fuel requirements over conventional equipment. These results are from work carried out at the Kayenta mine in Arizona, USA. Design considerations in the development of the blades are described. Descriptions of both the centre flow blades and the universal blades are given.

Design by theoretical and CFD analyses of a multi-blade screw pump evolving liquid lead for a Generation IV LFR

Energy Technology Data Exchange (ETDEWEB)

Ferrini, Marcello [GeNERG - DIME/TEC, University of Genova, via all’Opera Pia 15/a, 16145 Genova (Italy); Borreani, Walter [Ansaldo Nucleare S.p.A., Corso F.M. Perrone 25, 16152 Genova (Italy); INFN, Via Dodecaneso 33, 16146 Genova (Italy); Lomonaco, Guglielmo, E-mail: guglielmo.lomonaco@unige.it [GeNERG - DIME/TEC, University of Genova, via all’Opera Pia 15/a, 16145 Genova (Italy); INFN, Via Dodecaneso 33, 16146 Genova (Italy); Magugliani, Fabrizio [Ansaldo Nucleare S.p.A., Corso F.M. Perrone 25, 16152 Genova (Italy)

2016-02-15

Lead-cooled fast reactor (LFR) has both a long history and a penchant of innovation. With early work related to its use for submarine propulsion dating to the 1950s, Russian scientists pioneered the development of reactors cooled by heavy liquid metals (HLM). More recently, there has been substantial interest in both critical and subcritical reactors cooled by lead (Pb) or lead–bismuth eutectic (LBE), not only in Russia, but also in Europe, Asia, and the USA. The growing knowledge of the thermal-fluid-dynamic properties of these fluids and the choice of the LFR as one of the six reactor types selected by Generation IV International Forum (GIF) for further research and development has fostered the exploration of new geometries and new concepts aimed at optimizing the key components that will be adopted in the Advanced Lead Fast Reactor European Demonstrator (ALFRED), the 300 MW{sub t} pool-type reactor aimed at proving the feasibility of the design concept adopted for the European Lead-cooled Fast Reactor (ELFR). In this paper, a theoretical and computational analysis is presented of a multi-blade screw pump evolving liquid Lead as primary pump for the adopted reference conceptual design of ALFRED. The pump is at first analyzed at design operating conditions from the theoretical point of view to determine the optimal geometry according to the velocity triangles and then modeled with a 3D CFD code (ANSYS CFX). The choice of a 3D simulation is dictated by the need to perform a detailed spatial simulation taking into account the peculiar geometry of the pump as well as the boundary layers and turbulence effects of the flow, which are typically tri-dimensional. The use of liquid Lead impacts significantly the fluid dynamic design of the pump because of the key requirement to avoid any erosion affects. These effects have a major impact on the performance, reliability and lifespan of the pump. Albeit some erosion-related issues remain to be fully addressed, the results

Design by theoretical and CFD analyses of a multi-blade screw pump evolving liquid lead for a Generation IV LFR

International Nuclear Information System (INIS)

Ferrini, Marcello; Borreani, Walter; Lomonaco, Guglielmo; Magugliani, Fabrizio

2016-01-01

Lead-cooled fast reactor (LFR) has both a long history and a penchant of innovation. With early work related to its use for submarine propulsion dating to the 1950s, Russian scientists pioneered the development of reactors cooled by heavy liquid metals (HLM). More recently, there has been substantial interest in both critical and subcritical reactors cooled by lead (Pb) or lead–bismuth eutectic (LBE), not only in Russia, but also in Europe, Asia, and the USA. The growing knowledge of the thermal-fluid-dynamic properties of these fluids and the choice of the LFR as one of the six reactor types selected by Generation IV International Forum (GIF) for further research and development has fostered the exploration of new geometries and new concepts aimed at optimizing the key components that will be adopted in the Advanced Lead Fast Reactor European Demonstrator (ALFRED), the 300 MW t pool-type reactor aimed at proving the feasibility of the design concept adopted for the European Lead-cooled Fast Reactor (ELFR). In this paper, a theoretical and computational analysis is presented of a multi-blade screw pump evolving liquid Lead as primary pump for the adopted reference conceptual design of ALFRED. The pump is at first analyzed at design operating conditions from the theoretical point of view to determine the optimal geometry according to the velocity triangles and then modeled with a 3D CFD code (ANSYS CFX). The choice of a 3D simulation is dictated by the need to perform a detailed spatial simulation taking into account the peculiar geometry of the pump as well as the boundary layers and turbulence effects of the flow, which are typically tri-dimensional. The use of liquid Lead impacts significantly the fluid dynamic design of the pump because of the key requirement to avoid any erosion affects. These effects have a major impact on the performance, reliability and lifespan of the pump. Albeit some erosion-related issues remain to be fully addressed, the results of

Effects of Blade Boundary Layer Transition and Daytime Atmospheric Turbulence on Wind Turbine Performance Analyzed with Blade-Resolved Simulation and Field Data

Science.gov (United States)

Nandi, Tarak Nath

, ≈3 s) and sub-1P scale (changes in velocity vector inclination in the airfoil plane, modulated by eddy passage at longer time scales. Generator power is found to respond strongly to large-eddy wind modulations. The experimental data show that internal dynamics of blade boundary layer near the trailing edge is temporally modulated by the nonsteady external ABL flow that was measured at the leading edge, as well as blade generated turbulence motions. A blade boundary layer resolved CFD study of a GE 1.5MW wind turbine blade is carried out using a hybrid URANS/LES framework to quantify the influence of transition on the blade boundary layer dynamics and subsequent loadings, and also to predict the velocity magnitude data set measured by the trailing edge rakes in the experiment. A URANS based transition model is used as the near-wall model, and its ability to predict nonsteady boundary layer dynamics is assessed for flow over an oscillating airfoil exhibiting varying extents of nonsteady behavior. The CFD study shows that, at rated conditions, the transition and separation locations on the blade surface can be quite dynamic, but the transitional flow has negligible influence on the determination of the separation location and the overall pressure distribution at various blade sections, and subsequently the power output. But this conclusion should be accepted with caution for wind turbines running in off-design conditions (e.g. with significant yaw error, off-design pitch or rapid changes in pitch), where massive separation and dynamic stall may occur. Analysis of the near-blade flow field shows strong three dimensional flow in the inboard regions, which can possibly weaken the chordwise flow in the relatively outboard regions and make them more prone to separation. The trailing edge velocity profiles show qualitative resemblance with some specific cycles observed in the field experiment. The factors leading to the observed differences from the experimental data are

Development of a structure-dependent material model for complex, high-temperature environments and stresses. Example: turbine blades, turbine discs

International Nuclear Information System (INIS)

Schubert, F.

1988-01-01

For the optimum use of new high-temperature superalloys for turbine discs and blades, it is necessary to develop new design concepts which, on the one hand, permit a quantitative allocation of the structural characteristics to the deformation behaviour and damage mechanisms and, on the other hand, take into account the real course of stress. It is planned to use PM-Udinet 700 as material for turbine discs and IN 738 LC with supplementary tests of IN 100 for turbine blades. For turbine discs, a probabilistic model is developed, for turbine blades, cooled at the interior, first a deterministic model is developed and then a probabilistic model is prepared. The concept for the development of the models is dealt with in detail. The project started in April 1987, therefore only first investigation results can be reported. (orig.) [de

Development of High Performance Cooling Modules in Notebook PC's

Science.gov (United States)

Tanahashi, Kosei

The CPU power consumption in Notebook PCs is increasing every year. Video chips and HDDs are also continually using larger power for higher performance. In addition, since miniaturization is desired, the mounting of components is becoming more and more dense. Accordingly, the cooling mechanisms are increasingly important. The cooling modules have to dissipate larger amounts of heat in the same environmental conditions. Therefore, high capacity cooling capabilities is needed, while low costs and high reliability must be retained. Available cooling methods include air or water cooling systems and the heat conduction method. The air cooling system is to transmit heat by a cooling fan often using a heat pipe. The water cooling one employs the water to carry heat to the back of the display, which offers a comparatively large cooling area. The heat conduction method is to transfer the heat by thermal conduction to the case. This article describes the development of new and comparatively efficient cooling devices offering low cost and high reliability for air cooling system. As one of the development techniques, the heat resistance and performance are measured for various parts and layouts. Each cooling system is evaluated in the same measurement environment. With regards to the fans, an optimal shape of the fan blades to maximize air flow is found by using CFD simulation, and prototypes were built and tested.

A blade deflection monitoring system

DEFF Research Database (Denmark)

2017-01-01

A wind turbine blade comprising a system for monitoring the deflection of a wind turbine blade is described. The system comprises a wireless range-measurement system, having at least one wireless communication device located towards the root end of the blade and at least one wireless communication...

Design Procedure of 4-Bladed Propeller

African Journals Online (AJOL)

PROF. O. E. OSUAGWU

2013-09-01

Sep 1, 2013 ... West African Journal of Industrial and Academic Research Vol.8 No.1 September 2013 ..... Number of blades. 5. Taylor's wake friction (w). The speed of ship (Vs), the number of propeller revolution (n), the blade number (Z) and the blade area ratio.... .... moment of inertia of a blade, the approximate.

Large-area photogrammetry based testing of wind turbine blades

Science.gov (United States)

Poozesh, Peyman; Baqersad, Javad; Niezrecki, Christopher; Avitabile, Peter; Harvey, Eric; Yarala, Rahul

2017-03-01

An optically based sensing system that can measure the displacement and strain over essentially the entire area of a utility-scale blade leads to a measurement system that can significantly reduce the time and cost associated with traditional instrumentation. This paper evaluates the performance of conventional three dimensional digital image correlation (3D DIC) and three dimensional point tracking (3DPT) approaches over the surface of wind turbine blades and proposes a multi-camera measurement system using dynamic spatial data stitching. The potential advantages for the proposed approach include: (1) full-field measurement distributed over a very large area, (2) the elimination of time-consuming wiring and expensive sensors, and (3) the need for large-channel data acquisition systems. There are several challenges associated with extending the capability of a standard 3D DIC system to measure entire surface of utility scale blades to extract distributed strain, deflection, and modal parameters. This paper only tries to address some of the difficulties including: (1) assessing the accuracy of the 3D DIC system to measure full-field distributed strain and displacement over the large area, (2) understanding the geometrical constraints associated with a wind turbine testing facility (e.g. lighting, working distance, and speckle pattern size), (3) evaluating the performance of the dynamic stitching method to combine two different fields of view by extracting modal parameters from aligned point clouds, and (4) determining the feasibility of employing an output-only system identification to estimate modal parameters of a utility scale wind turbine blade from optically measured data. Within the current work, the results of an optical measurement (one stereo-vision system) performed on a large area over a 50-m utility-scale blade subjected to quasi-static and cyclic loading are presented. The blade certification and testing is typically performed using International

Internally gas-cooled radiofrequency applicators as an alternative to conventional radiofrequency and microwave ablation devices: An in vivo comparison

Energy Technology Data Exchange (ETDEWEB)

Rempp, Hansjörg, E-mail: Hansjoerg.rempp@med.uni-tuebingen.de [Eberhard Karls University of Tübingen, Tübingen University Hospital, Department of Diagnostic and Interventional Radiology, Hoppe-Seyler-Straße 3, Tübingen, 72076 (Germany); Voigtländer, Matthias [ERBE Elektromedizin GmbH, Waldhörnlestraße 17, 72072 Tübingen (Germany); Schenk, Martin [Eberhard Karls University of Tuebingen, Tübingen University Hospital, Department of General, Visceral and Transplant Surgery, Hoppe-Seyler-Straße 3, 72076 Tübingen (Germany); Enderle, Markus D. [ERBE Elektromedizin GmbH, Waldhörnlestraße 17, 72072 Tübingen (Germany); Scharpf, Marcus [Eberhard Karls University of Tuebingen, Insitute of Pathology, Department on General Pathology and Pathological Anatomy, Liebermeisterstraße 8, 72076 Tübingen (Germany); Greiner, Tim O. [Eberhard Karls University of Tuebingen, Tübingen University Hospital, Department of General, Visceral and Transplant Surgery, Hoppe-Seyler-Straße 3, 72076 Tübingen (Germany); Neugebauer, Alexander [ERBE Elektromedizin GmbH, Waldhörnlestraße 17, 72072 Tübingen (Germany); and others

2013-08-15

Purpose: To test the efficacy of internally CO{sub 2}-cooled radiofrequency (RF) ablation in vivo and to compare its effectiveness to a standard water-cooled RF probe and to a gas-cooled microwave (MW) device. Method and materials: 49 ablations were performed on 15 pigs under general anesthesia using 15G monopolar CO{sub 2}-cooled RF applicators, 17G monopolar water-cooled RF applicators and 15G internally CO{sub 2}-cooled microwave devices. The power of the MW device was 45 W, the current of the gas-cooled RF device was 1200–1600 mA. At the water-cooled RF probe, maximum power of 200 W was set. Ablation time was 15 min. The short and long axes of the ablation zone were measured. Histological analyses and NADH-staining were performed. The diameters and the ablation volumes were compared using an analysis of variance. Results: No spots of untreated tissue were observed close to the cooled needle track in any of the ablation zones. The largest short axis diameter was 3.4 ± 0.5 cm achieved with the gas-cooled monopolar applicator. With the water-cooled applicators, short axis diameter was significantly smaller, reaching 2.5 ± 0.4 cm. Gas-cooled MW probes achieved 2.9 ± 1.0 cm. The largest ablation volume was 31.5 ± 12 ml (gas-cooled RF), and the smallest was 12.7 ± 4 ml (water-cooled RF). Short/long axis ratio was largest for gas-cooled RF probes with 0.73 ± 0.08 versus 0.64 ± 0.04 for the water-cooled probes and 0.49 ± 0.25 for the microwave applicator. Conclusion: Gas-cooled RF applicators may have a higher potential for effective destruction of liver lesions than comparable water-cooled RF systems, and may be an alternative to standard RF and MW ablation devices.

Thermal and Fluid Mechanical Investigation of an Internally Cooled Piston Rod

Science.gov (United States)

Klotsche, K.; Thomas, C.; Hesse, U.

2017-08-01

The Internal Cooling of Reciprocating Compressor Parts (ICRC) is a promising technology to reduce the temperature of the thermally stressed piston and piston rod of process gas compressors. The underlying heat transport is based on the flow of a two-phase cooling medium that is contained in the hollow reciprocating assembly. The reciprocating motion forces the phases to mix, enabling an enhanced heat transfer. In order to investigate this heat transfer, experimental results from a vertically reciprocating hollow rod are presented that show the influence of different liquid charges for different working temperatures. In addition, pressure sensors are used for a crank angle dependent analysis of the fluid mechanical processes inside the rod. The results serve to investigate the two-phase flow in terms of the velocity and distribution of the liquid and vapour phase for different liquid fractions.

Analysis of impact resistance of composite fan blade. Fukugozai fan blade no taishogekisei no kaiseki

Energy Technology Data Exchange (ETDEWEB)

Miyachi, T; Okumura, H; Otake, K; Sofue, Y [Japan Society for Aeronautical and Space Sciences, Tokyo (Japan)

1992-01-05

Numerical analysis of impact response was carried out when a bird strike was simulated to study the applicability of fiber reinforced composite material to fan blades for turbo-fan engines. The validity of the numerical analysis was verified by comparing the analyzed results with impact tested results of a fan-blade model of Ti-alloy. The impact resistance was studied by applying this method to fan blades of composite materials such as carbon fiber, epoxy resin and carbon-silicate fiber reinforced Ti-alloy. The finite element method was used for the analysis by dividing the model into triangular flat elements. The relation between the impact load, the deformation of blade and the strain, the natural frequency characteristics, the elastic modulus and hetrogeneity of blade were considered to analyze the impact response. The impact load by the strike of 1.5 lbs bird is very severe to the fan blades for turbo-fan engines having the thrust of 5 ton class. 23 refs., 23 figs., 3 tabs.

Development and validation of a full-range performance analysis model for a three-spool gas turbine with turbine cooling

International Nuclear Information System (INIS)

Song, Yin; Gu, Chun-wei; Ji, Xing-xing

2015-01-01

The performance analysis of a gas turbine is important for both its design and its operation. For modern gas turbines, the cooling flow introduces a noteworthy thermodynamic loss; thus, the determination of the cooling flow rate will clearly influence the accuracy of performance calculations. In this paper, a full-range performance analysis model is established for a three-spool gas turbine with an open-circuit convective blade cooling system. A hybrid turbine cooling model is embedded in the analysis to predict the amount of cooling air accurately and thus to remove the errors induced by the relatively arbitrary value of cooling air requirements in the previous research. The model is subsequently used to calculate the gas turbine performance; the calculation results are validated with detailed test data. Furthermore, multistage conjugate heat transfer analysis is performed for the turbine section. The results indicate that with the same coolant condition and flow rate as those in the performance analysis, the blade metal has been effectively cooled; in addition, the maximum temperature predicted by conjugate heat transfer analysis is close to the corresponding value in the cooling model. Hence, the present model provides an effective tool for analyzing the performance of a gas turbine with cooling. - Highlights: • We established a performance model for a gas turbine with convective cooling. • A hybrid turbine cooling model is embedded in the performance analysis. • The accuracy of the model is validated with detailed test data of the gas turbine. • Conjugate heat transfer analysis is performed for the turbine for verification

Supply Chain and Blade Manufacturing Considerations in the Global Wind Industry (Presentation)

Energy Technology Data Exchange (ETDEWEB)

James, Ted [National Renewable Energy Lab. (NREL), Golden, CO (United States); Goodrich, Alan [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2013-12-12

This briefing provides an overview of supply chain developments in the global wind industry and a detailed assessment of blade manufacturing considerations for U.S. end-markets. The report discusses the international trade flows of wind power equipment, blade manufacturing and logistical costs, and qualitative issues that often influence factory location decisions. To help guide policy and research and development strategy decisions, this report offers a comprehensive perspective of both quantitative and qualitative factors that affect selected supply chain developments in the growing wind power industry.

Study on fundamental features of helium turbomachine for high temperature gas-cooled reactor

International Nuclear Information System (INIS)

Wang Jie; Gu Yihua

2004-01-01

The High temperature gas-cooled reactor (HTGR) coupled with helium turbine cycle is considered as one of the leading candidates for future nuclear power plants. The HTGR helium turbine cycle was analyzed and optimized. Then the focal point of investigation was concentrated on the fundamental thermodynamic and aerodynamic features of helium turbomachine. As a result, a helium turbomachine is different from a general combustion gas turbine in two main design features, that is a helium turbomachine has more blade stages and shorter blade length, which are caused by the helium property and the high pressure of a closed cycle, respectively. (authors)

''Football'' test coil: a simulated service test of internally-cooled, cabled superconductor

International Nuclear Information System (INIS)

Marston, P.G.; Iwasa, Y.; Thome, R.J.; Hoenig, M.O.

1981-01-01

Internally-cooled, cabled superconductor, (ICCS), appears from small-scale tests to be a viable alternative to pool-boiling cooled superconductors for large superconducting magnets. Potential advantages may include savings in helium inventory, smaller structure and ease of fabrication. Questions remain, however, about the structural performance of these systems. The ''football'' test coil has been designed to simulate the actual ''field-current-stress-thermal'' operating conditions of a 25 ka ICCS in a commercial scale MHD magnet. The test procedure will permit demonstration of the 20 year cyclic life of such a magnet in less than 20 days. This paper describes the design, construction and test of that coil which is wound of copper-stabilized niobium-titanium cable in steel conduit. 2 refs

The SNL100-02 blade :

Energy Technology Data Exchange (ETDEWEB)

Griffith, Daniel

2013-11-01

A series of design studies are performed to investigate the effects of advanced core materials and a new core material strategy on blade weight and performance for large blades using the Sandia 100-meter blade designs as a starting point. The initial core material design studies were based on the SNL100-01 100- meter carbon spar design. Advanced core material with improved performance to weight was investigated with the goal to reduce core material content in the design and reduce blade weight. A secondary element of the core study was to evaluate the suitability of core materials from natural, regrowable sources such as balsa and recyclable foam materials. The new core strategy for the SNL100-02 design resulted in a design mass of 59 tons, which is a 20% reduction from the most recent SNL100-01 carbon spar design and over 48% reduction from the initial SNL100-00 all-glass baseline blade. This document provides a description of the final SNL100-02 design, includes a description of the major design modifications, and summarizes the pertinent blade design information. This document is also intended to be a companion document to the distribution of the NuMAD blade model files for SNL100-02 that are made publicly available.

Effect of number of blades on aerodynamic forces on a straight-bladed Vertical Axis Wind Turbine

International Nuclear Information System (INIS)

Li, Qing'an; Maeda, Takao; Kamada, Yasunari; Murata, Junsuke; Furukawa, Kazuma; Yamamoto, Masayuki

2015-01-01

Small wind turbine performance and safety standard for straight-bladed Vertical Axis Wind Turbine (VAWT) have not been developed in the world because of the lack of fundament experimental data. This paper focuses on the evaluation of aerodynamic forces depending on several numbers of blades in wind tunnel experiment. In the present study, the test airfoil of blade is symmetry airfoil of NACA 0021 and the number of blades is from two to five. Pressure acting on the surface of rotor blade is measured during rotation by multiport pressure devices and transmitted to a stationary system through wireless LAN. And then, the aerodynamic forces (tangential force, normal force et al.) are discussed as a function of azimuth angle, achieving a quantitative analysis of the effect of numbers of blades. Finally, the loads are compared with the experimental data of six-component balance. As a result, it is clarified that the power coefficient decreases with the increase of numbers of blades. Furthermore, the power which is absorbed from wind by wind turbine mainly depends on upstream region of azimuth angle of θ = 0°∼180°. In this way, these results are very important for developing the simple design equations and applications for straight-bladed VAWT. - Highlights: • Aerodynamic forces are measured by not only torque meter but also six-component balance. • The pressure distribution on the surface of rotor blade is directly measured by multiport pressure devices. • The power coefficient decreases with the increase of numbers of blades. • The fluctuation amplitudes from six-component balance show larger value than the results of pressure distribution.

Turbine Airfoil Leading Edge Film Cooling Bibliography: 1972–1998

Directory of Open Access Journals (Sweden)

D. M. Kercher

2000-01-01

Full Text Available Film cooling for turbine airfoil leading edges has been a common practice for at least 35 years as turbine inlet gas temperatures and pressures have continually increased along with cooling air temperatures for higher engine cycle efficiency. With substantial engine cycle performance improvements from higher gas temperatures, it has become increasingly necessary to film cool nozzle and rotor blade leading edges since external heat transfer coefficients and thus heat load are the highest in this airfoil region. Optimum cooling air requirements in this harsh environment has prompted a significant number of film cooling investigations and analytical studies reported over the past 25 years from academia, industry and government agencies. Substantial progress has been made in understanding the complex nature of leading edge film cooling from airfoil cascades, simulated airfoil leading edges and environment. This bibliography is a report of the open-literature references available which provide information on the complex aero–thermo interaction of leading edge gaseous film cooling with mainstream flow. From much of this investigative information has come successful operational leading edge film cooling design systems capable of sustaining airfoil leading edge durability in very hostile turbine environments.

Mechanical property tests in hot gas environment for evaluation of life expectancy of aero-engine turbine blades and for assessment of procedures for prolonging service life. Mechanische Pruefung unter Heissgasatmosphaere zur Ermittlung der Lebenserwartung von Fluggasturbinenschaufeln und zur Bewertung von Verfahren zur Lebensdauerverlaengerung

Energy Technology Data Exchange (ETDEWEB)

Peichl, L

1984-01-01

The aim of this programme was the determination and optimization of mechanical testing procedures in order to enable a service life prediction for turbine blades as well as to measure the life consumption of blades which have already been in service. Under these testing conditions procedures were to be investigated which lead to a prolongation of the service life of the blades. The results have shown that the rig test at constant values of load and temperature, which are typical for service conditions, is sufficient for the laboratory simulation. The life consumption of blades run in the engine can be determined by measuring the residual creep life in the rig test. Using the resulting data the life consumption of a particular blade run in the engine can be estimated by the non-destructive measurement of its elongation. The precision of residual life prediction is raised by respecting the master heat and porosity of the blades. From the investigation of high-temperature corrosion resistant coatings it follows that IN 100 can be protected against the attack of sea salt over its whole creep life by coating with a precious metal modified aluminide or by LPPS- or EB-PVD-MCrAlY-coatings. By aluminising, the cooling channels of turbine blades can be protected against oxidation over more than 700 h in the temperature/load cycling test. However, the coating technique used is only applicable under laboratory conditions. In contrary, internal coating by pulse aluminising, which is compatible to production conditions, showed less oxidation resistance.

Distribution of defects in wind turbine blades and reliability assessment of blades containing defects

DEFF Research Database (Denmark)

Stensgaard Toft, Henrik; Branner, Kim; Berring, Peter

2009-01-01

on the assumption that one error in the production process tends to trigger several defects. For both models additional information about number, type and size of the defects is included as stochastic variables. The probability of failure for a wind turbine blade will not only depend on variations in the material......In the present paper two stochastic models for the distribution of defects in wind turbine blades are proposed. The first model assumes that the individual defects are completely randomly distributed in the blade. The second model assumes that the defects occur in clusters of different size based...... properties and the load but also on potential defects in the blades. As a numerical example the probability of failure is calculated for the main spar both with and without defects in terms of delaminations. The delaminations increase the probability of failure compared to a perfect blade, but by applying...

Contactless Diagnostics of Turbine Blade Vibration and Damage

Czech Academy of Sciences Publication Activity Database

Procházka, Pavel; Vaněk, František

2011-01-01

Roč. 305, č. 1 (2011), s. 1-11 E-ISSN 1742-6596. [International Conference on Damage Assessment of Structures (DAMAS 2011) /9./. Oxford, 11.07.2011-13.07.2011] Institutional research plan: CEZ:AV0Z20760514 Keywords : steam turbine * blade damage assessment * tip-timing method Subject RIV: JL - Materials Fatigue, Friction Mechanics http://iopscience.iop.org/1742-6596/305/1/012116

Fabrication development for ODS-superalloy, air-cooled turbine blades

Science.gov (United States)

Moracz, D. J.

1984-01-01

MA-600 is a gamma prime and oxide dispersion strengthened superalloy made by mechanical alloying. At the initiation of this program, MA-6000 was available as an experimental alloy only and did not go into production until late in the program. The objective of this program was to develop a thermal-mechanical-processing approach which would yield the necessary elongated grain structure and desirable mechanical properties after conventional press forging. Forging evaluations were performed to select optimum thermal-mechanical-processing conditions. These forging evaluations indicated that MA-6000 was extremely sensitive to die chilling. In order to conventionally hot forge the alloy, an adherent cladding, either the original extrusion can or a thick plating, was required to prevent cracking of the workpiece. Die design must reflect the requirement of cladding. MA-6000 was found to be sensitive to the forging temperature. The correct temperature required to obtain the proper grain structure after recrystallization was found to be between 1010-1065 C (1850-1950 F). The deformation level did not affect subsequent crystallization; however, sharp transition areas in tooling designs should be avoided in forming a blade shape because of the potential for grain structure discontinuities. Starting material to be used for forging should be processed so that it is capable of being zone annealed to a coarse elongated grain structure as bar stock. This conclusion means that standard processed bar materials can be used.

Local measurement and numerical modeling of mass/heat transfer from a turbine blade in a linear cascade with tip clearance

Science.gov (United States)

Jin, Peitong

2000-11-01

Local mass/heat transfer measurements from the turbine blade near-tip and the tip surfaces are performed using the naphthalene sublimation technique. The experiments are conducted in a linear cascade consisting of five high-pressure blades with a central test-blade configuration. The incoming flow conditions are close to those of the gas turbine engine environment (boundary layer displacement thickness is about 0.01 of chord) with an exit Reynolds number of 6.2 x 105. The effects of tip clearance level (0.86%--6.90% of chord), mainstream Reynolds number and turbulence intensity (0.2 and 12.0%) are investigated. Two methods of flow visualization---oil and lampblack, laser light sheet smoke wire---as well as static pressure measurement on the blade surface are used to study the tip leakage flow and vortex in the cascade. In addition, numerical modeling of the flow and heat transfer processes in the linear cascade with different tip clearances is conducted using commercial software incorporating advanced turbulence models. The present study confirms many important results on the tip leakage flow and vortex from the literature, contributes to the current understanding in the effects of tip leakage flow and vortex on local heat transfer from the blade near-tip and the tip surfaces, and provides detailed local and average heat/mass transfer data applicable to turbine blade tip cooling design.

Cooled-Spool Piston Compressor

Science.gov (United States)

Morris, Brian G.

1994-01-01

Proposed cooled-spool piston compressor driven by hydraulic power and features internal cooling of piston by flowing hydraulic fluid to limit temperature of compressed gas. Provides sufficient cooling for higher compression ratios or reactive gases. Unlike conventional piston compressors, all parts of compressed gas lie at all times within relatively short distance of cooled surface so that gas cooled more effectively.

Noise aspects at aerodynamic blade optimisation projects

International Nuclear Information System (INIS)

Schepers, J.G.

1997-06-01

The Netherlands Energy Research Foundation (ECN) has often been involved in industrial projects, in which blade geometries are created automatic by means of numerical optimisation. Usually, these projects aim at the determination of the aerodynamic optimal wind turbine blade, i.e. the goal is to design a blade which is optimal with regard to energy yield. In other cases, blades have been designed which are optimal with regard to cost of generated energy. However, it is obvious that the wind turbine blade designs which result from these optimisations, are not necessarily optimal with regard to noise emission. In this paper an example is shown of an aerodynamic blade optimisation, using the ECN-program PVOPT. PVOPT calculates the optimal wind turbine blade geometry such that the maximum energy yield is obtained. Using the aerodynamic optimal blade design as a basis, the possibilities of noise reduction are investigated. 11 figs., 8 refs

Electron cooling application for luminosity preservation in an experiment with internal targets at COSY

CERN Document Server

Meshkov, I N; Maier, R; Prasuhn, D; Sidorin, A O; Smirnov, A V; Stein, H J; Stockhorst, H; Trubnikov, G V

2003-01-01

This report is an investigation of the beam parameter evolution in the experiments with internal target. In calculations of the proton and deuteron beams we concentrated on cluster, atomic beam, storage cell and pellet targets at ANKE experiment mainly. In these calculations electron and stochastic cooling, intrabeam scattering, scattering on the target and residual gas atoms are taken into account. Beam parameter evolution is investigated in the long-term time scale, up to one hour, at different beam energies in the range from 1.0 to 2.7 GeV for proton beam and from 1 to 2.11 GeV for deuteron beam. The results of numerical simulations of the proton and deuteron beam parameters at different energies obtained using new version of BETACOOL program (elaborated at the first stage of this work [1]) are presented. Optimum parameters of the electron cooling system are estimated. The COSY experiment requirements can be satisfied even when electron cooling time is rather long. That allows to apply an electron cooling ...

Cooling equilibrium and beam loss with internal targets in high energy storage rings

International Nuclear Information System (INIS)

Boine-Frankenheim, O.; Hasse, R.; Hinterberger, F.; Lehrach, A.; Zenkevich, P.

2006-01-01

The beam cooling equilibrium with internal target interaction is analyzed for parameters relevant to the proposed High Energy Storage Ring (HESR). For the proposed experiments with anti-protons high luminosities together with low momentum spreads are required. Rate equations are used to predict the rms equilibrium beam parameters. The cooling and IBS rate coefficients are obtained from simplified models. Energy loss straggling in the target and the associated beam loss are analyzed analytically assuming a thin target. A longitudinal kinetic simulation code is used to study the evolution of the momentum distribution in coasting and bunched beams. Analytic expressions for the target induced momentum tail are found in good agreement with the simulation results

Ceramic blade with tip seal

Science.gov (United States)

Glezer, B.; Bhardwaj, N.K.; Jones, R.B.

1997-08-05

The present gas turbine engine includes a disc assembly defining a disc having a plurality of blades attached thereto. The disc has a preestablished rate of thermal expansion and the plurality of blades have a preestablished rate of thermal expansion being less than the preestablished rate of thermal expansion of the disc. A shroud assembly is attached to the gas turbine engine and is spaced from the plurality of blades a preestablished distance forming an interface there between. Positioned in the interface is a seal having a preestablished rate of thermal expansion being generally equal to the rate of thermal expansion of the plurality of blades. 4 figs.

Structural experiment of wind turbine blades; Fushayo blade no zairyo rikigakuteki jikken kenkyu

Energy Technology Data Exchange (ETDEWEB)

Seki, K; Shimizu, Y; Kuroyanagi, H [Tokai University, Tokyo (Japan)

1997-11-25

Aluminum, GFRP and composite of aluminum coated with carbon as structural materials for wind turbine blades were bending-tested, to improve blade bending stiffness, understand stress conditions at each position, and clarify structural dynamic strength by the bending-failure test. It is possible to estimate stress conditions at each position from the test results of displacement and strain at each load. The test results with GFRP are well explained qualitatively by the boundary theory, known as a theory for composite materials. The test gives reasonable material strength data, useful for designing wind turbines of high functions and safety. The results of the blade bending-failure test are in good agreement with the calculated structural blade strength. It is also found that GFRP is a good material of high structural strength for wind turbines. 8 refs., 6 tabs.

Adaptor assembly for coupling turbine blades to rotor disks

Science.gov (United States)

Garcia-Crespo, Andres Jose; Delvaux, John McConnell

2014-09-23

An adaptor assembly for coupling a blade root of a turbine blade to a root slot of a rotor disk is described. The adaptor assembly includes a turbine blade having a blade root and an adaptor body having an adaptor root. The adaptor body defines a slot having an open end configured to receive the blade root of the turbine blade such that the adaptor root of the adaptor body and the blade root of the turbine blade are adjacent to one another when the blade root of the turbine blade is positioned within the slot. Both the adaptor root of the adaptor body and the blade root of the turbine blade are configured to be received within the root slot of the rotor disk.

Theoretical analysis of the performance of different cooling strategies with the concept of cool exergy

DEFF Research Database (Denmark)

Kazanci, Ongun Berk; Shukuya, Masanori; Olesen, Bjarne W.

2016-01-01

The whole chains of exergy flows for different cooling systems were compared. The effects of cooling demand (internal vs. external solar shading), space cooling method (floor cooling vs. air cooling with ventilation system), and the availability of a nearby natural heat sink (intake air for the v......The whole chains of exergy flows for different cooling systems were compared. The effects of cooling demand (internal vs. external solar shading), space cooling method (floor cooling vs. air cooling with ventilation system), and the availability of a nearby natural heat sink (intake air...... for the ventilation system being outdoor air vs. air from the crawl-space, and air-to-water heat pump vs. ground heat exchanger as cooling source) on system exergy performance were investigated. It is crucial to minimize the cooling demand because it is possible to use a wide range of heat sinks (ground, lake, sea......-water, etc.) and indoor terminal units, only with a minimized demand. The water-based floor cooling system performed better than the air-based cooling system; when an air-to-water heat pump was used as the cooling source, the required exergy input was 28% smaller for the floor cooling system. The auxiliary...

Design optimization for active twist rotor blades

Science.gov (United States)

Mok, Ji Won

This dissertation introduces the process of optimizing active twist rotor blades in the presence of embedded anisotropic piezo-composite actuators. Optimum design of active twist blades is a complex task, since it involves a rich design space with tightly coupled design variables. The study presents the development of an optimization framework for active helicopter rotor blade cross-sectional design. This optimization framework allows for exploring a rich and highly nonlinear design space in order to optimize the active twist rotor blades. Different analytical components are combined in the framework: cross-sectional analysis (UM/VABS), an automated mesh generator, a beam solver (DYMORE), a three-dimensional local strain recovery module, and a gradient based optimizer within MATLAB. Through the mathematical optimization problem, the static twist actuation performance of a blade is maximized while satisfying a series of blade constraints. These constraints are associated with locations of the center of gravity and elastic axis, blade mass per unit span, fundamental rotating blade frequencies, and the blade strength based on local three-dimensional strain fields under worst loading conditions. Through pre-processing, limitations of the proposed process have been studied. When limitations were detected, resolution strategies were proposed. These include mesh overlapping, element distortion, trailing edge tab modeling, electrode modeling and foam implementation of the mesh generator, and the initial point sensibility of the current optimization scheme. Examples demonstrate the effectiveness of this process. Optimization studies were performed on the NASA/Army/MIT ATR blade case. Even though that design was built and shown significant impact in vibration reduction, the proposed optimization process showed that the design could be improved significantly. The second example, based on a model scale of the AH-64D Apache blade, emphasized the capability of this framework to

A Non-Uniformly Under-Sampled Blade Tip-Timing Signal Reconstruction Method for Blade Vibration Monitoring

Directory of Open Access Journals (Sweden)

Zheng Hu

2015-01-01

Full Text Available High-speed blades are often prone to fatigue due to severe blade vibrations. In particular, synchronous vibrations can cause irreversible damages to the blade. Blade tip-timing methods (BTT have become a promising way to monitor blade vibrations. However, synchronous vibrations are unsuitably monitored by uniform BTT sampling. Therefore, non-equally mounted probes have been used, which will result in the non-uniformity of the sampling signal. Since under-sampling is an intrinsic drawback of BTT methods, how to analyze non-uniformly under-sampled BTT signals is a big challenge. In this paper, a novel reconstruction method for non-uniformly under-sampled BTT data is presented. The method is based on the periodically non-uniform sampling theorem. Firstly, a mathematical model of a non-uniform BTT sampling process is built. It can be treated as the sum of certain uniform sample streams. For each stream, an interpolating function is required to prevent aliasing in the reconstructed signal. Secondly, simultaneous equations of all interpolating functions in each sub-band are built and corresponding solutions are ultimately derived to remove unwanted replicas of the original signal caused by the sampling, which may overlay the original signal. In the end, numerical simulations and experiments are carried out to validate the feasibility of the proposed method. The results demonstrate the accuracy of the reconstructed signal depends on the sampling frequency, the blade vibration frequency, the blade vibration bandwidth, the probe static offset and the number of samples. In practice, both types of blade vibration signals can be particularly reconstructed by non-uniform BTT data acquired from only two probes.

Nonlinear aeroelastic modelling for wind turbine blades based on blade element momentum theory and geometrically exact beam theory

International Nuclear Information System (INIS)

Wang, Lin; Liu, Xiongwei; Renevier, Nathalie; Stables, Matthew; Hall, George M.

2014-01-01

Due to the increasing size and flexibility of large wind turbine blades, accurate and reliable aeroelastic modelling is playing an important role for the design of large wind turbines. Most existing aeroelastic models are linear models based on assumption of small blade deflections. This assumption is not valid anymore for very flexible blade design because such blades often experience large deflections. In this paper, a novel nonlinear aeroelastic model for large wind turbine blades has been developed by combining BEM (blade element momentum) theory and mixed-form formulation of GEBT (geometrically exact beam theory). The nonlinear aeroelastic model takes account of large blade deflections and thus greatly improves the accuracy of aeroelastic analysis of wind turbine blades. The nonlinear aeroelastic model is implemented in COMSOL Multiphysics and validated with a series of benchmark calculation tests. The results show that good agreement is achieved when compared with experimental data, and its capability of handling large deflections is demonstrated. Finally the nonlinear aeroelastic model is applied to aeroelastic modelling of the parked WindPACT 1.5 MW baseline wind turbine, and reduced flapwise deflection from the nonlinear aeroelastic model is observed compared to the linear aeroelastic code FAST (Fatigue, Aerodynamics, Structures, and Turbulence). - Highlights: • A novel nonlinear aeroelastic model for wind turbine blades is developed. • The model takes account of large blade deflections and geometric nonlinearities. • The model is reliable and efficient for aeroelastic modelling of wind turbine blades. • The accuracy of the model is verified by a series of benchmark calculation tests. • The model provides more realistic aeroelastic modelling than FAST (Fatigue, Aerodynamics, Structures, and Turbulence)

Vibration analysis of gas turbine blade using FEM

International Nuclear Information System (INIS)

Iqbal, M.J.; Chohan, G.Y.; Khusnood, S.; Khan, M.A.

2003-01-01

In a typical turbo-machine, there is a stator row of blades, which guide the gases onto a rotor row of blades, to extract the mechanical power from the machine. A typical rotor blade was sees upstream disturbance from the stator row and as it rotates, receive a corresponding number of increasing and decreasing lift and moment forces alternating periodically, depending on the number of stator blades/nozzles/guide vanes. Thus all the blades in a turbo-machine receiver their major periodic excitation at a frequency equal to nozzle passing frequency. Since these forces are periodic, one has to consider several number of these harmonics in determining whether resonance takes place, when one of these harmonics coincides with any of the natural frequencies of the blades. Turbine blades have a variety of natural modes of vibration, predominantly as blade alone but also in combination with flexing of the disc rim. These mode occur at characteristic frequencies, which are determined by the distribution of mass and stiffness (in bending or torsion), resulting from the variable thickness over the blade area. Since the advent of steam turbines and their application in various sectors of industry, it is a common experience that a blade failure is a major cause of breakdown in these machines. Blade failures due to fatigue are predominantly vibration related. The dynamic loads on the blading can arise from many sources, the predominant being the source of the operation principles on which the machine is designed. This work deals with vibration analysis of a gas turbine blade using a finite element package ANSYS. Determined the natural frequencies and mode shapes for a turbine blade and a rectangular blade. Results have been validated experimentally using a rectangular blade. ANSYS results have also been compared against published results. (author)

Aerodynamic Analysis of Morphing Blades

Science.gov (United States)

Harris, Caleb; Macphee, David; Carlisle, Madeline

2016-11-01

Interest in morphing blades has grown with applications for wind turbines and other aerodynamic blades. This passive control method has advantages over active control methods such as lower manufacturing and upkeep costs. This study has investigated the lift and drag forces on individual blades with experimental and computational analysis. The goal has been to show that these blades delay stall and provide larger lift-to-drag ratios at various angles of attack. Rigid and flexible airfoils were cast from polyurethane and silicone respectively, then lift and drag forces were collected from a load cell during 2-D testing in a wind tunnel. Experimental data was used to validate computational models in OpenFOAM. A finite volume fluid-structure-interaction solver was used to model the flexible blade in fluid flow. Preliminary results indicate delay in stall and larger lift-to-drag ratios by maintaining more optimal angles of attack when flexing. Funding from NSF REU site Grant EEC 1358991 is greatly appreciated.

Performance analysis and optimization of power plants with gas turbines

Science.gov (United States)

Besharati-Givi, Maryam

The gas turbine is one of the most important applications for power generation. The purpose of this research is performance analysis and optimization of power plants by using different design systems at different operation conditions. In this research, accurate efficiency calculation and finding optimum values of efficiency for design of chiller inlet cooling and blade cooled gas turbine are investigated. This research shows how it is possible to find the optimum design for different operation conditions, like ambient temperature, relative humidity, turbine inlet temperature, and compressor pressure ratio. The simulated designs include the chiller, with varied COP and fogging cooling for a compressor. In addition, the overall thermal efficiency is improved by adding some design systems like reheat and regenerative heating. The other goal of this research focuses on the blade-cooled gas turbine for higher turbine inlet temperature, and consequently, higher efficiency. New film cooling equations, along with changing film cooling effectiveness for optimum cooling air requirement at the first-stage blades, and an internal and trailing edge cooling for the second stage, are innovated for optimal efficiency calculation. This research sets the groundwork for using the optimum value of efficiency calculation, while using inlet cooling and blade cooling designs. In the final step, the designed systems in the gas cycles are combined with a steam cycle for performance improvement.

Preliminary Design of Compressor Impeller for innovative Sodium Cooled Fast Reactor

Energy Technology Data Exchange (ETDEWEB)

Lee, Jekyoung; Cho, Seongkuk; Lee, Jeong Ik [KAIST, Daejeon (Korea, Republic of); Cha, Jae Eun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-05-15

For nuclear power plant application, applying S-CO{sub 2} Brayton cycle to Sodium cooled Fast Reactors and Small Modular Reactors are currently considered and active research is being performed by various research institutions and universities. As a part of research activities on the SCO{sub 2} Brayton cycle development for a nuclear power system, KAIST joint research team is currently working on an innovative Sodium cooled Fast Reactor (iSFR) development which utilizes S-CO{sub 2} Brayton cycle as its power conversion system. Various research subjects including reactor physics, thermo-hydraulics, material, cycle analysis and system integration are being considered as research issues currently. However, technical issues rising from dramatic change of thermodynamic property of CO{sub 2} near the critical point still remain as problems to be solved. As a result, 3D impeller model generation based on 1D mean stream line analysis results was successfully performed for non-airfoil blades. Since 3D model generation module works successfully, KAIST{sub T}MD can support 3D CFD analysis for internal flow structure in the designed impeller. Compressor loss mechanisms are complex phenomena and these are difficulties to be modeled while considering each loss mechanism separately.

Wind turbine blade shear web disbond detection using rotor blade operational sensing and data analysis.

Science.gov (United States)

Myrent, Noah; Adams, Douglas E; Griffith, D Todd

2015-02-28

A wind turbine blade's structural dynamic response is simulated and analysed with the goal of characterizing the presence and severity of a shear web disbond. Computer models of a 5 MW offshore utility-scale wind turbine were created to develop effective algorithms for detecting such damage. Through data analysis and with the use of blade measurements, a shear web disbond was quantified according to its length. An aerodynamic sensitivity study was conducted to ensure robustness of the detection algorithms. In all analyses, the blade's flap-wise acceleration and root-pitching moment were the clearest indicators of the presence and severity of a shear web disbond. A combination of blade and non-blade measurements was formulated into a final algorithm for the detection and quantification of the disbond. The probability of detection was 100% for the optimized wind speed ranges in laminar, 30% horizontal shear and 60% horizontal shear conditions. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Wind blade spar cap and method of making

Science.gov (United States)

Mohamed, Mansour H [Raleigh, NC

2008-05-27

A wind blade spar cap for strengthening a wind blade including an integral, unitary three-dimensional woven material having a first end and a second end, corresponding to a root end of the blade and a tip end of the blade, wherein the material tapers in width from the first to the second end while maintaining a constant thickness and decreasing weight therebetween, the cap being capable of being affixed to the blade for providing increased strength with controlled variation in weight from the root end to the tip end based upon the tapered width of the material thereof. The present inventions also include the method of making the wind blade spar cap and a wind blade including the wind blade spar cap.

Composite ceramic blade for a gas turbine

Energy Technology Data Exchange (ETDEWEB)

Rossmann, A; Hoffmueller, W; Krueger, W

1980-06-26

The gas turbine blade consists of a supporting metal core which has at its lower end a modelled root and a profile blade made of ceramics enclosing it at some distance. The invention deals with a reliable connection between these two parts of the rotor blade: from the top end of the blade core a head protrudes supporting the thin-walled profile blade from below with a projection each pointing into the interior. The design of the projections and supporting surfaces is described and illustrated by drawings.

Development of Wind Operated Passive Evaporative Cooling Structures for Storage of Tomatoes

Directory of Open Access Journals (Sweden)

M. O. Sunmonu

2016-08-01

Full Text Available A Wind operated passive evaporative cooler was developed. Two cooling chambers were made with clay container (cylindrical and square shapes. These two containers were separately inserted inside bigger clay pot inter- spaced with clay soil of 7 cm (to form pot-in-pot and wall-in wall with the outside structure wrapped with jute sack. The soil and the jute sacks were wetted with salt solution. Five blades were constructed inside the cooling chambers with aluminium material which were connected with a shaft to a vane located on a wooden cover outside the cooling chamber. The vanes (made of aluminium were to be powered by the wind which in turn rotates the blades inside the cooling chamber. The total volume of 40500cm3 and storage capacity of 31500cm3 were recorded for the square structures while total volume of 31792.5cm3 and storage capacity of 24727.5cm3 were recorded for the cylindrical structures. During the test period, the average temperatures of 27.07oC, 27.09oC and 33.6oC were obtained for the pot-in-pot (cylindrical, wall-in-wall (square and the ambient respectively. The average relative humidity of 92.27%, 91.99% and 69.41% were obtained for the pot-in-pot (cylindrical, wall-in-wall (square and the ambient respectively. The average minimum and maximum wind speed recorded for the month of October was 2.5m/s and 2.6m/s respectively

Identification and management of cracking in 410 stainless turbine blade roots

International Nuclear Information System (INIS)

Clark, M.A.; Lehockey, E.M.; Thompson, I.; Massey, R.

2003-01-01

amine (this case morpholine), and ingress of cooling water by way of condenser leaks. All these materials and by-products can ultimately accumulate in the turbine. The latter example demonstrates the importance of considering the implications of excursions in secondary side chemistry, condenser leaks, or other chronic mechanical and chemical factors that impact steam chemistry to ongoing turbine maintenance. This is particularly relevant in turbines containing older blades fabricated to specifications that permit wider than desirable variations in hardness which may render them susceptible to stress corrosion cracking in aggressive environments. A comprehensive inspection program based on in-situ hardness testing was instituted to identify and discard these high hardness blades. (author)

Turbine airfoil with laterally extending snubber having internal cooling system

Science.gov (United States)

Scribner, Carmen Andrew; Messmann, Stephen John; Marsh, Jan H.

2016-09-06

A turbine airfoil usable in a turbine engine and having at least one snubber with a snubber cooling system positioned therein and in communication with an airfoil cooling system is disclosed. The snubber may extend from the outer housing of the airfoil toward an adjacent turbine airfoil positioned within a row of airfoils. The snubber cooling system may include an inner cooling channel separated from an outer cooling channel by an inner wall. The inner wall may include a plurality of impingement cooling orifices that direct impingement fluid against an outer wall defining the outer cooling channel. In one embodiment, the cooling fluids may be exhausted from the snubber, and in another embodiment, the cooling fluids may be returned to the airfoil cooling system. Flow guides may be positioned in the outer cooling channel, which may reduce cross-flow by the impingement orifices, thereby increasing effectiveness.

Numerical analysis of turbine blade tip treatments

Science.gov (United States)

Gopalaswamy, Nath S.; Whitaker, Kevin W.

1992-01-01

Three-dimensional solutions of the Navier-Stokes equations for a turbine blade with a turning angle of 180 degrees have been computed, including blade tip treatments involving cavities. The geometry approximates a preliminary design for the GGOT (Generic Gas Oxidizer Turbine). The data presented here will be compared with experimental data to be obtained from a linear cascade using original GGOT blades. Results have been computed for a blade with 1 percent clearance, based on chord, and three different cavity sizes. All tests were conducted at a Reynolds number of 4 x 10 exp 7. The grid contains 39,440 points with 10 spanwise planes in the tip clearance region of 5.008E-04 m. Streamline plots and velocity vectors together with velocity divergence plots reveal the general flow behavior in the clearance region. Blade tip temperature calculations suggest placement of a cavity close to the upstream side of the blade tip for reduction of overall blade tip temperature. The solutions do not account for the relative motion between the endwall and the turbine blade. The solutions obtained are generally consistent with previous work done in this area,

Wind turbine blade waste in 2050.

Science.gov (United States)

Liu, Pu; Barlow, Claire Y

2017-04-01

Wind energy has developed rapidly over the last two decades to become one of the most promising and economically viable sources of renewable energy. Although wind energy is claimed to provide clean renewable energy without any emissions during operation, but it is only one side of the coin. The blades, one of the most important components in the wind turbines, made with composite, are currently regarded as unrecyclable. With the first wave of early commercial wind turbine installations now approaching their end of life, the problem of blade disposal is just beginning to emerge as a significant factor for the future. This paper is aimed at discovering the magnitude of the wind turbine blade waste problem, looking not only at disposal but at all stages of a blade's lifecycle. The first stage of the research, the subject of this paper, is to accurately estimate present and future wind turbine blade waste inventory using the most recent and most accurate data available. The result will provide a solid reference point to help the industry and policy makers to understand the size of potential environmental problem and to help to manage it better. This study starts by estimating the annual blade material usage with wind energy installed capacity and average blade weight. The effect of other waste contributing factors in the full lifecycle of wind turbine blades is then included, using industrial data from the manufacturing, testing and in-service stages. The research indicates that there will be 43 million tonnes of blade waste worldwide by 2050 with China possessing 40% of the waste, Europe 25%, the United States 16% and the rest of the world 19%. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

A Take Stock of Turbine Blades Failure Phenomenon

Science.gov (United States)

Roy, Abhijit

2018-02-01

Turbine Blade design and engineering is one of the most complicated and important aspects of turbine technology. Experiments with blades can be simple or very complicated, depending upon parameters of analysis. Turbine blades are subjected to vigorous environments, such as high temperatures, high stresses, and a potentially high vibration environment. All these factors can lead to blade failures, which can destroy the turbine, and engine, so careful design is the prime consideration to resist those conditions. A high cycle of fatigue of compressor and turbine blades due to high dynamic stress caused by blade vibration and resonance within the operating range of machinery is common failure mode for turbine machine. Continuous study and investigation on failure of turbine blades are going on since last five decades. Some review papers published during these days aiming to present a review on recent studies and investigations done on failures of turbine blades. All the detailed literature related with the turbine blades has not been described but emphasized to provide all the methodologies of failures adopted by various researches to investigate turbine blade. This paper illustrate on various factors of failure.

Wind Turbine Blade with Angled Girders

DEFF Research Database (Denmark)

2011-01-01

The present invention relates to a reinforced blade for a wind turbine, particularly to a blade having a new arrangement of two or more girders in the blade, wherein each of the girders is connected to the upper part and the lower part of the shell and forms an angle with another girder thereby...

Research on flow characteristics of supercritical CO2 axial compressor blades by CFD analysis

International Nuclear Information System (INIS)

Takagi, Kazuhisa; Muto, Yasushi; Ishizuka, Takao; Kikura, Hiroshige; Aritomi, Masanori

2010-01-01

A supercritical CO 2 gas turbine of 20MPa is suitable to couple with the Na-cooled fast reactor since Na - CO 2 reaction is mild at the outlet temperature of 800K, the cycle thermal efficiency is relatively high and the size of CO 2 gas turbine is very compact. In this gas turbine cycle, a compressor operates near the critical point. The property of CO 2 and then the behavior of compressible flow near the critical point changes very sharply. So far, such a behavior is not examined sufficiently. Then, it is important to clarify compressible flow near the critical point. In this paper, an aerodynamic design of the axial supercritical CO 2 compressor for this system has been carried out based on the existing aerodynamic design method of Cohen. The cycle design point was selected to achieve the maximum cycle thermal efficiency of 43.8%. For this point, the compressor design conditions were determined. They are a mass flow rate of 2035kg/s, an inlet temperature of 308K, an inlet static pressure of 8.26MPa, an outlet static pressure of 20.6MPa and a rotational speed of 3600rpm. The mean radius was constant through axial direction. The design point was determined so as to keep the diffusion factor and blade stress within the allowable limits. Number of stages and an expected adiabatic efficiency was 14 and 87%, respectively. CFD analyses by FLUENT have been done for this compressor blade. The blade model consists of one set of a guide vane, a rotor blade and a stator blade. The analyses were conducted under the assumption both of the real gas properties and also of the modified ideal gas properties. Using the real gas properties, analysis was conducted for the 14th blade, whose condition is remote from the critical point and the possibility of divergence is very small. Then, the analyses were conducted for the blade whose conditions are nearer to the critical point. Gradually, divergence of calculation was encountered. Convergence was relatively easy for the modified

Advances in wind turbine blade design and materials

DEFF Research Database (Denmark)

Wind energy is gaining critical ground in the area of renewable energy, with wind energy being predicted to provide up to 8% of the world’s consumption of electricity by 2021. Advances in wind turbine blade design and materials reviews the design and functionality of wind turbine rotor blades...... as well as the requirements and challenges for composite materials used in both current and future designs of wind turbine blades. Part one outlines the challenges and developments in wind turbine blade design, including aerodynamic and aeroelastic design features, fatigue loads on wind turbine blades......, and characteristics of wind turbine blade airfoils. Part two discusses the fatigue behavior of composite wind turbine blades, including the micromechanical modelling and fatigue life prediction of wind turbine blade composite materials, and the effects of resin and reinforcement variations on the fatigue resistance...

Contactless Diagnostics of Turbine Blade Vibration and Damage

International Nuclear Information System (INIS)

Prochazka, Pavel; Vanek, Frantisek

2011-01-01

The study deals with the contactless diagnostic method used for the identification of steam turbine blade strain, vibration and damage. The tip-timing method based on the evaluation of time differences of blade passages in different rotor revolutions has been modified and improved to provide more precise and reliable results. A new approach to the analysis of the amplitude and time differences of impulse signals generated by a blade passage has been applied. Amplitudes and frequencies of vibrations and static position of blades ascertained by the diagnostic process are used to establish the state of blade damage. A contactless diagnostic system VDS-UT based on magneto-resistive sensors was developed in the Institute of Thermomechanics Academy of Sciences of the Czech Republic. The system provides on-line monitoring of vibration amplitudes and frequencies of all blades and notification of possible blade damage. Evaluation of the axial and circumferential components of the deflections by measuring the amplitude of blade impulse signals results in an overall improvement of the method. Using magneto-resistive sensors, blade elongation and untwisting can be determined as well.

Doctor Blade-Coated Polymer Solar Cells

KAUST Repository

Cho, Nam Chul

2016-10-25

In this work, we report polymer solar cells based on blade-coated P3HT:PC71BM and PBDTTT-EFT:PC71BM bulk heterojunction photoactive layers. Enhanced power conversion efficiency of 2.75 (conventional structure) and 3.03% (inverted structure) with improved reproducibility was obtained from blade-coated P3HT:PC71BM solar cells, compared to spin-coated ones. Furthermore, by demonstrating 3.10% efficiency flexible solar cells using blade-coated PBDTTT-EFT:PC71BM films on the plastic substrates, we suggest the potential applicability of blade coating technique to the high throughput roll-to-roll fabrication systems.

Numerical simulation on a straight-bladed vertical axis wind turbine with auxiliary blade

Science.gov (United States)

Li, Y.; Zheng, Y. F.; Feng, F.; He, Q. B.; Wang, N. X.

2016-08-01

To improve the starting performance of the straight-bladed vertical axis wind turbine (SB-VAWT) at low wind speed, and the output characteristics at high wind speed, a flexible, scalable auxiliary vane mechanism was designed and installed into the rotor of SB-VAWT in this study. This new vertical axis wind turbine is a kind of lift-to-drag combination wind turbine. The flexible blade expanded, and the driving force of the wind turbines comes mainly from drag at low rotational speed. On the other hand, the flexible blade is retracted at higher speed, and the driving force is primarily from a lift. To research the effects of the flexible, scalable auxiliary module on the performance of SB-VAWT and to find its best parameters, the computational fluid dynamics (CFD) numerical calculation was carried out. The calculation result shows that the flexible, scalable blades can automatic expand and retract with the rotational speed. The moment coefficient at low tip speed ratio increased substantially. Meanwhile, the moment coefficient has also been improved at high tip speed ratios in certain ranges.

Vibration and flutter of mistuned bladed-disk assemblies

Science.gov (United States)

Kaza, K. R. V.; Kielb, R. E.

1984-01-01

An analytical model for investigating vibration and flutter of mistuned bladed disk assemblies is presented. This model accounts for elastic, inertial and aerodynamic coupling between bending and torsional motions of each individual blade, elastic and inertial couplings between the blades and the disk, and aerodynamic coupling among the blades. The disk was modeled as a circular plate with constant thickness and each blade was represented by a twisted, slender, straight, nonuniform, elastic beam with a symmetric cross section. The elastic axis, inertia axis, and the tension axis were taken to be noncoincident and the structural warping of the section was explicitly considered. The blade aerodynamic loading in the subsonic and supersonic flow regimes was obtained from two-dimensional unsteady, cascade theories. All the possible standing wave modes of the disk and traveling wave modes of the blades were included. The equations of motion were derived by using the energy method in conjunction with the assumed mode shapes for the disk and the blades. Continuities of displacement and slope at the blade-disk junction were maintained. The equations were solved to investigate the effects of blade-disk coupling and blade frequency mistuning on vibration and flutter. Results showed that the flexibility of practical disks such as those used for current generation turbofans did not have a significant influence on either the tuned or mistuned flutter characteristics. However, the disk flexibility may have a strong influence on some of the system frequencies and on forced response.

Piezoelectric Vibration Damping Study for Rotating Composite Fan Blades

Science.gov (United States)

Min, James B.; Duffy, Kirsten P.; Choi, Benjamin B.; Provenza, Andrew J.; Kray, Nicholas

2012-01-01

Resonant vibrations of aircraft engine blades cause blade fatigue problems in engines, which can lead to thicker and aerodynamically lower performing blade designs, increasing engine weight, fuel burn, and maintenance costs. In order to mitigate undesirable blade vibration levels, active piezoelectric vibration control has been investigated, potentially enabling thinner blade designs for higher performing blades and minimizing blade fatigue problems. While the piezoelectric damping idea has been investigated by other researchers over the years, very little study has been done including rotational effects. The present study attempts to fill this void. The particular objectives of this study were: (a) to develop and analyze a multiphysics piezoelectric finite element composite blade model for harmonic forced vibration response analysis coupled with a tuned RLC circuit for rotating engine blade conditions, (b) to validate a numerical model with experimental test data, and (c) to achieve a cost-effective numerical modeling capability which enables simulation of rotating blades within the NASA Glenn Research Center (GRC) Dynamic Spin Rig Facility. A numerical and experimental study for rotating piezoelectric composite subscale fan blades was performed. It was also proved that the proposed numerical method is feasible and effective when applied to the rotating blade base excitation model. The experimental test and multiphysics finite element modeling technique described in this paper show that piezoelectric vibration damping can significantly reduce vibrations of aircraft engine composite fan blades.

Development of Standard Approach for Sickle Blade Manufacturing

OpenAIRE

Noordin, M. N. A; Hudzari, R. M; Azuan, H. N; Zainon, M. S; Mohamed, S. B; Wafi, S. A

2016-01-01

The sickle blade used in the motorised palm cutter known as “CANTAS” provides fast, easy and safe pruning and harvesting for those hard to reach applications. Jariz Technologies Company is experiencing problem in the consistency of sickle blade which was supplied by various blade manufacturers. Identifying the proper blade material with a certain hardness value would produce a consistent as well as long lasting sickle blade. A Standard Operating Procedure (SOP) in the manufacturing of the sic...

Deflection estimation of a wind turbine blade using FBG sensors embedded in the blade bonding line

International Nuclear Information System (INIS)

Kim, Sang-Woo; Kang, Woo-Ram; Jeong, Min-Soo; Lee, In; Kwon, Il-Bum

2013-01-01

Estimating the deflection of flexible composite wind turbine blades is very important to prevent the blades from hitting the tower. Several researchers have used fiber Bragg grating (FBG) sensors—a type of optical fiber sensor (OFS)—to monitor the structural behavior of the blades. They can be installed on the surface and/or embedded in the interior of composites. However, the typical installation positions of OFSs present several problems, including delamination of sensing probes and a higher risk of fiber breakage during installation. In this study, we proposed using the bonding line between the shear web and spar cap as a new installation position of embedded OFSs for estimating the deflection of the blades. Laboratory coupon tests were undertaken preliminarily to confirm the strain measuring capability of embedded FBG sensors in adhesive layers, and the obtained values were verified by comparison with results obtained by electrical strain gauges and finite element analysis. We performed static loading tests on a 100 kW composite wind turbine blade to evaluate its deflections using embedded FBG sensors positioned in the bonding line. The deflections were estimated by classical beam theory considering a rigid body rotation near the tip of the blade. The evaluated tip deflections closely matched those measured by a linear variable differential transformer. Therefore, we verified the capability of embedded FBG sensors for evaluating the deflections of wind turbine blades. In addition, we confirmed that the bonding line between the shear web and spar cap is a practical location to embed the FBG sensors. (paper)

Composite Structural Analysis of Flat-Back Shaped Blade for Multi-MW Class Wind Turbine

Science.gov (United States)

Kim, Soo-Hyun; Bang, Hyung-Joon; Shin, Hyung-Ki; Jang, Moon-Seok

2014-06-01

This paper provides an overview of failure mode estimation based on 3D structural finite element (FE) analysis of the flat-back shaped wind turbine blade. Buckling stability, fiber failure (FF), and inter-fiber failure (IFF) analyses were performed to account for delamination or matrix failure of composite materials and to predict the realistic behavior of the entire blade region. Puck's fracture criteria were used for IFF evaluation. Blade design loads applicable to multi-megawatt (MW) wind turbine systems were calculated according to the Germanischer Lloyd (GL) guideline and the International Electrotechnical Commission (IEC) 61400-1 standard, under Class IIA wind conditions. After the post-processing of final load results, a number of principal load cases were selected and converted into applied forces at the each section along the blade's radius of the FE model. Nonlinear static analyses were performed for laminate failure, FF, and IFF check. For buckling stability, linear eigenvalue analysis was performed. As a result, we were able to estimate the failure mode and locate the major weak point.

Recycled wind turbine blades as a feedstock for second generation composites.

Science.gov (United States)

Mamanpush, Seyed Hossein; Li, Hui; Englund, Karl; Tabatabaei, Azadeh Tavousi

2018-06-01

With an increase in renewable wind energy via turbines, an underlying problem of the turbine blade disposal is looming in many areas of the world. These wind turbine blades are predominately a mixture of glass fiber composites (GFCs) and wood and currently have not found an economically viable recycling pathway. This work investigates a series of second generation composites fabricated using recycled wind turbine material and a polyurethane adhesive. The recycled material was first comminuted via a hammer-mill through a range of varying screen sizes, resinated and compressed to a final thickness. The refined particle size, moisture content and resin content were assessed for their influence on the properties of recycled composites. Static bending, internal bond and water sorption properties were obtained for all composites panels. Overall improvement of mechanical properties correlated with increase in resin content, moisture content, and particle size. The current investigation demonstrates that it is feasible and promising to recycle the wind turbine blade to fabricate value-added high-performance composite. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effects of Rotation at Different Channel Orientations on the Flow Field inside a Trailing Edge Internal Cooling Channel

Directory of Open Access Journals (Sweden)

Matteo Pascotto

2013-01-01

Full Text Available The flow field inside a cooling channel for the trailing edge of gas turbine blades has been numerically investigated with the aim to highlight the effects of channel rotation and orientation. A commercial 3D RANS solver including a SST turbulence model has been used to compute the isothermal steady air flow inside both static and rotating passages. Simulations were performed at a Reynolds number equal to 20000, a rotation number (Ro of 0, 0.23, and 0.46, and channel orientations of γ=0∘, 22.5°, and 45°, extending previous results towards new engine-like working conditions. The numerical results have been carefully validated against experimental data obtained by the same authors for conditions γ=0∘ and Ro = 0, 0.23. Rotation effects are shown to alter significantly the flow field inside both inlet and trailing edge regions. These effects are attenuated by an increase of the channel orientation from γ=0∘ to 45°.

Pin and roller attachment system for ceramic blades

Science.gov (United States)

Shaffer, J.E.

1995-07-25

In a turbine, a plurality of blades are attached to a turbine wheel by way of a plurality of joints which form a rolling contact between the blades and the turbine wheel. Each joint includes a pin and a pair of rollers to provide rolling contact between the pin and an adjacent pair of blades. Because of this rolling contact, high stress scuffing between the blades and the turbine wheel reduced, thereby inhibiting catastrophic failure of the blade joints. 3 figs.

Validation of CFD/Heat Transfer Software for Turbine Blade Analysis

Science.gov (United States)

Kiefer, Walter D.

2004-01-01

I am an intern in the Turbine Branch of the Turbomachinery and Propulsion Systems Division. The division is primarily concerned with experimental and computational methods of calculating heat transfer effects of turbine blades during operation in jet engines and land-based power systems. These include modeling flow in internal cooling passages and film cooling, as well as calculating heat flux and peak temperatures to ensure safe and efficient operation. The branch is research-oriented, emphasizing the development of tools that may be used by gas turbine designers in industry. The branch has been developing a computational fluid dynamics (CFD) and heat transfer code called GlennHT to achieve the computational end of this analysis. The code was originally written in FORTRAN 77 and run on Silicon Graphics machines. However the code has been rewritten and compiled in FORTRAN 90 to take advantage of more modem computer memory systems. In addition the branch has made a switch in system architectures from SGI's to Linux PC's. The newly modified code therefore needs to be tested and validated. This is the primary goal of my internship. To validate the GlennHT code, it must be run using benchmark fluid mechanics and heat transfer test cases, for which there are either analytical solutions or widely accepted experimental data. From the solutions generated by the code, comparisons can be made to the correct solutions to establish the accuracy of the code. To design and create these test cases, there are many steps and programs that must be used. Before a test case can be run, pre-processing steps must be accomplished. These include generating a grid to describe the geometry, using a software package called GridPro. Also various files required by the GlennHT code must be created including a boundary condition file, a file for multi-processor computing, and a file to describe problem and algorithm parameters. A good deal of this internship will be to become familiar with these

Thermal resistance of a convectively cooled plate with applied heat flux and variable internal heat generation

International Nuclear Information System (INIS)

Venkataraman, N.S.; Cardoso, H.P.; Oliveira Filho, O.B. de

1981-01-01

The conductive heat transfer in a rectangular plate with nonuniform internal heat generation, with one end convectively cooled and a part of the opposite end subjected to external heat flux is considered. The remaining part of this end as well as the other two sides are thermally insulated. The governing differential equation is solved by a finite difference scheme. The variation of the thermal resistance with Biot modulus, the plate geometry, the internal heat generation parameter and the type of profile of internal heat generation is discussed. (author) [pt

Fatigue lifespan of a mobile blade gas turbine with ceramic coating; Vida util por fatiga de un alabe movil de turbina de gas con recubrimiento ceramico

Energy Technology Data Exchange (ETDEWEB)

Garcia Illescas, Rafael; Z. Mazur Czerwiec, Zdzislaw; Islas Mungarro, Ricardo [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: rgi@iie.org.mx; mazur@iie.org.mx; rick_iie@terra.com.mx

2010-11-15

Fatigue analysis of a gas turbine moving blade made of IN738LC was carried out in order to evaluate useful life time. The life estimation was done from a previous 3D linear finite element analysis where thermal and mechanical stress calculation at high temperatures was done during steady and transient state i.e. normal start ups and shutdowns. Several load histories with different stresses and strains in the blade were used for different cooling conditions including a thermal barrier coating in comparison with to simple blade without such coating. The important effect of high temperatures on the blade material and stress calculations is shown. The analysis is focused on two different critical zones in the blade: the leading edge at the middle of the height and a cooling channel surface, where high stresses were found in numerical analysis as well as in reality. Finally, the benefit of the presence of a thermal barrier coating in the blade life is shown. [Spanish] Se realizo el analisis de fatiga de un alabe movil de turbina de gas fabricado de IN738LC a fin de evaluar su vida util. La estimacion de vida fue realizada a partir de simulaciones lineales de esfuerzos termomecanicos por elemento finito en 3D a altas temperaturas y durante el arranque y paro normal. Se utilizaron diversos historiales de carga, esfuerzos y deformaciones del alabe para diferentes configuraciones de enfriamiento incluyendo el recubrimiento ceramico tipo barrera termica en comparacion con los resultados sin incluir dicho recubrimiento. Se presenta el efecto importante de las temperaturas elevadas en las propiedades de fatiga del material del alabe y en sus esfuerzos. El analisis se centra en dos puntos de interes identificados como criticos: borde de entrada y un canal de enfriamiento, en donde esfuerzos elevados fueron encontrados tanto numericamente como en la realidad. Finalmente se muestra el beneficio del recubrimiento tipo barrera termica en la vida del alabe.

Advanced Blade Manufacturing Project - Final Report

Energy Technology Data Exchange (ETDEWEB)

POORE, ROBERT Z.

1999-08-01

The original scope of the project was to research improvements to the processes and materials used in the manufacture of wood-epoxy blades, conduct tests to qualify any new material or processes for use in blade design and subsequently build and test six blades using the improved processes and materials. In particular, ABM was interested in reducing blade cost and improving quality. In addition, ABM needed to find a replacement material for the mature Douglas fir used in the manufacturing process. The use of mature Douglas fir is commercially unacceptable because of its limited supply and environmental concerns associated with the use of mature timber. Unfortunately, the bankruptcy of FloWind in June 1997 and a dramatic reduction in AWT sales made it impossible for ABM to complete the full scope of work. However, sufficient research and testing were completed to identify several promising changes in the blade manufacturing process and develop a preliminary design incorporating these changes.

Study of the strength of the internal can for internally and externally cooled fuel elements intended for gas graphite reactors

International Nuclear Information System (INIS)

Boudouresque, B.; Courcon, P.; Lestiboubois, G.

1964-01-01

The cartridge of an internally and externally cooled annular fuel element used in gas-graphite reactors is made up of an uranium fuel tube, an external can and an internal can made of magnesium alloy. For the thermal exchange between the internal can and the fuel to be satisfactory, it is necessary for the can to stay in contact with the uranium under all temperature conditions. This report, based on a theoretical study, shows how the internal can fuel gap varies during the processes of canning, charging into the reactor and thermal cycling. The following parameters are considered: tube diameter, pressure of the heat carrying gas, gas entry temperature, plasticity of the can alloy. It is shown that for all operating conditions the internal can of a 77 x 95 element, planned for a gas-graphite reactor with a 40 kg/cm 2 gas pressure, should remain in contact with the fuel. (authors) [fr

Korean experience with steam turbine blade inspection

International Nuclear Information System (INIS)

Jung, Hyun Kyu; Park, D.Y.; Park, Hyung Jin; Chung, Min Hwa

1990-01-01

Several turbine blade accidents in Korea have emphasized the importance of their adequate periodic inspection. As a typical example, a broken blade was found in the Low Pressure (LP) turbine at the 950 MWe KORI unit 3 during the 1986 overhaul after one year commercial operation. Since then the Manufacturer and the Utility company (KEPCO) have been concerned about the need of blade root inspection. The ultrasonic testing was applied to detect cracks in the blade roots without removing the blades from rotor. Due to the complex geometry of the roots, the test results could not be evaluated easily. We feel that the currently applied UT technique seems to be less reliable and more effective method of inspection must be developed in the near future. This paper describes the following items: The causes and analysis of blade damage The inspection techniques and results The remedial action to be taken (Repair and Replacement) The future plan

Methodology for wind turbine blade geometry optimization

Energy Technology Data Exchange (ETDEWEB)

Perfiliev, D.

2013-11-01

Nowadays, the upwind three bladed horizontal axis wind turbine is the leading player on the market. It has been found to be the best industrial compromise in the range of different turbine constructions. The current wind industry innovation is conducted in the development of individual turbine components. The blade constitutes 20-25% of the overall turbine budget. Its optimal operation in particular local economic and wind conditions is worth investigating. The blade geometry, namely the chord, twist and airfoil type distributions along the span, responds to the output measures of the blade performance. Therefore, the optimal wind blade geometry can improve the overall turbine performance. The objectives of the dissertation are focused on the development of a methodology and specific tool for the investigation of possible existing wind blade geometry adjustments. The novelty of the methodology presented in the thesis is the multiobjective perspective on wind blade geometry optimization, particularly taking simultaneously into account the local wind conditions and the issue of aerodynamic noise emissions. The presented optimization objective approach has not been investigated previously for the implementation in wind blade design. The possibilities to use different theories for the analysis and search procedures are investigated and sufficient arguments derived for the usage of proposed theories. The tool is used for the test optimization of a particular wind turbine blade. The sensitivity analysis shows the dependence of the outputs on the provided inputs, as well as its relative and absolute divergences and instabilities. The pros and cons of the proposed technique are seen from the practical implementation, which is documented in the results, analysis and conclusion sections. (orig.)

Liquid metal cooled nuclear reactor

International Nuclear Information System (INIS)

Guidez, Joel; Jarriand, Paul.

1975-01-01

The invention concerns a fast neutron nuclear reactor cooled by a liquid metal driven through by a primary pump of the vertical drive shaft type fitted at its lower end with a blade wheel. To each pump is associated an exchanger, annular in shape, fitted with a central bore through which passes the vertical drive shaft of the pump, its wheel being mounted under the exchanger. A collector placed under the wheel comprises an open upward suction bell for the liquid metal. A hydrostatic bearing is located above the wheel to guide the drive shaft and a non detachable diffuser into which at least one delivery pipe gives, envelopes the wheel [fr

Sensitivity-Based Simulation Software for Optimization of Turbine Blade Cooling Strategies, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — In recent years, there has been a tendency to use ever-higher gas turbine inlet temperatures, resulting in ever-higher heat loads necessitating efficient cooling....

The effect of cooling conditions on convective heat transfer and flow in a steam-cooled ribbed duct

International Nuclear Information System (INIS)

Shui, Linqi; Gao, Jianmin; Shi, Xiaojun; Liu, Jiazeng; Xu, Liang

2014-01-01

This work presents a numerical and experimental investigation on the heat transfer and turbulent flow of cooling steam in a rectangular duct with 90 .deg. ribs and studies the effect of cooling conditions on the heat transfer augmentation of steam. In the calculation, the variation range of Reynolds is from 10,000 to 190,000, the inlet temperature varies from 300 .deg. C to 500 .deg. C and the outlet pressure is from 0.5MPa to 6MPa. The aforementioned wide ranges of flow parameters cover the actual operating condition of coolant used in the gas turbine blades. The computations are carried with four turbulence models (the standard k-ε, the renormalized group (RNG) k-ε, the Launder-Reece-Rodi (LRR) and the Speziale-Sarkar-Gatski (SSG) turbulence models). The comparison of numerical and experimental results reveals that the SSG turbulence model is suitable for steam flow in the ribbed duct. Therefore, adopting the conjugate calculation technique, further study on the steam heat transfer and flow characteristics is performed with SSG turbulence model. The results show that the variation of cooling condition strongly impacts the forced convection heat transfer of steam in the ribbed duct. The cooling supply condition of a relative low temperature and medium pressure could bring a considerable advantage on steam thermal enhancement. In addition, comparing the heat transfer level between steam flow and air flow, the performance advantage of using steam is also influenced by the cooling supply condition. Changing Reynolds number has little effect on the performance superiority of steam cooling. Increasing pressure would strengthen the advantage, but increasing temperature gives an opposite result.

The effect of cooling conditions on convective heat transfer and flow in a steam-cooled ribbed duct

Energy Technology Data Exchange (ETDEWEB)

Shui, Linqi; Gao, Jianmin; Shi, Xiaojun; Liu, Jiazeng; Xu, Liang [Xi' an Jiaotong University, Xi' an (China)

2014-01-15

This work presents a numerical and experimental investigation on the heat transfer and turbulent flow of cooling steam in a rectangular duct with 90 .deg. ribs and studies the effect of cooling conditions on the heat transfer augmentation of steam. In the calculation, the variation range of Reynolds is from 10,000 to 190,000, the inlet temperature varies from 300 .deg. C to 500 .deg. C and the outlet pressure is from 0.5MPa to 6MPa. The aforementioned wide ranges of flow parameters cover the actual operating condition of coolant used in the gas turbine blades. The computations are carried with four turbulence models (the standard k-ε, the renormalized group (RNG) k-ε, the Launder-Reece-Rodi (LRR) and the Speziale-Sarkar-Gatski (SSG) turbulence models). The comparison of numerical and experimental results reveals that the SSG turbulence model is suitable for steam flow in the ribbed duct. Therefore, adopting the conjugate calculation technique, further study on the steam heat transfer and flow characteristics is performed with SSG turbulence model. The results show that the variation of cooling condition strongly impacts the forced convection heat transfer of steam in the ribbed duct. The cooling supply condition of a relative low temperature and medium pressure could bring a considerable advantage on steam thermal enhancement. In addition, comparing the heat transfer level between steam flow and air flow, the performance advantage of using steam is also influenced by the cooling supply condition. Changing Reynolds number has little effect on the performance superiority of steam cooling. Increasing pressure would strengthen the advantage, but increasing temperature gives an opposite result.

Crack of a first stage blade in a steam turbine

Directory of Open Access Journals (Sweden)

M. Nurbanasari

2014-10-01

Full Text Available The failure of the first stage blade in a steam turbine of 55 MW was investigated. The blade was made of 17-4 PH stainless steel and has been used for 12 years before failure. The current work aims to find out the main cause of the first stage blade failure. The methods for investigation were metallurgical analysis, chemical composition test, and hardness measurement. The result showed that there was no evidence the blade failure was due to material. The damage found on the blade namely crack on the blade root. Two locations of the crack observed at the blade root, which was at the tang and the fillet, with different failure modes. In general, the damage of the blade was started by the corrosion occurred on the blade root. The crack at the blade root tang was due to corrosion fatigue and the crack occurred at the blade root fillet owing to stress corrosion cracking.

Status of the international Muon ionization cooling experiment

International Nuclear Information System (INIS)

Palladino, V.; Bonesini, M.

2009-01-01

Muon ionization cooling provides the only practical solution to prepare high brilliance beams necessary for a neutrino factory or muon colliders. The muon ionization cooling experiment (MICE) is under development at the Rutherford Appleton Laboratory (UK). It comprises a dedicated beam line to generate a range of input emittance and momentum, with time-of-flight and Cherenkov detectors to ensure a pure muon beam. A first measurement of emittance is performed in the upstream magnetic spectrometer with a scintillating fiber tracker. A cooling cell will then follow, alternating energy loss in liquid hydrogen and RF acceleration. A second spectrometer identical to the first one and a particle identification system provide a measurement of the outgoing emittance. By July 2009 it is expected that the beam and first set of detectors will have been commissioned and a first measurement of input beam emittance may be reported. Along with the steps in the measurement of emittance reduction (cooling) that will follow later and in 2010. (authors)

Preliminary study on the adjonction of a cooling system and internal target ring to the GEPL project

International Nuclear Information System (INIS)

Potaux, D.

1983-01-01

Various heavy particle storage rings (LEAR, Indiana, Uppsala) are planned for operation with combined electron cooling system and internal ultra-thin targets. The advantage of adding a similar device to the IPN cyclotron project is discussed [fr

Mach number scaling of helicopter rotor blade/vortex interaction noise

Science.gov (United States)

Leighton, Kenneth P.; Harris, Wesley L.

1985-01-01

A parametric study of model helicopter rotor blade slap due to blade vortex interaction (BVI) was conducted in a 5 by 7.5-foot anechoic wind tunnel using model helicopter rotors with two, three, and four blades. The results were compared with a previously developed Mach number scaling theory. Three- and four-bladed rotor configurations were found to show very good agreement with the Mach number to the sixth power law for all conditions tested. A reduction of conditions for which BVI blade slap is detected was observed for three-bladed rotors when compared to the two-bladed baseline. The advance ratio boundaries of the four-bladed rotor exhibited an angular dependence not present for the two-bladed configuration. The upper limits for the advance ratio boundaries of the four-bladed rotors increased with increasing rotational speed.

Modal characteristics and fatigue strength of compressor blades

International Nuclear Information System (INIS)

Kim, Kyung Kook; Lee, Young Shin

2014-01-01

High-cycle fatigue (HCF) has been identified as one of the primary causes of gas turbine engine failure. The modal characteristics and endurance strength of a 5 MW gas turbine engine blade developed by Doosan Heavy Industries and Construction Co., Ltd. in HCF fracture were verified through analysis and tests to determine the reliability of the compressor blade. A compressor blade design procedure that considers HCF life was performed in the following order: airfoil and blade profile design, modal analysis, stress distribution test, stress endurance limit test, and fatigue life verification. This study analyzed the Campbell diagram and estimated resonance risk on the basis of the natural frequency analysis and modal test of the compressor blade to guarantee safe and operational reliability. In addition, the maximum stress point of the compressor blade was determined through stress distribution analysis and test. The bonding point of the strain gage was determined by using fatigue test. Stress endurance limit test was performed based on the results of these tests. This research compared and verified the modal characteristics and endurance strengths of the compressor blades to prevent HCF fracture, which is among the major causes of gas turbine engine damage. A fatigue life design procedure of compressor blades was established. The 5 MW class gas turbine compressor blade is well designed in terms of resonance stability and fatigue endurance limit.

Modal characteristics and fatigue strength of compressor blades

Energy Technology Data Exchange (ETDEWEB)

Kim, Kyung Kook [Doosan Heavy Industries and Construction, Changwon (Korea, Republic of); Lee, Young Shin [Chungnam National University, Daejeon (Korea, Republic of)

2014-04-15

High-cycle fatigue (HCF) has been identified as one of the primary causes of gas turbine engine failure. The modal characteristics and endurance strength of a 5 MW gas turbine engine blade developed by Doosan Heavy Industries and Construction Co., Ltd. in HCF fracture were verified through analysis and tests to determine the reliability of the compressor blade. A compressor blade design procedure that considers HCF life was performed in the following order: airfoil and blade profile design, modal analysis, stress distribution test, stress endurance limit test, and fatigue life verification. This study analyzed the Campbell diagram and estimated resonance risk on the basis of the natural frequency analysis and modal test of the compressor blade to guarantee safe and operational reliability. In addition, the maximum stress point of the compressor blade was determined through stress distribution analysis and test. The bonding point of the strain gage was determined by using fatigue test. Stress endurance limit test was performed based on the results of these tests. This research compared and verified the modal characteristics and endurance strengths of the compressor blades to prevent HCF fracture, which is among the major causes of gas turbine engine damage. A fatigue life design procedure of compressor blades was established. The 5 MW class gas turbine compressor blade is well designed in terms of resonance stability and fatigue endurance limit.

Active Blade Vibration Control Being Developed and Tested

Science.gov (United States)

Johnson, Dexter

2003-01-01

Gas turbine engines are currently being designed to have increased performance, lower weight and manufacturing costs, and higher reliability. Consequently, turbomachinery components, such as turbine and compressor blades, have designs that are susceptible to new vibration problems and eventual in-service failure due to high-cycle fatigue. To address this problem, researchers at the NASA Glenn Research Center are developing and testing innovative active blade vibration control concepts. Preliminary results of using an active blade vibration control system, involving a rotor supported by an active magnetic bearing in Glenn's Dynamic Spin Rig, indicate promising results (see the photograph). Active blade vibration control was achieved using feedback of blade strain gauge signals within the magnetic bearing control loop. The vibration amplitude was reduced substantially (see the graphs). Also, vibration amplitude amplification was demonstrated; this could be used to enhance structural mode identification, if desired. These results were for a nonrotating two-bladed disk. Tests for rotating blades are planned. Current and future active blade vibration control research is planned to use a fully magnetically suspended rotor and smart materials. For the fully magnetically suspended rotor work, three magnetic bearings (two radial and one axial) will be used as actuators instead of one magnetic bearing. This will allow additional degrees of freedom to be used for control. For the smart materials work, control effectors located on and off the blade will be considered. Piezoelectric materials will be considered for on-the-blade actuation, and actuator placement on a stator vane, or other nearby structure, will be investigated for off-the-blade actuation. Initial work will focus on determining the feasibility of these methods by performing basic analysis and simple experiments involving feedback control.

Preliminary Aerodynamic Investigation of Fan Rotor Blade Morphing

Science.gov (United States)

Tweedt, Daniel L.

2012-01-01

Various new technologies currently under development may enable controlled blade shape variability, or so-called blade morphing, to be practically employed in aircraft engine fans and compressors in the foreseeable future. The current study is a relatively brief, preliminary computational fluid dynamics investigation aimed at partially demonstrating and quantifying the aerodynamic potential of fan rotor blade morphing. The investigation is intended to provide information useful for near-term planning, as well as aerodynamic solution data sets that can be subsequently analyzed using advanced acoustic diagnostic tools, for the purpose of making fan noise comparisons. Two existing fan system models serve as baselines for the investigation: the Advanced Ducted Propulsor fan with a design tip speed of 806 ft/sec and a pressure ratio of 1.294, and the Source Diagnostic Test fan with a design tip speed of 1215 ft/sec and a pressure ratio of 1.470. Both are 22-in. sub-scale, low-noise research fan/nacelle models that have undergone extensive experimental testing in the 9- by 15-foot Low Speed Wind Tunnel at the NASA Glenn Research Center. The study, restricted to fan rotor blade morphing only, involves a fairly simple blade morphing technique. Specifically, spanwise-linear variations in rotor blade-section setting angle are applied to alter the blade shape; that is, the blade is linearly retwisted from hub to tip. Aerodynamic performance comparisons are made between morphed-blade and corresponding baseline configurations on the basis of equal fan system thrust, where rotor rotational speed for the morphed-blade fan is varied to change the thrust level for that configuration. The results of the investigation confirm that rotor blade morphing could be a useful technology, with the potential to enable significant improvements in fan aerodynamic performance. Even though the study is very limited in scope and confined to simple geometric perturbations of two existing fan

Failure analysis of turbine blades

International Nuclear Information System (INIS)

Iorio, A.F.; Crespi, J.C.

1989-01-01

Two 20 MW gas turbines suffered damage in blades belonging to the 2nd. stage of the turbine after 24,000 hours of duty. From research it arises that the fuel used is not quite adequate to guarantee the blade's operating life due to the excess of SO 3 , C and Na existing in combustion gases which cause pitting to the former. Later, the corrosion phenomenon is presented under tension produced by working stress enhanced by pitting where Pb is its main agent. A change of fuel is recommended thus considering the blades will reach the operational life they were designed for. (Author) [es

Integrity assessment of stationary blade ring for nuclear power plant

International Nuclear Information System (INIS)

Park, Jung Yong; Chung, Yong Keun; Park, Jong Jin; Kang, Yong Ho

2004-01-01

The inner side between HP stationary blades in no.1 turbine of nuclear power plant A is damaged by the FAC(Flow Assisted Corrosion) which is exposed to moisture. For many years the inner side is repaired by welding the damaged part, however, the FAC continues to deteriorate the original material of the welded blade ring. In this study, we have two stages to verify the integrity of stationary blade ring in nuclear power plant A. In the stage I, replication of blade ring is performed to survey the microstructure of blade ring. In the stage II, the stress analysis of blade ring is performed to verify the structural safety of blade ring. Throughout the two stages analysis of blade ring, the stationary blade ring had remained undamaged

Structural Analysis of Basalt Fiber Reinforced Plastic Wind Turbine Blade

Directory of Open Access Journals (Sweden)

Mengal Ali Nawaz

2014-07-01

Full Text Available In this study, Basalt fiber reinforced plastic (BFRP wind turbine blade was analyzed and compared with Glass fiber reinforced plastic blade (GFRP. Finite element analysis (FEA of blade was carried out using ANSYS. Data for FEA was obtained by using rule of mixture. The shell element in ANSYS was used to simulate the wind turbine blade and to conduct its strength analysis. The structural analysis and comparison of blade deformations proved that BFRP wind turbine blade has better strength compared to GFRP wind turbine blade.

Applied modal analysis of wind turbine blades

DEFF Research Database (Denmark)

Pedersen, H.B.; Kristensen, O.J.D.

2003-01-01

In this project modal analysis has been used to determine the natural frequencies, damping and the mode shapes for wind turbine blades. Different methods to measure the position and adjust the direction of the measuring points are discussed. Differentequipment for mounting the accelerometers...... is investigated by repeated measurement on the same wind turbine blade. Furthermore the flexibility of the test set-up is investigated, by use ofaccelerometers mounted on the flexible adapter plate during the measurement campaign. One experimental campaign investigated the results obtained from a loaded...... and unloaded wind turbine blade. During this campaign the modal analysis are performed on ablade mounted in a horizontal and a vertical position respectively. Finally the results obtained from modal analysis carried out on a wind turbine blade are compared with results obtained from the Stig Øyes blade_EV1...

Computational method for the design of wind turbine blades

Energy Technology Data Exchange (ETDEWEB)

Vitale, A.J. [Instituto Argentino de Oceanografia, Camino La Carrindanga Km. 7.5, CC 804, B8000FWB Bahia Blanca (Argentina); Universidad Tecnologica Nacional Facultad Regional Bahia Blanca, GESE, 11 de Abril 461, B8000LMI Bahia Blanca (Argentina); Universidad Nacional del Sur, Dpto. de Ing. Electrica y de Computadoras, Av. Alem 1253, 8000 Bahia Blanca (Argentina); Rossi, A.P. [Universidad Tecnologica Nacional Facultad Regional Bahia Blanca, GESE, 11 de Abril 461, B8000LMI Bahia Blanca (Argentina); Universidad Nacional del Sur, Dpto. de Ing. Electrica y de Computadoras, Av. Alem 1253, 8000 Bahia Blanca (Argentina)

2008-07-15

Zeus Disenador was developed to design low-power, horizontal-axis wind turbine blades, by means of an iterative algorithm. With this software, it is possible to obtain the optimum blade shape for a wind turbine to satisfy energy requirements of an electric system with optimum rotor efficiency. The number of blades, the airfoil curves and the average wind velocity can be specified by the user. The user can also request particular edge conditions for the width of the blades and for the pitch angle. Results are provided in different windows. Two- and three-dimensional graphics show the aspect of the resultant blade. Numerical results are displayed for blade length, blade surface, pitch angle variation along the blade span, rotor angular speed, rotor efficiency and rotor output power. Software verifications were made by comparing rotor power and rotor efficiency for different designs. Results were similar to those provided by commercial wind generator manufacturers. (author)

Repairing methods of steam turbine blades using welding procedures

International Nuclear Information System (INIS)

Mazur, Z.; Cristalinas, V.; Kubiak, J.

1995-01-01

The steam turbine blades are subjected to the natural permanent wear or damage, which may be of mechanical or metallurgical origin. The typical damage occurring during the lifetime of turbine blading may be erosion, corrosion, foreign objects damage, rubbing and cracking caused by high cycle fatigue and creep crack growth. The nozzle and diaphragm vanes (stationary blades) of the steam turbine are elements whose damage is commonly occurring and they require special repair processes. The damage of the blade trailing edge of nozzle and diaphragm vanes, due to the former causes, may be refurbished by welding deposits or stainless steel inserts welded to the blades. Both repair methods of the stationary steam turbine blades are presented. The results of the blades refurbishment are an increase of the turbine availability, reliability and efficiency, and a decrease of the risk that failure will occur. Also, the repair cost versus the spare blades cost represent significant reduction of expenditure. 7 refs

Determination of Turbine Blade Life from Engine Field Data

Science.gov (United States)

Zaretsky, Erwin V.; Litt, Jonathan S.; Hendricks, Robert C.; Soditus, Sherry M.

2013-01-01

It is probable that no two engine companies determine the life of their engines or their components in the same way or apply the same experience and safety factors to their designs. Knowing the failure mode that is most likely to occur minimizes the amount of uncertainty and simplifies failure and life analysis. Available data regarding failure mode for aircraft engine blades, while favoring low-cycle, thermal-mechanical fatigue (TMF) as the controlling mode of failure, are not definitive. Sixteen high-pressure turbine (HPT) T-1 blade sets were removed from commercial aircraft engines that had been commercially flown by a single airline and inspected for damage. Each set contained 82 blades. The damage was cataloged into three categories related to their mode of failure: (1) TMF, (2) Oxidation/erosion (O/E), and (3) Other. From these field data, the turbine blade life was determined as well as the lives related to individual blade failure modes using Johnson-Weibull analysis. A simplified formula for calculating turbine blade life and reliability was formulated. The L10 blade life was calculated to be 2427 cycles (11 077 hr). The resulting blade life attributed to O/E equaled that attributed to TMF. The category that contributed most to blade failure was Other. If there were no blade failures attributed to O/E and TMF, the overall blade L(sub 10) life would increase approximately 11 to 17 percent.

The Dynamic Locking Blade Plate : innovation in the treatment of femoral neck fractures

NARCIS (Netherlands)

Roerdink, W.H.

2011-01-01

The scope of this thesis was to describe the design and development of the Dynamic Locking Blade Plate (DLBP), an improved internal fixation (IF) device for intracapsular hip fractures. This thesis focuses on intracapsular hip fractures since the results of current surgical treatment of this type of

Sweep-twist adaptive rotor blade : final project report.

Energy Technology Data Exchange (ETDEWEB)

Ashwill, Thomas D.

2010-02-01

Knight & Carver was contracted by Sandia National Laboratories to develop a Sweep Twist Adaptive Rotor (STAR) blade that reduced operating loads, thereby allowing a larger, more productive rotor. The blade design used outer blade sweep to create twist coupling without angled fiber. Knight & Carver successfully designed, fabricated, tested and evaluated STAR prototype blades. Through laboratory and field tests, Knight & Carver showed the STAR blade met the engineering design criteria and economic goals for the program. A STAR prototype was successfully tested in Tehachapi during 2008 and a large data set was collected to support engineering and commercial development of the technology. This report documents the methodology used to develop the STAR blade design and reviews the approach used for laboratory and field testing. The effort demonstrated that STAR technology can provide significantly greater energy capture without higher operating loads on the turbine.

Full-Scale Fatigue Testing of a Wind Turbine Blade in Flapwise Direction and Examining the Effect of Crack Propagation on the Blade Performance

Directory of Open Access Journals (Sweden)

Othman Al-Khudairi

2017-10-01

Full Text Available In this paper, the sensitivity of the structural integrity of wind turbine blades to debonding of the shear web from the spar cap was investigated. In this regard, modal analysis, static and fatigue testing were performed on a 45.7 m blade for three states of the blade: (i as received blade (ii when a crack of 200 mm was introduced between the web and the spar cap and (iii when the crack was extended to 1000 mm. Calibration pull-tests for all three states of the blade were performed to obtain the strain-bending moment relationship of the blade according to the estimated target bending moment (BM which the blade is expected to experience in its service life. The resultant data was used to apply appropriate load in the fatigue tests. The blade natural frequencies in flapwise and edgewise directions over a range of frequency domain were found by modal testing for all three states of the blade. The blade first natural frequency for each state was used for the flapwise fatigue tests. These were performed in accordance with technical specification IEC TS 61400-23. The fatigue results showed that, for a 200 mm crack between the web and spar cap at 9 m from the blade root, the crack did not propagate at 50% of the target BM up to 62,110 cycles. However, when the load was increased to 70% of target BM, some damages were detected on the pressure side of the blade. When the 200 mm crack was extended to 1000 mm, the crack began to propagate when the applied load exceeded 100% of target BM and the blade experienced delaminations, adhesive joint failure, compression failure and sandwich core failure.

Full-Scale Fatigue Testing of a Wind Turbine Blade in Flapwise Direction and Examining the Effect of Crack Propagation on the Blade Performance.

Science.gov (United States)

Al-Khudairi, Othman; Hadavinia, Homayoun; Little, Christian; Gillmore, Gavin; Greaves, Peter; Dyer, Kirsten

2017-10-03

In this paper, the sensitivity of the structural integrity of wind turbine blades to debonding of the shear web from the spar cap was investigated. In this regard, modal analysis, static and fatigue testing were performed on a 45.7 m blade for three states of the blade: (i) as received blade (ii) when a crack of 200 mm was introduced between the web and the spar cap and (iii) when the crack was extended to 1000 mm. Calibration pull-tests for all three states of the blade were performed to obtain the strain-bending moment relationship of the blade according to the estimated target bending moment (BM) which the blade is expected to experience in its service life. The resultant data was used to apply appropriate load in the fatigue tests. The blade natural frequencies in flapwise and edgewise directions over a range of frequency domain were found by modal testing for all three states of the blade. The blade first natural frequency for each state was used for the flapwise fatigue tests. These were performed in accordance with technical specification IEC TS 61400-23. The fatigue results showed that, for a 200 mm crack between the web and spar cap at 9 m from the blade root, the crack did not propagate at 50% of the target BM up to 62,110 cycles. However, when the load was increased to 70% of target BM, some damages were detected on the pressure side of the blade. When the 200 mm crack was extended to 1000 mm, the crack began to propagate when the applied load exceeded 100% of target BM and the blade experienced delaminations, adhesive joint failure, compression failure and sandwich core failure.

Cooling Scenario for the HESR Complex

International Nuclear Information System (INIS)

Stockhorst, H.; Prasuhn, D.; Maier, R.; Lorentz, B.

2006-01-01

The High-Energy Storage Ring (HESR) of the future International Facility for Antiproton and Ion Research (FAIR) at GSI in Darmstadt is planned as an anti-proton cooler ring in the momentum range from 1.5 to 15 GeV/c. An important and challenging feature of the new facility is the combination of phase space cooled beams with internal targets. The required beam parameters and intensities are prepared in two operation modes: the high luminosity mode with beam intensities up to 1011 anti-protons, and the high resolution mode with 1010 anti-protons cooled down to a relative momentum spread of only a few 10-5. Consequently, powerful phase space cooling is needed, taking advantage of high-energy electron cooling and high-bandwidth stochastic cooling. Both cooling techniques are envisaged here theoretically, including the effect of beam-target interaction and intra-beam scattering to find especially for stochastic cooling the best system parameters

Spacer grid with mixing blades for nuclear fuel assembly

International Nuclear Information System (INIS)

Noailly, J.

1986-01-01

The spacer grid for nuclear fuel assembly has two sets of intersecting metal plates provided with blades and defining cells. The plates are fitted only with half-blades associated with a single grid opening. The half-blades of adjacent cells are arranged at 90deg C to each other and each plate has at most one half-blade at each corner of a cell. The invention concerns fuel assemblies of pressurized water reactors. The blades arranged on a single side of the plate provide a good hydraulic uniformity. The invention provides a uniform distribution of blades (and thus of absorbing material in each hydraulic cell) [fr

Simple method for thick blade calculation. Part 2. Application to a thin blade; Kanbenna ichiatsuyoku keisanho (zokuho). Usui tsubasa eno tekiyo

Energy Technology Data Exchange (ETDEWEB)

Maita, S; Ando, J; Nakatake, K [Kyushu University, Fukuoka (Japan). Faculty of Engineering

1996-04-10

A source and QCM (SQCM) method has been developed, by which the blade performance can be calculated in a short time with satisfying the Kutta`s condition without repeating calculations even for the three-dimensional blade. Performances were calculated for the two-dimensional and three-dimensional blades. The SQCM has provided appropriate results. However, it was found that there are some problems for thin blades. In this study, the SQCM has been applied to a thin blade. The conventional eddy model equation of SQCM is not a continuous distribution in the strict sense. In this study, this problem has been modified. When point eddies with constant strength are in line continuously within the interval, the induced velocity at an arbitrary position can be expressed by the integral equation using a position of marginal point of the interval. This equation can be analyzed by the integral of influence coefficient. The position of marginal point of the interval is a position of control point determined by the QCM theory. As a result of the modification, it was found that the SQCM in response to a thin blade has provided precise calculation results stably even for an ultra thin blade with the blade thickness ratio of 0.001. 1 ref., 8 figs.

Internal target effects in ion storage rings with beam cooling

International Nuclear Information System (INIS)

Gostishchev, Vitaly

2008-06-01

The accurate description of internal target effects is important for the prediction of operation conditions which are required for experiments in the planned storage rings of the FAIR facility. The BETACOOL code developed by the Dubna group has been used to evaluate beam dynamics in ion storage rings, where electron cooling in combination with an internal target is applied. Systematic benchmarking experiments of this code were carried out at the ESR storage ring at GSI. A mode with vanishing dispersion in the target position was applied to evaluate the influence of the dispersion function on the parameters when the target is heating the beam. The influence of the internal target on the beam parameters is demonstrated in the present work. A comparison of experimental results with simple models describing the energy loss of the beam particles in the target as well as with more sophisticated simulations with the BETACOOL code is given. In order to study the conditions which can be achieved in the proposed experiments the simulation results were quantitatively compared with experimental results and simulations for the ESR. The results of this comparison are discussed in the present thesis. BETACOOL simulations of target effects were performed for the NESR and the HESR of the future FAIR facility in order to predict the beam parameters for the planned experiments. (orig.)

Internal target effects in ion storage rings with beam cooling

Energy Technology Data Exchange (ETDEWEB)

Gostishchev, Vitaly

2008-06-15

The accurate description of internal target effects is important for the prediction of operation conditions which are required for experiments in the planned storage rings of the FAIR facility. The BETACOOL code developed by the Dubna group has been used to evaluate beam dynamics in ion storage rings, where electron cooling in combination with an internal target is applied. Systematic benchmarking experiments of this code were carried out at the ESR storage ring at GSI. A mode with vanishing dispersion in the target position was applied to evaluate the influence of the dispersion function on the parameters when the target is heating the beam. The influence of the internal target on the beam parameters is demonstrated in the present work. A comparison of experimental results with simple models describing the energy loss of the beam particles in the target as well as with more sophisticated simulations with the BETACOOL code is given. In order to study the conditions which can be achieved in the proposed experiments the simulation results were quantitatively compared with experimental results and simulations for the ESR. The results of this comparison are discussed in the present thesis. BETACOOL simulations of target effects were performed for the NESR and the HESR of the future FAIR facility in order to predict the beam parameters for the planned experiments. (orig.)

Eighth meeting of the International Working Group on Gas-Cooled Reactors Vienna, 30 January - 1 February 1989. Summary report. Part 2

International Nuclear Information System (INIS)

1989-12-01

The Eighth Meeting of the IAEA International Working Group on Gas-Cooled Reactors was held in Vienna, Austria, from 30 January - 1 February, 1989. The Summary Report (Part II) contains the papers which review the national programmes in the field of Gas-Cooled Reactors and other presentations at the Meeting. Refs, figs and tabs

Applied modal analysis of wind turbine blades

Energy Technology Data Exchange (ETDEWEB)

Broen Pedersen, H.; Dahl Kristensen, O.J.

2003-02-01

In this project modal analysis has been used to determine the natural frequencies, damping and the mode shapes for wind turbine blades. Different methods to measure the position and adjust the direction of the measuring points are discussed. Different equipment for mounting the accelerometers are investigated and the most suitable are chosen. Different excitation techniques are tried during experimental campaigns. After a discussion the pendulum hammer were chosen, and a new improved hammer was manufactured. Some measurement errors are investigated. The ability to repeat the measured results is investigated by repeated measurement on the same wind turbine blade. Furthermore the flexibility of the test set-up is investigated, by use of accelerometers mounted on the flexible adapter plate during the measurement campaign. One experimental campaign investigated the results obtained from a loaded and unloaded wind turbine blade. During this campaign the modal analysis are performed on a blade mounted in a horizontal and a vertical position respectively. Finally the results obtained from modal analysis carried out on a wind turbine blade are compared with results obtained from the Stig Oeyes blade{sub E}V1 program. (au)

Blade profile optimization of kaplan turbine using cfd analysis

International Nuclear Information System (INIS)

Janjua, A.B.; Khalil, M.S.

2013-01-01

Utilization of hydro-power as renewable energy source is of prime importance in the world now. Hydropower energy is available in abundant in form of falls, canals rivers, dams etc. It means, there are various types of sites with different parameters like flow rate, heads, etc. Depending upon the sites, water turbines are designed and manufactured to avail hydro-power energy. Low head turbines on runof-river are widely used for the purpose. Low head turbines are classified as reaction turbines. For runof-river, depending upon the variety of site data, low head Kaplan turbines are selected, designed and manufactured. For any given site requirement, it becomes very essential to design the turbine runner blades through optimization of the CAD model of blades profile. This paper presents the optimization technique carried out on a complex geometry of blade profile through static and dynamic computational analysis. It is used through change of the blade profile geometry at five different angles in the 3D (Three Dimensional) CAD model. Blade complex geometry and design have been developed by using the coordinates point system on the blade in PRO-E /CREO software. Five different blade models are developed for analysis purpose. Based on the flow rate and heads, blade profiles are analyzed using ANSYS software to check and compare the output results for optimization of the blades for improved results which show that by changing blade profile angle and its geometry, different blade sizes and geometry can be optimized using the computational techniques with changes in CAD models. (author)

Blade Profile Optimization of Kaplan Turbine Using CFD Analysis

Directory of Open Access Journals (Sweden)

Aijaz Bashir Janjua

2013-10-01

Full Text Available Utilization of hydro-power as renewable energy source is of prime importance in the world now. Hydropower energy is available in abundant in form of falls, canals rivers, dams etc. It means, there are various types of sites with different parameters like flow rate, heads, etc. Depending upon the sites, water turbines are designed and manufactured to avail hydro-power energy. Low head turbines on runof-river are widely used for the purpose. Low head turbines are classified as reaction turbines. For runof river, depending upon the variety of site data, low head Kaplan turbines are selected, designed and manufactured. For any given site requirement, it becomes very essential to design the turbine runner blades through optimization of the CAD model of blades profile. This paper presents the optimization technique carried out on a complex geometry of blade profile through static and dynamic computational analysis. It is used through change of the blade profile geometry at five different angles in the 3D (Three Dimensional CAD model. Blade complex geometry and design have been developed by using the coordinates point system on the blade in PRO-E /CREO software. Five different blade models are developed for analysis purpose. Based on the flow rate and heads, blade profiles are analyzed using ANSYS software to check and compare the output results for optimization of the blades for improved results which show that by changing blade profile angle and its geometry, different blade sizes and geometry can be optimized using the computational techniques with changes in CAD models.

Piezoelectric actuation of helicopter rotor blades

Science.gov (United States)

Lieven, Nicholas A. J.

2001-07-01

The work presented in this paper is concerned with the application of embedded piezo-electric actuators in model helicopter rotor blades. The paper outlines techniques to define the optimal location of actuators to excite particular modes of vibration whilst the blade is rotating. Using composite blades the distribution of strain energy is defined using a Finite Element model with imposed rotor-dynamic and aerodynamics loads. The loads are specified through strip theory to determine the position of maximum bending moment and thus the optimal location of the embedded actuators. The effectiveness of the technique is demonstrated on a 1/4 scale fixed cyclic pitch rotor head. Measurement of the blade displacement is achieved by using strain gauges. In addition a redundant piezo-electric actuator is used to measure the blades' response characteristics. The addition of piezo-electric devices in this application has been shown to exhibit adverse aeroelastic effects, such as counter mass balancing and increased drag. Methods to minimise these effects are suggested. The outcome of the paper is a method for defining the location and orientation of piezo-electric devices in rotor-dynamic applications.

Individual blade pitch for yaw control

International Nuclear Information System (INIS)

Navalkar, S T; Van Wingerden, J W; Van Kuik, G A M

2014-01-01

Individual pitch control (IPC) for reducing blade loads has been investigated and proven successful in recent literature. For IPC, the multi-blade co-ordinate (MBC) transformation is used to process the blade load signals from the rotating to a stationary frame of reference. In the stationary frame of reference, the yaw error of a turbine can be appended to generate IPC actions that are able to achieve turbine yaw control for a turbine in free yaw. In this paper, IPC for yaw control is tested on a high-fidelity numerical model of a commercially produced wind turbine in free yaw. The tests show that yaw control using IPC has the distinct advantage that the yaw system loads and support structure loading are substantially reduced. However, IPC for yaw control also shows a reduction in IPC blade load reduction potential and causes a slight increase in pitch activity. Thus, the key contribution of this paper is the concept demonstration of IPC for yaw control. Further, using IPC for yaw as a tuning parameter, it is shown how the best trade-off between blade loading, pitch activity and support structure loading can be achieved for wind turbine design

Active Piezoelectric Vibration Control of Subscale Composite Fan Blades

Science.gov (United States)

Duffy, Kirsten P.; Choi, Benjamin B.; Provenza, Andrew J.; Min, James B.; Kray, Nicholas

2012-01-01

As part of the Fundamental Aeronautics program, researchers at NASA Glenn Research Center (GRC) are investigating new technologies supporting the development of lighter, quieter, and more efficient fans for turbomachinery applications. High performance fan blades designed to achieve such goals will be subjected to higher levels of aerodynamic excitations which could lead to more serious and complex vibration problems. Piezoelectric materials have been proposed as a means of decreasing engine blade vibration either through a passive damping scheme, or as part of an active vibration control system. For polymer matrix fiber composite blades, the piezoelectric elements could be embedded within the blade material, protecting the brittle piezoceramic material from the airflow and from debris. To investigate this idea, spin testing was performed on two General Electric Aviation (GE) subscale composite fan blades in the NASA GRC Dynamic Spin Rig Facility. The first bending mode (1B) was targeted for vibration control. Because these subscale blades are very thin, the piezoelectric material was surface-mounted on the blades. Three thin piezoelectric patches were applied to each blade two actuator patches and one small sensor patch. These flexible macro-fiber-composite patches were placed in a location of high resonant strain for the 1B mode. The blades were tested up to 5000 rpm, with patches used as sensors, as excitation for the blade, and as part of open- and closed-loop vibration control. Results show that with a single actuator patch, active vibration control causes the damping ratio to increase from a baseline of 0.3% critical damping to about 1.0% damping at 0 RPM. As the rotor speed approaches 5000 RPM, the actively controlled blade damping ratio decreases to about 0.5% damping. This occurs primarily because of centrifugal blade stiffening, and can be observed by the decrease in the generalized electromechanical coupling with rotor speed.

Effect of Blade Pitch Angle on the Aerodynamic Characteristics of a Straight-bladed Vertical Axis Wind Turbine Based on Experiments and Simulations

Directory of Open Access Journals (Sweden)

Yanzhao Yang

2018-06-01

Full Text Available The blade pitch angle has a significant influence on the aerodynamic characteristics of horizontal axis wind turbines. However, few research results have revealed its impact on the straight-bladed vertical axis wind turbine (Sb-VAWT. In this paper, wind tunnel experiments and CFD simulations were performed at the Sb-VAWT to investigate the effect of different blade pitch angles on the pressure distribution on the blade surface, the torque coefficient, and the power coefficient. In this study, the airfoil type was NACA0021 with two blades. The Sb-VAWT had a rotor radius of 1.0 m with a spanwise length of 1.2 m. The simulations were based on the k-ω Shear Stress Transport (SST turbulence model and the wind tunnel experiments were carried out using a high-speed multiport pressure device. As a result, it was found that the maximum pressure difference on the blade surface was obtained at the blade pitch angle of β = 6° in the upstream region. However, the maximum pressure coefficient was shown at the blade pitch angle of β = 8° in the downstream region. The torque coefficient acting on a single blade reached its maximum value at the blade pitch angle of β = 6°. As the tip speed ratio increased, the power coefficient became higher and reached the optimum level. Subsequently, further increase of the tip speed ratio only led to a quick reversion of the power coefficient. In addition, the results from CFD simulations had also a good agreement with the results from the wind tunnel experiments. As a result, the blade pitch angle did not have a significant influence on the aerodynamic characteristics of the Sb-VAWT.

Research overview on vibration damping of mistuned bladed disk assemblies

Directory of Open Access Journals (Sweden)

Liang ZHANG

2016-04-01

Full Text Available Bladed disk assemblies are very important parts in auto engine and gas turbine, and is widely used in practical engineering. The mistuning existing commonly in the bladed disk assemblies can destroy the vibration characteristics of the bladed disk assemblies, which is one of the reasons for the high cycle fatigue failure of bladed disk assemblies, so it is necessary to research how to reduce the vibration of the bladed disk assemblies. On the basis of the review of relevant research at home and abroad, the mistuning vibration mechanism of the bladed disk assemblies is introduced, and the main technical methods of the vibration damping of bladed disk assemblies are reviewed, such as artificially active mistuning, collision damping, friction damping and optimization of the blade position. Some future research directions are presented.

Methodology for Structural Integrity Analysis of Gas Turbine Blades

Directory of Open Access Journals (Sweden)

Tiago de Oliveira Vale

2012-03-01

Full Text Available One of the major sources of stress arising in turbomachinery blades are the centrifugal loads acting at any section of the airfoil. Accounting for this phenomenon stress evaluation of the blade attachment region in the disc has to be performed in order to avoid blade failure. Turbomachinery blades are generally twisted, and the cross section area varies from the root of the blade to the tip. The blade root shape at the attachment region is of great concern. Stress concentrations are predictable at this contact region. In this paper, a finite element model has been created for the purpose of assessing stress at the joint region connecting the blade to the disc slot. Particular attention was paid to the geometric modeling of the "fir-tree" fixing, which is now used in the majority of gas turbine engines. This study has been performed using the commercial software ANSYS 13.0. The disc and blade assembly are forced to move with a certain rotational velocity. Contact connections are predicted on the common faces of the blade and on the disc at the root. Solutions can be obtained to allow the evaluation of stresses. Results can be compared with the mechanical properties of the adopted material.

Numerical Simulation of Non-Rotating and Rotating Coolant Channel Flow Fields. Part 1

Science.gov (United States)

Rigby, David L.

2000-01-01

Future generations of ultra high bypass-ratio jet engines will require far higher pressure ratios and operating temperatures than those of current engines. For the foreseeable future, engine materials will not be able to withstand the high temperatures without some form of cooling. In particular the turbine blades, which are under high thermal as well as mechanical loads, must be cooled. Cooling of turbine blades is achieved by bleeding air from the compressor stage of the engine through complicated internal passages in the turbine blades (internal cooling, including jet-impingement cooling) and by bleeding small amounts of air into the boundary layer of the external flow through small discrete holes on the surface of the blade (film cooling and transpiration cooling). The cooling must be done using a minimum amount of air or any increases in efficiency gained through higher operating temperature will be lost due to added load on the compressor stage. Turbine cooling schemes have traditionally been based on extensive empirical data bases, quasi-one-dimensional computational fluid dynamics (CFD) analysis, and trial and error. With improved capabilities of CFD, these traditional methods can be augmented by full three-dimensional simulations of the coolant flow to predict in detail the heat transfer and metal temperatures. Several aspects of turbine coolant flows make such application of CFD difficult, thus a highly effective CFD methodology must be used. First, high resolution of the flow field is required to attain the needed accuracy for heat transfer predictions, making highly efficient flow solvers essential for such computations. Second, the geometries of the flow passages are complicated but must be modeled accurately in order to capture all important details of the flow. This makes grid generation and grid quality important issues. Finally, since coolant flows are turbulent and separated the effects of turbulence must be modeled with a low Reynolds number

Modeling of uncertainties for wind turbine blade design

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard; Toft, Henrik Stensgaard

2014-01-01

Wind turbine blades are designed by a combination of tests and numerical calculations using finite element models of the blade. The blades are typically composite structures with laminates of glass-fiber and/or carbon-fibers glued together by a matrix material. This paper presents a framework...

Blade size and weight effects in shovel design.

Science.gov (United States)

Freivalds, A; Kim, Y J

1990-03-01

The shovel is a basic tool that has undergone only nominal systematic design changes. Although previous studies found shovel-weight and blade-size effects of shovelling, the exact trade-off between the two has not been quantified. Energy expenditure, heart rate, ratings of perceived exertion and shovelling performance were measured on five subjects using five shovels with varying blade sizes and weights to move sand. Energy expenditure, normalised to subject weight and load handled, varied quadratically with the blade-size/shovel-weight (B/W) ratio. Minimum energy cost was at B/W = 0.0676 m2/kg, which for an average subject and average load would require an acceptable 5.16 kcal/min of energy expenditure. Subjects, through the ratings of perceived exertion, also strongly preferred the lighter shovels without regard to blade size. Too large a blade or too heavy a shovel increased energy expenditure beyond acceptable levels, while too small a blade reduced efficiency of the shovelling.

Flow characteristics in nuclear steam turbine blade passage

International Nuclear Information System (INIS)

Ahn, H.J.; Yoon, W.H.; Kwon, S.B.

1995-01-01

The rapid expansion of condensable gas such as moist air or steam gives rise to nonequilibrium condensation. As a result of irreversibility of condensation process in the nuclear steam turbine blade passage, the entropy of the flow increases, and the efficiency of the turbine decreases. In the present study, in order to investigate the flow characteristics of moist air in two-dimensional turbine blade passage which is made from the configuration of the last stage tip section of the actual nuclear steam turbine moving blade, the static pressures along both pressure and suction sides of blade are measured by static pressure taps and the distribution of Mach number on both sides of the blade are obtained by using the measured static pressure. Also, the flow field is visualized by a Schlieren system. From the experimental results, the effects of the stagnation temperature and specific humidity on the flow properties in the two dimensional steam turbine blade passage are clearly identified

49 CFR 236.707 - Blade, semaphore.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Blade, semaphore. 236.707 Section 236.707 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Blade, semaphore. The extended part of a semaphore arm which shows the position of the arm. ...

A New Hoe Blade for Inter-Row Weeding

DEFF Research Database (Denmark)

Green, O.; Znova, L.; Melander, Bo

2016-01-01

and weeds are relatively small. The term ‘Ducksfoot’ covers a range of hoe blade configurations where all have some resemblance with the shape of a ducks foot. However, the ‘Ducksfoot’ blade is not an optimal solution for weed control in narrow inter-row spaces. Several disadvantages have been encountered...... and the draft forces needed to pull it were approx. half those measured for a ‘Ducksfoot’ blade. The weeding features of the new L-blade will be further studied under field conditions....

Investigation of the effect of bending twisting coupling on the loads in wind turbines with superelement blade definition

International Nuclear Information System (INIS)

Gözcü, M O; Kayran, A

2014-01-01

Bending-twisting coupling in the composite blades is exploited for load alleviation in the whole turbine system. For the purpose of the study, inverse design of a reference blade is performed such that sectional beam properties of the 3D blade design approximately match the sectional beam properties of NREL's 5MW turbine blade. In order to appropriately account for the bending-twisting coupling effect, dynamic superelement of the blade is created and introduced into the multi-body dynamic model of the wind turbine system. Initially, a comparative study is conducted on the performance of wind turbines which have blades defined as superelements and geometrically nonlinear beams, and conclusions are inferred with regard to the appropriateness of the use of superelement blade definition in the transient analysis of the 5MW wind turbine system that is set up in the present study. Multi-body dynamic simulations of the wind turbine system are performed for the power production load case with the constant wind and the normal turbulence model as external wind loadings. For the internal loads, fatigue damage equivalent load is used as the metric to assess the effect of bending-twisting coupling on the load alleviation in the whole wind turbine system. Results show that in the overall, through the bending-twisting coupling induced with the use of off-axis plies in the main spar caps of the blade, damage equivalent loads associated with the critical load components can be reduced in the wind turbine system

Non-invasive dynamic measurement of helicopter blades

Science.gov (United States)

Serafini, J.; Bernardini, G.; Mattioni, L.; Vezzari, V.; Ficuciello, C.

2017-08-01

This paper presents the development and the application on helicopter blades of a measurement system based on FBG strain gauges. Here, the main goal is the structural characterization of the main rotor blades, with the aim of showing the potentialities of such a system in blades quality check applications, as well as in the development of structural health monitoring and rotor state feedback devices. The device has been used in both non-rotating and rotating tests, and does not require the presence of slip rings or optical joint since it is completely allocated in the rotating system. It has been successfully applied to characterize the frequency response of blades lead-lag, flap and torsion deformations, up to 250 Hz.

Laser-based gluing of diamond-tipped saw blades

Science.gov (United States)

Hennigs, Christian; Lahdo, Rabi; Springer, André; Kaierle, Stefan; Hustedt, Michael; Brand, Helmut; Wloka, Richard; Zobel, Frank; Dültgen, Peter

2016-03-01

To process natural stone such as marble or granite, saw blades equipped with wear-resistant diamond grinding segments are used, typically joined to the blade by brazing. In case of damage or wear, they must be exchanged. Due to the large energy input during thermal loosening and subsequent brazing, the repair causes extended heat-affected zones with serious microstructure changes, resulting in shape distortions and disadvantageous stress distributions. Consequently, axial run-out deviations and cutting losses increase. In this work, a new near-infrared laser-based process chain is presented to overcome the deficits of conventional brazing-based repair of diamond-tipped steel saw blades. Thus, additional tensioning and straightening steps can be avoided. The process chain starts with thermal debonding of the worn grinding segments, using a continuous-wave laser to heat the segments gently and to exceed the adhesive's decomposition temperature. Afterwards, short-pulsed laser radiation removes remaining adhesive from the blade in order to achieve clean joining surfaces. The third step is roughening and activation of the joining surfaces, again using short-pulsed laser radiation. Finally, the grinding segments are glued onto the blade with a defined adhesive layer, using continuous-wave laser radiation. Here, the adhesive is heated to its curing temperature by irradiating the respective grinding segment, ensuring minimal thermal influence on the blade. For demonstration, a prototype unit was constructed to perform the different steps of the process chain on-site at the saw-blade user's facilities. This unit was used to re-equip a saw blade with a complete set of grinding segments. This saw blade was used successfully to cut different materials, amongst others granite.

Status of international HTGR [high-temperature gas-cooled reactor] development

International Nuclear Information System (INIS)

Homan, F.J.; Simon, W.A.

1988-01-01

Programs for the development of high-temperature gas-cooled reactor (HTGR) technology over the past 30 years in eight countries are briefly described. These programs have included both government sector and industrial participation. The programs have produced four electricity-producing prototype/demonstration reaactors, two in the United States, and two in the Federal Republic of Germany. Key design parameters for these reactors are compared with the design parameters planned for follow-on commercial-scale HTGRs. The development of HTGR technology has been enhanced by numerous cooperative agreements over the years, involving both government-sponsored national laboratories and industrial participants. Current bilateral cooperative agreements are described. A relatively new component in the HTGR international cooperation is that of multinational industrial alliances focused on supplying commercial-scale HTGR power plants. Current industrial cooperative agreements are briefly discussed

Super titanium blades for advanced steam turbines

International Nuclear Information System (INIS)

Coulon, P.A.

1990-01-01

In 1986, the Alsthom Steam Turbines Department launched the manufacture of large titanium alloy blades: airfoil length of 1360 mm and overall length of 1520 mm. These blades are designed for the last-stage low pressure blading of advanced steam turbines operating at full speed (3000 rpm) and rating between 300 and 800 MW. Using titanium alloys for steam turbine exhaust stages as substitutes for chrome steels, due to their high strength/density ratio and their almost complete resistance to corrosion, makes it possible to increase the length of blades significantly and correspondingly that steam passage section (by up to 50%) with a still conservative stresses level in the rotor. Alsthom relies on 8 years of experience in the field of titanium, since as early as 1979 large titanium blades (airfoil length of 1240 mm, overall length of 1430 mm) were erected for experimental purposes on the last stage of a 900 MW unit of the Dampierre-sur-Loire power plant and now totals 45,000 operating hours without problems. The paper summarizes the main properties (chemical, mechanical and structural) recorded on very large blades and is based in particular on numerous fatigue corrosion test results to justify the use of the Ti 6 Al 4 V alloy in a specific context of micrographic structure

Effects of large bending deflections on blade flutter limits

Energy Technology Data Exchange (ETDEWEB)

Kallesoee, Bjarne Skovmose; Hartvig Hansen, Morten

2008-04-15

The coupling of bending and torsion due to large blade bending are assumed to have some effects of the flutter limits of wind turbines. In the present report, the aeroelastic blade model suggested by Kallesoee, which is similar to a second order model, is used to investigate the aeroelastic stability limits of the RWT blade with and without the effects of the large blade deflection. The investigation shows no significant change of the flutter limit on the rotor speed due to the blade deflection,whereas the first edgewise bending mode becomes negatively damped due to the coupling with blade torsion which causes a change of the effective direction of blade vibration. These observations are confirmed by nonlinear aeroelastic simulations using HAWC2. This work is part of the UpWind project funded by the European Commission under the contract number SES6-CT-2005-019945 which is gratefully acknowledged. This report is the deliverable D2.3 of the UpWind project. (au)

Experimental Investigation of Inter-Blade Vortices in a Model Francis Turbine

Science.gov (United States)

LIU, Demin; LIU, Xiaobing; ZHAO, Yongzhi

2017-07-01

The inter-blade vortex in a Francis turbine becomes one of the main hydraulic factors that are likely to cause blade erosion at deep part load operating conditions. However, the causes and the mechanism of inter-blade vortex are still under investigation according to present researches. Thus the causes of inter-blade vortex and the effect of different hydraulic parameters on the inter-blade vortex are investigated experimentally. The whole life cycle of the inter-blade vortex is observed by a high speed camera. The test results illustrate the whole life cycle of the inter-blade vortex from generation to separation and even to fading. It is observed that the inter-blade vortex becomes stronger with the decreasing of flow and head, which leads to pressure fluctuation. Meanwhile, the pressure fluctuations in the vane-less area and the draft tube section become stronger when inter-blade vortices exist in the blade channel. The turbine will be damaged if operating in the inter-blade vortex zone, so its operating range must be far away from that zone. This paper reveals the main cause of the inter-blade vortex which is the larger incidence angle between the inflow angle and the blade angle on the leading edge of the runner at deep part load operating conditions.

Non-equilibrium effects of core-cooling and time-dependent internal heating on mantle flush events

Directory of Open Access Journals (Sweden)

D. A. Yuen

1995-01-01

Full Text Available We have examined the non-equilibrium effects of core-cooling and time-dependent internal-heating on the thermal evolution of the Earth's mantle and on mantle flush events caused by the two major phase transitions. Both two- and three-dimensional models have been employed. The mantle viscosity responds to the secular cooling through changes in the averaged temperature field. A viscosity which decreases algebraically with the average temperature has been considered. The time-dependent internal-heating is prescribed to decrease exponentially with a single decay time. We have studied the thermal histories with initial Rayleigh numbers between 2 x 107 and 108 . Flush events, driven by the non-equilibrium forcings, are much more dramatic than those produced by the equilibrium boundary conditions and constant internal heating. Multiple flush events are found under non-equilibrium conditions in which there is very little internal heating or very fast decay rates of internal-heating. Otherwise, the flush events take place in a relatively continuous fashion. Prior to massive flush events small-scale percolative structures appear in the 3D temperature fields. Time-dependent signatures, such as the surface heat flux, also exhibits high frequency oscillatory patterns prior to massive flush events. These two observations suggest that the flush event may be a self-organized critical phenomenon. The Nusselt number as a function of the time-varying Ra does not follow the Nusselt vs. Rayleigh number power-law relationship based on equilibrium (constant temperature boundary conditions. Instead Nu(t may vary non-monotonically with time because of the mantle flush events. Convective processes in the mantle operate quite differently under non-equilibrium conditions from its behaviour under the usual equilibrium situations.

Development of 52 inches last stage blade for steam turbines

International Nuclear Information System (INIS)

Suzuki, Atsuhide; Hisa, Shoichi; Nagao, Shinichiro; Ogata, Hisao

1986-01-01

The last stage blades of steam turbines are the important component controlling the power output and performance of plants. In order to realize a unit of large capacity and high efficiency, the proper exhaust area and the last stage blades having good performance are indispensable. Toshiba Corp. has completed the development of the 52 inch last stage blades for 1500 and 1800 rpm steam turbines. The 52 inch last stage blades are the longest in the world, which have the annular exhaust area nearly 1.5 times as much as that of 41 inch blades used for 1100 MW, 1500 rpm turbines in nuclear power stations. By adopting these 52 inch blades, the large capacity nuclear power plants up to 1800 MW can be economically constructed, the rate of heat consumption of 1350 MW plants is improved by 3 ∼ 4 % as compared with 41 inch blades, and in the plants up to 1100 MW, LP turbines can be reduced from three sets to two. The features of 52 inch blades, the flow pattern and blade form design, the structural strength analysis and the erosion withstanding property, and the verification by the rotation test of the actual blades, the performance test using a test turbine, the vibration analysis of the actually loaded blades and the analysis of wet steam behavior are reported. (Kako, I.)

Development of 52 inch last stage blade for steam turbine

International Nuclear Information System (INIS)

Kadoya, Yoshiki; Harada, Masakatsu; Watanabe, Eiichiro

1985-01-01

Mitsubishi Heavy Industries, Ltd. has developed the last stage blades with 1320 mm length for a 1800 rpm LP turbine, and the verification by rotating vibration test using actual blades was finished, thus the blades were completed. In a nuclear power plant with an A-PWR of 3800 MW thermal output, the 1350 MW steam turbine has one HP turbine and three LP turbines coupled in tandem, and the optimum last stage blades for the LP turbines became the 1320 mm blades. The completion of these blades largely contributes to the improvement of thermal efficiency and the increase of generator output in large nuclear power plants, and has the possibility to decrease three LP turbines to two in 900 MW plants, which reduces the construction cost. The velocity energy of steam coming out of last stage blades is abandoned as exhaust loss in a condenser, which is the largest loss in a turbine. The increase of exhaust area using long blades reduces this loss. The economy of the 1320 mm blades, the features of the 1320 mm blades, the aerodynamic design and its verification, the prevention of the erosion of the 1320 mm blades due to wet steam, the strength design, the anti-vibration design and its verification, and the CAD/CAM system are reported. (Kako, I.)

Accelerated rain erosion of wind turbine blade coatings

DEFF Research Database (Denmark)

Zhang, Shizhong

. There are four chapters in the thesis. In chapter 1, a literature survey provides background information to the field. Topics discussed are the global wind energy development, possible wind turbine constructions, blade structures and materials, blade coatings, and liquid erosion mechanisms. In chapter 2......During operation, the fast-moving blades of wind turbines are exposed to continuous impacts with rain droplets, hail, insects, or solid particles. This can lead to erosion of the blades, whereby the electrical efficiency is compromised and expensive repairs may be required. One possible solution...

3X-100 blade field test.

Energy Technology Data Exchange (ETDEWEB)

Zayas, Jose R.; Johnson, Wesley D.

2008-03-01

In support of a Work-For-Other (WFO) agreement between the Wind Energy Technology Department at Sandia National Laboratories and 3TEX, one of the three Micon 65/13M wind turbines at the USDA Agriculture Research Service (ARS) center in Bushland, Texas, has been used to test a set of 9 meter wind turbine blades, manufactured by TPI composites using the 3TEX carbon material for the spar cap. Data collected from the test has been analyzed to evaluate both the aerodynamic performance and the structural response from the blades. The blades aerodynamic and structural performance, the meteorological inflow and the wind turbine structural response has been monitored with an array of 57 instruments: 15 to characterize the blades, 13 to characterize inflow, and 15 to characterize the time-varying state of the turbine. For the test, data was sampled at a rate of 40 Hz using the ATLAS II (Accurate GPS Time-Linked Data Acquisition System) data acquisition system. The system features a time-synchronized continuous data stream and telemetered data from the turbine rotor. This paper documents the instruments and infrastructure that have been developed to monitor these blades, turbines and inflow, as well as both modeling and field testing results.

Global Cooling: Policies to Cool the World and Offset Global Warming from CO2 Using Reflective Roofs and Pavements

Energy Technology Data Exchange (ETDEWEB)

Akbari, Hashem; Levinson, Ronnen; Rosenfeld, Arthur; Elliot, Matthew

2009-08-28

Increasing the solar reflectance of the urban surface reduce its solar heat gain, lowers its temperatures, and decreases its outflow of thermal infrared radiation into the atmosphere. This process of 'negative radiative forcing' can help counter the effects of global warming. In addition, cool roofs reduce cooling-energy use in air conditioned buildings and increase comfort in unconditioned buildings; and cool roofs and cool pavements mitigate summer urban heat islands, improving outdoor air quality and comfort. Installing cool roofs and cool pavements in cities worldwide is a compelling win-win-win activity that can be undertaken immediately, outside of international negotiations to cap CO{sub 2} emissions. We propose an international campaign to use solar reflective materials when roofs and pavements are built or resurfaced in temperate and tropical regions.

An aerodynamic study on flexed blades for VAWT applications

Science.gov (United States)

Micallef, Daniel; Farrugia, Russell; Sant, Tonio; Mollicone, Pierluigi

2014-12-01

There is renewed interest in aerodynamics research of VAWT rotors. Lift type, Darrieus designs sometimes use flexed blades to have an 'egg-beater shape' with an optimum Troposkien geometry to minimize the structural stress on the blades. While straight bladed VAWTs have been investigated in depth through both measurements and numerical modelling, the aerodynamics of flexed blades has not been researched with the same level of detail. Two major effects may have a substantial impact on blade performance. First, flexing at the equator causes relatively strong trailing vorticity to be released. Secondly, the blade performance at each station along the blade is influenced by self-induced velocities due to bound vorticity. The latter is not present in a straight bladed configuration. The aim of this research is to investigate these effects in relation to an innovative 4kW wind turbine concept being developed in collaboration with industry known as a self-adjusting VAWT (or SATVAWT). The approach used in this study is based on experimental and numerical work. A lifting line free-wake vortex model was developed. Wind tunnel power and hot-wire velocity measurements were performed on a scaled down, 60cm high, three bladed model in a closed wind tunnel. Results show a substantial axial wake induction at the equator resulting in a lower power generation at this position. This induction increases with increasing degree of flexure. The self-induced velocities caused by blade bound vorticity at a particular station was found to be relatively small.

An aerodynamic study on flexed blades for VAWT applications

International Nuclear Information System (INIS)

Micallef, Daniel; Farrugia, Russell; Sant, Tonio; Mollicone, Pierluigi

2014-01-01

There is renewed interest in aerodynamics research of VAWT rotors. Lift type, Darrieus designs sometimes use flexed blades to have an 'egg-beater shape' with an optimum Troposkien geometry to minimize the structural stress on the blades. While straight bladed VAWTs have been investigated in depth through both measurements and numerical modelling, the aerodynamics of flexed blades has not been researched with the same level of detail. Two major effects may have a substantial impact on blade performance. First, flexing at the equator causes relatively strong trailing vorticity to be released. Secondly, the blade performance at each station along the blade is influenced by self-induced velocities due to bound vorticity. The latter is not present in a straight bladed configuration. The aim of this research is to investigate these effects in relation to an innovative 4kW wind turbine concept being developed in collaboration with industry known as a self-adjusting VAWT (or SATVAWT). The approach used in this study is based on experimental and numerical work. A lifting line free-wake vortex model was developed. Wind tunnel power and hot-wire velocity measurements were performed on a scaled down, 60cm high, three bladed model in a closed wind tunnel. Results show a substantial axial wake induction at the equator resulting in a lower power generation at this position. This induction increases with increasing degree of flexure. The self-induced velocities caused by blade bound vorticity at a particular station was found to be relatively small

Structural optimization procedure of a composite wind turbine blade for reducing both material cost and blade weight

Science.gov (United States)

Hu, Weifei; Park, Dohyun; Choi, DongHoon

2013-12-01

A composite blade structure for a 2 MW horizontal axis wind turbine is optimally designed. Design requirements are simultaneously minimizing material cost and blade weight while satisfying the constraints on stress ratio, tip deflection, fatigue life and laminate layup requirements. The stress ratio and tip deflection under extreme gust loads and the fatigue life under a stochastic normal wind load are evaluated. A blade element wind load model is proposed to explain the wind pressure difference due to blade height change during rotor rotation. For fatigue life evaluation, the stress result of an implicit nonlinear dynamic analysis under a time-varying fluctuating wind is converted to the histograms of mean and amplitude of maximum stress ratio using the rainflow counting algorithm Miner's rule is employed to predict the fatigue life. After integrating and automating the whole analysis procedure an evolutionary algorithm is used to solve the discrete optimization problem.

Helicopter blades running elevation measurement using omnidirectional vision

Directory of Open Access Journals (Sweden)

Chengtao CAI

2017-12-01

Full Text Available Omnidirectional dynamic space parameters of high-speed rotating helicopter blades are precise 3D vector description of the blades. In particular, the elevation difference is directly related to the aerodynamic performance and maneuverability of the helicopter. The state of the art detection techniques based on optics and common vision have several drawbacks, such as high demands on devices but poor extensibility, limited measurement range and fixed measurement position. In this paper, a novel approach of helicopter blades running elevation measurement is proposed based on omnidirectional vision. With the advantages of panoramic visual imaging integration, 360° field of view and rotation in-variance, high-resolution images of all rotating blades positions are obtained at one time. By studying the non-linear calibration and calculation model of omnidirectional vision system, aiming at solving the problem of inaccurate visual space mapping model, the omnidirectional and full-scale measurement of the elevation difference are finalized. Experiments are carried out on our multifunctional simulation blades test system and the practical blades test tower, respectively. The experimental results demonstrate the effectiveness of the proposed method and show that the proposed method can considerably reduce the complexity of measurement. Keywords: Full-scale measurement, Helicopter blades elevation, Non-linear calibration, Omnidirectional vision, Unified sphere model

KNOW-BLADE task-3.2 report: Tip shape study

DEFF Research Database (Denmark)

Sørensen, Niels N.; Johansen, Jeppe; Conway, S.

2005-01-01

For modern rotor blades with their very large aspect ratio, the blade tip is a very limited part of the overall rotor, and as such of limited importance for the overall aerodynamics of the rotor. Even though they may not be very important for the overallpower production, the tip noise can be very...... important for the acoustics of the rotor [15], and the blade tips can as well be important for the aerodynamic damping properties of the rotor blades [13]. Unfortunately, not many options exists for predictingthe aerodynamic behavior of blade tips using computational methods. Experimentally it is di...

New Design of Blade Untwisting Device of Cyclone Unit

Directory of Open Access Journals (Sweden)

D. I. Misiulia

2010-01-01

Full Text Available The paper presents a new design of a blade untwisting device where blades are considered as a main element of the device. A profile of the blades corresponds to a circular arch. An inlet angle of  the blades is determined by stream aerodynamics in an exhaust pipe, and an exit angle is determined by rectilinear gas motion. Optimum geometrical parameters of the untwisting device have been determined and its application allows to reduce a pressure drop in the ЦН-15 cyclones by 28–30 % while screw-blade untwisting device recovers only 19–20 % of energy.

Fundamental investigation on the impact strength of hollow fan blades

Energy Technology Data Exchange (ETDEWEB)

Ikeda, T; Miyachi, T; Sofue, Y

1985-01-01

Models of hollow fan blades were made and tested to prove that their strength is sufficient for use in real engines. The hollow blades were fabricated by diffusion bonding of two titanium alloy (6Al-4V-Ti) plates, one of which had three spanwise stiffners and the other being flat plate. The model as a nontwisted tapered blade. Impact tests were carried out on the hollow fan blade models in which the ingestion of a 1.5 pounds bird was simulated. Solid blades with the same external form were also tested by similar methods for comparison. The results of these tests show that properly designed hollow blades have sufficient stiffness and strength for use as fan blades in the turbo-fan engine.

Family of airfoil shapes for rotating blades. [for increased power efficiency and blade stability

Science.gov (United States)

Noonan, K. W. (Inventor)

1983-01-01

An airfoil which has particular application to the blade or blades of rotor aircraft such as helicopters and aircraft propellers is described. The airfoil thickness distribution and camber are shaped to maintain a near zero pitching moment coefficient over a wide range of lift coefficients and provide a zero pitching moment coefficient at section Mach numbers near 0.80 and to increase the drag divergence Mach number resulting in superior aircraft performance.

Blade Bearing Friction Estimation of Operating Wind Turbines

DEFF Research Database (Denmark)

Perisic, Nevena; Pedersen, Bo Juul; Kirkegaard, Poul Henning

2012-01-01

Blade root bearing on a wind turbine (WTG) enables pitching of blades for power control and rotor braking and is a WTG critical component. As the size of modern WTGs is constantly increasing, this leads to relatively less rigid bearings, more sensitive to deformations, thus WTG operational...... reliability can be increased by continuous monitoring of blade bearing. High blade bearing friction is undesirable, as it may be associated with excessive heating of the surfaces, damage and/or inefficient operation. Thus, continuous observation of bearing friction level is crucial for blade bearing health...... monitoring systems. A novel algorithm for online monitoring of bearing friction level is developed combining physical knowledge about pitch system dynamics with state estimator, i.e. observer theory and signal processing assuming realistic sensor availability. Results show estimation of bearing friction...

Development of tooling suitable for stall regulated blades

Energy Technology Data Exchange (ETDEWEB)

Hancock, M.

2001-07-01

The objectives of the project were to make significant improvements in the production of stall regulated blades in the areas of (a) the tip box, its housing, its mechanism and small GRP parts; (b) mould technology; (c) resins and glues and (d) root tooling. Although wood composite had been identified as a competitive technology for blades, compared with GRP blades, production volumes had been lower; reasons are given. The way in which the four areas identified for investigation were tackled are discussed. The study showed that the mould cycle time can be reduced to two days for a stall regulated blade and the blade quality can be improved by using the composite tip box and new resins. The time required for replication of moulds can be reduced by 40%.

Influence of delayed excitation on vibrations of turbine blades couple

Directory of Open Access Journals (Sweden)

Půst L.

2013-06-01

Full Text Available In the presented paper, the computational model of the turbine blade couple is investigated with the main attention to the influence two harmonic excitation forces, having the same frequency and amplitude but with moderate delay in time. Time delay between the exciting harmonic forces depends on the revolutions of bladed disk, on the number of blades on a rotating disk and on the number of stator blades. The reduction of resonance vibrations realized by means of dry friction between the shroud blade-heads increases roughly proportional to the difference of stator and rotor blade-numbers and also to the magnitude of dry friction force. From the analysis of blade couple with direct contact it was proved that the increase of friction forces causes decrease of resonance peaks, but the influence of elastic micro-deformations in the contact surfaces (modeled e.g. by the modified Coulomb dry friction law is rather small. Analysis of a blade couple with a friction element shows that the lower number of stator blades has negligible influence on the amplitudes of both blades, but decreases amplitudes of the friction element oscillations. Similarly the increase of friction forces causes a decrease of resonance peaks, but an increase of friction element amplitudes.

Unsteady potential flow past a propeller blade section

Science.gov (United States)

Takallu, M. A.

1990-01-01

An analytical study was conducted to predict the effect of an oscillating stream on the time dependent sectional pressure and lift coefficients of a model propeller blade. The assumption is that as the blade sections encounter a wake, the actual angles of attack vary in a sinusoidal manner through the wake, thus each blade is exposed to an unsteady stream oscillating about a mean value at a certain reduced frequency. On the other hand, an isolated propeller at some angle of attack can experience periodic changes in the value of the flow angle causing unsteady loads on the blades. Such a flow condition requires the inclusion of new expressions in the formulation of the unsteady potential flow around the blade sections. These expressions account for time variation of angle of attack and total shed vortices in the wake of each airfoil section. It was found that the final expressions for the unsteady pressure distribution on each blade section are periodic and that the unsteady circulation and lift coefficients exhibit a hysteresis loop.

Design and evaluation of low-cost laminated wood composite blades for intermediate size wind turbines: Blade design, fabrication concept, and cost analysis

Science.gov (United States)

Lieblein, S.; Gaugeon, M.; Thomas, G.; Zueck, M.

1982-01-01

As part of a program to reduce wind turbine costs, an evaluation was conducted of a laminated wood composite blade for the Mod-OA 200 kW wind turbine. The effort included the design and fabrication concept for the blade, together with cost and load analyses. The blade structure is composed of laminated Douglas fir veneers for the primary spar and nose sections, and honeycomb cored plywood panels for the trailing edges sections. The attachment of the wood blade to the rotor hub was through load takeoff studs bonded into the blade root. Tests were conducted on specimens of the key structural components to verify the feasibility of the concept. It is concluded that the proposed wood composite blade design and fabrication concept is suitable for Mod-OA size turbines (125-ft diameter rotor) at a cost that is very competitive with other methods of manufacture.

Second meeting of the International Working Group on Advanced Technologies for Water Cooled Reactors, Helsinki, 6-9 June 1988

International Nuclear Information System (INIS)

1989-05-01

The Second Meeting of the IAEA International Working Group on Advanced Technologies for Water Cooled Reactors (IWGATWR) was held in Helsinki, Finland, from 6-9 June 1988. The Summary Report (Part II) contains the papers which review the national programmes since the first meeting of IWGATWR in May 1987 in the field of Advanced Technologies for Water Cooled Reactors and other presentations at the Meeting. A separate abstract was prepared for each of these 12 papers presented at the meeting. Figs and tabs

Optimizing the multicycle subrotational internal cooling of diatomic molecules

Science.gov (United States)

Aroch, A.; Kallush, S.; Kosloff, R.

2018-05-01

Subrotational cooling of the AlH+ ion to the miliKelvin regime, using optimally shaped pulses, is computed. The coherent electromagnetic fields induce purity-conserved transformations and do not change the sample temperature. A decrease in a sample temperature, manifested by an increase of purity, is achieved by the complementary uncontrolled spontaneous emission which changes the entropy of the system. We employ optimal control theory to find a pulse that stirs the system into a population configuration that will result in cooling, upon multicycle excitation-emission steps. The obtained optimal transformation was shown capable to cool molecular ions to the subkelvins regime.

Effects of the number of inducer blades on the anti-cavitation characteristics and external performance of a centrifugal pump

International Nuclear Information System (INIS)

Guo, XiaoMei; Shi, GaoPing; Zhu, ZuChao; Cui, BaoLing

2016-01-01

Installing an inducer upstream of the main impeller is an effective approach for improving the anti-cavitation performance of a high speed centrifugal pump. For a high-speed centrifugal pump with an inducer, the number of inducer blades can affect its internal flow and external performance. We studied the manner in which the number of inducer blades can affect the anti-cavitation characteristics and external performance of a centrifugal pump. We first use the Rayleigh-Plesset equation and the mixture model to simulate the vapor liquid flow in a centrifugal pump with an inducer, and then predict its external performance. Finally, we tested the external performance of a centrifugal pump with 2-, 3- and 4-bladed inducers, respectively. The results show that the simulations of external performance in a centrifugal pump are in accordance with our experiments. Based on this, we obtained vapor volume fraction distributions for the inducer, the impeller, and in the corresponding whole flow parts. We discovered that the vapor volume fraction of a centrifugal pump with a 3- bladed inducer is less than that of a centrifugal pump with 2- or 4-bladed inducers, which means that a centrifugal pump with a 3-bladed inducer has a better external and anti-cavitation performance.

Static Structural and Modal Analysis of Gas Turbine Blade

Science.gov (United States)

Ranjan Kumar, Ravi; Pandey, K. M., Prof.

2017-08-01

Gas turbine is one of the most versatile items of turbo machinery nowadays. It is used in different modes such as power generation, oil and gas, process plants, aviation, domestic and related small industries. This paper is based on the problems concerning blade profile selection, material selection and turbine rotor blade vibration that seriously impact the induced stress-deformation and structural functioning of developmental gas turbine engine. In this paper for generating specific power by rotating blade at specific RPM, blade profile and material has been decided by static structural analysis. Gas turbine rotating blade RPM is decided by Modal Analysis so that the natural frequency of blade should not match with the excitation frequency. For the above blade profile has been modeled in SOLIDWORKS and analysis has been done in ANSYS WORKBENCH 14. Existing NACA6409 profile has been selected as base model and then it is modified by bending it through 72.5° and 145°. Hence these three different blade profiles have been analyzed for three different materials viz. Super Alloy X, Nimonic 80A and Inconel 625 at three different speed viz. 20000, 40000 and 60000RPM. It is found that NACA6409 with 72.5° bent gives best result for all material at all speed. Among all the material Inconel 625 gives best result. Hence Blade of Inconel 625 having 72.5° bent profile is the best combination for all RPM.

Damage detection in wind turbine blades using acoustic techniques

Energy Technology Data Exchange (ETDEWEB)

Juengert, A., E-mail: anne.juengert@mpa.uni-stuttgart.de [Univ. of Stuttgart, Materialpruefungsanstalt Stuttgart, Stuttgart (Germany)

2013-05-15

Facing climate change, the use of renewable energy gains importance. The wind energy sector grows very fast. Bigger and more powerful wind turbines will be built in the coming decades and the safety and reliability of the turbines will become more important. Wind turbine blades have to be inspected at regular intervals, because they are highly stressed during operation and a blade breakdown can cause big economic damages. The turbine blades consist of fiber reinforced plastics (GFRP/CFRP) and sandwich areas containing wood or plastic foam. The blades are manufactured as two halves and glued together afterwards. Typical damages are delaminations within the GFRP or the sandwich and missing adhesive or deficient bond at the bonding surfaces. The regular inspections of wind turbine blades are performed manually by experts and are limited to visual appraisals and simple tapping tests. To improve the inspections of wind turbine blades non-destructive testing techniques using acoustic waves are being developed. To detect delaminations within the laminates of the turbine blade, a local resonance spectroscopy was used. To detect missing bond areas from the outside of the blade the impulse-echo-technique was applied. This paper is an updated reprint of an article published on ndt.net in 2008. (author)

Damage detection in wind turbine blades using acoustic techniques

International Nuclear Information System (INIS)

Juengert, A.

2013-01-01

Facing climate change, the use of renewable energy gains importance. The wind energy sector grows very fast. Bigger and more powerful wind turbines will be built in the coming decades and the safety and reliability of the turbines will become more important. Wind turbine blades have to be inspected at regular intervals, because they are highly stressed during operation and a blade breakdown can cause big economic damages. The turbine blades consist of fiber reinforced plastics (GFRP/CFRP) and sandwich areas containing wood or plastic foam. The blades are manufactured as two halves and glued together afterwards. Typical damages are delaminations within the GFRP or the sandwich and missing adhesive or deficient bond at the bonding surfaces. The regular inspections of wind turbine blades are performed manually by experts and are limited to visual appraisals and simple tapping tests. To improve the inspections of wind turbine blades non-destructive testing techniques using acoustic waves are being developed. To detect delaminations within the laminates of the turbine blade, a local resonance spectroscopy was used. To detect missing bond areas from the outside of the blade the impulse-echo-technique was applied. This paper is an updated reprint of an article published on ndt.net in 2008. (author)

Computational Fluid Dynamic Analysis of a Vibrating Turbine Blade

Directory of Open Access Journals (Sweden)

Osama N. Alshroof

2012-01-01

Full Text Available This study presents the numerical fluid-structure interaction (FSI modelling of a vibrating turbine blade using the commercial software ANSYS-12.1. The study has two major aims: (i discussion of the current state of the art of modelling FSI in gas turbine engines and (ii development of a “tuned” one-way FSI model of a vibrating turbine blade to investigate the correlation between the pressure at the turbine casing surface and the vibrating blade motion. Firstly, the feasibility of the complete FSI coupled two-way, three-dimensional modelling of a turbine blade undergoing vibration using current commercial software is discussed. Various modelling simplifications, which reduce the full coupling between the fluid and structural domains, are then presented. The one-way FSI model of the vibrating turbine blade is introduced, which has the computational efficiency of a moving boundary CFD model. This one-way FSI model includes the corrected motion of the vibrating turbine blade under given engine flow conditions. This one-way FSI model is used to interrogate the pressure around a vibrating gas turbine blade. The results obtained show that the pressure distribution at the casing surface does not differ significantly, in its general form, from the pressure at the vibrating rotor blade tip.

AERFORCE: Subroutine package for unsteady blade-element/momentum calculations

Energy Technology Data Exchange (ETDEWEB)

Bjoerck, Anders

2000-05-01

A subroutine package, called AERFORCE, for the calculation of aerodynamic forces of wind turbine rotors has been written. The subroutines are written in FORTRAN. AERFORCE requires the input of airfoil aerodynamic data via tables as function of angle of attack, the turbine blade and rotor geometry and wind and blade velocities as input. The method is intended for use in an aeroelastic code. Wind and blade velocities are given at a sequence of time steps and blade forces are returned. The aerodynamic method is basically a Blade-Element/Momentum method. The method is fast and coded to be used in time simulations. In order to obtain a steady state solution a time simulation to steady state conditions has to be carried out. The BEM-method in AERFORCE includes extensions for: Dynamic inflow: Unsteady modeling of the inflow for cases with unsteady blade loading or unsteady wind. Extensions to BEM-theory for inclined flow to the rotor disc (yaw model). Unsteady blade aerodynamics: The inclusion of 2D attached flow unsteady aerodynamics and a semi-empirical model for 2D dynamic stall.

Multi-spectral temperature measurement method for gas turbine blade

Science.gov (United States)

Gao, Shan; Feng, Chi; Wang, Lixin; Li, Dong

2016-02-01

One of the basic methods to improve both the thermal efficiency and power output of a gas turbine is to increase the firing temperature. However, gas turbine blades are easily damaged in harsh high-temperature and high-pressure environments. Therefore, ensuring that the blade temperature remains within the design limits is very important. There are unsolved problems in blade temperature measurement, relating to the emissivity of the blade surface, influences of the combustion gases, and reflections of radiant energy from the surroundings. In this study, the emissivity of blade surfaces has been measured, with errors reduced by a fitting method, influences of the combustion gases have been calculated for different operational conditions, and a reflection model has been built. An iterative computing method is proposed for calculating blade temperatures, and the experimental results show that this method has high precision.

A highly efficient Francis turbine designed for energy recovery in cooling towers

Directory of Open Access Journals (Sweden)

Daqing Zhou

2015-03-01

Full Text Available In China, cooling water entering cooling towers still retains surplus pressure between 39,240 and 147,150 Pa. In order to utilize this wasted energy, it is suggested that the surplus water energy can be harnessed to drive a type of hydroturbine installed in the inner platform of cooling tower and make the fan rotate via its coupled shafts. However, conventional hydroturbines are not suited for this job because of their low efficiency or unmatched rotating speed with that of the fan under the operating conditions of cooling towers. In this article, according to the requirements of turbine work environment in cooling towers, a new type of hydroturbine, Francis turbine with ultra-low specific speed (ns  = 50 m.kW, was designed to replace the fan motor in a cooling tower. Primarily, the shape, position, and number of runner blades were designed and optimized through theoretical analyses and computational fluid dynamics simulations. Additionally, metal elliptical volute and single-row ring guide vanes were applied to scale down the structural dimensions. Finally, the optimal scheme of the new Francis turbine was proven to have a high efficiency of 88% and good operation stability through testing of a physical model and can achieve the goal of harvesting renewable energy in the cooling tower.

A novel folding blade of wind turbine rotor for effective power control

International Nuclear Information System (INIS)

Xie, Wei; Zeng, Pan; Lei, Liping

2015-01-01

Highlights: • A novel folding blade for wind turbine power control is proposed. • Wind tunnel experiments were conducted to analyze folding blade validity. • Folding blade is valid to control wind turbine power output. • Compared to pitch control, thrust was reduced by fold control in power regulation. • Optimum fold angles were found for wind turbine start up and aerodynamic brake. - Abstract: A concept of novel folding blade of horizontal axis wind turbine is proposed in current study. The folding blade comprises a stall regulated root blade section and a folding tip blade section with the fold axis inclined relative to blade span. By folding blade, lift force generated on the tip blade section changes and the moment arm also shortens, which leads to variations of power output. The blade folding actuation mechanism with servo motor and worm-gear reducer was designed. Wind turbine rotor control scheme and servo system with double feedback loops for blade fold angle control were proposed. In this study, a small folding blade model was tested in a wind tunnel to analyze its performance. The blade model performance was estimated in terms of rotation torque coefficient and thrust coefficient. Wind tunnel experiments were also conducted for pitch control using the same blade model in order to make a direct comparison. The power control, start up and aerodynamic brake performance of the folding blade were analyzed. According to the wind tunnel experiment results, fold angle magnitude significantly affected blade aerodynamic performance and the thrust characteristic together with the rotation torque characteristic of folding blade were revealed. The experiment results demonstrated that the folding blade was valid to control power output and had advantages in reducing thrust with maximum reduction of 51.1% compared to pitch control. Optimum fold angles of 55° and 90° were also found for start up and aerodynamic brake, respectively

Report on the Audit of Performnce and Reliability of Cobra Helicopter Rotor Blades

Science.gov (United States)

1991-05-21

We are providing this final report for your information and use. The audit was made from January to March 1991. The audit objective was to evaluate...internal controls. The audit was made in response to concerns raised by personnel at the Sharpe Army Depot about the K747 blade’s performance, maintenance, and reliability.

Dynamic response characteristics of dual flow-path integrally bladed rotors

Science.gov (United States)

Beck, Joseph A.; Brown, Jeffrey M.; Scott-Emuakpor, Onome E.; Cross, Charles J.; Slater, Joseph C.

2015-02-01

New turbine engine designs requiring secondary flow compression often look to dual flow-path integrally bladed rotors (DFIBRs) since these stages have the ability to perform work on the secondary, or bypassed, flow-field. While analogous to traditional integrally bladed rotor stages, DFIBR designs have many differences that result in unique dynamic response characteristics that must be understood to avoid fatigue. This work investigates these characteristics using reduced-order models (ROMs) that incorporate mistuning through perturbations to blade frequencies. This work provides an alternative to computationally intensive geometric-mistuning approaches for DFIBRs by utilizing tuned blade mode reductions and substructure coupling in cyclic coordinates. Free and forced response results are compared to full finite element model (FEM) solutions to determine if any errors are related to the reduced-order model formulation reduction methods. It is shown that DFIBRs have many more frequency veering regions than their single flow-path integrally blade rotor (IBR) counterparts. Modal families are shown to transition between system, inner-blade, and outer-blade motion. Furthermore, findings illustrate that while mode localization of traditional IBRs is limited to a single or small subset of blades, DFIBRs can have modal energy localized to either an inner- or outer-blade set resulting in many blades responding above tuned levels. Lastly, ROM forced response predictions compare well to full FEM predictions for the two test cases shown.

Direct Numerical Simulations of a Full Stationary Wind-Turbine Blade

Science.gov (United States)

Qamar, Adnan; Zhang, Wei; Gao, Wei; Samtaney, Ravi

2014-11-01

Direct numerical simulation of flow past a full stationary wind-turbine blade is carried out at Reynolds number, Re = 10,000 placed at 0 and 5 (degree) angle of attack. The study is targeted to create a DNS database for verification of solvers and turbulent models that are utilized in wind-turbine modeling applications. The full blade comprises of a circular cylinder base that is attached to a spanwise varying airfoil cross-section profile (without twist). An overlapping composite grid technique is utilized to perform these DNS computations, which permits block structure in the mapped computational space. Different flow shedding regimes are observed along the blade length. Von-Karman shedding is observed in the cylinder shaft region of the turbine blade. Along the airfoil cross-section of the blade, near body shear layer breakdown is observed. A long tip vortex originates from the blade tip region, which exits the computational plane without being perturbed. Laminar to turbulent flow transition is observed along the blade length. The turbulent fluctuations amplitude decreases along the blade length and the flow remains laminar regime in the vicinity of the blade tip. The Strouhal number is found to decrease monotonously along the blade length. Average lift and drag coefficients are also reported for the cases investigated. Supported by funding under a KAUST OCRF-CRG grant.

Modal analysis of wind turbine blades

Energy Technology Data Exchange (ETDEWEB)

Larsen, G.C.; Hansen, M.H.; Baumgart, A.; Carlen, I.

2002-02-01

The modal analysis technique has been used to identify essential dynamic properties of wind turbine blades like natural frequencies, damping characteristics and mode shapes. Different experimental procedures have been considered, and the most appropriate of these has been selected. Although the comparison is based on measurements on a LM 19 m blade, the recommendations given are believed to be valid for other wind turbine blades as well. The reliability of the selected experimental analysis has been quantified by estimating the unsystematic variations in the experimental findings. Satisfactory results have been obtained for natural frequencies, damping characteristics and for the dominating deflection direction of the investigated mode shapes. For the secondary deflection directions, the observed experimental uncertainty may be considerable - especially for the torsional deflection. The experimental analysis of the LM 19 m blade has been compared with results from a state-of-the-art FE-modeling of the same blade. For some of the higher modes substantial discrepancies between the natural frequencies originating from the FE-modeling and the modal analysis, respectively, are observed. In general the qualitative features of measured and computed modes shapes are in good agreement. However, for the secondary deflection directions, substantial deviations in the absolute values may occur (when normalizing with respect to the primary deflection direction). Finally, suggestions of potential future improvements of the experimental procedure are discussed. (au)

Advanced LP turbine blade design

International Nuclear Information System (INIS)

Jansen, M.; Pfeiffer, R.; Termuehlen, H.

1990-01-01

In the 1960's and early 1970's, the development of steam turbines for the utility industry was mainly influenced by the demand for increasing unit sizes. Nuclear plants in particular, required the design of LP turbines with large annulus areas for substantial mass and volumetric steam flows. Since then the development of more efficient LP turbines became an ongoing challenge. Extensive R and D work was performed in order to build efficient and reliable LP turbines often exposed to severe corrosion, erosion and dynamic excitation conditions. This task led to the introduction of an advanced disk-type rotor design for 1800 rpm LP turbines and the application of a more efficient, reaction-type blading for all steam turbine sections including the first stages of LP turbines. The most recent developments have resulted in an advanced design of large LP turbine blading, typically used in the last three stages of each LP turbine flow section. Development of such blading required detailed knowledge of the three dimensional, largely transonic, flow conditions of saturated steam. Also the precise assessment of blade stressing from dynamic conditions, such as speed and torsional resonance, as well as stochastic and aerodynamic excitation is of extreme importance

Resonant vibration control of three-bladed wind turbine rotors

DEFF Research Database (Denmark)

Krenk, Steen; Svendsen, Martin Nymann; Høgsberg, Jan Becker

2012-01-01

Rotors with blades, as in wind turbines, are prone to vibrations due to the flexibility of the blades and the support. In the present paper a theory is developed for active control of a combined set of vibration modes in three-bladed rotors. The control system consists of identical collocated...... to influence of other nonresonant modes. The efficiency of the method isdemonstrated byapplication to a rotor with 42 m blades, where the sensor/actuator system is implemented in the form of an axial extensible strut near the root of each blade. The load is provided by a simple but fully threedimensional...... correlated wind velocity field. It is shown by numerical simulations that the active damping system can provide a significant reduction in the response amplitude of the targeted modes, while applying control moments to the blades that are about 1 order of magnitude smaller than the moments from the external...

Numerical study of aero-excitation of steam-turbine rotor blade self-oscillations

Science.gov (United States)

Galaev, S. A.; Makhnov, V. Yu.; Ris, V. V.; Smirnov, E. M.

2018-05-01

Blade aero-excitation increment is evaluated by numerical solution of the full 3D unsteady Reynolds-averaged Navier-Stokes equations governing wet steam flow in a powerful steam-turbine last stage. The equilibrium wet steam model was adopted. Blade surfaces oscillations are defined by eigen-modes of a row of blades bounded by a shroud. Grid dependency study was performed with a reduced model being a set of blades multiple an eigen-mode nodal diameter. All other computations were carried out for the entire blade row. Two cases are considered, with an original-blade row and with a row of modified (reinforced) blades. Influence of eigen-mode nodal diameter and blade reinforcing on aero-excitation increment is analyzed. It has been established, in particular, that maximum value of the aero-excitation increment for the reinforced-blade row is two times less as compared with the original-blade row. Generally, results of the study point definitely to less probability of occurrence of blade self-oscillations in case of the reinforced blade-row.

Structural dynamics of shroudless, hollow fan blades with composite in-lays

Science.gov (United States)

Aiello, R. A.; Hirschbein, M. S.; Chamis, C. C.

1982-01-01

Structural and dynamic analyses are presented for a shroudless, hollow titanium fan blade proposed for future use in aircraft turbine engines. The blade was modeled and analyzed using the composite blade structural analysis computer program (COBSTRAN); an integrated program consisting of mesh generators, composite mechanics codes, NASTRAN, and pre- and post-processors. Vibration and impact analyses are presented. The vibration analysis was conducted with COBSTRAN. Results show the effect of the centrifugal force field on frequencies, twist, and blade camber. Bird impact analysis was performed with the multi-mode blade impact computer program. This program uses the geometric model and modal analysis from the COBSTRAN vibration analysis to determine the gross impact response of the fan blades to bird strikes. The structural performance of this blade is also compared to a blade of similar design but with composite in-lays on the outer surface. Results show that the composite in-lays can be selected (designed) to substantially modify the mechanical performance of the shroudless, hollow fan blade.

On the performance analysis of Savonius rotor with twisted blades

Energy Technology Data Exchange (ETDEWEB)

Saha, U.K.; Rajkumar, M. Jaya [Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Guwahati-781 039 (India)

2006-09-15

The present investigation is aimed at exploring the feasibility of twisted bladed Savonius rotor for power generation. The twisted blade in a three-bladed rotor system has been tested in a low speed wind tunnel, and its performance has been compared with conventional semicircular blades (with twist angle of 0{sup o}). Performance analysis has been made on the basis of starting characteristics, static torque and rotational speed. Experimental evidence shows the potential of the twisted bladed rotor in terms of smooth running, higher efficiency and self-starting capability as compared to that of the conventional bladed rotor. Further experiments have been conducted in the same setup to optimize the twist angle. (author)

Impact force identification for composite helicopter blades using minimal sensing

Science.gov (United States)

Budde, Carson N.

In this research a method for online impact identification using minimal sensors is developed for rotor hubs with composite blades. Modal impact data and the corresponding responses are recorded at several locations to develop a frequency response function model for each composite blade on the rotor hub. The frequency response model for each blade is used to develop an impact identification algorithm which can be used to identify the location and magnitude of impacts. Impacts are applied in two experimental setups, including a four-blade spin test rig and a cantilevered full-sized composite blade. The impacts are estimated to have been applied at the correct location 92.3% of the time for static fiberglass blades, 97.4% of the time for static carbon fiber blades and 99.2% of the time for a full sized-static blade. The estimated location is assessed further and determined to have been estimated in the correct chord position 96.1% of the time for static fiberglass, 100% of the time for carbon fiber blades and 99.2% of the time for the full-sized blades. Projectile impacts are also applied statically and during rotation to the carbon fiber blades on the spin test rig at 57 and 83 RPM. The applied impacts can be located to the correct position 63.9%, 41.7% and 33.3% for the 0, 57 and 83 RPM speeds, respectively, while the correct chord location is estimated 100% of the time. The impact identification algorithm also estimates the force of an impact with an average percent difference of 4.64, 2.61 and 1.00 for static fiberglass, full sized, and carbon fiber blades, respectively. Using a load cell and work equations, the force of impact for a projectile fired from a dynamic firing setup is estimated at about 400 N. The average force measured for applied projectile impacts to the carbon fiber blades, rotating at 0, 57 and 83 RPM, is 368.8, 373.7 and 432.4 N, respectively.

UWB Wind Turbine Blade Deflection Sensing for Wind Energy Cost Reduction.

Science.gov (United States)

Zhang, Shuai; Jensen, Tobias Lindstrøm; Franek, Ondrej; Eggers, Patrick C F; Olesen, Kim; Byskov, Claus; Pedersen, Gert Frølund

2015-08-12

A new application of utilizing ultra-wideband (UWB) technology to sense wind turbine blade deflections is introduced in this paper for wind energy cost reduction. The lower UWB band of 3.1-5.3 GHz is applied. On each blade, there will be one UWB blade deflection sensing system, which consists of two UWB antennas at the blade root and one UWB antenna at the blade tip. The detailed topology and challenges of this deflection sensing system are addressed. Due to the complexity of the problem, this paper will first realize the on-blade UWB radio link in the simplest case, where the tip antenna is situated outside (and on the surface of) a blade tip. To investigate this case, full-blade time-domain measurements are designed and conducted under different deflections. The detailed measurement setups and results are provided. If the root and tip antenna locations are properly selected, the first pulse is always of sufficient quality for accurate estimations under different deflections. The measured results reveal that the blade tip-root distance and blade deflection can be accurately estimated in the complicated and lossy wireless channels around a wind turbine blade. Some future research topics on this application are listed finally.

Accelerated fatigue testing of LM 19.1 blades

DEFF Research Database (Denmark)

Kristensen, Ole Jesper Dahl; Jørgensen, E.

2003-01-01

A series of 19.1 metre wind turbine blades manufactured by LM Glasfiber A/S of Lunderskov, Denmark were subjected to a series of flapwise fatigue tests. The object of these fatigue tests is to evaluate the impact of an increased load on the blade in afatigue test and to give information...... if it is possible to increase the load in fatigue test to shorten test time. The tests were carried out as a part of a project financed by the Danish Energy Agency. During the fatigue tests the blades have beensurveyed with thermal imaging equipment to determine how an increase in fatigue load affects the blade...... material. In addition to the thermal imaging surveillance the blades were instrumented with strain gauges. This report presents the temperature duringtest, calibration test results, moment range measurements, strain statistics, thermal imaging registrations and a determination of the size and cause...

Wind turbine blade testing system using base excitation

Science.gov (United States)

Cotrell, Jason; Thresher, Robert; Lambert, Scott; Hughes, Scott; Johnson, Jay

2014-03-25

An apparatus (500) for fatigue testing elongate test articles (404) including wind turbine blades through forced or resonant excitation of the base (406) of the test articles (404). The apparatus (500) includes a testing platform or foundation (402). A blade support (410) is provided for retaining or supporting a base (406) of an elongate test article (404), and the blade support (410) is pivotally mounted on the testing platform (402) with at least two degrees of freedom of motion relative to the testing platform (402). An excitation input assembly (540) is interconnected with the blade support (410) and includes first and second actuators (444, 446, 541) that act to concurrently apply forces or loads to the blade support (410). The actuator forces are cyclically applied in first and second transverse directions. The test article (404) responds to shaking of its base (406) by oscillating in two, transverse directions (505, 507).

Numerical Investigation of the Tip Vortex of a Straight-Bladed Vertical Axis Wind Turbine with Double-Blades

Directory of Open Access Journals (Sweden)

Yanzhao Yang

2017-10-01

Full Text Available Wind velocity distribution and the vortex around the wind turbine present a significant challenge in the development of straight-bladed vertical axis wind turbines (VAWTs. This paper is intended to investigate influence of tip vortex on wind turbine wake by Computational Fluid Dynamics (CFD simulations. In this study, the number of blades is two and the airfoil is a NACA0021 with chord length of c = 0.265 m. To capture the tip vortex characteristics, the velocity fields are investigated by the Q-criterion iso-surface (Q = 100 with shear-stress transport (SST k-ω turbulence model at different tip speed ratios (TSRs. Then, mean velocity, velocity deficit and torque coefficient acting on the blade in the different spanwise positions are compared. The wind velocities obtained by CFD simulations are also compared with the experimental data from wind tunnel experiments. As a result, we can state that the wind velocity curves calculated by CFD simulations are consistent with Laser Doppler Velocity (LDV measurements. The distribution of the vortex structure along the spanwise direction is more complex at a lower TSR and the tip vortex has a longer dissipation distance at a high TSR. In addition, the mean wind velocity shows a large value near the blade tip and a small value near the blade due to the vortex effect.

Moving blade for steam turbines with axial flow

International Nuclear Information System (INIS)

Raschke, K.; Wehle, G.

1976-01-01

The invention concerns the improvement of the production of moving blades for steam turbines with axial flow, especially of multi-blades produced by welding of the top plates. It is proposed to weld the top plates before the moving blades are fitted into the rotor. Welding is this made much easier and can be carried out under protective gas and with better results. (UWI) [de

Investigating for failure of central ventilation fan blade

International Nuclear Information System (INIS)

Koo, Jae Raeyang; Ko Woo Sig; Kim, Yeon Hwan; Park, Kwang Ha

2002-01-01

During the operation, central ventilation fan stopped when switch 'on' condition. When central ventilation fan disassemble, ten blades of fan fractured. We have searched cause of failure. We had modeling one of the fan blades and analysis with computer programs. Thus we have find that fracture of central ventilation fan blades is alternative stress and vibration at hub. In this paper, we have described cause of failure

Turbine blade having a constant thickness airfoil skin

Science.gov (United States)

Marra, John J

2012-10-23

A turbine blade is provided for a gas turbine comprising: a support structure comprising a base defining a root of the blade and a framework extending radially outwardly from the base, and an outer skin coupled to the support structure framework. The skin has a generally constant thickness along substantially the entire radial extent thereof. The framework and the skin define an airfoil of the blade.

Optimization design of spar cap layup for wind turbine blade

Institute of Scientific and Technical Information of China (English)

2012-01-01

Based on the aerodynamic shape and structural form of the blade are fixed,a mathematical model of optimization design for wind turbine blade is established.The model is pursued with respect to minimum the blade mass to reduce the cost of wind turbine production.The material layup numbers of the spar cap are chosen as the design variables;while the demands of strength,stiffness and stability of the blade are employed as the constraint conditions.The optimization design for a 1.5 MW wind turbine blade is carried out by combing above objective and constraint conditions at the action of ultimate flapwise loads with the finite element software ANSYS.Compared with the original design,the optimization design result achieves a reduction of 7.2% of the blade mass,the stress and strain distribution of the blade is more reasonable,and there is no occurrence of resonance,therefore its effectiveness is verified.

Antenna Gain Impact on UWB Wind Turbine Blade Deflection Sensing

DEFF Research Database (Denmark)

Zhang, Shuai; Franek, Ondrej; Byskov, Claus

2018-01-01

effective (or equivalent) isotropic radiated power (EIRP), an HG tip antenna inside a blade gives stronger direct pulse amplitudes and better pulse waveforms for accurate and reliable distance estimations than the LG. Moreover, the direct pulse with the HG antenna is also closer to the blade surface, which...... in free space have similar realized gain when allocated inside blades, so that the emission power for the HG and LG antennas in blades can be the same. The antenna gain impacts on time-domain pulse waveforms and power distributions around a blade are carefully investigated (with the tip antenna inside...... a blade). Higher antenna gain enlarges both direct pulse and multipath but in different levels. To verify the simulations, time-domain measurements are performed with a full 37-meter blade. Pulse waveforms and power delay profiles are measured. From all the studies, it follows that: with the similar...

Research on the nonintrusive measurement of the turbine blade vibration

Science.gov (United States)

Zhang, Shi hai; Li, Lu-ping; Rao, Hong-de

2008-11-01

It's one of the important ways to monitor the change of dynamic characteristic of turbine blades for ensuring safety operation of turbine unit. Traditional measurement systems for monitoring blade vibration generally use strain gauges attached to the surface of turbine blades, each strain gauge gives out an analogue signal related to blade deformation, it's maximal defect is only a few blades could be monitored which are attached by strain gauge. But the noncontact vibration measurement will be discussed would solve this problem. This paper deals with noncontact vibration measurement on the rotor blades of turbine through experiments. In this paper, the noncontact vibration measurement - Tip Timing Measurement will be presented, and will be improved. The statistics and DFT will be used in the improved measurement. The main advantage of the improved measurement is that only two sensors over the top of blades and one synchronous sensor of the rotor are used to get the exact vibration characteristics of the each blade in a row. In our experiment, we adopt NI Company's DAQ equipment: SCXI1001 and PCI 6221, three optical sensors, base on the graphics program soft LabVIEW to develop the turbine blade monitor system. At the different rotational speed of the rotor (1000r/m and 1200r/m) we do several experiments on the bench of the Turbine characteristic. Its results indicated that the vibration of turbine blade could be real-time monitored and accurately measured by the improved Tip Timing Measurement.

Rotor blade online monitoring and fault diagnosis technology research

DEFF Research Database (Denmark)

Tesauro, Angelo; Pavese, Christian; Branner, Kim

Rotor blade online monitoring and fault diagnosis technology is an important way to find blade failure mechanisms and thereby improve the blade design. Condition monitoring of rotor blades is necessary in order to ensure the safe operation of the wind turbine, make the maintenance more economical...... of the rotor, icing and lightning. Research is done throughout the world in order to develop and improve such measurement systems. Commercial hardware and software available for the described purpose is presented in the report....

Remote inspection of steam turbine blades

International Nuclear Information System (INIS)

Anon.

1987-01-01

During the past five years Reinhart and Associates, Inc. has been involved in remote examination of L-0 and L-1 steam turbine blade rows of in-place LP turbines using visual and eddy current techniques. These tests have concentrated on the trailing edge and blade-to-rotor attachment (Christmas tree) areas. These remote nondestructive examinations were performed through hand access ports of the inner shell. Since the remote scanning system was in a prototype configuration, the inspection was highly operator-dependent. Refinement of the scanning equipment would considerably improve the efficiency of the test; however, the feasibility of remote in-place inspection of turbine blades was established. To further improve this technology, and to provide for remote inspection of other areas of the blade and additional turbine designs, EPRI is funding a one-year project with Reinhart and Associates, Inc. This project will develop a new system that employs state-of-the-art multifrequency eddy current techniques, a miniature charged coupled device (CCD) television camera, and remote positioning equipment. Project results from the first six months are presented

Aero-structural optimization of wind turbine blades using a reduced set of design load cases including turbulence

DEFF Research Database (Denmark)

Sessarego, Matias; Shen, Wen Zhong

2018-01-01

Modern wind turbine aero-structural blade design codes generally use a smaller fraction of the full design load base (DLB) or neglect turbulent inflow as defined by the International Electrotechnical Commission standards. The current article describes an automated blade design optimization method...... based on surrogate modeling that includes a very large number of design load cases (DLCs) including turbulence. In the present work, 325 DLCs representative of the full DLB are selected based on the message-passing-interface (MPI) limitations in Matlab. Other methods are currently being investigated, e.......g. a Python MPI implementation, to overcome the limitations in Matlab MPI and ultimately achieve a full DLB optimization framework. The reduced DLB and the annual energy production are computed using the state-of-the-art aero-servo-elastic tool HAWC2. Furthermore, some of the interior dimensions of the blade...

Eddy current inspection of stationary blade rings

International Nuclear Information System (INIS)

Krzywosz, K.J.; Hastings, S.N.

1994-01-01

Stationary turbine blade rings in a US power plant have experienced chloride-induced cracking. Failure analysis determined two types of cracking mechanisms: corrosion fatigue cracking confined to the leading edge of the outer shroud; and stress corrosion cracking present all over the blade surface. Fluorescent dye penetrant is typically used to detect and size cracks. However, it requires cleaning the blade rings by sandblasting to obtain reliable inspection results. Sand blasting in turn requires sealing the lower half of the turbine housing to prevent sand from contaminating the rest of the power plant components. Furthermore, both the penetrant examination and the removal of the sand are time consuming and costly. An alternative NDE technique is desirable which requires no pre-cleaning of the blade and a quick go/no-go inspection with the capability of estimating the crack length. This paper presents an innovative eddy current technique which meets the desired objectives by incorporating the use of specially designed contoured scanners equipped with an array of pancake coils. A set of eddy current pancake coils housed in three different scanners is used to manually scan and inspect the convex side of the stationary blade rings. The pancake coils are operated in a transmit/receive mode using two separate eddy current instruments. This paper presents the inspection concept, including scanner and probe designs, and test results from the various stages of multiple blade rings

Numerical investigations on axial and radial blade rubs in turbo-machinery

Science.gov (United States)

Abdelrhman, Ahmed M.; Tang, Eric Sang Sung; Salman Leong, M.; Al-Qrimli, Haidar F.; Rajamohan, G.

2017-07-01

In the recent years, the clearance between the rotor blades and stator/casing had been getting smaller and smaller prior improving the aerodynamic efficiency of the turbomachines as demand in the engineering field. Due to the clearance reduction between the blade tip and the rotor casing and between rotor blades and stator blades, axial and radial blade rubbing could be occurred, especially at high speed resulting into complex nonlinear vibrations. The primary aim of this study is to address the blade axial rubbing phenomenon using numerical analysis of rotor system. A comparison between rubbing caused impacts of axial and radial blade rubbing and rubbing forces are also aims of this study. Tow rotor models (rotor-stator and rotor casing models) has been designed and sketched using SOILDSWORKS software. ANSYS software has been used for the simulation and the numerical analysis. The rubbing conditions were simulated at speed range of 1000rpm, 1500rpm and 2000rpm. Analysis results for axial blade rubbing showed the appearance of blade passing frequency and its multiple frequencies (lx, 2x 3x etc.) and these frequencies will more excited with increasing the rotational speed. Also, it has been observed that when the rotating speed increased, the rubbing force and the harmonics frequencies in x, y and z-direction become higher and severe. The comparison study showed that axial blade rub is more dangerous and would generate a higher vibration impacts and higher blade rubbing force than radial blade rub.

A deflection monitoring system for a wind turbine blade

DEFF Research Database (Denmark)

2017-01-01

A wind turbine blade comprising a system for monitoring the deflection of a wind turbine blade is described. The system comprises a wireless range-measurement system, having at least one wireless communication device located towards the root end of the blade and at least one wireless communication...

Channel flow analysis. [velocity distribution throughout blade flow field

Science.gov (United States)

Katsanis, T.

1973-01-01

The design of a proper blade profile requires calculation of the blade row flow field in order to determine the velocities on the blade surfaces. An analysis theory is presented for several methods used for this calculation and associated computer programs that were developed are discussed.

Blade Vibration Measurement System for Unducted Fans

Science.gov (United States)

Marscher, William

2014-01-01

With propulsion research programs focused on new levels of efficiency and noise reduction, two avenues for advanced gas turbine technology are emerging: the geared turbofan and ultrahigh bypass ratio fan engines. Both of these candidates are being pursued as collaborative research projects between NASA and the engine manufacturers. The high bypass concept from GE Aviation is an unducted fan that features a bypass ratio of over 30 along with the accompanying benefits in fuel efficiency. This project improved the test and measurement capabilities of the unducted fan blade dynamic response. In the course of this project, Mechanical Solutions, Inc. (MSI) collaborated with GE Aviation to (1) define the requirements for fan blade measurements; (2) leverage MSI's radar-based system for compressor and turbine blade monitoring; and (3) develop, validate, and deliver a noncontacting blade vibration measurement system for unducted fans.

Measurements of blade aerodynamics on a rotor in the field

Energy Technology Data Exchange (ETDEWEB)

Graham, J.M.R. [Imperical College, Dept. of Aeronautics, London (United Kingdom)

1997-12-31

This contribution describes the field test measurements undertaken on an instrumented rotor at the Rutherford Appleton Laboratory, Oxfordshire, UK, during the period 1994 - 97. The programme was directed at improving the prediction of the steady and unsteady rotor blade loading, particularly the loads arising from the stalling of the blade. The measured data consisted of blade surface pressure distributions sampled at 50Hz at 6 sections along the span of one blade of the 17m diameter, 3 bladed, fixed pitch, upwind H.A.W.T., together with measurements of the incident velocity. (au)

Study of Pumping Capacity of Pitched Blade Impellers

Directory of Open Access Journals (Sweden)

I. Fořt

2002-01-01

Full Text Available A study was made of the pumping capacity of pitched blade impellers in a cylindrical pilot plant vessel with four standard radial baffles at the wall under a turbulent regime of flow. The pumping capacity was calculated from the radial profile of the axial flow, under the assumption of axial symmetry of the discharge flow. The mean velocity was measured using laser Doppler anemometry in a transparent vessel of diameter T = 400 mm, provided with a standard dished bottom. Three and six blade pitched blade impellers (the pitch angle varied within the interval a Îá24°; 45°ń of impeller/vessel diameter ratio D/T = 0.36, as well as a three blade pitched blade impeller with folded blades of the same diameter, were tested. The calculated results were compared with the results of experiments mentioned in the literature, above all in cylindrical vessels with a flat bottom. Both arrangements of the agitated system were described by the impeller energetic efficiency, i.e, a criterion including in dimensionless form both the impeller energy consumption (impeller power input and the impeller pumping effect (impeller pumping capacity. It follows from the results obtained with various geometrical configurations that the energetic efficiency of pitched blade impellers is significantly lower for configurations suitable for mixing solid-liquid suspensions (low impeller off bottom clearances than for blending miscible liquids in mixing (higher impeller off bottom clearances.

Near net shape forging of titanium alloy turbine blade

International Nuclear Information System (INIS)

Morita, Akiyasu; Hattori, Shigeo; Tani, Kazuhito; Takemura, Atsushi; Ashida, Yoshio

1991-01-01

The isothermal forging process has been developed to produce turbine blades made of near β Ti-alloy Ti-10V-2Fe-3Al. It is important to set the preform at the optimum position of the die in order to get a high precision product. The deformation analysis by using FEM is effective to determine the optimum position. And also it is necessary to avoid buckling induced by the restriction of axial elongation of the material. As a result, Ti-10V-2Fe-3Al blades could be formed precisely by using only one stage of forging, and machining was needed only at the root. The thickness of the oxide layer induced on the surface of the forged blade was only 70μm. The mechanical properties of Ti-10V-2Fe-3Al blades after forging and annealing were superior to those of Ti-6Al-4V blades and were nearly uniform across the length of the blades. (author)

Optimization of the blade trailing edge geometric parameters for a small scale ORC turbine

Science.gov (United States)

Zhang, L.; Zhuge, W. L.; Peng, J.; Liu, S. J.; Zhang, Y. J.

2013-12-01

In general, the method proposed by Whitfield and Baines is adopted for the turbine preliminary design. In this design procedure for the turbine blade trailing edge geometry, two assumptions (ideal gas and zero discharge swirl) and two experience values (WR and γ) are used to get the three blade trailing edge geometric parameters: relative exit flow angle β6, the exit tip radius R6t and hub radius R6h for the purpose of maximizing the rotor total-to-static isentropic efficiency. The method above is established based on the experience and results of testing using air as working fluid, so it does not provide a mathematical optimal solution to instruct the optimization of geometry parameters and consider the real gas effects of the organic, working fluid which must be taken into consideration for the ORC turbine design procedure. In this paper, a new preliminary design and optimization method is established for the purpose of reducing the exit kinetic energy loss to improve the turbine efficiency ηts, and the blade trailing edge geometric parameters for a small scale ORC turbine with working fluid R123 are optimized based on this method. The mathematical optimal solution to minimize the exit kinetic energy is deduced, which can be used to design and optimize the exit shroud/hub radius and exit blade angle. And then, the influence of blade trailing edge geometric parameters on turbine efficiency ηts are analysed and the optimal working ranges of these parameters for the equations are recommended in consideration of working fluid R123. This method is used to modify an existing ORC turbine exit kinetic energy loss from 11.7% to 7%, which indicates the effectiveness of the method. However, the internal passage loss increases from 7.9% to 9.4%, so the only way to consider the influence of geometric parameters on internal passage loss is to give the empirical ranges of these parameters, such as the recommended ranges that the value of γ is at 0.3 to 0.4, and the value

Optimization of the blade trailing edge geometric parameters for a small scale ORC turbine

International Nuclear Information System (INIS)

Zhang, L; Zhuge, W L; Liu, S J; Zhang, Y J; Peng, J

2013-01-01

In general, the method proposed by Whitfield and Baines is adopted for the turbine preliminary design. In this design procedure for the turbine blade trailing edge geometry, two assumptions (ideal gas and zero discharge swirl) and two experience values (W R and γ) are used to get the three blade trailing edge geometric parameters: relative exit flow angle β 6 , the exit tip radius R 6t and hub radius R 6h for the purpose of maximizing the rotor total-to-static isentropic efficiency. The method above is established based on the experience and results of testing using air as working fluid, so it does not provide a mathematical optimal solution to instruct the optimization of geometry parameters and consider the real gas effects of the organic, working fluid which must be taken into consideration for the ORC turbine design procedure. In this paper, a new preliminary design and optimization method is established for the purpose of reducing the exit kinetic energy loss to improve the turbine efficiency η ts , and the blade trailing edge geometric parameters for a small scale ORC turbine with working fluid R123 are optimized based on this method. The mathematical optimal solution to minimize the exit kinetic energy is deduced, which can be used to design and optimize the exit shroud/hub radius and exit blade angle. And then, the influence of blade trailing edge geometric parameters on turbine efficiency η ts are analysed and the optimal working ranges of these parameters for the equations are recommended in consideration of working fluid R123. This method is used to modify an existing ORC turbine exit kinetic energy loss from 11.7% to 7%, which indicates the effectiveness of the method. However, the internal passage loss increases from 7.9% to 9.4%, so the only way to consider the influence of geometric parameters on internal passage loss is to give the empirical ranges of these parameters, such as the recommended ranges that the value of γ is at 0.3 to 0.4, and the

observer-based diagnostics and monitoring of vibrations in nuclear reactor core cooling system

International Nuclear Information System (INIS)

Siry, S.A K.

2007-01-01

analysis and diagnostics of vibration in industrial systems play a significant rule to prevent severe severe damages . drive shaft vibration is a complicated phenomenon composed of two independent forms of vibrations, translational and torsional. translational vibration measurements in case of the reactor core cooling system are introduced. the system under study consists of the three phase induction motor, flywheel, centrifugal pump, and two coupling between motor-flywheel, and flywheel-pump. this system structure is considered to be one where the blades are pegged into the discs fitting into the shafts. a non-linear model to simulate vibration in the reactor core cooling system will be introduced. simulation results of an operating reactor core cooling system using the actual parameters will be presented to validate the accuracy and reliability of the proposed analytical method the accuracy in analyzing the results depends on the system model. the shortcomings of the conventional model will be avoided through the use of that accurate nonlinear model which improve the simulation of the reactor core cooling system

Composite hub/metal blade compressor rotor

Science.gov (United States)

Yao, S.

1978-01-01

A low cost compressor rotor was designed and fabricated for a small jet engine. The rotor hub and blade keepers were compression molded with graphite epoxy. Each pair of metallic blades was held in the hub by a keeper. All keepers were locked in the hub with circumferential windings. Feasibility of fabrication was demonstrated in this program.

Turbulence modeling needs of commercial CFD codes: Complex flows in the aerospace and automotive industries

Science.gov (United States)

Befrui, Bizhan A.

1995-01-01

This viewgraph presentation discusses the following: STAR-CD computational features; STAR-CD turbulence models; common features of industrial complex flows; industry-specific CFD development requirements; applications and experiences of industrial complex flows, including flow in rotating disc cavities, diffusion hole film cooling, internal blade cooling, and external car aerodynamics; and conclusions on turbulence modeling needs.

International working group on gas-cooled reactors. Summary report

Energy Technology Data Exchange (ETDEWEB)

1981-01-15

The purpose of the meeting was to provide a forum for exchange of information on safety and licensing aspects for gas-cooled reactors in order to provide comprehensive review of the present status and of directions for future applications and development. Contributions were made concerning the operating experience of the Fort St. Vrain (FSV) HTGR Power Plant in the United States of America, the experimental power station Arbeitsgemeinschaft Versuchsreaktor (AVR) in the Federal Republic of Germany, and the CO/sub 2/-cooled reactors in the United Kingdom such as Hunterson B and Hinkley Point B. The experience gained at each of these reactors has proved the high safety potential of Gas-cooled Reactor Power Plants.

Measurement of Rotorcraft Blade Deformation Using Projection Moiré Interferometry

Directory of Open Access Journals (Sweden)

Gary A. Fleming

2000-01-01

Full Text Available Projection Moiré Interferometry (PMI has been used to obtain near instantaneous, quantitative blade deformation measurements of a generic rotorcraft model at several test conditions. These laser-based measurements provide quantitative, whole field, dynamic blade deformation profiles conditionally sampled as a function of rotor azimuth. The instantaneous nature of the measurements permits computation of the mean and unsteady blade deformation, blade bending, and twist. The PMI method is presented, and the image processing steps required to obtain quantitative deformation profiles from PMI interferograms are described. Experimental results are provided which show blade bending, twist, and unsteady motion. This initial proof-of-concept test has demonstrated the capability of PMI to acquire accurate, full field rotorcraft blade deformation data.

Digital radiographic technology; non-destructive testing of tubine blades

NARCIS (Netherlands)

Penumadu, P.S.

2014-01-01

Inspection of turbine blades has always been a big challenge. Any irregularities in the blade have a huge impact on the gas turbine, so these blades have to be manufactured and inspected in the most sophisticated way possible. The evolution of digital radiographic technology took a leap forward to

Compressor blade setting angle accuracy study, volume 1

Science.gov (United States)

Holman, F. F.; Kidwell, J. R.

1976-01-01

The aerodynamic test of a small, single stage, highly loaded, axial flow transonic compressor is covered. The stage was modified by fabricating a 24 blade rotor with mis-set blades in a repeating pattern - two degrees closed from nominal, two degrees open from nominal and nominal. The unit was instrumented to determine overall performance and average blade element data. High-response, dynamic pressure probes were installed to record pressure patterns at selected points in the flowpath. Testing was conducted at speeds from 70 to 94% of design equivalent speed with a conventional casing and also with circumferential grooves over the rotor tip. Testing indicated severe performance penalties were incurred as a result of the mis-set blading. Lower flow, pressure ratio, and efficiency were observed for the stage with or without casing treatment. Periodic pressure variations were detected at every location where high response pressure sensors were located and were directly related to blading geometry.

Analysis of Different Blade Architectures on small VAWT Performance

Science.gov (United States)

Battisti, L.; Brighenti, A.; Benini, E.; Raciti Castelli, M.

2016-09-01

The present paper aims at describing and comparing different small Vertical Axis Wind Turbine (VAWT) architectures, in terms of performance and loads. These characteristics can be highlighted by resorting to the Blade Element-Momentum (BE-M) model, commonly adopted for rotor pre-design and controller assessment. After validating the model with experimental data, the paper focuses on the analysis of VAWT loads depending on some relevant rotor features: blade number (2 and 3), airfoil camber line (comparing symmetrical and asymmetrical profiles) and blade inclination (straight versus helical blade). The effect of such characteristics on both power and thrusts (in the streamwise direction and in the crosswise one) as a function of both the blades azimuthal position and their Tip Speed Ratio (TSR) are presented and widely discussed.

A Long-Period Grating Sensor for Wind Turbine Blades

DEFF Research Database (Denmark)

Glavind, Lars

This PhD project concerns the applied research for providing a novel sensor for measurements on wind turbine blades, based on Long-Period Gratings. The idea is based on the utilization of a special asymmetrical optical fibre with Long-Period Gratings for directional sensitive bend sensing...... blade material, where a suitable process and recoating material were investigated. The sensor was implemented and tested on a full scale wind turbine blade placed on a test rig. This first prototype has demonstrated the capability of the sensor for wind turbine blade monitoring, particular...... the possibility to distinguish between the flap- and edge-wise bend directions on the wind turbine blade, providing a selective sensor. The sensor has proven to be very robust and suitable for this application....

Simulated Measurements of Cooling in Muon Ionization Cooling Experiment

Energy Technology Data Exchange (ETDEWEB)

Mohayai, Tanaz [IIT, Chicago; Rogers, Chris [Rutherford; Snopok, Pavel [Fermilab

2016-06-01

Cooled muon beams set the basis for the exploration of physics of flavour at a Neutrino Factory and for multi-TeV collisions at a Muon Collider. The international Muon Ionization Cooling Experiment (MICE) measures beam emittance before and after an ionization cooling cell and aims to demonstrate emittance reduction in muon beams. In the current MICE Step IV configuration, the MICE muon beam passes through low-Z absorber material for reducing its transverse emittance through ionization energy loss. Two scintillating fiber tracking detectors, housed in spectrometer solenoid modules upstream and downstream of the absorber are used for reconstructing position and momentum of individual muons for calculating transverse emittance reduction. However, due to existence of non-linear effects in beam optics, transverse emittance growth can be observed. Therefore, it is crucial to develop algorithms that are insensitive to this apparent emittance growth. We describe a different figure of merit for measuring muon cooling which is the direct measurement of the phase space density.

Coupling analysis of wind turbine blades based on aeroelastics and aerodynsmics

DEFF Research Database (Denmark)

Wang, Xudong; Chen, Jin; Zhang, Shigiang

2010-01-01

The structural dynamic equations of blades were constructed for blades of wind turbines. The vibration velocity of blades and the relative flow velocity were calculated using the structural dynamics model. Based on the BEM (Blade Element Momentum) theory and traditional areodynamics, the coupling...

Heat transfer analysis in internally-cooled fuel elements by means of a conformal mapping approach

International Nuclear Information System (INIS)

Sarmiento, G.S.; Laura, P.A.A.

1981-01-01

The present paper deals with an approximate solution of the steady-state heat conduction problem in internally cooled fuel elements of fast breeder reactors. Explicit expressions for the dimensionless temperature distribution in terms of the governing physical and geometrical parameters are determined by means of a coupled conformal mapping-variational approach. The results obtained are found to be in very good agreement with those calculated by means of a finite element code. (orig.)

Construction of low-cost, Mod-OA wood composite wind turbine blades

Science.gov (United States)

Lark, R. F.

1983-01-01

Two sixty-foot, low-cost, wood composite blades for service on 200 kW Mod-OA wind turbines were constructed. The blades were constructed of epoxy resin-bonded Douglas fir veneers for the leading edge sections, and paper honeycombcored, birch plywood faced panels for the afterbody sections. The blades were joined to the wind turbine hub by epoxy resin-bonded steel load take-off studs embedded into the root end of the blades. The blades were installed on the 200 kW Mod-OA wind turbine facility at Kahuku, Hawaii, The blades completed nearly 8,000 hours of operation over an 18 month period at an average power of 150 kW prior to replacement with another set of wood composite blades. The blades were replaced because of a corrosion failure of the steel shank on one stud. Inspections showed that the wood composite structure remained in excellent condition.

Force Measurements on a VAWT Blade in Parked Conditions

Directory of Open Access Journals (Sweden)

Anders Goude

2017-11-01

Full Text Available The forces on a turbine at extreme wind conditions when the turbine is parked is one of the most important design cases for the survivability of a turbine. In this work, the forces on a blade and its support arms have been measured on a 12 kW straight-bladed vertical axis wind turbine at an open site. Two cases are tested: one during electrical braking of the turbine, which allows it to rotate slowly, and one with the turbine mechanically fixed with the leading edge of the blade facing the main wind direction. The force variations with respect to wind direction are investigated, and it is seen that significant variations in forces depend on the wind direction. The measurements show that for the fixed case, when subjected to the same wind speed, the forces are lower when the blade faces the wind direction. The results also show that due to the lower forces at this particular wind direction, the average forces for the fixed blade are notably lower. Hence, it is possible to reduce the forces on a turbine blade, simply by taking the dominating wind direction into account when the turbine is parked. The measurements also show that a positive torque is generated from the blade for most wind directions, which causes the turbine to rotate in the electrically-braked case. These rotations will cause increased fatigue loads on the turbine blade.

Manufacturing a 9-Meter Thermoplastic Composite Wind Turbine Blade: Preprint

Energy Technology Data Exchange (ETDEWEB)

Murray, Robynne [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Snowberg, David R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Berry, Derek S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Beach, Ryan [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rooney, Samantha A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Swan, Dana [Arkema Inc.

2017-12-06

Currently, wind turbine blades are manufactured from a combination of glass and/or carbon fiber composite materials with a thermoset resin such as epoxy, which requires energy-intensive and expensive heating processes to cure. Newly developed in-situ polymerizing thermoplastic resin systems for composite wind turbine blades polymerize at room temperature, eliminating the heating process and significantly reducing the blade manufacturing cycle time and embodied energy, which in turn reduces costs. Thermoplastic materials can also be thermally welded, eliminating the need for adhesive bonds between blade components and increasing the overall strength and reliability of the blades. As well, thermoplastic materials enable end-of-life blade recycling by reheating and decomposing the materials, which is a limitation of existing blade technology. This paper presents a manufacturing demonstration for a 9-m-long thermoplastic composite wind turbine blade. This blade was constructed in the Composites Manufacturing Education and Technology facility at the National Wind Technology Center at the National Renewable Energy Laboratory (NREL) using a vacuum-assisted resin transfer molding process. Johns Manville fiberglass and an Arkema thermoplastic resin called Elium were used. Additional materials included Armacell-recycled polyethylene terephthalate foam from Creative Foam and low-cost carbon- fiber pultruded spar caps (manufactured in collaboration with NREL, Oak Ridge National Laboratory, Huntsman, Strongwell, and Chomarat). This paper highlights the development of the thermoplastic resin formulations, including an additive designed to control the peak exothermic temperatures. Infusion and cure times of less than 3 hours are also demonstrated, highlighting the efficiency and energy savings associated with manufacturing thermoplastic composite blades.

Bimetallic Blisks with Shrouded Turbine Blades for Gas Turbine Engines

Directory of Open Access Journals (Sweden)

L. A. Magerramova

2015-01-01

Full Text Available The paper discusses prospects of using blisks with shrouded blades. Increasing an engine life and efficiency as well as mass reduction can also be achieved by increasing blade numbers and decreasing disk diameter. But design engineers are faced with the problem of blade placement because of the disk size and root dimensions.The problem of increasing life and cyclic durability, vibration strength, and lightweight design of the turbine gas turbine wheels, can be solved by an elimination of blade - disk locks.The technology of manufacturing one-piece blisks by connecting the blades with the disc part using hot isostatic pressing was developed. This technology allows us to use blades with shrouds. It is necessary to increase efficiency and to improve high cycle fatigue performance of rotor blades.One of the pressing problems is to ensure the necessary position of shrouds in relation to each other in the manufacturing process as well as in the service. Numerical studies of the influence of the shroud mounting position on blade strength during operation allowed us to develop a methodology of choosing a shroud mounting position.Based on the two turbine wheels (LPT and HPT calculations advantages of blisk design with respect to the lock-based design were shown. Application of bimetallic blisks with shrouded blades resulted in a lifespan increase and weight reduction.In addition, other advantages of blisk design are as follows: possible reduction in the number of parts, elimination of leaks and fretting that take place in the blade - disk locks, exception of expensive broaching operations and disk alloy saving. The shortcoming is elimination of damping in root connection. In addition, there are no widely used repair methods.Despite these disadvantages the usage of bimetallic turbine blisks with shrouded blades is very promising.

Wind Turbine Blade Design System - Aerodynamic and Structural Analysis

Science.gov (United States)

Dey, Soumitr

2011-12-01

The ever increasing need for energy and the depletion of non-renewable energy resources has led to more advancement in the "Green Energy" field, including wind energy. An improvement in performance of a Wind Turbine will enhance its economic viability, which can be achieved by better aerodynamic designs. In the present study, a design system that has been under development for gas turbine turbomachinery has been modified for designing wind turbine blades. This is a very different approach for wind turbine blade design, but will allow it to benefit from the features inherent in the geometry flexibility and broad design space of the presented system. It starts with key overall design parameters and a low-fidelity model that is used to create the initial geometry parameters. The low-fidelity system includes the axisymmetric solver with loss models, T-Axi (Turbomachinery-AXIsymmetric), MISES blade-to-blade solver and 2D wing analysis code XFLR5. The geometry parameters are used to define sections along the span of the blade and connected to the CAD model of the wind turbine blade through CAPRI (Computational Analysis PRogramming Interface), a CAD neutral API that facilitates the use of parametric geometry definition with CAD. Either the sections or the CAD geometry is then available for CFD and Finite Element Analysis. The GE 1.5sle MW wind turbine and NERL NASA Phase VI wind turbine have been used as test cases. Details of the design system application are described, and the resulting wind turbine geometry and conditions are compared to the published results of the GE and NREL wind turbines. A 2D wing analysis code XFLR5, is used for to compare results from 2D analysis to blade-to-blade analysis and the 3D CFD analysis. This kind of comparison concludes that, from hub to 25% of the span blade to blade effects or the cascade effect has to be considered, from 25% to 75%, the blade acts as a 2d wing and from 75% to the tip 3D and tip effects have to be taken into account

Structure of three Zlatoust bulats (Damascus-steel blades)

Science.gov (United States)

Schastlivtsev, V. M.; Gerasimov, V. Yu.; Rodionov, D. P.

2008-08-01

Chemical composition, structure, and hardness of samples of three Zlatoust bulats (Damascus steels), namely, an Anosov bulat blade (1841), Obukhov bulat blade (1859), and a Shvetsov forged bulat-steel blank (crucible steel) have been investigated. The Anosov bulat possesses all signs of the classical Damascus steel; this is a hypereutectoid carbon steel with a structure formed from chains of carbides against the background of fine pearlite (troostite). A banded pattern is revealed on the surface of the blade. The Obukhov blade cannot be referred to classical Damascus steel. The pattern on the surface of the blade is absent, despite the fact that the initial steel is hypereutectoid. The structure of the blade does not correspond to the structure of classical Damascus steel; this is bainite with numerous cementite particles. The Shvetsov sample cannot be regarded as Damascus steel since it is made from a hypereutectoid steel alloyed by managanese and tungsten. The pattern on the surface of the metal is a consequence of the dendritic structure of the ingot which is developed during forging. The structure of this pattern differs from classical damascene pattern, since the latter is formed due to a specific arrangement of a variety of carbide particles against the pearlitic or some other background obtained during heat treatment.

Vibrational analysis of vertical axis wind turbine blades

Science.gov (United States)

Kapucu, Onur

The goal of this research is to derive a vibration model for a vertical axis wind turbine blade. This model accommodates the affects of varying relative flow angle caused by rotating the blade in the flow field, uses a simple aerodynamic model that assumes constant wind speed and constant rotation rate, and neglects the disturbance of wind due to upstream blade or post. The blade is modeled as elastic Euler-Bernoulli beam under transverse bending and twist deflections. Kinetic and potential energy equations for a rotating blade under deflections are obtained, expressed in terms of assumed modal coordinates and then plugged into Lagrangian equations where the non-conservative forces are the lift and drag forces and moments. An aeroelastic model for lift and drag forces, approximated with third degree polynomials, on the blade are obtained assuming an airfoil under variable angle of attack and airflow magnitudes. A simplified quasi-static airfoil theory is used, in which the lift and drag coefficients are not dependent on the history of the changing angle of attack. Linear terms on the resulting equations of motion will be used to conduct a numerical analysis and simulation, where numeric specifications are modified from the Sandia-17m Darrieus wind turbine by Sandia Laboratories.

UWB Wind Turbine Blade Deflection Sensing for Wind Energy Cost Reduction

DEFF Research Database (Denmark)

Zhang, Shuai; Jensen, Tobias Lindstrøm; Franek, Ondrej

2015-01-01

A new application of utilizing ultra-wideband (UWB) technology to sense wind turbine blade deflections is introduced in this paper for wind energy cost reduction. The lower UWB band of 3.1–5.3 GHz is applied. On each blade, there will be one UWB blade deflection sensing system, which consists...... is always of sufficient quality for accurate estimations under different deflections. The measured results reveal that the blade tip-root distance and blade deflection can be accurately estimated in the complicated and lossy wireless channels around a wind turbine blade. Some future research topics...

Fracture analysis of adhesive joints in wind turbine blades

DEFF Research Database (Denmark)

Eder, Martin Alexander; Bitsche, Robert

2015-01-01

Modern wind turbine rotor blades are usually made from fibre-reinforced composite subcomponents. In the final assembly stage, these subcomponents are bonded together by several adhesive joints. One important adhesive joint is situated at the trailing edge, which refers to the downstream edge where...... the air-flow rejoins and leaves the blade. Maintenance inspections of wind turbine rotor blades show that among other forms of damage, local debonding of the shells along the trailing edge is a frequent failure type. The cause of trailing edge failure in wind turbine blades is complex, and detailed...

Noise from Propellers with Symmetrical Sections at Zero Blade Angle

Science.gov (United States)

Deming, A F

1937-01-01

A theory has been deduced for the "rotation noise" from a propeller with blades of symmetrical section about the chord line and set at zero blade angle. Owing to the limitation of the theory, the equations give without appreciable error only the sound pressure for cases where the wave lengths are large compared with the blade lengths. With the aid of experimental data obtained from a two-blade arrangement, an empirical relation was introduced that permitted calculation of higher harmonics. The generality of the final relation given is indicated by the fundamental and second harmonic of a four-blade arrangement.

Analysis and improvement of gas turbine blade temperature measurement error

International Nuclear Information System (INIS)

Gao, Shan; Wang, Lixin; Feng, Chi; Daniel, Ketui

2015-01-01

Gas turbine blade components are easily damaged; they also operate in harsh high-temperature, high-pressure environments over extended durations. Therefore, ensuring that the blade temperature remains within the design limits is very important. In this study, measurement errors in turbine blade temperatures were analyzed, taking into account detector lens contamination, the reflection of environmental energy from the target surface, the effects of the combustion gas, and the emissivity of the blade surface. In this paper, each of the above sources of measurement error is discussed, and an iterative computing method for calculating blade temperature is proposed. (paper)

Analysis and improvement of gas turbine blade temperature measurement error

Science.gov (United States)

Gao, Shan; Wang, Lixin; Feng, Chi; Daniel, Ketui

2015-10-01

Gas turbine blade components are easily damaged; they also operate in harsh high-temperature, high-pressure environments over extended durations. Therefore, ensuring that the blade temperature remains within the design limits is very important. In this study, measurement errors in turbine blade temperatures were analyzed, taking into account detector lens contamination, the reflection of environmental energy from the target surface, the effects of the combustion gas, and the emissivity of the blade surface. In this paper, each of the above sources of measurement error is discussed, and an iterative computing method for calculating blade temperature is proposed.

PROTOTIPE ALAT PENGEKSTRAK PATI SAGU TIPE MIXER ROTARY BLADE BERTENAGA MOTOR BAKAR Prototype of Mixer Rotary Blade of Sago Starch Extractor Powered by Internal Combustion Engine

Directory of Open Access Journals (Sweden)

Darma Darma

2012-05-01

Full Text Available Papua and West Papua Province have a large potential of sago. Approximately 994,000 hectares, mostly natural sago forest was existed in this area. Sago starch has long been an important source of nutrition troughout Papua. Product of sago palm is not only starch as source of carbohydrate for food stuff, but also for basic material of industries such as paper, plywood, hardboard, and food indutries. Traditional methods are used for starch extraction in almost all part of Papu, which is not efficient and production capacity is very low. The effort to increase sago starch production could be carry out by introducing mechanical equipment (traditional to mechanized processing. The objective of this research was to design mixer rotary blade of sago starch extraction powered by internal combustion engine. The result was prototype of mechanical sago starch extractor. The prototype has high performance with extraction capacity 160 kg of disintegrated pith per hour or equal to 33 kg of wet starch per hour, extractable starch more than 99 % while starch losses in hampas less lhan 1 %. Hopefully, application of this machine to the sago farmer will transform agricultural system from subsistence to commercial. It means that increasing of economic income. In conclusion, technically and economically this prototype was feasible. ABSTRAK Provinsi Papua dan Papua Barat memiliki potensi sagu yang sangat besar. Sekitar 994.000 hektar yang sebagian besar merupakan hutan sagu alam terdapat di kedua provinsi ini. Pati sagu telah lama digunakan sebagai sumber nutrisi bagi penduduk asli papua. Pati sagu tidak hanya digunakan sebagai sumber karbohidrat, namun juga digunakan seba- gai bahan dasar industri kertas, plywood, hardbord, dan pangan. Pengolahan sagu secara tradisional yang dilakukan oleh masyarakat tidak efisien dan kapasitas produksinya sangat rendah. Peningkatan produksi dapat dilakukan dengan mengintroduksi peralatan pengolahan mekanis untuk merubah metode

Fatigue strength ofcomposite wind turbine blade structures

DEFF Research Database (Denmark)

Ardila, Oscar Gerardo Castro

Wind turbines are normally designed to withstand 20-30 years of life. During this period, the blades, which are the main rotating structures of a wind turbine, are subjected to high fluctuating load conditions as a result of a combination of gravity, inertia, and aeroelastic forces. For this reason......, fatigue is one of the foremost concerns during the design of these structures. However, current standard fatigue methods used for designing wind turbine blades seem not to be completely appropriate for these structures because they are still based on methods developed for metals and not for composite...... materials from which the blades are made. In this sense, the aim of this work is to develop more accurate and reliable fatigue-life prediction models for composite wind turbine blades. In this project, two types of fatigue models are implemented: fatigue-life models and damage mechanics models. In the first...

Influence of Icing on the Modal Behavior of Wind Turbine Blades

Directory of Open Access Journals (Sweden)

Sudhakar Gantasala

2016-10-01

Full Text Available Wind turbines installed in cold climate sites accumulate ice on their structures. Icing of the rotor blades reduces turbine power output and increases loads, vibrations, noise, and safety risks due to the potential ice throw. Ice accumulation increases the mass distribution of the blade, while changes in the aerofoil shapes affect its aerodynamic behavior. Thus, the structural and aerodynamic changes due to icing affect the modal behavior of wind turbine blades. In this study, aeroelastic equations of the wind turbine blade vibrations are derived to analyze modal behavior of the Tjaereborg 2 MW wind turbine blade with ice. Structural vibrations of the blade are coupled with a Beddoes-Leishman unsteady attached flow aerodynamics model and the resulting aeroelastic equations are analyzed using the finite element method (FEM. A linearly increasing ice mass distribution is considered from the blade root to half-length and thereafter constant ice mass distribution to the blade tip, as defined by Germanischer Lloyd (GL for the certification of wind turbines. Both structural and aerodynamic properties of the iced blades are evaluated and used to determine their influence on aeroelastic natural frequencies and damping factors. Blade natural frequencies reduce with ice mass and the amount of reduction in frequencies depends on how the ice mass is distributed along the blade length; but the reduction in damping factors depends on the ice shape. The variations in the natural frequencies of the iced blades with wind velocities are negligible; however, the damping factors change with wind velocity and become negative at some wind velocities. This study shows that the aerodynamic changes in the iced blade can cause violent vibrations within the operating wind velocity range of this turbine.

Estimation of the energy loss at the blades in rowing: common assumptions revisited.

Science.gov (United States)

Hofmijster, Mathijs; De Koning, Jos; Van Soest, A J

2010-08-01

In rowing, power is inevitably lost as kinetic energy is imparted to the water during push-off with the blades. Power loss is estimated from reconstructed blade kinetics and kinematics. Traditionally, it is assumed that the oar is completely rigid and that force acts strictly perpendicular to the blade. The aim of the present study was to evaluate how reconstructed blade kinematics, kinetics, and average power loss are affected by these assumptions. A calibration experiment with instrumented oars and oarlocks was performed to establish relations between measured signals and oar deformation and blade force. Next, an on-water experiment was performed with a single female world-class rower rowing at constant racing pace in an instrumented scull. Blade kinematics, kinetics, and power loss under different assumptions (rigid versus deformable oars; absence or presence of a blade force component parallel to the oar) were reconstructed. Estimated power losses at the blades are 18% higher when parallel blade force is incorporated. Incorporating oar deformation affects reconstructed blade kinematics and instantaneous power loss, but has no effect on estimation of power losses at the blades. Assumptions on oar deformation and blade force direction have implications for the reconstructed blade kinetics and kinematics. Neglecting parallel blade forces leads to a substantial underestimation of power losses at the blades.

Beamstrahlung Photon Load on the TESLA Extraction Septum Blade(LCC-0104)

Energy Technology Data Exchange (ETDEWEB)

Seryi, A

2003-10-02

This note describes work performed in the framework of the International Linear Collider Technical Review Committee [1] to estimate the power load on the TESLA extraction septum blade due to beamstrahlung photons. It is shown, that under realistic conditions the photon load can be several orders of magnitude higher than what was estimated in the TESLA TDR [2] for the ideal Gaussian beams, potentially representing a serious limitation of the current design.

Beamstrahlung Photon Load on the TESLA Extraction Septum Blade(LCC-0104)

International Nuclear Information System (INIS)

Seryi, A

2003-01-01

This note describes work performed in the framework of the International Linear Collider Technical Review Committee [1] to estimate the power load on the TESLA extraction septum blade due to beamstrahlung photons. It is shown, that under realistic conditions the photon load can be several orders of magnitude higher than what was estimated in the TESLA TDR [2] for the ideal Gaussian beams, potentially representing a serious limitation of the current design

Flutter of Darrieus wind turbine blades

Science.gov (United States)

Ham, N. D.

1978-01-01

The testing of Darrieus wind turbines has indicated that under certain conditions, serious vibrations of the blades can occur, involving flatwise bending, torsion, and chordwise bending. A theoretical method of predicting the aeroelastic stability of the coupled bending and torsional motion of such blades with a view to determining the cause of these vibrations, and a means of suppressing them was developed.

First meeting of the International Working Group on Advanced Technologies for Water Cooled Reactors, Vienna, 18-21 May 1987. (Pt. 2)

International Nuclear Information System (INIS)

1987-12-01

The First Meeting of the IAEA International Working Group on Advanced Technologies for Water Cooled Reactors was held in Vienna, Austria from 18-21 May 1987. The Summary Report (Pt. 2) contains the papers which review the national programmes in the field of Advanced Technologies for Water Cooled Reactors and other presentations at the Meeting. A separate abstract was prepared for each of the 10 papers presented at this meeting. Refs, figs

A CLINICAL ASSESSMENT OF MACINTOSH BLADE, MILLER BLADE AND KING VISIONTM VIDEOLARYNGOSCOPE FOR LARYNGEAL EXPOSURE AND DIFFICULTY IN ENDOTRACHEAL INTUBATION

Directory of Open Access Journals (Sweden)

Apoorva Mahendera

2016-03-01

Full Text Available CONTEXT Previous studies suggest glottic view is better achieved with straight blades while tracheal intubation is easier with curved blades and videolaryngoscope is better than conventional laryngoscope. AIMS Comparison of conventional laryngoscope (Macintosh blade and Miller blade with channelled videolaryngoscope (King Vision TM with respect to laryngeal visualisation and difficulty in endotracheal intubation. SETTINGS AND DESIGN This prospective randomised comparative study was conducted at a tertiary care hospital (in ASA I and ASA II patients after approval from the Institutional Ethics Committee. METHODS We compared Macintosh, Miller, and the King VisionTM videolaryngoscope for glottic visualisation and ease of tracheal intubation. Patients undergoing elective surgeries under general anaesthesia requiring endotracheal intubation were randomly divided into three groups (N=180. After induction of anaesthesia, laryngoscopy was performed and trachea intubated. We recorded visualisation of glottis (Cormack-Lehane grade-CL, ease of intubation, number of attempts, need to change blade, and need for external laryngeal manipulation. STATISTICAL ANALYSIS Demographic data, Mandibular length, Mallampati classification were compared using ANOVA, Chi-square test, Kruskal-Wallis Test, where P value <0.005 is statically significant. RESULTS CL grade 1 was most often observed in King Vision -TM VL group (90% which is followed by Miller (28.33%, and Macintosh group (15%. We found intubation was to be easier (grade 1 with King Vision -TM VL group (73.33%, followed by Macintosh (38.33%, and Miller group (1.67%. External manipulation (BURP was needed more frequently in patients in Miller group (71.67%, followed by Macintosh (28.33% and in King Vision -TM VL group (6.67%. All (100% patients were intubated in the 1 st attempt with King Vision -TM VL group, followed by Macintosh group (90% and Miller group (58.33%. CONCLUSIONS In patients with normal airway

Retention system and method for the blades of a rotary machine

Science.gov (United States)

Pedersen, Poul D.; Glynn, Christopher C.; Walker, Roger C.

2002-01-01

A retention system and method for the blades of a rotary machine for preventing forward or aft axial movement of the rotor blades includes a circumferential hub slot formed about a circumference of the machine hub. The rotor blades have machined therein a blade retention slot which is aligned with the circumferential hub slot when the blades are received in correspondingly shaped openings in the hub. At least one ring segment is secured in the blade retention slots and the circumferential hub slot to retain the blades from axial movement. A key assembly is used to secure the ring segments in the aligned slots via a hook portion receiving the ring segments and a threaded portion that is driven radially outwardly by a nut. A cap may be provided to provide a redundant back-up load path for the centrifugal loads on the key. Alternatively, the key assembly may be formed in the blade dovetail.

Blade vortex interaction noise reduction techniques for a rotorcraft

Science.gov (United States)

Charles, Bruce D. (Inventor); Hassan, Ahmed A. (Inventor); Tadghighi, Hormoz (Inventor); JanakiRam, Ram D. (Inventor); Sankar, Lakshmi N. (Inventor)

1996-01-01

An active control device for reducing blade-vortex interactions (BVI) noise generated by a rotorcraft, such as a helicopter, comprises a trailing edge flap located near the tip of each of the rotorcraft's rotor blades. The flap may be actuated in any conventional way, and is scheduled to be actuated to a deflected position during rotation of the rotor blade through predetermined regions of the rotor azimuth, and is further scheduled to be actuated to a retracted position through the remaining regions of the rotor azimuth. Through the careful azimuth-dependent deployment and retraction of the flap over the rotor disk, blade tip vortices which are the primary source for BVI noise are (a) made weaker and (b) pushed farther away from the rotor disk (that is, larger blade-vortex separation distances are achieved).

Evaporative cooling in polymer electrolyte fuel cell

Energy Technology Data Exchange (ETDEWEB)

Shimotori, S; Sonai, A [Toshiba Corp. Tokyo (Japan)

1996-06-05

The concept of the evaporative cooling for the internally humidified PEFC was confirmed by the experiment. The evaporative cooling rates at the anode and the cathode were mastered under the various temperatures and air utilizations. At a high temperature the proportion of the evaporative cooling rate to the heat generation rate got higher, the possibility of the evaporative cooling was demonstrated. 2 refs., 7 figs., 1 tab.

Gas turbine engine turbine blade damaging estimate in maintenance

Directory of Open Access Journals (Sweden)

Ель-Хожайрі Хусейн

2004-01-01

Full Text Available  The factors determining character and intensity of corrosive damages of gas turbine blades are analyzed in the article. The classification of detrimental impurities polluting gas turbine airflow duct and injuring blade erosion damages are given. Common features of the method of turbine blade corrosive damage estimation are shown in the article.

Cooling Performance of ALIP according to the Air or Sodium Cooling Type

Energy Technology Data Exchange (ETDEWEB)

Ye, Huee-Youl; Yoon, Jung; Lee, Tae-Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-05-15

ALIP pumps the liquid sodium by Lorentz force produced by the interaction of induced current in the liquid metal and their associated magnetic field. Even though the efficiency of the ALIP is very low compared to conventional mechanical pumps, it is very useful due to the absence of moving parts, low noise and vibration level, simplicity of flow rate regulation and maintenance, and high temperature operation capability. Problems in utilization of ALIP concern a countermeasure for elevation of internal temperature of the coil due to joule heating and how to increase magnetic flux density of Na channel gap. The conventional ALIP usually used cooling methods by circulating the air or water. On the other hand, GE-Toshiba developed a double stator pump adopting the sodium-immersed self-cooled type, and it recovered the heat loss in sodium. Therefore, the station load factor of the plant could be reduced. In this study, the cooling performance with cooling types of ALIP is analyzed. We developed thermal analysis models to evaluate the cooling performance of air or sodium cooling type of ALIP. The cooling performance is analyzed for operating parameters and evaluated with cooling type. 1-D and 3-D thermal analysis model for IHTS ALIP was developed, and the cooling performance was analyzed for air or sodium cooling type. The cooling performance for air cooling type was better than sodium cooling type at higher air velocity than 0.2 m/s. Also, the air temperature of below 270 .deg. demonstrated the better cooling performance as compared to sodium.

Proton-antiproton colliding beam electron cooling

International Nuclear Information System (INIS)

Derbenev, Ya.S.; Skrinskij, A.N.

1981-01-01

A possibility of effective cooling of high-energy pp tilde beams (E=10 2 -10 3 GeV) in the colliding mode by accompanying radiationally cooled electron beam circulating in an adjacent storage ring is studied. The cooling rate restrictions by the pp tilde beam interaction effects while colliding and the beam self-heating effect due to multiple internal scattering are considered. Some techniques permitting to avoid self-heating of a cooling electron beam or suppress its harmful effect on a heavy particle beam cooling are proposed. According to the estimations the cooling time of 10 2 -10 3 s order can be attained [ru

Structural health monitoring of wind turbine blades

Science.gov (United States)

Rumsey, Mark A.; Paquette, Joshua A.

2008-03-01

As electric utility wind turbines increase in size, and correspondingly, increase in initial capital investment cost, there is an increasing need to monitor the health of the structure. Acquiring an early indication of structural or mechanical problems allows operators to better plan for maintenance, possibly operate the machine in a de-rated condition rather than taking the unit off-line, or in the case of an emergency, shut the machine down to avoid further damage. This paper describes several promising structural health monitoring (SHM) techniques that were recently exercised during a fatigue test of a 9 meter glass-epoxy and carbon-epoxy wind turbine blade. The SHM systems were implemented by teams from NASA Kennedy Space Center, Purdue University and Virginia Tech. A commercial off-the-shelf acoustic emission (AE) NDT system gathered blade AE data throughout the test. At a fatigue load cycle rate around 1.2 Hertz, and after more than 4,000,000 fatigue cycles, the blade was diagnostically and visibly failing at the out-board blade spar-cap termination point at 4.5 meters. For safety reasons, the test was stopped just before the blade completely failed. This paper provides an overview of the SHM and NDT system setups and some current test results.

Effect of steady deflections on the aeroelastic stability of a turbine blade

DEFF Research Database (Denmark)

Kallesøe, Bjarne Skovmose

2011-01-01

This paper deals with effects of geometric non-linearities on the aeroelastic stability of a steady-state defl ected blade. Today, wind turbine blades are long and slender structures that can have a considerable steady-state defl ection which affects the dynamic behaviour of the blade. The fl...... apwise blade defl ection causes the edgewise blade motion to couple to torsional blade motion and thereby to the aerodynamics through the angle of attack. The analysis shows that in the worst case for this particular blade, the edgewise damping can be decreased by half. Copyright © 2010 John Wiley & Sons......, Ltd....

Study on Determination Method of Fatigue Testing Load for Wind Turbine Blade

Science.gov (United States)

Liao, Gaohua; Wu, Jianzhong

2017-07-01

In this paper, the load calculation method of the fatigue test was studied for the wind turbine blade under uniaxial loading. The characteristics of wind load and blade equivalent load were analyzed. The fatigue property and damage theory of blade material were studied. The fatigue load for 2MW blade was calculated by Bladed, and the stress calculated by ANSYS. Goodman modified exponential function S-N curve and linear cumulative damage rule were used to calculate the fatigue load of wind turbine blades. It lays the foundation for the design and experiment of wind turbine blade fatigue loading system.

KNOW-BLADE, task-3.2 report, tip shape study

Energy Technology Data Exchange (ETDEWEB)

Soerensen, N.N.; Johansen, J.; Conway, S.; Voutsinas, S.; Hansen, M.O.L.; Stuermer, A.

2005-01-01

For modern rotor blades with their very large aspect ratio, the blade tip is a very limited part of the overall rotor, and as such of limited importance for the overall aerodynamics of the rotor. Even though they may not be very important for the overall power production, the tip noise can be very important for the acoustics of the rotor [15], and the blade tips can as well be important for the aerodynamic damping properties of the rotor blades [13]. Unfortunately, not many options exists for predicting the aerodynamic behavior of blade tips using computational methods. Experimentally it is dicult to perform detailed measurements in the form of pressure and velocity measurements in natural wind conditions on modern large scale turbines due to the inherent unsteadiness in the natural wind. The present study describes the application of four different Navier-Stokes solvers to tip shape studies, and shows that these codes are well suited to study the flow around different tip shape geometries, and can predict the pressure distributions at the blade tip quite accurately. (au)

Quench pressure, thermal expulsion, and normal zone propagation in internally cooled superconductors

International Nuclear Information System (INIS)

Dresner, L.

1988-01-01

When a nonrecovering normal zone appears in an internally cooled superconductor, the pressure in the conductor rises, helium is expelled from its ends, and the normal zone grows in size. This paper presents a model of these processes that allows calculation of the pressure, the expulsion velocity, and the propagation velocity with simple formulas. The model is intended to apply to conductors such as the cable-in-conduit conductor of the Westinghouse LCT (WH-LCT) coil, the helium volumes of which have very large length-to-diameter ratios (3 /times/ 10 5 ). The predictions of the model agree with the rather limited data available from propagation experiments carried out on the WH-LCT coil. 3 refs., 1 fig

The influence of the mould cooling temperature on the surface appearance and the internal quality of ESR ingots

Science.gov (United States)

Kubin, M.; Ofner, B.; Holzgruber, H.; Schneider, R.; Enzenhofer, D.; Filzwieser, A.; Konetschnik, S.

2016-07-01

One of the main benefits of the ESR process is to obtain an ingot surface which is smooth and allows a subsequent forging operation without any surface dressing. The main influencing factor on surface quality is the precise controlling of the process such as melt rate and electrode immersion depth. However, the relatively strong cooling effect of water as a cooling medium can result in the solidification of the meniscus of the liquid steel on the boundary liquid steel and slag which is most likely the origin of surface defects. The usage of different cooling media like ionic liquids, a salt solution which can be heated up to 250°C operating temperature might diminish the meniscus solidification phenomenon. This paper shows the first results of the usage of an ionic liquid as a mould cooling medium. In doing so, 210mm diameter ESR ingots were produced with the laboratory scale ESR furnace at the university of applied science using an ionic liquid cooling device developed by the company METTOP. For each trial melt different inlet and outlet temperatures of the ionic liquid were chosen and the impact on the surface appearance and internal quality were analyzed. Furthermore the influence on the energy balance is also briefly highlighted. Ultimately, an effect of the usage of ionic liquids as a cooling medium could be determined and these results will be described in detail within the scope of this paper.

Microstructure Based Material-Sand Particulate Interactions and Assessment of Coatings for High Temperature Turbine Blades

Science.gov (United States)

Murugan, Muthuvel; Ghoshal, Anindya; Walock, Michael; Nieto, Andy; Bravo, Luis; Barnett, Blake; Pepi, Marc; Swab, Jeffrey; Pegg, Robert Tyler; Rowe, Chris;

Performance improvement of small-scale rotors by passive blade twist control

OpenAIRE

Lv, Peng; Prothin, Sebastien; Mohd Zawawi, Fazila; Bénard, Emmanuel; Morlier, Joseph; Moschetta, Jean-Marc

2015-01-01

A passive twist control is proposed as an adaptive way to maximize the overall efficiency of the small-scale rotor blade for multifunctional aircrafts. Incorporated into a database of airfoil characteristics, Blade Element Momentum Theory is implemented to obtain the blade optimum twist rates for hover and forward flight. In order to realize the required torsion of blade between hover and forward flight, glass/epoxy laminate blade is proposed based on Centrifugal Force Induced Twist concept. ...

Gas Turbine Blade Damper Optimization Methodology

Directory of Open Access Journals (Sweden)

R. K. Giridhar

2012-01-01

Full Text Available The friction damping concept is widely used to reduce resonance stresses in gas turbines. A friction damper has been designed for high pressure turbine stage of a turbojet engine. The objective of this work is to find out effectiveness of the damper while minimizing resonant stresses for sixth and ninth engine order excitation of first flexure mode. This paper presents a methodology that combines three essential phases of friction damping optimization in turbo-machinery. The first phase is to develop an analytical model of blade damper system. The second phase is experimentation and model tuning necessary for response studies while the third phase is evaluating damper performance. The reduced model of blade is developed corresponding to the mode under investigation incorporating the friction damper then the simulations were carried out to arrive at an optimum design point of the damper. Bench tests were carried out in two phases. Phase-1 deals with characterization of the blade dynamically and the phase-2 deals with finding optimal normal load at which the blade resonating response is minimal for a given excitation. The test results are discussed, and are corroborated with simulated results, are in good agreement.

Guidelines to Interpret Results of Mechanical Blade Test

International Nuclear Information System (INIS)

Arias Vega, F.; Sanz Martin, J. C.

1999-01-01

This report shows the interpretation of full scale rotor blade test results and describes the engineering testing models and coefficients for any feasible rotor blade design, in order to accept and to certify any final manufactured blade as an allowable product, fit for use and working with a completely security during all the wind turbines lifetime. This work was carried out at the Wind Energy Division of the CIEMAT.DER and it is based on the authors technical experience in this field, after many years working on testing blades. Also, this paper contains results of the European wind turbine Standards II relevant to the European Project: JOULE III R.D. where the Wind Energy Division took part as participant too. (Author)

Guidelines to Interpret Results of Mechanical Blade Test

Energy Technology Data Exchange (ETDEWEB)

Arias Vega, F.; Sanz Martin, J. C. [Ciemat, Madrid (Spain)

2000-07-01

This report shows the interpretation of full scale rotor blade test results and describes the engineering testing models and coefficients for any feasible rotor blade design, in order to accept and to certify any final manufactured blades as an allowable product, fit for use and working with a completely security during all the windturbine's lifetime. This work was carried out at the Wind Energy Division of the CIEMAT.DER and it is based on the author's technical experience in this field, after many years working on testing blades. Also, this paper contains results of the European wind turbine Standards II relevant to the European Project: JOULE III R.D. where the Wind Energy Division took part as participant too. (Author)

Implicit geometric representations for optimal design of gas turbine blades

International Nuclear Information System (INIS)

Mansour, T.; Ghaly, W.

2004-01-01

Shape optimization requires a proper geometric representation of the blade profile; the parameters of such a representation are usually taken as design variables in the optimization process. This implies that the model must possess three specific features: flexibility, efficiency, and accuracy. For the specific task of aerodynamic optimization for turbine blades, it is critical to have flexibility in both the global and local design spaces in order to obtain a successful optimization. This work is concerned with the development of two geometric representations of turbine blade profiles that are appropriate for aerodynamic optimization: the Modified Rapid Axial Turbine Design (MRATD) model where the blade is represented by five low-order curves that satisfy eleven designer parameters; this model is suitable for a global search of the design space. The second model is NURBS parameterization of the blade profile that can be used for a local refinement. The two models are presented and are assessed for flexibility and accuracy when representing several typical turbine blade profiles. The models will be further discussed in terms of curve smoothness and blade shape representation with a multi-NURBS curve versus one curve and its effect on the flow field, in particular the pressure distribution along the blade surfaces, will be elaborated. (author)

Sub-scale Inverse Wind Turbine Blade Design Using Bound Circulation

Science.gov (United States)

Kelley, Christopher; Berg, Jonathan

2014-11-01

A goal of the National Rotor Testbed project at Sandia is to design a sub-scale wind turbine blade that has similitude to a modern, commercial size blade. However, a smaller diameter wind turbine operating at the same tip-speed-ratio exhibits a different range of operating Reynolds numbers across the blade span, thus changing the local lift and drag coefficients. Differences to load distribution also affect the wake dynamics and stability. An inverse wind turbine blade design tool has been implemented which uses a target, dimensionless circulation distribution from a full-scale blade to find the chord and twist along a sub-scale blade. In addition, airfoil polar data are interpolated from a few specified span stations leading to a smooth, manufacturable blade. The iterative process perturbs chord and twist, after running a blade element momentum theory code, to reduce the residual sum of the squares between the modeled sub-scale circulation and the target full-scale circulation. It is shown that the converged sub-scale design also leads to performance similarity in thrust and power coefficients. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy under Contract DE-AC04-94AL85000.

Experimental convective heat transfer characterization of pulsating jet in cross flow: influence of Strouhal number excitation on film cooling effectiveness

International Nuclear Information System (INIS)

Lalizel, Gildas; Sultan, Qaiser; Fénot, Matthieu; Dorignac, Eva

2012-01-01

In actual gas turbine system, unsteadiness of the mainstream flow influences heat transfer and surface pressure distribution on the blade. In order to simulate these conditions, an experimental film cooling study with externally imposed pulsation is performed with purpose of characterizing both effects of turbine unsteadiness on film cooling (with frequency ranges typical to actual turbine), and also to figure out the range of Strouhal number pulsation under various blowing conditions, which could possibly deliver a performance improvement in film cooling. Influence of injection flow pulsation on adiabatic effectiveness and convective heat transfer coefficient are determined from IR-thermography of the wall for distances to the hole exit between 0 and 30 D.

On the Cutting Performance of Segmented Diamond Blades when Dry-Cutting Concrete.

Science.gov (United States)

Sánchez Egea, A J; Martynenko, V; Martínez Krahmer, D; López de Lacalle, L N; Benítez, A; Genovese, G

2018-02-09

The objective of the present study is to analyze and compare the cutting performance of segmented diamond blades when dry-cutting concrete. A cutting criteria is proposed to characterize the wear of the blades by measuring the variation of the external diameter and the weight loss of the blade. The results exhibit the cutting blade SB-A, which has twice the density of diamonds and large contact area, exhibits less wear even though the material removal rate is higher compared with the other two cutting blades. Additionally, the surface topography of the different blades is evaluated to examine the impact of wear depending on the surface profile and the distribution of the diamonds in the blade's matrix. Large number of diamonds pull-out are found in blades type SB-C, which additionally shows the worst wear resistant capability. As a conclusion, the cutting efficiency of the blade is found to be related to the density of embedded diamonds and the type of the surface profile of the cutting blade after reaching the stop criteria.

Effect of a rough surface on the aerodynamic characteristics of a two-bladed wind-powered engine with cylindrical blades

Science.gov (United States)

Tanasheva, N. K.; Kunakbaev, T. O.; Dyusembaeva, A. N.; Shuyushbayeva, N. N.; Damekova, S. K.

2017-11-01

We have reported the results of experiments on determining the drag coefficient and the thrust coefficient of a two-bladed wind-powered engine based on the Magnus effect with rotating rough cylinders in the range of air flow velocity of 4-10 m/s (Re = 26800-90000) for a constant rotation number of a cylindrical blade about its own axis. The results show that an increase in the Reynolds number reduces the drag coefficient and the thrust coefficient. The extent of the influence of the relative roughness on the aerodynamic characteristics of the two-bladed wind-powered engine has been experimentally established.

Aircraft rotor blade with passive tuned tab

Science.gov (United States)

Campbell, T. G. (Inventor)

1985-01-01

A structure for reducing vibratory airloading in a rotor blade with a leading edge and a trailing edge includes a cut out portion at the trailing edge. A substantially wedge shaped cross section, inertially deflectable tab, also with a leading edge and a trailing edge is pivotally mounted in the cut out portion. The trailing edge of the tab may move above and below the rotor blade. A torsion strap applies force against the tab when the trailing edge of the tab is above and below the rotor blade. A restraining member is slidably movable along the torsion strap to vary torsional biasing force supplied by the torsion bar to the tab. A plurality of movable weights positioned between plates vary a center of gravity of the tab. Skin of the tab is formed from unidirectional graphite and fiberglass layers. Sliders coupled with a pinned degree of freedom at rod eliminate bending of tab under edgewise blade deflection.

On the inverse problem of blade design for centrifugal pumps and fans

Science.gov (United States)

Kruyt, N. P.; Westra, R. W.

2014-06-01

The inverse problem of blade design for centrifugal pumps and fans has been studied. The solution to this problem provides the geometry of rotor blades that realize specified performance characteristics, together with the corresponding flow field. Here a three-dimensional solution method is described in which the so-called meridional geometry is fixed and the distribution of the azimuthal angle at the three-dimensional blade surface is determined for blades of infinitesimal thickness. The developed formulation is based on potential-flow theory. Besides the blade impermeability condition at the pressure and suction side of the blades, an additional boundary condition at the blade surface is required in order to fix the unknown blade geometry. For this purpose the mean-swirl distribution is employed. The iterative numerical method is based on a three-dimensional finite element method approach in which the flow equations are solved on the domain determined by the latest estimate of the blade geometry, with the mean-swirl distribution boundary condition at the blade surface being enforced. The blade impermeability boundary condition is then used to find an improved estimate of the blade geometry. The robustness of the method is increased by specific techniques, such as spanwise-coupled solution of the discretized impermeability condition and the use of under-relaxation in adjusting the estimates of the blade geometry. Various examples are shown that demonstrate the effectiveness and robustness of the method in finding a solution for the blade geometry of different types of centrifugal pumps and fans. The influence of the employed mean-swirl distribution on the performance characteristics is also investigated.

On the inverse problem of blade design for centrifugal pumps and fans

International Nuclear Information System (INIS)

Kruyt, N P; Westra, R W

2014-01-01

The inverse problem of blade design for centrifugal pumps and fans has been studied. The solution to this problem provides the geometry of rotor blades that realize specified performance characteristics, together with the corresponding flow field. Here a three-dimensional solution method is described in which the so-called meridional geometry is fixed and the distribution of the azimuthal angle at the three-dimensional blade surface is determined for blades of infinitesimal thickness. The developed formulation is based on potential-flow theory. Besides the blade impermeability condition at the pressure and suction side of the blades, an additional boundary condition at the blade surface is required in order to fix the unknown blade geometry. For this purpose the mean-swirl distribution is employed. The iterative numerical method is based on a three-dimensional finite element method approach in which the flow equations are solved on the domain determined by the latest estimate of the blade geometry, with the mean-swirl distribution boundary condition at the blade surface being enforced. The blade impermeability boundary condition is then used to find an improved estimate of the blade geometry. The robustness of the method is increased by specific techniques, such as spanwise-coupled solution of the discretized impermeability condition and the use of under-relaxation in adjusting the estimates of the blade geometry. Various examples are shown that demonstrate the effectiveness and robustness of the method in finding a solution for the blade geometry of different types of centrifugal pumps and fans. The influence of the employed mean-swirl distribution on the performance characteristics is also investigated. (paper)