Journal articles: 'Turbomachinery flow'

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Sazonov, Yuri A., Mikhail A. Mokhov, Inna V. Gryaznova, Victoria V. Voronova, Khoren A. Tumanyan, Mikhail A. Frankov, and Nikolay N. Balaka. "Simulation of Hybrid Mesh Turbomachinery using CFD and Additive Technologies." Civil Engineering Journal 8, no. 12 (December 1, 2022): 3815–30. http://dx.doi.org/10.28991/cej-2022-08-12-011.

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This paper develops schematics and evaluates the performance of hybrid mesh turbomachinery at the patenting stage of individual technical solutions. This type of turbomachine uses reduced-sized blades and also forms flow channels with a mesh structure between the blades. The research methods are based on simulations using computational fluid dynamics (CFD) and additive technologies. An intermediate conclusion is that a new scientific direction for investigating and creating hybrid mesh turbomachinery equipped with mesh jet control systems was formed to develop Euler's ideas. This paper describes new possibilities for the simultaneous implementation of two workflows in a single impeller: 1) Turbine workflow, and 2) Compressor workflow. Calculation methods showed possible improvements in the performance of the new turbomachines. This paper considers options for mesh turbomachine operation in the two-stage gas generator mode with partial involvement of atmospheric air in the workflow. Preliminary calculations based on examples show that it is possible to expect a two- to four-times increase in thrust when using hybrid mesh turbomachines. Ongoing studies mainly focus on developing multi-mode turbomachinery that works in complicated conditions, such as offshore oil and gas fields, but some research results are applicable in other industries, for example, in developing hybrid propulsion systems or propulsors. Doi: 10.28991/CEJ-2022-08-12-011 Full Text: PDF

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Sazonov, Yuri Appolonievich, Mikhail A. Mokhov, Inna Vladimirovna Gryaznova, Victoria Vasilievna Voronova, Khoren Arturovich Tumanyan, Mikhail Alexandrovich Frankov, and Nikolay Nikolaevich Balaka. "Designing Mesh Turbomachinery with the Development of Euler’s Ideas and Investigating Flow Distribution Characteristics." Civil Engineering Journal 8, no. 11 (November 1, 2022): 2598–627. http://dx.doi.org/10.28991/cej-2022-08-11-017.

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This research discusses developing an Euler turbine-based hybrid mesh turbomachinery. Within the framework of mechanical engineering science, turbomachinery classification and a novel method for mesh turbomachinery design were considered. In such a turbomachine, large blades are replaced by a set of smaller blades, which are interconnected to form flow channels in a mesh structure. Previous studies (and reasoning within the framework of inductive and deductive logic) showed that the jet mesh control system allows for operation with several flows simultaneously and provides a pulsed flow regime in flow channels. This provides new opportunities for expanding the control range and reducing the thermal load on the turbomachine blades. The novel method for performance evaluation was confirmed by the calculation: the possibility of implementing pulsed cooling of blades periodically washed by a hot working gas flow (at a temperature of 1000°C) and a cold gas flow (at a temperature of 20°C) was shown. The temperature of the blade walls remained 490–525°C. New results of ongoing research are focused on creating multi-mode turbomachinery that operates in complicated conditions, e.g., in offshore gas fields. Gas energy is lost and dissipated in the throttle at the mouth of each high-pressure well. Within the framework of ongoing research, the environmentally friendly net reservoir energy of high-pressure well gas should be rationally used for operating a booster compressor station. Here, the energy consumption from an external power source can be reduced by 50%, according to preliminary estimates. Doi: 10.28991/CEJ-2022-08-11-017 Full Text: PDF

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Bogdanovic-Jovanovic, Jasmina, Bozidar Bogdanovic, and Dragica Milenkovic. "Determination of averaged axisymmetric flow surfaces according to results obtained by numerical simulation of flow in turbomachinery." Thermal Science 16, suppl. 2 (2012): 577–91. http://dx.doi.org/10.2298/tsci120426193b.

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In the increasing need for energy saving worldwide, the designing process of turbomachinery, as an essential part of thermal and hydroenergy systems, goes in the direction of enlarging efficiency. Therefore, the optimization of turbomachinery designing strongly affects the energy efficiency of the entire system. In the designing process of turbomachinery blade profiling, the model of axisymmetric fluid flows is commonly used in technical practice, even though this model suits only the profile cascades with infinite number of infinitely thin blades. The actual flow in turbomachinery profile cascades is not axisymmetric, and it can be fictively derived into the axisymmetric flow by averaging flow parameters in the blade passages according to the circular coordinate. Using numerical simulations of flow in turbomachinery runners, its operating parameters can be preliminarily determined. Furthermore, using the numerically obtained flow parameters in the blade passages, averaged axisymmetric flow surfaces in blade profile cascades can also be determined. The method of determination of averaged flow parameters and averaged meridian streamlines is presented in this paper, using the integral continuity equation for averaged flow parameters. With thus obtained results, every designer can be able to compare the obtained averaged flow surfaces with axisymmetric flow surfaces, as well as the specific work of elementary stages, which are used in the procedure of blade designing. Numerical simulations of flow in an exemplary axial flow pump, used as a part of the thermal power plant cooling system, were performed using Ansys CFX.

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FUNAZAKI, Ken-ichi. "Unsteady Flow Phenomena in Turbomachinery." Proceedings of Mechanical Engineering Congress, Japan 2020 (2020): K05200. http://dx.doi.org/10.1299/jsmemecj.2020.k05200.

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Nishi, Michihiro, Shimpei Mizuki, and Hiroshi Tsukamoto. "Unsteday Flow Phenomena in Turbomachinery." Transactions of the Japan Society of Mechanical Engineers Series B 61, no. 591 (1995): 3811–16. http://dx.doi.org/10.1299/kikaib.61.3811.

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Schröder, Tilman Raphael, Hans-Josef Dohmen, Dieter Brillert, and Friedrich-Karl Benra. "Impact of Leakage Inlet Swirl Angle in a Rotor–Stator Cavity on Flow Pattern, Radial Pressure Distribution and Frictional Torque in a Wide Circumferential Reynolds Number Range." International Journal of Turbomachinery, Propulsion and Power 5, no. 2 (April 17, 2020): 7. http://dx.doi.org/10.3390/ijtpp5020007.

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In the side-chambers of radial turbomachinery, which are rotor–stator cavities, complex flow patterns develop that contribute substantially to axial thrust on the shaft and frictional torque on the rotor. Moreover, leakage flow through the side-chambers may occur in both centripetal and centrifugal directions which significantly influences rotor–stator cavity flow and has to be carefully taken into account in the design process: precise correlations quantifying the effects of rotor–stator cavity flow are needed to design reliable, highly efficient turbomachines. This paper presents an experimental investigation of centripetal leakage flow with and without pre-swirl in rotor–stator cavities through combining the experimental results of two test rigs: a hydraulic test rig covering the Reynolds number range of 4 × 10 5 ≤ R e ≤ 3 × 10 6 and a test rig for gaseous rotor–stator cavity flow operating at 2 × 10 7 ≤ R e ≤ 2 × 10 8 . This covers the operating ranges of hydraulic and thermal turbomachinery. In rotor–stator cavities, the Reynolds number R e is defined as R e = Ω b 2 ν with angular rotor velocity Ω , rotor outer radius b and kinematic viscosity ν . The influence of circumferential Reynolds number, axial gap width and centripetal through-flow on the radial pressure distribution, axial thrust and frictional torque is presented, with the through-flow being characterised by its mass flow rate and swirl angle at the inlet. The results present a comprehensive insight into the flow in rotor–stator cavities with superposed centripetal through-flow and provide an extended database to aid the turbomachinery design process.

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RAHMATI, M. T. "APPLICATION OF A PRESSURE CORRECTION METHOD FOR MODELING INCOMPRESSIBLE FLOW THROUGH TURBOMACHINES." International Journal of Computational Methods 06, no. 03 (September 2009): 399–411. http://dx.doi.org/10.1142/s0219876209001905.

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This article presents the application of a RANS algorithm based on a pressure correction method for incompressible flow simulations of low-speed rotating machines. A numerical scheme is developed by extending a flow analysis in a stationary frame to a rotating frame for turbomachinery applications. The numerical scheme is explained with emphasis on the effect of rotation on the flow fields and turbulence modeling. The results of the numerical calculations for flow through an enclosed turbomachine and an extended turbomachine are compared with the experimental data to judge them on realistic flow patterns. The numerical solutions have shown reasonable agreement with the experimental data which demonstrates the merits and robustness of this numerical scheme.

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Bonalumi, Davide, Antonio Giuffrida, and Federico Sicali. "Thermo-economic analysis of a supercritical CO₂-based waste heat recovery system." E3S Web of Conferences 312 (2021): 08022. http://dx.doi.org/10.1051/e3sconf/202131208022.

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This work investigates the performance of a supercritical CO2 cycle as the bottoming cycle of a commercial gas turbine with 4.7 MW of electric power output. In detail, the partial heating cycle is the layout chosen for the interesting trade-off between heat recovery and cycle efficiency with a limited number of components. Single-stage radial turbomachines are selected according to the theory of similitude. In particular, the compressor is a troublesome turbomachine as it works near the critical point where significant variations of the CO2 properties occur. Efficiency values for turbomachinery are not fixed at first glance but result from actual size and running conditions, based on flow rates, enthalpy variations as well as rotational speeds. In addition, a limit is set for the machine Mach numbers in order to avoid heavily loaded turbomachinery. The thermodynamic study of the bottoming cycle is carried out by means of the mass and energy balance equations. A parametric analysis is carried out with particular attention to a number of specific parameters. Considering the power output calculated for the supercritical CO2 cycle, economic calculations are also carried out and the related costs compared to those specific of organic Rankine cycles with similar power output.

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Basson, A., and B. Lakshminarayana. "Numerical Simulation of Tip Clearance Effects in Turbomachinery." Journal of Turbomachinery 117, no. 3 (July 1, 1995): 348–59. http://dx.doi.org/10.1115/1.2835668.

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The numerical formulation developed here includes an efficient grid generation scheme, particularly suited to computational grids for the analysis of turbulent turbo-machinery flows and tip clearance flows, and a semi-implicit, pressure-based computational fluid dynamics scheme that directly includes artificial dissipation, and is applicable to both viscous and inviscid flows. The value of this artificial dissipation is optimized to achieve accuracy and convergency in the solution. The numerical model is used to investigate the structure of tip clearance flows in a turbine nozzle. The structure of leakage flow is captured accurately, including blade-to-blade variation of all three velocity components, pitch and yaw angles, losses and blade static pressures in the tip clearance region. The simulation also includes evaluation of such quantities as leakage mass flow, vortex strength, losses, dominant leakage flow regions, and the spanwise extent affected by the leakage flow. It is demonstrated, through optimization of grid size and artificial dissipation, that the tip clearance flow field can be captured accurately.

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10

Martelli, F., and V. Michelassi. "Viscous flow calculations in turbomachinery channels." Journal de Physique III 3, no. 2 (February 1993): 237–53. http://dx.doi.org/10.1051/jp3:1993129.

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Dring, R. P., and H. D. Joslyn. "Through-Flow Modeling of Axial Turbomachinery." Journal of Engineering for Gas Turbines and Power 108, no. 2 (April 1, 1986): 246–53. http://dx.doi.org/10.1115/1.3239895.

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Through-flow analysis, which is at the heart of the aerodynamic design of turbomachinery, requires as aerodynamic input a row-by-row description of the airfoil loss, deviation, and blockage. Loss and deviation have been investigated extensively in both cascades and rotating rigs as well as in numerous two- and three-dimensional analytical studies. Blockage, however, has received far less attention. As defined herein, blockage is a measure of the departure of the flow field from the condition of axisymmetry which is assumed in the through-flow analysis. The full-span blockage distributions calculated from measured single-stage rotor wake data were used to provide the input to the through-flow analysis, along with the measured full-span distributions of loss and deviation. Measured and computed results are compared for the single-stage rotor operating with both thick and thin inlet hub and tip boundary layers. It is demonstrated that both the level and the spanwise and streamwise distributions of blockage have a strong impact on the computed rotor exit flow field.

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INOUE, Masahiro, and Masato FURUKAWA. "Measurements of Flow Field in Turbomachinery." Journal of the Society of Mechanical Engineers 89, no. 814 (1986): 1020–26. http://dx.doi.org/10.1299/jsmemag.89.814_1020.

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13

Lenherr, Christian, Martin Oschwald, Anestis I. Kalfas, and Reza S. Abhari. "Flow adaptive aerodynamic probe for turbomachinery flows." E3S Web of Conferences 345 (2022): 01007. http://dx.doi.org/10.1051/e3sconf/202234501007.

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In order to enable turbomachinery research to obtain data highly resolved in space and time, a novel flow adaptive aerodynamic probe concept has been developed and presented in this paper. The algorithm selects the measurement positions of the probe automatically and therefore provides higher measurement fidelity compared to traditional methods. The development of the adaptive algorithm has been done in several steps. First an automatic 1Dtraversing algorithm has been developed. The following steps dealt with the subject of a 2D adaptive flow concept development, whereas primarily visual programming language-computer package simulations of the new 2D algorithm have been done based on data from previous test series at the Turbomachinery Laboratory. The new 2D traversing algorithm is fully selfcontrolled and requires minimal input such as blade count and hub and tip diameters. Furthermore, areas of interest (e.g. secondary flows, wake) are detected automatically and higher measuring point resolutions are ensured in these regions. After the successful simulations, the intelligent 2D algorithm has been adapted to an object oriented programming environment used for automated data acquisition and reduction. An evaluation of the flow adaptive aerodynamic flow concept has been done on a pressure turbine facility by means of a steady pneumatic probe. The measurement results show that the new 2D algorithm has the potential to detect new flow phenomena. In contrast to traditional algorithms, which in case of a possible enhancement demand a knowledge of the position of interesting areas such as the wake and vortical structures before starting the measurement, the new algorithm detects the right areas and enhances the resolution fully self controlled in these areas. Furthermore, the new 2D flow adaptive probe concept shows a significant improvement regarding the needed time for one measurement.

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He, L., and K. Sato. "Numerical Solution of Incompressible Unsteady Flows in Turbomachinery." Journal of Fluids Engineering 123, no. 3 (April 5, 2000): 680–85. http://dx.doi.org/10.1115/1.1383595.

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A three-dimensional incompressible viscous flow solver of the thin-layer Navier-Stokes equations was developed for the unsteady turbomachinery flow computations. The solution algorithm for the unsteady flows combines the dual time stepping technique with the artificial compressibility approach for solving the incompressible unsteady flow governing equations. For time accurate calculations, subiterations are introduced by marching the equations in the pseudo-time to fully recover the incompressible continuity equation at each real time step, accelerated with a multi-grid technique. Computations of test cases show satisfactory agreements with corresponding theoretical and experimental results, demonstrating the validity and applicability of the present method to unsteady incompressible turbomachinery flows.

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Wissink, J. G., and W. Rodi. "Direct Numerical Simulations of Transitional Flow in Turbomachinery." Journal of Turbomachinery 128, no. 4 (February 2, 2006): 668–78. http://dx.doi.org/10.1115/1.2218517.

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An overview is provided of various direct numerical simulations (DNS) of transitional flows in turbine-related geometries. Two flow cases are considered: the first case concerns separating flow over a flat plate and the second case flows in turbine cascades. In the first case, in which Re=60,000, either an oscillating oncoming flow (1) or a uniform flow with and without oncoming turbulent free-stream fluctuations (2) is prescribed at the inlet. In both subcases (1) and (2), separation is induced by a contoured upper wall. In (1), the separated boundary layer is found to roll up due to a Kelvin-Helmholtz (KH) instability. This rolled-up shear layer is subject to spanwise instability and disintegrates rapidly into turbulent fluctuations. In (2), a massive separation bubble is obtained in the simulation without oncoming free-stream fluctuations. A KH instability is eventually triggered by numerical round-off error and is followed again by a rapid transition. With oncoming turbulent fluctuations, this KH instability is triggered much earlier and transition is enhanced, which leads to a drastic reduction in size of the separation bubble. The second case, concerning flow in turbine cascades, includes (1) flow in the T106 turbine cascade with periodically oncoming wakes at Re=51,800 and (2) flow and heat transfer in a MTU cascade with oncoming wakes and background turbulence at Re=72,000. In the simulation of flow in the T106 cascade with oncoming wakes, the boundary layer along the downstream half of the suction side is found to separate intermittently and subsequently rolls up due to a KH instability leading to separation-induced transition. At times when the wakes impinge separation is suppressed. In the simulations of flow around a MTU turbine blade, evidence of by-pass transition in the suction-side boundary-layer flow is observed while the pressure-side boundary layer remains laminar in spite of significant fluctuations present. In agreement with the experiments, the impinging wakes cause the heat transfer coefficient to increase significantly in the transitional suction-side region close to the trailing edge and by about 30% on the pressure side. The large increase in heat transfer in the pre-transitional suction-side region observed in the experiments could not be reproduced. The discrepancy is explained by differences in spectral contents of the turbulence in the oncoming wakes.

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Denton, J. D., and L. Xu. "The exploitation of three-dimensional flow in turbomachinery design." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 213, no. 2 (February 1, 1998): 125–37. http://dx.doi.org/10.1243/0954406991522220.

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Many of the phenomena involved in turbomachinery flow can be understood and predicted on a two-dimensional (2D) or quasi-three-dimensional (Q3D) basis, but some aspects of the flow must be considered as fully three-dimensional (3D) and cannot be understood or predicted by the Q3D approach. Probably the best known of these fully 3D effects is secondary flow, which can only be predicted by a fully 3D calculation which includes the vorticity at inlet to the blade row. It has long been recognized that blade sweep and lean also produce fully 3D effects and approximate methods of calculating these have been developed. However, the advent of fully 3D flow field calculation methods has made predictions of these complex effects much more readily available and accurate so that they are now being exploited in design. This paper will attempt to describe and discuss fully 3D flow effects with particular reference to their use to improve turbomachine performance. Although the discussion is restricted to axial flow machines, many of the phenomena discussed are equally applicable to mixed and radial flow turbines and compressors.

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Korakianitis, T., J. I. Hochstein, and D. Zou. "Prediction of the Transient Thermodynamic Response of a Closed-Cycle Regenerative Gas Turbine." Journal of Engineering for Gas Turbines and Power 127, no. 1 (January 1, 2005): 57–64. http://dx.doi.org/10.1115/1.1806449.

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Instantaneous-response and transient-flow component models for the prediction of the transient response of gas turbine cycles are presented. The component models are based on applications of the principles of conservation of mass, energy, and momentum. The models are coupled to simulate the system transient thermodynamic behavior, and used to predict the transient response of a closed-cycle regenerative Brayton cycle. Various system transients are simulated using: the instantaneous-response turbomachinery models coupled with transient-flow heat-exchanger models; and transient-flow turbomachinery models coupled with transient-flow heat-exchanger models. The component sizes are comparable to those for a solar-powered Space Station (radial turbomachinery), but the models can easily be expanded to other applications with axial turbomachinery. An iterative scheme based on the principle of conservation of working-fluid mass in the system is used to compute the mass-flow rate at the solar-receiver inlet during the transients. In the process the mass-flow rate of every component at every time step is also computed. Representative results of different system models are compared and discussed.

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Adamczyk, John J. "Aerodynamic Analysis of Multistage Turbomachinery Flows in Support of Aerodynamic Design." Journal of Turbomachinery 122, no. 2 (February 1, 1999): 189–217. http://dx.doi.org/10.1115/1.555439.

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This paper summarizes the state of 3D CFD based models of the time-averaged flow field within axial flow multistage turbomachines. Emphasis is placed on models that are compatible with the industrial design environment and those models that offer the potential of providing credible results at both design and off-design operating conditions. The need to develop models free of aerodynamic input from semiempirical design systems is stressed. The accuracy of such models is shown to be dependent upon their ability to account for the unsteady flow environment in multistage turbomachinery. The relevant flow physics associated with some of the unsteady flow processes present in axial flow multistage machinery are presented along with procedures that can be used to account for them in 3D CFD simulations. Sample results are presented for both axial flow compressors and axial flow turbines that help to illustrate the enhanced predictive capabilities afforded by including these procedures in 3D CFD simulations. Finally, suggestions are given for future work on the development of time-averaged flow models. [S0889-504X(00)02002-X]

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Yang, Hyeonmo, Kyoung-Yong Lee, Youngseok Choi, and Kyungseok Jeong. "Visualization of Flow inside a Regenerative Turbomachinery." International Journal of Fluid Machinery and Systems 7, no. 2 (June 30, 2014): 80–85. http://dx.doi.org/10.5293/ijfms.2014.7.2.080.

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HAYAMI, Hiroshi. "Flow in Turbomachinery and Application of PIV." Proceedings of the Fluids engineering conference 2004 (2004): 3. http://dx.doi.org/10.1299/jsmefed.2004.3.

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Schafer, O. "Simulation of unsteady compressible flow in turbomachinery." Progress in Computational Fluid Dynamics, An International Journal 2, no. 1 (2002): 1. http://dx.doi.org/10.1504/pcfd.2002.003212.

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Choi, Jong-Soo. "Discharge flow measurements of a centrifugal turbomachinery." KSME Journal 8, no. 2 (June 1994): 152–60. http://dx.doi.org/10.1007/bf02953264.

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Zhou, Xin, Zhitao Zuo, Qi Liang, Hucan Hou, Hongtao Tang, and Haisheng Chen. "Synergy Methodology for Internal Flow of Turbomachinery." Journal of Thermal Science 29, no. 3 (November 5, 2019): 730–42. http://dx.doi.org/10.1007/s11630-019-1205-6.

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Chew, John W., and Nicholas J. Hills. "Computational fluid dynamics for turbomachinery internal air systems." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 365, no. 1859 (May 22, 2007): 2587–611. http://dx.doi.org/10.1098/rsta.2007.2022.

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Considerable progress in development and application of computational fluid dynamics (CFD) for aeroengine internal flow systems has been made in recent years. CFD is regularly used in industry for assessment of air systems, and the performance of CFD for basic axisymmetric rotor/rotor and stator/rotor disc cavities with radial throughflow is largely understood and documented. Incorporation of three-dimensional geometrical features and calculation of unsteady flows are becoming commonplace. Automation of CFD, coupling with thermal models of the solid components, and extension of CFD models to include both air system and main gas path flows are current areas of development. CFD is also being used as a research tool to investigate a number of flow phenomena that are not yet fully understood. These include buoyancy-affected flows in rotating cavities, rim seal flows and mixed air/oil flows. Large eddy simulation has shown considerable promise for the buoyancy-driven flows and its use for air system flows is expected to expand in the future.

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Wadia, A. R., and B. F. Beacher. "Three-Dimensional Relief in Turbomachinery Blading." Journal of Turbomachinery 112, no. 4 (October 1, 1990): 587–96. http://dx.doi.org/10.1115/1.2927697.

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The leading edge region of turbomachinery blading in the vicinity of the endwalls is typically characterized by an abrupt increase in the inlet flow angle and a reduction in total pressure associated with endwall boundary layer flow. Conventional two-dimensional cascade analysis of the airfoil sections at the endwalls indicates large leading edge loadings, which are apparently detrimental to the performance. However, experimental data exist that suggest that cascade leading edge loading conditions are not nearly as severe as those indicated by a two-dimensional cascade analysis. This discrepancy between two-dimensional cascade analyses and experimental measurements has generally been attributed to inviscid three-dimensional effects. This article reports on two and three-dimensional calculations of the flow within two axial-flow compressor stators operating near their design points. The computational results of the three-dimensional analysis reveal a significant three-dimensional relief near the casing endwall that is absent in the two-dimensional calculations. The calculated inviscid three-dimensional relief at the endwall is substantiated by airfoil surface static pressure measurements on low-speed research compressor blading designed to model the flow in the high-speed compressor. A strong spanwise flow toward the endwall along the leading edge on the suction surface of the airfoil is responsible for the relief in the leading edge loading at the endwall. This radial migration of flow results in a more uniform spanwise loading compared to that predicted by two-dimensional calculations.

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Lakshminarayana, B. "An Assessment of Computational Fluid Dynamic Techniques in the Analysis and Design of Turbomachinery—The 1990 Freeman Scholar Lecture." Journal of Fluids Engineering 113, no. 3 (September 1, 1991): 315–52. http://dx.doi.org/10.1115/1.2909503.

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The objective of this paper is to review and assess various computational fluid dynamic techniques used for the analysis and design of turbomachinery. Assessments of accuracy, efficiency, range of applicability, effect of physical approximations, and turbulence models are carried out. Suggestions are made as to the most appropriate technique to be used in a given situation. The emphasis of the paper is on the Euler and Navier-Stokes solvers with a brief assessment of boundary layer solutions, quasi three-dimensional and quasi-viscous techniques. A brief review of the techniques and assessment of the following methods are carried out: pressure-based method, explicit and implicit time marching techniques, pseudo-compressibility technique for incompressible flow, and zonal techniques. Recommendations are made with regard to the most appropriate technique for various flow regimes and types of turbomachinery, incompressible and compressible flows, cascades, rotors, stators, liquid-handling and gas-handling turbomachinery. Computational fluid dynamics has reached a high level of maturity; Euler codes are routinely used in design and analysis, and the Navier-Stokes codes will also be commonplace before the end of this decade. But to capture the realism in turbomachinery rotors and multi-stage turbomachinery, it is necessary to integrate the physical models along with the computational techniques. Turbulence and transition modeling, grid generation, and numerical techniques play a key role. Finally, recommendations are made for future research, including the need for validation data, improved acceleration schemes, techniques for two-phase flow, improved turbulence and transition models, development of zonal techniques, and grid generation techniques to handle complex geometries.

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Hall, K. C., W. S. Clark, and C. B. Lorence. "A Linearized Euler Analysis of Unsteady Transonic Flows in Turbomachinery." Journal of Turbomachinery 116, no. 3 (July 1, 1994): 477–88. http://dx.doi.org/10.1115/1.2929437.

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A computational method for efficiently predicting unsteady transonic flows in two-and three-dimensional cascades is presented. The unsteady flow is modeled using a linearized Euler analysis whereby the unsteady flow field is decomposed into a nonlinear mean flow plus a linear harmonically varying unsteady flow. The equations that govern the perturbation flow, the linearized Euler equations, are linear variable coefficient equations. For transonic flows containing shocks, shock capturing is used to model the shock impulse (the unsteady load due to the harmonic motion of the shock). A conservative Lax–Wendroff scheme is used to obtain a set of linearized finite volume equations that describe the harmonic small disturbance behavior of the flow. Conditions under which such a discretization will correctly predict the shock impulse are investigated. Computational results are presented that demonstrate the accuracy and efficiency of the present method as well as the essential role of unsteady shock impulse loads on the flutter stability of fans.

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Cumpsty, N. A., and J. H. Horlock. "Averaging Nonuniform Flow for a Purpose." Journal of Turbomachinery 128, no. 1 (February 1, 2005): 120–29. http://dx.doi.org/10.1115/1.2098807.

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Averaging nonuniform flow is important for the analysis of measurements in turbomachinery and gas turbines; more recently an important need for averaging arises with results of computational fluid dynamics (CFD). In this paper we show that there is a method for averaging which is “correct,” in the sense of preserving the essential features of the nonuniform flow, but that the type of averaging which is appropriate depends on the application considered. The crucial feature is the decision to retain or conserve those quantities which are most important in the case considered. Examples are given to demonstrate the appropriate methods to average nonuniform flows in the accounting for turbomachinery blade row performance, production of thrust in a nozzle, and mass flow capacity in a choked turbine. It is also shown that the numerical differences for different types of averaging are, in many cases, remarkably small.

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Panwalker, A. S., A. Rajamani, and V. Ramamurti. "Turbomachinery Blade Dynamics -- a Review." Shock and Vibration Digest 22, no. 12 (December 1, 1990): 3–9. http://dx.doi.org/10.1177/058310249002201203.

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Vitale, Salvatore, Tim A. Albring, Matteo Pini, Nicolas R. Gauger, and Piero Colonna. "Fully turbulent discrete adjoint solver for non-ideal compressible flow applications." Journal of the Global Power and Propulsion Society 1 (November 22, 2017): Z1FVOI. http://dx.doi.org/10.22261/jgpps.z1fvoi.

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Abstract Non-Ideal Compressible Fluid-Dynamics (NICFD) has recently been established as a sector of fluid mechanics dealing with the flows of dense vapors, supercritical fluids, and two-phase fluids, whose properties significantly depart from those of the ideal gas. The flow through an Organic Rankine Cycle (ORC) turbine is an exemplary application, as stators often operate in the supersonic and transonic regime, and are affected by NICFD effects. Other applications are turbomachinery using supercritical CO2 as working fluid or other fluids typical of the oil and gas industry, and components of air conditioning and refrigeration systems. Due to the comparably lower level of experience in the design of this fluid machinery, and the lack of experimental information on NICFD flows, the design of the main components of these processes (i.e., turbomachinery and nozzles) may benefit from adjoint-based automated fluid-dynamic shape optimization. Hence, this work is related to the development and testing of a fully-turbulent adjoint method capable of treating NICFD flows. The method was implemented within the SU2 open-source software infrastructure. The adjoint solver was obtained by linearizing the discretized flow equations and the fluid thermodynamic models by means of advanced Automatic Differentiation (AD) techniques. The new adjoint solver was tested on exemplary turbomachinery cases. Results demonstrate the method effectiveness in improving simulated fluid-dynamic performance, and underline the importance of accurately modeling non-ideal thermodynamic and viscous effects when optimizing internal flows influenced by NICFD phenomena.

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Gossweiler, C. R., P. Kupferschmied, and G. Gyarmathy. "On Fast-Response Probes: Part 1—Technology, Calibration, and Application to Turbomachinery." Journal of Turbomachinery 117, no. 4 (October 1, 1995): 611–17. http://dx.doi.org/10.1115/1.2836579.

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A system for fast-response probe measurements in turbomachine flows has been developed and tested. The system has been designed for 40 kHz bandwidth and used with various in-house built probes accommodating up to four piezoresistive pressure transducers. The present generation of probes works accurately up to several bar pressure and 120°C temperature. The probes were found to be quite robust. The use of a miniature pressure transducer placed in the head of a probe showed that a precise packaging technique and a careful compensation of errors can considerably improve the accuracy of the pressure measurement. Methods for aerodynamic probe calibration and off-line data evaluation are briefly presented. These aimed, e.g., in the case of a four-hole probe, at measuring the velocity fluctuations as characterized by yaw, pitch, total pressure, and static pressure and at deriving mean values and spectral or turbulence parameters. Applications of the measuring system to turbomachinery flow in a radial compressor and to a turbulent pipe flow demonstrate the performance of the measuring system.

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32

Terzis, Alexandros, Pavlos K. Zachos, Bernard A. Charnley, and Anestis I. Kalfas. "Application of oil and dye flow visualization in incompressible turbomachinery flows." E3S Web of Conferences 345 (2022): 02003. http://dx.doi.org/10.1051/e3sconf/202234502003.

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Flow visualization is one of many available tools in experimental fluid mechanics and is used from the primary stages of fluid mechanics research in order to identify the physical sizes and locations of the flow features under consideration. Most of the fluids used in engineering applications are transparent (water, air, etc) and flow visualization techniques are used in order to make their flow patterns visible. Simple flow visualization experiments are relatively inexpensive and they can be easily implemented providing with a first feeling of the characteristics of the flow domain. Subsequently, flow visualization techniques are of great applicability in complex flow fields and especially in turbomachinery applications where the flow is characterized by three dimensional and secondary flow patterns. In general, fluid motion can be visualized by surface flow visualization, by particle tracer methods or by optical methods. The former flow visualization technique reveals the streamlines of fluid flows around a solid surface. In this paper flow visualization techniques applied in two different cases of experimental testing (fans in crossflow and cascade experiment) are presented. In both cases, the mixture of paint was prepared using a highly volatile light mineral or heavy machine oil of viscosities of approximately 100cP and 200cP, respectively, together with very fine pigments of Titanium Dioxide (TiO2) or fluorescein sodium in various colors. After the preparation of the mixture, a homogenous thin film was applied onto the whole plate surface by painting it with a soft brush. The air stream which flows over the surface of the plate, modifies the concentration and the homogeneity of the oil film, according to the flow conditions very close to the wall. The film was dried by the airflow and photographed for further consideration while the time taken for drying depended on the wind tunnel velocity as well as, on the pigmentation of the mixture. Successful and un-successful flow visualization tests are herein presented while each case is respectively commented as far as the mixtures, the proportions used and the application onto the rigs are concerned.

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CHEN, Haisheng. "Review of investigation into internal flow of turbomachinery." Chinese Journal of Mechanical Engineering 43, no. 02 (2007): 1. http://dx.doi.org/10.3901/jme.2007.02.001.

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Lenherr, C., A. I. Kalfas, and R. S. Abhari. "A flow adaptive aerodynamic probe concept for turbomachinery." Measurement Science and Technology 18, no. 8 (July 11, 2007): 2599–608. http://dx.doi.org/10.1088/0957-0233/18/8/035.

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35

Carstens, Volker, Ralf Kemme, and Stefan Schmitt. "Coupled simulation of flow-structure interaction in turbomachinery." Aerospace Science and Technology 7, no. 4 (June 2003): 298–306. http://dx.doi.org/10.1016/s1270-9638(03)00016-6.

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36

Madavan, N. K. "Unsteady turbomachinery flow simulations on massively parallel architectures." Computing Systems in Engineering 3, no. 1-4 (January 1992): 241–49. http://dx.doi.org/10.1016/0956-0521(92)90109-v.

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37

Weber, K. F., D. W. Thoe, and R. A. Delaney. "Analysis of Three-Dimensional Turbomachinery Flows on C-Type Grids Using an Implicit Euler Solver." Journal of Turbomachinery 112, no. 3 (July 1, 1990): 362–69. http://dx.doi.org/10.1115/1.2927668.

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A three-dimensional Euler analysis for turbomachinery flows on a C-type grid is presented. The analysis is based on the Beam and Warming implicit algorithm for solution of the unsteady Euler equations and is derived from the ARC3D code developed by Pulliam at NASA Ames Research Center. Modifications made to convert this code from external flow applications to internal turbomachinery flows are given in detail. These changes include the addition of inflow, outflow, and periodic boundary point calculation procedures. Also presented are the C-grid construction procedures. Finally, results of code experimental verification studies for three-dimensional compressor cascade and rotor flows are presented.

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Song, Kang, Ben Zhao, Harold Sun, and Weilin Yi. "A physics-based zero-dimensional model for the mass flow rate of a turbocharger compressor with uniform/distorted inlet condition." International Journal of Engine Research 20, no. 6 (May 14, 2018): 624–39. http://dx.doi.org/10.1177/1468087418773673.

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Turbocharger compressor, when fitted to a vehicle, usually operates with a curved inlet pipe which leads to distorted inlet flow field, hence deteriorating compressor flow capability. During the measurement of compressor performance, turbocharger-engine matching and controller design, the inlet flow field is, however, assumed to be uniform, which deviates from the real-world conditions. Consequently, the overall system performance could be compromised if the inlet distortion effect is ignored. To address this issue, in this article, a turbomachinery physics-based zero-dimensional model was proposed for the mass flow rate of a compressor with distorted inlet flow field due to 90° and 180° bent inlet pipe. The non-uniform flow is approximated as two-zone flow field, similar to parallel compressors, with the total pressure deviation between two zones modeled as a function of the flow velocity and pipe geometry. For each flow zone, the corresponding mass flow rate is estimated by approximating each sub-compressor as an adiabatic nozzle, where the fluid is driven by external work delivered by a compressor wheel governed by Euler’s turbomachinery equation. By including turbomachinery physics and compressor geometry information into the modeling, the model achieves high fidelity in compressor map interpretation and extrapolation, which is validated in experiments and the three-dimensional computational fluid dynamic simulation.

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Chew, J. W. "Developments in turbomachinery internal air systems." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 223, no. 1 (December 1, 2008): 189–234. http://dx.doi.org/10.1243/09544062jmes1140.

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Development of turbomachinery technology, including aircraft propulsion, has been an outstanding achievement of the last 50 years and, as illustrated by Ruffles in his paper ‘The future of aircraft propulsion’ (2000), further advances are expected in the future. Here, one particular aspect of turbomachinery technology, the internal air system is considered. An article by Dixon et al., published by the Institution of Mechanical Engineers in 2004, shows how computational modelling has become central to the design process and the importance of the internal air system in engine design. Bayley and Conway's 1964 paper, motivated by shortcomings in industrial design methods and understanding, was one of the first investigations of flow and heat transfer in rotating disc cavities typical of internal air systems. During the study, a theoretical or numerical treatment was considered intractable and so experiments were undertaken. These paved the way for an extensive research in this area. Today, the use of computational fluid dynamics (CFD) in industry for internal air flow prediction is commonplace. In this review, it is shown that the unshrouded disc cavity flow considered by Bayley and Conway is still challenging for modern CFD methods, and so the experimental data remain of interest to researchers in the field.

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Cinnella, P., P. De Palma, G. Pascazio, and M. Napolitano. "A Numerical Method for Turbomachinery Aeroelasticity." Journal of Turbomachinery 126, no. 2 (April 1, 2004): 310–16. http://dx.doi.org/10.1115/1.1738122.

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This work provides an accurate and efficient numerical method for turbomachinery flutter. The unsteady Euler or Reynolds-averaged Navier-Stokes equations are solved in integral form, the blade passages being discretised using a background fixed C-grid and a body-fitted C-grid moving with the blade. In the overlapping region data are exchanged between the two grids at every time step, using bilinear interpolation. The method employs Roe’s second-order-accurate flux difference splitting scheme for the inviscid fluxes, a standard second-order discretisation of the viscous terms, and a three-level backward difference formula for the time derivatives. The dual-time-stepping technique is used to evaluate the nonlinear residual at each time step. The state-of-the-art second-order accuracy of unsteady transonic flow solvers is thus carried over to flutter computations. The code is proven to be accurate and efficient by computing the 4th Aeroelastic Standard Configuration, namely, the subsonic flow through a turbine cascade with flutter instability in the first bending mode, where viscous effect are found practically negligible. Then, for the very severe 11th Aeroelastic Standard Configuration, namely, transonic flow through a turbine cascade at off-design conditions, benchmark solutions are provided for various values of the inter-blade phase angle.

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Rossikhin, Anton A. "Frequency-domain method for multistage turbomachine tone noise calculation." International Journal of Aeroacoustics 16, no. 6 (September 2017): 491–506. http://dx.doi.org/10.1177/1475472x17730458.

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A method of frequency-domain calculation of the multistage turbomachinery tone noise is presented. The method is based on the kinematic relations featuring dependence of flow fields in a turbomachine on time and circumferential angle. It solves the flow in several blade passages inside each row and can be used in conjunction with nonlinear equations. The method is developed at Central Institute of Aviation Motor and implemented in the Three Dimensional Acoustics Solver in-house solver. The multi-passage method is verified on two numerical problems. One is the tone noise generation by a 2D two stage turbine. The other is the problem of nonlinear interaction of circumferential modes in a 2D cylindrical channel.

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Kirk, R. G., K. V. S. Raju, and K. Ramesh. "PC-Based Analysis of Turbomachinery Vibration." Shock and Vibration Digest 31, no. 6 (November 1, 1999): 449–54. http://dx.doi.org/10.1177/058310249903100602.

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43

Ferguson, T., and R. McGlynn. "Validation of Turbomachinery Computational Fluid Dynamic Models Using Laser Velocimetry." Journal of the IEST 42, no. 6 (November 17, 1999): 19–25. http://dx.doi.org/10.17764/jiet.42.6.y0162422x862g242.

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Computational fluid dynamic (CFD) codes are powerful tools for flow field modeling. The codes, however, must be calibrated with data from actual flows if the predictions of the analysis are to be applied with confidence. Laser velocimetry is one method whereby the predictions of the codes can be anchored with accurate, noninvasive flow-field data. This paper explores the process from initial CFD concerns to the application of the velocimeter in the test facility.

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Wiedermann, Alexander, Kazuyoshi Miyagawa, and Tsuyoshi Eguchi. "On the Development of Viscous Solvers for Computation of Transient Flows in Turbomachines." International Journal of Rotating Machinery 5, no. 4 (1999): 251–61. http://dx.doi.org/10.1155/s1023621x99000226.

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This paper focuses on development and validation of a viscous solver for the computation of unsteady flows in turbomachinery blade rows and stages consisting of rotors and stators. The code has been evolved from steady-state single flow solvers developed by Wiedermann based on time-marching finite difference schemes. A two-equation eddy viscosity model is applied, and the wall boundary conditions are determined by they+-distance of the first grid line away from the wall. For the solution of transient flow fields the original time-stepping algorithm is replaced by a time-accurate scheme.The emphasis of the code validation will be on blade-row interaction in a complete turbomachinery stage. A 3-D example will be discussed and those parameters evaluated which are important for actual blading design.

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Kämmerer, Steffen, Jürgen F. Mayer, Heinz Stetter, Meinhard Paffrath, Utz Wever, and Alexander R. Jung. "Development of a Three-Dimensional Geometry Optimization Method for Turbomachinery Applications." International Journal of Rotating Machinery 10, no. 5 (2004): 373–85. http://dx.doi.org/10.1155/s1023621x04000387.

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This article describes the development of a method for optimization of the geometry of three-dimensional turbine blades within a stage configuration. The method is based on flow simulations and gradient-based optimization techniques. This approach uses the fully parameterized blade geometry as variables for the optimization problem. Physical parameters such as stagger angle, stacking line, and chord length are part of the model. Constraints guarantee the requirements for cooling, casting, and machining of the blades.The fluid physics of the turbomachine and hence the objective function of the optimization problem are calculated by means of a three-dimensional Navier-Stokes solver especially designed for turbomachinery applications. The gradients required for the optimization algorithm are computed by numerically solving the sensitivity equations. Therefore, the explicitly differentiated Navier-Stokes equations are incorporated into the numerical method of the flow solver, enabling the computation of the sensitivity equations with the same numerical scheme as used for the flow field solution.This article introduces the components of the fully automated optimization loop and their interactions. Furthermore, the sensitivity equation method is discussed and several aspects of the implementation into a flow solver are presented. Flow simulations and sensitivity calculations are presented for different test cases and parameters. The validation of the computed sensitivities is performed by means of finite differences.

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46

Sandberg, Richard D., and Vittorio Michelassi. "Fluid Dynamics of Axial Turbomachinery: Blade- and Stage-Level Simulations and Models." Annual Review of Fluid Mechanics 54, no. 1 (January 5, 2022): 255–85. http://dx.doi.org/10.1146/annurev-fluid-031221-105530.

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The current generation of axial turbomachines is the culmination of decades of experience, and detailed understanding of the underlying flow physics has been a key factor for achieving high efficiency and reliability. Driven by advances in numerical methods and relentless growth in computing power, computational fluid dynamics has increasingly provided insights into the rich fluid dynamics involved and how it relates to loss generation. This article presents some of the complex flow phenomena occurring in bladed components of gas turbines and illustrates how simulations have contributed to their understanding and the challenges they pose for modeling. The interaction of key aerodynamic features with deterministic unsteadiness, caused by multiple blade rows, and stochastic unsteadiness, i.e., turbulence, is discussed. High-fidelity simulations of increasingly realistic configurations and models improved with help of machine learning promise to further grow turbomachinery performance and reliability and, thus, help fluid mechanics research have a greater industrial impact.

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47

Eastwood, Simon J., Paul G. Tucker, Hao Xia, and Christian Klostermeier. "Developing large eddy simulation for turbomachinery applications." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 367, no. 1899 (July 28, 2009): 2999–3013. http://dx.doi.org/10.1098/rsta.2008.0281.

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For jets, large eddy resolving simulations are compared for a range of numerical schemes with no subgrid scale (SGS) model and for a range of SGS models with the same scheme. There is little variation in results for the different SGS models, and it is shown that, for schemes which tend towards having dissipative elements, the SGS model can be abandoned, giving what can be termed numerical large eddy simulation (NLES). More complex geometries are investigated, including coaxial and chevron nozzle jets. A near-wall Reynolds-averaged Navier–Stokes (RANS) model is used to cover over streak-like structures that cannot be resolved. Compressor and turbine flows are also successfully computed using a similar NLES–RANS strategy. Upstream of the compressor leading edge, the RANS layer is helpful in preventing premature separation. Capturing the correct flow over the turbine is particularly challenging, but nonetheless the RANS layer is helpful. In relation to the SGS model, for the flows considered, evidence suggests issues such as inflow conditions, problem definition and transition are more influential.

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Sbardella, L., and M. Imregun. "Linearized Unsteady Viscous Turbomachinery Flows Using Hybrid Grids." Journal of Turbomachinery 123, no. 3 (February 1, 2001): 568–82. http://dx.doi.org/10.1115/1.1371777.

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The paper describes the theory and the numerical implementation of a three-dimensional finite volume scheme for the solution of the linearized, unsteady Favre-averaged Navier–Stokes equations for turbomachinery applications. A further feature is the use of mixed element grids, consisting of triangles and quadrilaterals in two dimensions, and of tetrahedra, triangular prisms, and hexahedra in three dimensions. The linearized unsteady viscous flow equations are derived by assuming small harmonic perturbations from a steady-state flow and the resulting equations are solved using a pseudo-time marching technique. Such an approach enables the same numerical algorithm to be used for both the nonlinear steady and the linearized unsteady flow computations. The important features of the work are the discretization of the flow domain via a single, unified edge-data structure for mixed element meshes, the use of a Laplacian operator, which results in a nearest neighbor stencil, and the full linearization of the Spalart–Allmaras turbulence model. Four different test cases are presented for the validation of the proposed method. The first one is a comparison against the classical subsonic flat plate cascade theory, the so-called LINSUB benchmark. The aim of the second test case is to check the computational results against the asymptotic analytical solution derived by Lighthill for an unsteady laminar flow. The third test case examines the implications of using inviscid, frozen-turbulence, and fully turbulent models when linearizing the unsteady flow over a transonic turbine blade, the so-called 11th International Standard Configuration. The final test case is a rotor/stator interaction, which not only checks the validity of the formulation for a three-dimensional example, but also highlights other issues, such as the need to linearize the wall functions. Detailed comparisons were carried out against measured steady and unsteady flow data for the last two cases and good overall agreement was obtained.

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Wilcock, R. C., J. B. Young, and J. H. Horlock. "The Effect of Turbine Blade Cooling on the Cycle Efficiency of Gas Turbine Power Cycles." Journal of Engineering for Gas Turbines and Power 127, no. 1 (January 1, 2005): 109–20. http://dx.doi.org/10.1115/1.1805549.

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A thermodynamic cycle analysis computer code for the performance prediction of cooled gas turbines has been used to calculate the efficiency of plants with varying combustor outlet temperature, compressor pressure ratio, and turbomachinery polytropic efficiency. It is shown that the polytropic efficiency exerts a major influence on the optimum operating point of cooled gas turbines: for moderate turbomachinery efficiency the search for enhanced combustor outlet temperature is shown to be logical, but for high turbomachinery efficiency this is not necessarily so. The sensitivity of the cycle efficiency to variation in the parameters determining the cooling flow rates is also examined. While increases in allowable blade metal temperature and film cooling effectiveness are more beneficial than improvements in other parameters, neither is as important as increase in turbomachinery aerodynamic efficiency.

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Farrell, K. J., and M. L. Billet. "A Correlation of Leakage Vortex Cavitation in Axial-Flow Pumps." Journal of Fluids Engineering 116, no. 3 (September 1, 1994): 551–57. http://dx.doi.org/10.1115/1.2910312.

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Tip clearance flow in turbomachinery can lead to losses in efficiency and stall margin. In liquid handling turbomachinery, the vortical flow field, formed from the interaction of the leakage flow with the through-flow, is subject to cavitation. Furthermore, this flow field is complex and not well understood. A correlation of variables which predict the vortex minimum pressure has been formulated. Measurements of the important variables for this correlation have been made on a high Reynolds number (3 × 106) axial-flow test rig. The correlation has been applied to the measured data and other data sets from the literature with good agreement. An optimum tip clearance has been theoretically identified as experiments have shown. Observations of cavitation indicate a second vortex originating along the suction side trailing edge.

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Journal articles on the topic 'Turbomachinery flow'

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