Journal articles on the topic 'Turbine disk'
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1
Vinnes, Magnus K., Stefano Gambuzza, Bharathram Ganapathisubramani, and R. Jason Hearst. "The far wake of porous disks and a model wind turbine: Similarities and differences assessed by hot-wire anemometry." Journal of Renewable and Sustainable Energy 14, no. 2 (March 2022): 023304. http://dx.doi.org/10.1063/5.0074218.
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The wakes of two different porous disks have been evaluated experimentally. Such disks are commonly used as physical actuator disk analogs for wind turbines. One disk is made of a uniform wire mesh, while the other has a nonuniform design with radial spars connected by rings. The disks have the same solidity and produce approximately the same drag. The wakes have also been compared to the wake of a model wind turbine and a solid disk. In contrast to earlier studies, the far wake, up to 30 diameters downstream, is included in the comparison. In the near wake, the velocity deficit and turbulence intensity profiles of the disk wakes differ significantly. High levels of turbulence intensity in the wake of the nonuniform disk increase the transverse transport in the wake, which leads to faster spreading and lower velocity deficits in the far wake, compared to the uniform disk and the wind turbine. High velocity gradients in the wake of the uniform disk give rise to turbulence production farther downstream, maintaining higher turbulence levels in the far wake. In addition, coherent vortex shedding is only identified in the wake of the nonuniform disk. None of the disks were able to replicate the asymmetric features of the wind turbine wake. Nonetheless, the results highlight important flow physics that should be considered in the design process of a porous disk used as a wind turbine surrogate.
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Hamdani Umar, Teuku Muhammad Kashogi, Sarwo Edhy Sofyan, Razali Thaib, and Akram. "CFD Simulation of Tesla Turbines Performance Driven by Flue Gas of Internal Combustion Engine." Journal of Advanced Research in Applied Mechanics 98, no. 1 (October 15, 2022): 1–11. http://dx.doi.org/10.37934/aram.98.1.111.
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The reduced production of fossil energy, especially petroleum, has encouraged researchers to continuously increase the role of new and renewable energy as part of energy security and independence. A Tesla turbine is a device that can be used to recover wasted energy from exhaust gases, thereby increasing the overall energy use. The purpose of this study was to assess the performance of a Tesla turbine using various parameters such as engine speed, the gap between the disks, the diameter of the disks, and the number of disks. In this study, the performance of a Tesla turbine was simulated using computational fluid dynamics (CFD). The reference dimensions of this Tesla turbine are made with a slit diameter of 44 mm, a hole diameter of 10 mm, disc diameter of 140 mm, a disc width of 1.5 mm, a disc gap of 35 mm, a disc gap width of 4 mm, and a shaft length of 50 mm. The results of this study were in the form of torque and pressure drop values. In the variation of engine speed, the highest torque was at 1800 rpm with a torque value of 0.422 Nm, and the highest pressure drop was at 1800 rpm with a pressure drop value of 79161.5 Pa. In the disk gap variation, the highest torque is at a 7 mm disk gap with a torque value of 0.54 Nm and the highest pressure drop is at a 4 mm disk gap with a pressure drop value of 79161.5 Pa. In the variation of disk diameter, the highest torque was found on the disk with a diameter of 180 mm and a torque value of 0.831 Nm, and the highest pressure drop was on a disk with a diameter of 180 mm and a pressure drop value of 86753.5 Pa. In the variation of the number of disks, the highest torque was found at eight disks with a torque value of 0.765 Nm, and the highest pressure drop was found at eight disks with a pressure drop value of 82031.3 Pa. After performing this simulation, it can be concluded that at variations in engine speed, the higher the engine speed, the higher the value obtained and the variations in the disk gap, disk diameter, and number of disks. There are several values of torque that increase and decrease because the input value given cannot always increase the torque value in these variations.
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Zhou, Wan Lin, Wen Hao Chen, and Fu Jun Zhang. "Forming Process Simulation and Optimization of Nickel-Base Superalloy Turbine Disk." Advanced Materials Research 1004-1005 (August 2014): 1156–61. http://dx.doi.org/10.4028/www.scientific.net/amr.1004-1005.1156.
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Turbine disc is the key component of aviation engine, its performance is important to ensure the reliability and safety of the whole aviation engine. In this paper, forging forming of GH4169 alloy turbine disks of certain type aero-engine are discsimulated by DEFORM-3D soft system,these forming methods include next three kinds: common hot die forging, isothermal forging and composite sheath hot die forging.The influences of various forging ways on turbine disk forging quality and the used die are analyzed in order to find the most suitable way of forging. The forging defects in the forging process are analyzed . For basically eliminating these defects, the forging process of superalloy turbine disk are optimized based on the most economical and simple principles and some useful methds are gained，which will provide a reference to actual superalloy turbine disk forging process.
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Traum, Matthew J., and Hope L. Weiss. "Tiny Tesla Turbine Analytical Performance Validation Via Dynamic Dynamometry." E3S Web of Conferences 113 (2019): 03024. http://dx.doi.org/10.1051/e3sconf/201911303024.
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Tesla turbines produce power at high rotation rate and low torque relative to other prime movers. At a tiny scale, this attribute renders Tesla turbines poorly matched to dynamometers designed to characterize electricand gasoline-powered radio-controlled vehicles and kit cars. Techniques are needed to enable Tesla turbine design and performance evaluation. An analytical modelling approach was recently developed by Carey, and a complimentary experimental technique, dynamic dynamometry, can determine Tesla turbine power curves without a dynamometer. This paper mutually validates these approaches by comparing them to each other using results from a 3D printed 4-disk tiny Tesla turbine with characteristic disk inner/outer diameter of 11.54 ± 0.01 mm and 24.85 ± 0.01 mm respectively. The Carey model predicts maximum power output of 0.077 ± 0.015 W, and dynamic dynamometry predicts 0.122 ± 0.008 W, a 36.9% difference. Bounding assumptions were used and more accurate parameter measurements will drive these values closer together. Peculiarities of tiny Tesla turbine operation are also described, including the discovery that turbine spin-down rotational velocity is not linear with time. This phenomenon is likely caused by fluid boundary layer shear between the housing and outer disks. It is not observed in larger Tesla turbines, suggesting a speed, size and/or disk count threshold at which this phenomenon introduces non-trivial parasitic reduction in performance.
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Daniels, W. A., B. V. Johnson, and D. J. Graber. "Aerodynamic and Torque Characteristics of Enclosed Co/Counterrotating Disks." Journal of Turbomachinery 113, no. 1 (January 1, 1991): 67–74. http://dx.doi.org/10.1115/1.2927739.
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Experiments were conducted to determine the aerodynamic and torque characteristics of adjacent rotating disks enclosed in a shroud. These experiments were performed to obtain an extended data base for advanced turbine designs such as the counterrotating turbine. Torque measurements were obtained on both disks in the rotating frame of reference for corotating, counterrotating, and one-rotating/one-static disk conditions. The disk models used in the experiments included disks with typical smooth turbine geometry, disks with bolts, disks with bolts and partial bolt covers, and flat disks. A windage diaphragm was installed at midcavity for some experiments. The experiments were conducted with various amounts of coolant throughflow injected into the disk cavity from the disk hub or from the disk o.d. with swirl. The experiments were conducted at disk tangential Reynolds number up to 1.6 × 107 with air as the working fluid. The results of this investigation indicated that the static shroud contributes a significant amount to the total friction within the disk system, the torque on counterrotating disks is essentially independent of coolant flow total rate, flow direction, and tangential Reynolds number over the range of conditions tested, and a static windage diaphragm reduces disk friction in counterrotating disk systems.
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Shlyannikov, V. N. "Critical Zone Approach for Structural Integrity of Power Engineering Components." Applied Mechanics and Materials 750 (April 2015): 89–95. http://dx.doi.org/10.4028/www.scientific.net/amm.750.89.
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This study is concerned with assessing the integrity of cracked steam turbine rotors components which operate under cyclic loading conditions. Damage accumulation and growth have occurred on the inner surface of slot fillet of key and in a disk and blade rivet attachment. Full-size stress-strain state analysis of turbine disk was performed for different stage of lifetime under considering loading conditions. As a result accumulated damage in critical zones of turbine disks depending on time of loading is defined. The tensile tests were performed for determination the main mechanical properties of disk’s material after loading history. The smooth and notched specimens were cut out from critical zones of turbine disk with given operating time. The low-cycle fatigue tests were performed with the harmonic test-cycle. Additional tests were performed on special designed program test-cycle, which equivalent to start-stop cycle of turbine disk. An engineering approach to the prediction of residual lifetime of turbine disks which is sensitive to the loading history at maintenance is proposed. Approximate estimations of carrying capacity are presented for the different stress-strain state of steam turbine disks at the operation.
7
Lee, Seungjin, Daehan Kim, and Joong Park. "Harmonisation of Coolant Flow Pattern with Wake of Stator Vane to Improve Sealing Effectiveness Using a Wave-Shaped Rim Seal." Energies 12, no. 6 (March 19, 2019): 1060. http://dx.doi.org/10.3390/en12061060.
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The rim seal of the gas turbine is intended to protect the material of the turbine disk from hot combustion gases. The study of the rim seal structure is important to minimise the coolant flow and maximise the sealing effect. In this paper, a wave-shaped rim seal for stator disks is proposed and its effect is confirmed by numerical analysis. To characterise the flow phenomena near the wave-shaped rim seal, a simplified model of the wave-shaped rim seal (Type 1 model), which excludes the rotor blade and stator vane, is analysed and compared with the conventional rim seal. Then, through analysis of the wave-shaped rim seal geometry (Type 2 model), which includes the rotor blade and stator vane, a reduction in egress and ingress flow was observed owing to the wave-shaped rim seal, and the sealing effectiveness on the stator disk of turbine was increased by up to 3.8%. Implementation of the wave-shape geometry in the radial seal is a novel choice for turbine designers to consider in future for better-performing and more-efficient turbines.
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Wharton, Sonia, and Kathryn Foster. "Deploying Taller Turbines in Complex Terrain: A Hill Flow Study (HilFlowS) Perspective." Energies 15, no. 7 (April 6, 2022): 2672. http://dx.doi.org/10.3390/en15072672.
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Terrain-induced flow acceleration is presented for the summertime, peak power season at Lawrence Livermore National Laboratory’s Site 300 for the Hill Flow Study (HilFlowS). HilFlowS, designed as an adjunct field campaign to the Department of Energy’s Second Wind Forecasting Improvement Project (WFIP2), provides wind profile observations at a second location in complex terrain for validating numerical atmospheric model simulations and for better understanding flow behavior over hills for wind power generation. One unique feature of HilFlowS was the inclusion of an undergraduate university student who helped plan and execute the experiment as well as analyze wind data from two remote sensing laser detection and ranging (lidar) instruments deployed along parallel ridgelines. HilFlowS examines the trend of building higher into the atmosphere for the purpose of increasing wind turbine power production and evaluates the wind resource in the Altamont Pass Region of Northern California for a set of wind turbines of differing hub-heights and rotor-disk diameters found in the area. The wind profiles show strongly channeled onshore flow above both hills, enhanced by strong subsidence aloft, which produces a wind maximum (Umax) around z = 10 m and strong negative shear throughout all of the evaluated rotor-disks for much of the summer wind season. Under these conditions, shear becomes more negative with increasing hub-height and increasing rotor-disk size. Rotor-disk equivalent wind speed (Uequiv), a measure of the average wind speed across the entire rotor-disk, is compared to hub-height, rotor length, and rated capacity factor for the set of turbines. Uequiv is most closely related to turbine hub-height and is negatively correlated given the low altitude of Umax. Based on these results, building the largest capacity, large rotor-disk wind turbine at the lowest possible hub-height appears to provide turbines in the Altamont with a fast, near-surface, onshore wind resource during the peak power season.
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Yuan, Zhen Wei, Jun Zhang, and Dong Shuai Zhu. "Spanwise Penetration Depth with Turbine Disk Inclination." Advanced Materials Research 945-949 (June 2014): 887–91. http://dx.doi.org/10.4028/www.scientific.net/amr.945-949.887.
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Spanwise penetration depth as a new correlating parameter was introduced in the cascade profile loss correlation of a new loss breakdown scheme for turbine cascade reported in the literature. For the case of an inclined turbine disk, when a turbine disk is inclined to its design position, the blade incidence or inlet flow angle varies with the position of blade on the turbine disk circumference, leading to the variation of spanwise penetration depth. To examine the influences of turbine disk inclination on the spanwise penetration depth, new correlations were developed and numerical simulations were performed with MATLAB. The role that turbine disk inclination plays in the spanwise penetration depth is manifested in a modified inlet flow angle expression on account of turbine disk inclination. It is concluded that the turbine disk inclination has considerable influences on the spanwise penetration depth in the turbine cascade passage.
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Hu, Bo, Xuesong Li, Yanxia Fu, Chunwei Gu, Xiaodong Ren, and Jiaxing Lu. "Axial Thrust, Disk Frictional Losses, and Heat Transfer in a Gas Turbine Disk Cavity." Energies 12, no. 15 (July 29, 2019): 2917. http://dx.doi.org/10.3390/en12152917.
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The gas turbine is a kind of high-power and high-performance energy machine. Currently, it is a hot issue to improve the efficiency of the gas turbines by reducing the amount of secondary air used in the disk cavity. The precondition is to understand the effects of the through-flow rate on the axial thrust, the disk frictional losses, and the characteristics of heat transfer under various experimental conditions. In this paper, experiments are conducted to analyze the characteristics of flow and heat transfer. To ensure the safe operation of the gas turbine, the pressure distribution and the axial thrust are measured for various experimental conditions. The axial thrust coefficient is found to decrease as the rotational speed and the through-flow rate increases. By torque measurements, the amounts of the moment coefficient drop as the rotational speed increases while increase with through-flow rate. In order to better analyze the temperature field within the cavity, both the local and the average Nusselt number are investigated with the help of thermochromic liquid crystal technique. Four correlations for the local Nusselt number are determined according to the amounts of a through-flow coefficient. The results in this study can help the designers to better design the secondary air system in a gas turbine.
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Lei, Lin, Ming-ze Ding, Hong-wei Hu, Yun-xiao Gao, Hai-lin Xiong, and Wei Wang. "Structural Strength and Reliability Analysis of Important Parts of Marine Diesel Engine Turbocharger." Mathematical Problems in Engineering 2021 (April 19, 2021): 1–20. http://dx.doi.org/10.1155/2021/5547762.
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Supercharging is the main method to improve the output power of marine diesel engines. Nowadays, most marine diesel engines use turbocharging technology, which increases the air pressure and density into the cylinder and the amount of fuel injected correspondingly so as to achieve the purpose of improving the power. In a marine diesel engine, the turbocharger has become an indispensable part. The performance of turbochargers in a harsh working environment of high temperature and high pressure for a long time will directly affect the performance of diesel engine. Based on the market feedback data from manufacturers, the failure modes of compressor impeller, turbine blade, and turbine disk of marine diesel turbocharger are analyzed, and the statistical model of random factors is established. Using DOE design, the structural strength simulation data of 46 compressors and 62 turbines are obtained, and the response surface model is constructed. On this basis, Monte Carlo sampling is carried out to analyze the reliability of the compressor and turbine. The reliability of the compressor is good, while that of the turbine disk is 0.943 and that of the turbine blade is 0.96, which still has the potential of reliability optimization space. Therefore, a multiobjective optimization method based on the NSGA-II genetic algorithm is proposed to obtain the multiobjective optimization scheme data with the reliability and processing cost of turbine disk and blade as the objective function. After optimization, the reliability of turbine disk and blade is 1, the stress value of turbine blade is optimized by 4.7941%, the stress value of turbine disk is optimized by 3.0136%, the machining cost of the turbine blade is reduced by 15.5087%, and the machining cost of turbine disk is reduced by 3.9907%. At the same time, it is verified by simulation, the data based on NSGA-II multiobjective genetic algorithm are more accurate and have practical engineering reference value. The optimized data based on NSGA-II multiobjective genetic algorithm are used to manufacture new turbine samples, and the accelerated test of simulation samples is carried out. The cycle life of the optimized turbine can reach 101,697 cycles and 118,687 cycles, which is 51.75% and 77.11% longer than that of the unoptimized turbine. It can be seen that the optimized turbine can meet the requirements of the reliability index while reducing the manufacturing cost.
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Yuan, Zhen Wei, Jun Zhang, and Dong Shuai Zhu. "Profile Loss Correlations Accounting for Turbine Disk Inclination." Applied Mechanics and Materials 529 (June 2014): 159–63. http://dx.doi.org/10.4028/www.scientific.net/amm.529.159.
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Incidence can significantly affect turbine cascade aerodynamic losses, including profile, secondary and tip-clearance losses. In previous works, correlations for these losses were developed on a convention that the whole cascade has a universal incidence angle. But in reality, there exist exceptional situations when a turbine disk is inclined to its design position. In such cases, the incidence varies with the location of blade on the circumference, leading to loss deviation from its design value. The present paper is motivated to work out new correlations for the profile losses with turbine disk inclinations and examine the effects of turbine disk inclination. Based on the state-of-the-art works, new correlations are developed to take into account the incidence variation by redefining the inlet flow angle in terms of turbine disk inclination angle and location angle of blade on turbine disk circumference. The effects of turbine disk inclination on profile losses were examined through numerical simulations. It is concluded that the turbine disk inclination has considerable influences on the profile losses of turbine cascade.
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Huang, Xiaoyu, Pan Wang, Haihe Li, and Zheng Zhang. "Fatigue reliability and sensitivity analysis of turbine disk with fuzzy failure status." Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University 39, no. 6 (December 2021): 1312–19. http://dx.doi.org/10.1051/jnwpu/20213961312.
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Low-cycle fatigue is typical failure mode of aero-engine turbine disk, traditional reliability analysis method based on the binary state assumption has certain limitations for turbine disk reliability evaluation, because it doesn't consider the change of damage strength parameter caused by loading sequences and the enhanced damage by small load. On the basis of fatigue reliability analysis of the turbine disk, this paper considers the fuzzy state assumption of turbine disk, then select the membership function and indicate fuzzy failure probability of turbine disk, which can be transformed into a series of conventional failure probability by Gaussian quadrature. An active learning Kriging model is used to orderly calculate the failure probability corresponding to different limit state functions and the fuzzy failure probability of turbine disk. A global sensitivity index based on fuzzy failure probability is established to analyze the influence of input variables on the fuzzy failure probability, which is helpful to the reliability design and structural optimization of the turbine disk.
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Yu, Ming, Xin Ke Yu, Wen Jin Wang, Jing Zhang, and Ling Li Zhang. "Weak-Points Diagnosis of Gas Turbine Disk by Modal Parameter Identification." Key Engineering Materials 584 (September 2013): 112–16. http://dx.doi.org/10.4028/www.scientific.net/kem.584.112.
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In order to keep gas turbine disk safe and reliable, and to provide reliable data for the dynamic design or modification of a gas turbine disk, dynamic characteristic of the gas turbine disk has to be obtained. In the paper, the method based on the combination of calculation mode and the experiment mode is proposed to analysis the dynamic characteristic of the gas turbine disk. The modal parameters and the mode shapes are calculated through ANSYS program. On the basis of these modal parameters, the faults of the gas turbine disk are shown and its weak points of the design are illustrated. The reason for deformation is analyzed and relevant measures employed to reduce faults are proposed. By these improvements in question, a guarantee of the gas turbine disk working normally has been available.
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Gao, Yang, Chang Jun Yang, Kai Lin, and Qing Gao. "Reliability Analysis of LCF Life for a Turbine Disk." Advanced Materials Research 146-147 (October 2010): 1379–85. http://dx.doi.org/10.4028/www.scientific.net/amr.146-147.1379.
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Cyclic stress-strain curve and cyclic strain-life curve appear distinct scatters, and the scatter of fatigue life increases with reducing of the strain levels. A methodology for reliability simulation of low cycle fatigue (LCF) life for turbine disk structures is developed in this paper. First, probabilistic cyclic stress-strain model and linear heteroscedastic probabilistic cyclic strain-life model are founded based on the fatigue test data. Second, three dimensional model of a turbine disk is built, and the fatigue reliability analysis of this turbine disk is implemented in probabilistic design module (PDS) of ANSYS by the combination of response surface method (RSM) and Monte Carlo simulation (MCS). The predicted life with reliability 0.9987 is well consistent with the technology life obtained from disks LCF tests by scatter factors method.
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Cairo, R. R., and K. A. Sargent. "Twin Web Disk: A Step Beyond Convention." Journal of Engineering for Gas Turbines and Power 124, no. 2 (March 26, 2002): 298–302. http://dx.doi.org/10.1115/1.1445440.
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This paper will discuss a study of an innovative design for an advanced turbine rotor that could have a great impact on future engines. The design challenge is to provide a minimum weight turbine rotor system that can withstand beyond state-of-the-art levels of AN2 (turbine annulus area multiplied by speed squared). An AN2 limit has been reached for high-pressure turbine (HPT) disks configured in conventional (single web) geometry with state-of-the-art nickel alloys. The problem has reached the point where increased AN2 has been declared a “break-through” technology. The twin-web disk has the potential to provide this break through. This paper will present the history of this turbine rotor design, analytical results, material/component processing, and concept validation results. All work was performed under an Air Force sponsored program entitled “Composite Ring Reinforced Turbine” (CRRT).
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Moraga, G., C. Valero, D. Valentín, M. Egusquiza, X. Xia, L. Zhou, and A. Presas. "Characterization of the Fluid Damping in Simplified Models of Pump-Turbines and High Head Francis Runners." IOP Conference Series: Earth and Environmental Science 1079, no. 1 (September 1, 2022): 012091. http://dx.doi.org/10.1088/1755-1315/1079/1/012091.
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Abstract In order to satisfy the power demand in the electrical grid, hydraulic turbine units frequently work under off-design operation conditions and pass through transient events. These operation conditions can lead to high vibration amplitudes in the turbine runners, decreasing their useful life, and in some cases to premature failures. To determine and to understand the behaviour of the fluid damping is a relevant topic, because this parameter limits the maximum amplitude in resonance conditions. The runner of some types of turbines, such as reversible pump-turbine and high head Francis turbine, can be modelled as a disk-like structure, due to their similar mode shapes. Because of this, in this work, the fluid damping of a vibrating disk was studied. The disk was submerged in water and was put in a resonant state at different vibration amplitudes. Moreover, this structure was excited at different distances to a rigid surface, in order to analyse the effects of the distance between the runner and the casing. The main effects on the fluid damping were determined and characterized, showing a dependency of the fluid damping ratio on the different parameters.
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Amano, R. S., K. D. Wang, and V. Pavelic. "A Study of Rotor Cavities and Heat Transfer in a Cooling Process in a Gas Turbine." Journal of Turbomachinery 116, no. 2 (April 1, 1994): 333–38. http://dx.doi.org/10.1115/1.2928369.
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A high-temperature flow through a gas turbine produces a high rate of turbulent heat transfer between the fluid flow field and the turbine components. The heat transfer process through rotor disks causes thermal stress due to the thermal gradient just as the centrifugal force causes mechanical stresses; thus an accurate analysis for the evaluation of thermal behavior is needed. This paper presents a numerical study of thermal flow analysis in a two-stage turbine in order to understand better the detailed flow and heat transfer mechanisms through the cavity and the rotating rotor-disks. The numerical computations were performed to predict thermal fields throughout the rotating disks. The method used in this paper is the “segregation” method, which requires a much smaller number of grids than actually employed in the computations. The results are presented for temperature distributions through the disk and the velocity fields, which illustrate the interaction between the cooling air flow and gas flow created by the disk rotation. The temperature distribution in the disks shows a reasonable trend. The numerical method developed in this study shows that it can be easily adapted for similar computations for air cooling flow patterns through any rotating blade disks in a gas turbine.
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Ghosh, N. C. "Thermal Effect on the Transverse Vibration of High-Speed Rotating Anisotropic Disk." Journal of Applied Mechanics 52, no. 3 (September 1, 1985): 543–48. http://dx.doi.org/10.1115/1.3169098.
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An attempt has been made to consider the thermal effect on the transverse vibration of a high-speed rotating disk in a steady-state heat conduction. The material of the disk, in this case, is assumed to be thermomechanically anisotropic. The present attempt is made with an objective to provide some theoretical studies on the problem that may serve as a base from which more detailed investigations with regard to the usage of composite material may be attempted to gain new and needed design information regarding turbine disks and thereby to reduce the chances of turbine failure. In this connection a new critical speed of disk rotation has been obtained and consequently this critical speed is found to depend on central temperature, thermomechanical anisotropy, and so forth.
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Nakata, Y., J. Y. Murthy, and D. E. Metzger. "Computation of Laminar Flow and Heat Transfer Over an Enclosed Rotating Disk With and Without Jet Impingement." Journal of Turbomachinery 114, no. 4 (October 1, 1992): 881–90. http://dx.doi.org/10.1115/1.2928043.
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Convection heat transfer phenomena on rotating disks are of general interest in relation to turbomachineray design. In gas turbine engines, for example, knowledge of the temperature distribution on turbine disks that are bounded by a fluid cavity is required to predict stresses and durability. Cooling air is generally provided by the compressor section and routed to the turbine disk cavities where it is utilized for cooling both the rotating and stationary components. Since the production and pumping of the compressed cooling air imposes performance penalties on the engine cycle, a goal of the designer is always to minimize cooling air consumption. This requirement produces a need for accurate and detailed knowledge of the convection heat transfer and flow characteristics associated with disk cavity flows for a large variety of possible cooling configurations. In the past, most reliable information on disk cavity flow and heat transfer has been derived from empirical studies, but the large range of possible geometries and flow conditions precludes a complete coverage by experiment alone. In the future, it should be possible to supplement disk cavity flow experiments with numerical computations both to aid in interpretation of and to extend empirical results. The present numerical study of laminar flow cases is intended to complement previous experimental information for disk convection with jet impingment. The computational method is described and applied first to a baseline case of a rotating disk in an enclosure where results are found to compare favorably with the experiments of Daily and Nece. The two-dimensional approach used to model the inclusion of an impinging jet is described, and the computational method is applied to predict both flow and heat transfer characteristics in the vicinity of the interaction between impinging jet and rotating disk. The computed results partition into impingment-dominated and rotational-dominated regimes similar to the findings of prior experimental studies.
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Nordquist, J., S. Abrahamson, J. Wechkin, and J. Eaton. "Visualization Studies in Rotating Disk Cavity Flows." Journal of Turbomachinery 112, no. 2 (April 1, 1990): 308–10. http://dx.doi.org/10.1115/1.2927656.
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An experimental study was performed in a simplified turbine disk cavity consisting of a single disk rotating near a stationary flat plate, bounded radially by an axial seal fixed to the plate. The disk Reynolds number was 6.2 × 105. Cooling flow was supplied axially at a dimensionless radius of 0.33. Flow visualization showed boundary layers on both the rotating and stationary disks with the core between the layers rotating in solid body motion. At intermediate cooling flow rates, large vortical structures aligned with the disk spin axis and spanning the core were observed.
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Shahriari, B., Mohammadhadi Jalali, and MR Karamooz Ravari. "Vibration analysis of a rotating variable thickness bladed disk for aircraft gas turbine engine using generalized differential quadrature method." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 231, no. 14 (January 8, 2017): 2739–49. http://dx.doi.org/10.1177/0954410016684360.
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In this paper, free vibration analysis of rotating variable thickness annular bladed disk suitable to be used in aircraft gas turbine engine is investigated. The numerical generalized differential quadrature method is introduced in this paper as a fast and efficient numerical method to be used for vibration analysis of bladed disks of real gas turbine engines. The boundary conditions are supposed to be similar to those of the real bladed disk used in the aircraft engines i.e. clamped for the inner edge and free for the outer edge. Considering the thickness of the disk to vary as a power function and the blades of the bladed disk to be rigid, the numerical solution is performed and the effects of thickness variation, geometric parameters, angular velocity, and number of blades on the natural frequencies and critical speeds are investigated. The obtained numerical results are compared with those reported in the literature indicating a good agreement.
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Yuan, Zhen Wei, Jun Zhang, and Dong Shuai Zhu. "Cascade Aerodynamic Loss Correlations Accounting for Turbine Disk Inclination." Applied Mechanics and Materials 575 (June 2014): 370–75. http://dx.doi.org/10.4028/www.scientific.net/amm.575.370.
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Turbine cascade aerodynamic losses are heavily related to incidence. Conventional researches have been focused on a single blade row upon the convention that the whole turbine cascade has a universal incidence for all blades on the cascade and accordingly the overall aerodynamic loss of the cascade is the same as a single blade row. However, there are exceptional situations in engineering practice that each blade of a turbine cascade has a different incidence. When a turbine disk is inclined to its design position due to manufacturing errors and/or operating malfunctions, the incidence for a blade on the cascade varies along the circumference of the turbine disk. For such case, the conventional research conclusions are no longer adequate. The present paper is motivated to extend the conventional researches to account for such case. Based on the-state-of-the-art works in this field, new sophisticated correlations for turbine cascade aerodynamic losses were developed to cope with the problems with turbine disk inclination. Numerical simulations were performed to examine the effects of turbine disk inclination on the aerodynamic losses. Beneficial conclusions and remarks are given in the end.
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Vogel, C. R., and R. H. J. Willden. "Designing multi-rotor tidal turbine fences." International Marine Energy Journal 1, no. 1 (Aug) (September 3, 2018): 61–70. http://dx.doi.org/10.36688/imej.1.61-70.
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An embedded Reynolds-Averaged Navier-Stokes blade element actuator disk model is used to investigate the hydrodynamic design of tidal turbines and their performance in a closely spaced cross-stream fence. Turbines designed for confined flows are found to require a larger blade solidity ratio than current turbine design practices imply in order to maximise power. Generally, maximum power can be increased by operating turbines in more confined flows than they were designed for, although this also requires the turbines to operate at a higher rotational speed, which may increase the likelihood of cavitation inception. In-array turbine performance differs from that predicted from single turbine analyses, with cross-fence variation in power and thrust developing between the inboard and outboard turbines. As turbine thrust increases the cross-fence variation increases, as the interference effects between adjacent turbines strengthen as turbine thrust increases, but it is observed that cross-stream variation can be mitigated through strategies such as pitch-to-feather power control. It was found that overall fence performance was maximised by using turbines designed for moderately constrained (blocked) flows, with greater blockage than that based solely on fence geometry, but lower blockage than that based solely on the turbine and local flow passage geometry to balance the multi-scale flow phenomena around tidal fences.
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Bondar, V. S., D. A. Alkhimov, A. I. Fakeev, Y. M. Temis, D. A. Yakushev, and A. V. Pestov. "Computer-aided design of gas turbine engines rotors." Izvestiya MGTU MAMI 9, no. 1-4 (July 10, 2015): 10–20. http://dx.doi.org/10.17816/2074-0530-67096.
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The technology of the optimal design when designing the structure of the rotor disc for turbomachines is showed. The features of the organization of computer-aided design of gas turbine engine rotor are considered. The calculations of gas turbine engine rotor parts optimal form were made. Structural optimization (shape optimization) was applied to optimal design of compressor disk depending on various factors of loading and optimization criteria.
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Jianhua, Yu, Li Xun, Zhao Wenshuo, Qin Bin, and Zhang Yu. "A brief review on the status of machining technology of fir-tree slots on aero-engine turbine disk." Advances in Mechanical Engineering 14, no. 7 (July 2022): 168781322211134. http://dx.doi.org/10.1177/16878132221113420.
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The machining precision and its consistency of turbine disk fir-tree slots have a direct influence on the performance of aero-engine rotor components. However, the structural dimensions of fir-tree slot are small, and the cutting performance of materials is extremely poor, which lead to great difficulty in machining and very few available machining methods. With the application of new materials in the aero-engines, the machining precision and quality requirements of fir-tree slots are further improved. Therefore, many research achievements on the high-efficiency, high-quality and low-cost machining technology of turbine disk fir-tree slots have been obtained. By summarizing and classifying the machining methods of aero-engine turbine disk fir-tree slots, a brief review on the characteristics of different methods are presented in detail, which provide a reference for selecting the appropriate machining method of turbine disk fir-tree slots in the field of aviation manufacturing. Meanwhile, combined with the research and application status of machining technology of turbine disk fir-tree slots, it is presented that multi-process compound machining is an effective method to realize high-efficiency, high-quality and low-cost precision machining of turbine disk fir-tree slots, such as wire electro discharge machining (wire-EDM) and profiled grinding, wire electrochemical machining (wire-ECM) and profiled grinding, wire-EDM and broaching, milling and broaching.
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Yarullin, R. R., V. N. Shlyannikov, and A. G. Sulamanidze. "The Crack Growth in the Imitation Model of a GTE Turbine Disk under Operating Loading Conditions." PNRPU Mechanics Bulletin, no. 2 (December 15, 2021): 203–17. http://dx.doi.org/10.15593/perm.mech/2021.2.18.
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The paper presents the experimental results of growing surface cracks in the turbine disk of a gas turbine engine (GTE) under cyclic tension at room and elevated temperatures. The geometry of the imitation model of the GTE turbine disk with a stress concentration zone in the form of a bolt hole was justified. In order to ensure the similarity of the initial damage of the imitation model and the GTE turbine disc in the plane of symmetry of the stress concentration zone, a semi-elliptical notch was made. The loading conditions of the imitation model were developed based on results of a comparative stress-strain state (SSS) analysis of the stress concentration zone of the imitation model and the GTE turbine disc. As a result of the fatigue test of the imitation model at room and elevated temperatures, the experimental positions and sizes of the crack fronts with respect to the drop potential signal on the crack edges were obtained. The fixed positions and sizes of the crack fronts were used as the basis for the numerical calculation of the fracture resistance parameters. For the numerical studies, ten three-dimensional finite element models with different positions and sizes of the crack fronts were considered. The numerical calculation results based on the finite element method were used to determine the distributions of the elastic stress intensity factors along each crack front. The crack growth rate characteristics both on the free surface and at the deepest point of the crack front were obtained at room and elevated temperature conditions. A technique for the automation tests that simulate the block-type loading of the disk material at elevated temperatures was proposed.
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Davidson, David L. "Gas turbine disk-blade attachment crack." Journal of Failure Analysis and Prevention 5, no. 1 (February 2005): 55–71. http://dx.doi.org/10.1361/15477020522104.
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Zhang, D., and C. H. Tao. "Investigation of a turbine disk failure." Engineering Failure Analysis 5, no. 3 (September 1998): 229–34. http://dx.doi.org/10.1016/s1350-6307(98)00003-x.
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Layton, Richard A., and John J. Marra. "Conceptual Basis for a New Approach to Bladed-Disk Design." Journal of Engineering for Gas Turbines and Power 122, no. 2 (October 25, 1999): 321–25. http://dx.doi.org/10.1115/1.483210.
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A central issue in gas turbine engine design today is the demand for higher performance, greater reliability, shorter lead times, and lower cost. The design of bladed disks (fans, compressors and turbines) is one area in which suitable design tools are sought to meet this demand. In this paper is presented the conceptual basis for a new, energy-based approach to design and an outline for future development of the approach as a software-based design tool. Technical tasks and risks associated with this development are summarized. It is hoped that this study will facilitate dialogue among practitioners of the various disciplines involved in bladed-disk design. [S0742-4795(00)00302-1]
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Liu, Ben Wu, Jian Jun Wang, and Hui Yi Yuan. "Analysis on a Gas Turbine Sealing Disk Structure and Material Strength." Applied Mechanics and Materials 492 (January 2014): 60–70. http://dx.doi.org/10.4028/www.scientific.net/amm.492.60.
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To study the cause for fatigue cracking failure at pressure-balanced holes of a gas turbine compressor sealing disk, the damage impression, fractography and material composition of the damaged section were studied. Some manufacturing defects at the pressure-balanced hole edge were found, and the cracks at pressure-balanced holes are caused by high cycle fatigue (HCF). Stress analysis on the sealing disks of two types of different materials under assembly conditions and different structure dimensions were performed. The analysis results revealed that the high radial stress of pressure-balanced holes is the weak point of the original sealing disk design, and the manufacturing defects will prompt the cracking failure of holes. The studied work is valuable for performing similar fatigue failure analysis and new sealing disk structure design improvement.
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Schreiber, Johannes, Carlo L. Bottasso, and Marta Bertelè. "Field testing of a local wind inflow estimator and wake detector." Wind Energy Science 5, no. 3 (July 7, 2020): 867–84. http://dx.doi.org/10.5194/wes-5-867-2020.
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Abstract. This paper presents the field validation of a method to estimate the local wind speed on different sectors of a turbine rotor disk. Each rotating blade is used as a scanning sensor that, traveling across the rotor disk, samples the inflow. From the local speed estimates, the method can reconstruct the vertical wind shear and detect the presence and location on an impinging wake shed by an upstream wind turbine. Shear and wake awareness have multiple uses, from turbine and farm control to monitoring and forecasting. This validation study is conducted with an experimental data set obtained with two multi-megawatt wind turbines and a hub-tall met mast. Practical and simple procedures are presented and demonstrated to correct for the possible miscalibration of sensors. Results indicate a very good correlation between the estimated vertical shear and the one measured by the met mast. Additionally, the proposed method exhibits a remarkable ability to locate and track the motion of an impinging wake on an affected rotor.
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Chaney, Ken, Alfred J. Eggers,, Patrick J. Moriarty, and William E. Holley. "Skewed Wake Induction Effects on Thrust Distribution on Small Wind Turbine Rotors." Journal of Solar Energy Engineering 123, no. 4 (July 1, 2001): 290–95. http://dx.doi.org/10.1115/1.1410109.
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Accurate prediction of both the center of thrust location and the magnitude of the thrust on a rotor disk are critical to satisfactory modeling of the yawing of small wind turbines to large angles to passively control overshoots in power and loads at higher wind speeds. Of the two, the prediction of the center of thrust location upwind of the center of a yawed rotor disk appears to be the most uncertain and potentially in serious error. This error is due to uncertainties in skewed wake effects on the thrust distribution on the disk. Three skewed wake models are examined to better understand the potential sources of error. First is the dynamic inflow model originally developed for helicopters, and second is a modification of this model developed for wind turbines. Third is an earlier cylindrical vortex wake model which pioneered the study of skewed wake effects for helicopters, and which can be generalized for wind turbine applications. It is concluded that this generalized model and the original dynamic inflow model are the most promising for small wind turbine applications, and their predictions of center of thrust and blade root moments are compared for an idealized rotor. The focus is on static equilibrium loads, and note is taken of the potential importance of accounting for expanding wake effects. The basic results of the study are applicable to large as well as small wind turbine rotors.
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Bhavnani, S. H., J. M. Khodadadi, J. S. Goodling, and J. Waggott. "An Experimental Study of Fluid Flow in Disk Cavities." Journal of Turbomachinery 114, no. 2 (April 1, 1992): 454–61. http://dx.doi.org/10.1115/1.2929165.
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Results are presented for an experimental study of fluid flow in models of gas turbine disk cavities. Experiments were performed on 70-cm-dia disks for rotational Reynolds numbers up to 2.29 × 106. Velocity and pressure distributions are presented and compared to previous theoretical and experimental studies for a free disk, and an unshrouded plane Rotor–Stator disk system. Minimum coolant flow rates for the prevention of ingress, determined for the case of a simple axial rim seal, compare well with previously published data.
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Zhang, Chun-Yi, Zhe-Shan Yuan, Ze Wang, Cheng-Wei Fei, and Cheng Lu. "Probabilistic Fatigue/Creep Optimization of Turbine Bladed Disk with Fuzzy Multi-Extremum Response Surface Method." Materials 12, no. 20 (October 15, 2019): 3367. http://dx.doi.org/10.3390/ma12203367.
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To effectively perform the probabilistic fatigue/creep coupling optimization of a turbine bladed disk, this paper develops the fuzzy multi-extremum response surface method (FMERSM) for the comprehensive probabilistic optimization of multi-failure/multi-component structures, which absorbs the ideas of the extremum response surface method, hierarchical strategy, and fuzzy theory. We studied the approaches of FMERSM modeling and fatigue/creep damage evaluation of turbine bladed disks, and gave the procedure for the fuzzy probabilistic fatigue/creep optimization of a multi-component structure with FMERSM. The probabilistic fatigue/creep coupling optimization of turbine bladed disks was implemented by regarding the rotor speed, temperature, and density as optimization parameters; the creep stress, creep strain, fatigue damage, and creep damage as optimization objectives; and the reliability and GH4133B fatigue/creep damages as constraint functions. The results show that gas temperature T and rotor speed ω are the key parameters that should be controlled in bladed disk optimization, and respectively reduce by 85 K and 113 rad/s after optimization, which is promising to extend bladed disk life and decrease failure damages. The simulation results show that this method has a higher modeling accuracy and computational efficiency than the Monte Carlo method (MCM). The efforts of this study provide a new useful method for overall probabilistic multi-failure optimization and enrich mechanical reliability theory.
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Pilbrow, R., H. Karabay, M. Wilson, and J. M. Owen. "Heat Transfer in a “Cover-Plate” Preswirl Rotating-Disk System." Journal of Turbomachinery 121, no. 2 (April 1, 1999): 249–56. http://dx.doi.org/10.1115/1.2841308.
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In most gas turbines, blade-cooling air is supplied from stationary preswirl nozzles that swirl the air in the direction of rotation of the turbine disk. In the “cover-plate” system, the preswirl nozzles are located radially inward of the blade-cooling holes in the disk, and the swirling airflows radially outward in the cavity between the disk and a cover-plate attached to it. In this combined computational and experimental paper, an axisymmetric elliptic solver, incorporating the Launder–Sharma and the Morse low-Reynolds-number k–ε turbulence models, is used to compute the flow and heat transfer. The computed Nusselt numbers for the heated “turbine disk” are compared with measured values obtained from a rotating-disk rig. Comparisons are presented, for a wide range of coolant flow rates, for rotational Reynolds numbers in the range 0.5 X 106 to 1.5 X 106, and for 0.9 < βp < 3.1, where βp is the preswirl ratio (or ratio of the tangential component of velocity of the cooling air at inlet to the system to that of the disk). Agreement between the computed and measured Nusselt numbers is reasonably good, particularly at the larger Reynolds numbers. A simplified numerical simulation is also conducted to show the effect of the swirl ratio and the other flow parameters on the flow and heat transfer in the cover-plate system.
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Liu, C., and D. D. Macdonald. "Prediction of Failures of Low-Pressure Steam Turbine Disks." Journal of Pressure Vessel Technology 119, no. 4 (November 1, 1997): 393–400. http://dx.doi.org/10.1115/1.2842321.
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Localized corrosion phenomena, including pitting corrosion, stress corrosion cracking, and corrosion fatigue, are the principal causes of corrosion-induced damage in electric power-generating facilities and typically result in more than 50 percent of the unscheduled outages. In this paper, we describe a deterministic method for predicting localized corrosion damage in low-pressure steam turbine disks downstream of the Wilson line, where a condensed, thin electrolyte layer exists on the steel disk surfaces. Our calculations show that the initiation and propagation of stress corrosion cracking (SCC) is not very sensitive to the oxygen content of the steam, but is sensitive to the conductivity of the condensed liquid layer and the stresses (residual and operational) that the disk experiences in service.
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Tucker, V. A. "A Mathematical Model of Bird Collisions With Wind Turbine Rotors." Journal of Solar Energy Engineering 118, no. 4 (November 1, 1996): 253–62. http://dx.doi.org/10.1115/1.2871788.
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When a bird flies through the disk swept out by the blades of a wind turbine rotor, the probability of collision depends on the motions and dimensions of the bird and the blades. The collision model in this paper predicts the probability for birds that glide upwind, downwind, and across the wind past simple one-dimensional blades represented by straight lines, and upwind and downwind past more realistic three-dimensional blades with chord and twist. Probabilities vary over the surface of the disk, and in most cases, the tip of the blade is less likely to collide with a bird than parts of the blade nearer the hub. The mean probability may be found by integration over the disk area. The collision model identifies the rotor characteristics that could be altered to make turbines safer for birds.
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Wdowiński, Wojciech, Elżbieta Szymczyk, Jerzy Jachimowicz, and Grzegorz Moneta. "Design and Strength Analysis of Curved-Root Concept for Compressor Rotor Blade in Gas Turbine." Fatigue of Aircraft Structures 2017, no. 9 (December 1, 2017): 137–55. http://dx.doi.org/10.1515/fas-2017-0011.
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AbstractThe motivation of the article is fatigue and fretting issue of the compressor rotor blades and disks. These phenomena can be caused by high contact pressures leading to fretting occurring on contact faces in the lock (blade-disk connection, attachment of the blade to the disk). Additionally, geometrical notches and high cyclic loading can initiate cracks and lead to engine failures. The paper presents finite element static and modal analyses of the axial compressor 3rd rotor stage (disk and blades) of the K-15 turbine engine. The analyses were performed for the original trapezoidal/dovetail lock geometry and its two modifications (new lock concepts) to optimize the stress state of the disk-blade assembly. The cyclic symmetry formulation was used to reduce modelling and computational effort.
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Zhang, Jun Hong, Feng Lv, and Wen Peng Ma. "Multi-Axial Fatigue Life Model Evaluation and Life Prediction for Turbine Disk." Applied Mechanics and Materials 130-134 (October 2011): 2330–34. http://dx.doi.org/10.4028/www.scientific.net/amm.130-134.2330.
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Multi-axial low cycle fatigue was the main failure mode of turbine disk. Critical plane approach was an idea method for the prediction of multi-axial fatigue life. A lot of models based on critical plane approach have been put forward, but there is not a universal prediction model. In order to find a model for turbine disk, linear heteroscedastic regression analysis of the standard low cycle fatigue data was carried out to obtained fatigue parameters. After verifying the accuracy of the finite element model, the stress and strain history of the danger point was obtained based on elastic-plastic finite element analysis. The critical plane and the damage of it was found by the method of coordinate transformation. The fatigue life of turbine disk was estimated by different models, and the results were quite different. SWT-Bannantine model was more suitable for the turbine disk.
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Liu, J. J., and T. P. Hynes. "The Investigation of Turbine and Exhaust Interactions in Asymmetric Flows— Blade-Row Models Applied." Journal of Turbomachinery 125, no. 1 (January 1, 2003): 121–27. http://dx.doi.org/10.1115/1.1516812.
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This paper describes the blade-row models applied to the asymmetric flow-field coupling between turbine and exhaust system. Numerical actuator disk is applied to represent a turbine blade row around the whole annulus and flow properties across the disk can jump to achieve required flow turning and entropy rise. The derivation of disk boundary conditions and the implementation in CFD solvers are described in detail. Validation of the actuator disk model and sample application of the present numerical approach are presented.
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Park, Juhyeon, Hoyong Lee, Gyejo Jung, and Jinyi Lee. "Nondestructive testing of turbine disk roots using solid-state GMR sensor arrays and an axial directional scanning system." International Journal of Applied Electromagnetics and Mechanics 64, no. 1-4 (December 10, 2020): 525–31. http://dx.doi.org/10.3233/jae-209360.
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A nondestructive testing device, consisting of a scanner and signal processing circuits was developed to detect cracks in turbine disk roots. The scanner consists of a longitudinal feeder and a fir-tree-shaped sensor probe. The feeder inserted the sensor probe along the grooves of the turbine blade attachment. Meanwhile, permanent magnets were placed in opposite direction, to generate a closed magnetic field between the magnetic sensors located on the crests of the sensor probe. The fatigue crack in the turbine disk root occurred in the circumferential direction of the turbine. As a result, magnetic flux leakage was caused by disturbing the flow of closed magnetic field by permanent magnets. The magnetic flux leakage was measured by a magnetic sensor. The effectiveness of the proposed device has been verified using artificial defects introduced into the turbine disk roots by electric discharge machining.
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Ammara, Idriss, Christophe Leclerc, and Christian Masson. "A Viscous Three-Dimensional Differential/Actuator-Disk Method for the Aerodynamic Analysis of Wind Farms." Journal of Solar Energy Engineering 124, no. 4 (November 1, 2002): 345–56. http://dx.doi.org/10.1115/1.1510870.
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Computational Fluid Dynamics (CFD) is a promising tool for the analysis and optimization of wind turbine positioning inside wind parks (also known as wind farms) in order to maximize power production. In this paper, 3-D, time-averaged, steady-state, incompressible Navier-Stokes equations, in which wind turbines are represented by surficial forces, are solved using a Control-Volume Finite Element Method (CVFEM). The fundamentals of developing a practical 3-D method are discussed in this paper, with an emphasis on some of the challenges that arose during their implementation. For isolated turbines, results have indicated that the proposed 3-D method attains the same level of accuracy, in terms of performance predictions, as the previously developed 2-D axisymmetric method and the well-known momentum-strip theory. Furthermore, the capability of the proposed method to predict wind turbine wake characteristics is also illustrated. Satisfactory agreement with experimental measurements has been achieved. The analysis of a two-row periodic wind farm in neutral atmospheric boundary layers demonstrate the existence of positive interference effects (venturi effects) as well as the dominant influence of mutual interference on the performance of dense wind turbine clusters.
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Mirzaee, I., P. Quinn, M. Wilson, and J. M. Owen. "Heat Transfer in a Rotating Cavity With a Stationary Stepped Casing." Journal of Turbomachinery 121, no. 2 (April 1, 1999): 281–87. http://dx.doi.org/10.1115/1.2841312.
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In the system considered here, corotating “turbine” disks are cooled by air supplied at the periphery of the system. The system comprises two corotating disks, connected by a rotating cylindrical hub and shrouded by a stepped, stationary cylindrical outer casing. Cooling air enters the system through holes in the periphery of one disk, and leaves through the clearances between the outer casing and the disks. The paper describes a combined computational and experimental study of the heat transfer in the above-described system. In the experiments, one rotating disk is heated, the hub and outer casing are insulated, and the other disk is quasi-adiabatic. Thermocouples and fluxmeters attached to the heated disc enable the Nusselt numbers, Nu, to be determined for a wide range of rotational speeds and coolant flow rates. Computations are carried out using an axisymmetric elliptic solver incorporating the Launder–Sharma low-Reynolds-number k–ε turbulence model. The flow structure is shown to be complex and depends strongly on the so-called turbulent flow parameter, λT, which incorporates both rotational speed and flow rate. For a given value λT, the computations show that Nu increases as Reφ, the rotational Reynolds number, increases. Despite the complexity of the flow, the agreement between the computed and measured Nusselt numbers is reasonably good.
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Langston, Lee S. "Gas Turbine Progress through Trouble." Mechanical Engineering 133, no. 02 (February 1, 2011): 51. http://dx.doi.org/10.1115/1.2011-feb-7.
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This article discusses some specific incidents of uncontained jet engine failures. Such incidents usually involve the failure and disintegration of a rotating disc associated with the fan, compressor, or turbine of the gas turbine. Armed with enormous rotational kinetic energy, the disintegrated parts of a failed disk and its blading can become dangerous flying projectiles. Such was the case of the inflight failure of the Rolls-Royce Trent 900 engine on Qantas Flight QF32 on the morning of November 4, 2010, with 466 passengers and crew onboard. Fortunately, all Flight QF32 passengers and crew were safe and uninjured, after this uncontained engine failure. A similar incident occurred in 1989 with flight DC-10-10, N1819U flight 232 operated by United Airlines. As a result of this incident, the gas turbine industry, airlines, and regulatory agencies have worked diligently over the intervening years to improve disc inspection, crack detection, manufacturing techniques, and fracture mechanics models.
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Liu, Jing-Sheng, Geoffrey T. Parks, and P. John Clarkson. "Optimization of Turbine Disk Profiles by Metamorphic Development." Journal of Mechanical Design 124, no. 2 (May 16, 2002): 192–200. http://dx.doi.org/10.1115/1.1467079.
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A novel topology/shape optimization method, Metamorphic Development, is applied to an axisymmetric thermo-elasticity design problem. Based on solid modeling and finite element analysis, optimal profiles of minimum mass turbine disks are sought by growing and degenerating simple initial structures subject to both response and geometric constraints. Radial stress, axial stress, hoop stress and von Mises stress are analyzed throughout the optimization and a constraint is imposed on von Mises stress everywhere in the disk. The optimal structures are developed metamorphically in specified infinite design domains using both quadrilateral and triangular axisymmetric finite elements. Comparisons are made of the results obtained for different optimization scenarios: (a) with and without thermal loading; (b) with and without centrifugal body forces; (c) with and without a fit pressure on the inner surface of the hub; and (d) operating at different rotational speeds.
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West, Jacob R., and Sanjiva K. Lele. "Wind Turbine Performance in Very Large Wind Farms: Betz Analysis Revisited." Energies 13, no. 5 (March 1, 2020): 1078. http://dx.doi.org/10.3390/en13051078.
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The theoretical limit for wind turbine performance, the so-called Betz limit, arises from an inviscid, irrotational analysis of the streamtube around an actuator disk. In a wind farm in the atmospheric boundary layer, the physics are considerably more complex, encompassing shear, turbulent transport, and wakes from other turbines. In this study, the mean flow streamtube around a wind turbine in a wind farm is investigated with large eddy simulations of a periodic array of actuator disks in half-channel flow at a range of turbine thrust coefficients. Momentum and mean kinetic energy budgets are presented, connecting the energy budget for an individual turbine to the wind farm performance as a whole. It is noted that boundary layer turbulence plays a key role in wake recovery and energy conversion when considering the entire wind farm. The wind farm power coefficient is maximized when the work done by Reynolds stress on the periphery of the streamtube is maximized, although some mean kinetic energy is also dissipated into turbulence. This results in an optimal value of thrust coefficient lower than the traditional Betz result. The simulation results are used to evaluate Nishino’s model of infinite wind farms, and design trade-offs described by it are presented.
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Lin, Mou, and Fernando Porté-Agel. "Large-eddy simulation of a wind-turbine array subjected to active yaw control." Wind Energy Science 7, no. 6 (November 8, 2022): 2215–30. http://dx.doi.org/10.5194/wes-7-2215-2022.
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Abstract. This study validates large-eddy simulation (LES) for predicting the flow through a wind turbine array subjected to active yaw control. The wind turbine array consists of three miniature wind turbines operated in both non-yawed and yawed configurations under full-wake and partial-wake conditions, for which wind tunnel flow measurements are available. The turbine-induced forces are parametrised by three different models: the standard actuator disk model (ADM-std), the blade element actuator disk model (ADM-BE), also referred to as the rotational actuator disk model (ADM-R), and the actuator line model (ALM). The time-averaged turbine power outputs and the profiles of the wake flow statistics (normalised streamwise mean velocity and streamwise turbulence intensity) obtained from the simulations using the ADM-std, the ADM-BE and the ALM are compared with experimental results. We find that simulations using the ADM-BE and ALM yield flow statistics that are in good agreement with the wind-tunnel measurements for all the studied configurations. In contrast, the results from LES with the ADM-std show discrepancies with the measurements obtained under yawed and/or partial-wake conditions. These errors are due to the fact that the ADM-std assumes a uniform thrust force, thus failing to capture the inherently inhomogeneous distribution of the turbine-induced forces under partial wake conditions. In terms of power prediction, we find that LES using the ADM-BE yields better power predictions than the ADM-std and the ALM in the cases considered in this study. As a result, we conclude that LES using the ADM-BE provides a good balance of accuracy and computational cost for simulations of the flow through wind farms subjected to AYC.
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Virr, G. P., J. W. Chew, and J. Coupland. "Application of Computational Fluid Dynamics to Turbine Disk Cavities." Journal of Turbomachinery 116, no. 4 (October 1, 1994): 701–8. http://dx.doi.org/10.1115/1.2929463.
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A CFD code for the prediction of flow and heat transfer in rotating turbine disk cavities is described and its capabilities demonstrated through comparison with available experimental data. Application of the method to configurations typically found in aeroengine gas turbines is illustrated and discussed. The code employs boundary-fitted coordinates and uses the k–ε turbulence model with alternative near-wall treatments. The wall function approach and a one-equation near-wall model are compared and it is shown that there are particular limitations in the use of wall functions at low rotational Reynolds number. Validation of the code includes comparison with earlier CFD calculations and measurements of heat transfer, disk moment, and fluid velocities. It is concluded that, for this application CFD is a valuable design tool capable of predicting the flow at engine operating conditions, thereby offering the potential for reduced engine testing through enhanced understanding of the physical processes.
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Farthing, P. R., and J. M. Owen. "The Effect of Disk Geometry on Heat Transfer in a Rotating Cavity With a Radial Outflow of Fluid." Journal of Engineering for Gas Turbines and Power 110, no. 1 (January 1, 1988): 70–77. http://dx.doi.org/10.1115/1.3240089.
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Flow visualization and heat transfer measurements have been made in a cavity comprising two nonplane disks of 762 mm diameter and a peripheral shroud, all of which could be rotated up to 2000 rpm. “Cobs,” made from a lightweight foam material and shaped to model the geometry of turbine disks, were attached to the center of each disk. Cooling air at flow rates up to 0.1 kg/s entered the cavity through the center of the “upstream” disk and left via holes in the shroud. The flow structure was found to be similar to that observed in earlier tests for the plane-disk case: a source region, Ekman layers, sink layer, and interior core were observed by flow visualization. Providing the source region did not fill the entire cavity, solutions of the turbulent integral boundary-layer equations provided a reasonable approximation to the Nusselt numbers measured on the heated “downstream” disk.