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3 TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk
2 Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka

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The Development of new CFD Solver for 3D Turbomachinery Flow Computations

Yershov S., Yakovlev V., Derevyanko A., Gryzun M., Kozyrets D.

Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka

2012

nr 141

15-24

The concept of the new CFD solver for the 3D turbomachinery flow simulation using the RANS equations is considered. The governing equations are supplemented with the k-ω SST turbulence model. The realisability constraints and the special boundary conditions for adverse pressure gradient flows are shown to be important. An improved numerical technique is suggested to increase efficiency and robustness of the computational procedure. Numerical results for selected test cases are presented. Screenshots of the developed software are shown.

Prediction of Laminar-Turbulent Transition with the Low-Reynolds Model and Kinetic Energy Production Limiter

Derevyanko A., Yershov S.

Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka

2012

nr 141

7-14

A bypass transition model has been implemented in the FlowER solver. The model is based on the Shear Stress Transport turbulence model and Low-Reynolds transition model with the kinetic energy production limiter. The modifications of transition model are implemented to enable fully turbulent flow beyond the transition region. Test cases include the classical flat-plate boundary flows and low-pressure compressor cascade. It is shown that proposed model allows an approximate simulation of some effects in a transitional flow.

3D shape optimisation of turbomachinery blading

Lampart P., Yershov S.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

2002

Vol. 6, No 1

113-125

The shape of HP gas and steam turbine stages, as well as of an LP exit stage of a steam turbine, is optimised numerically using a code Optimus and 3D RANS solver FLowER. The numerical method draws on direct constrained optimisation based on the method of deformed polyhedron. Values of the minimised objective function, that is stage losses with the exit energy are found from 3D viscous compressible computations. There are constraints imposed on the mass flow rate, exit swirl angle and reactions. Among the optimised parameters are stator and rotor blade numbers, stagger and twist angles, stator sweep and lean, both straight and compound. The optimisation gives new 3D designs with increased efficiencies.

3D multistage computations of turbine flows using different state equations

Rusanov A. V., Yershov S., Lampart P., Świrdyczuk J., Gardzielewicz A.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

2002

Vol. 6, No 4

591-600

The paper describes the implementation of a modified state equation for perfect gas and Tammann equation into a 3D RANS solver FlowER. In the modification the specific heats are assumed as linear functions of temperature. A 5-stage LP steam turbine stage is calculated, and the comparison of results for constant and variable specific heats is illustrated. The modification significantly improves the correctness of determination of thermodynamic parameters in the entire flow region, especially in the exit stage.

Numerical simulation of 3D flow in axial turbomachines

Yershov S., Rusanov A. V., Gardzielewicz A., Lampart P., Świrdyczuk J.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

1998

Vol. 2, No 2

319-347

The paper is intended to describe a method for the calculation of 3D viscous compressible (subsonic or supersonic) flow in axial turbomachines described in the form of thin-layer Reynolds-averaged Navier-Stokes equations. The method draws on Godunov-type upwind differencing and ENO reconstruction suggested by Harten (1987), so as to assure monotonicity preservation and high accuracy of computational results. The computational efficiency is achieved thanks to the implementation of a simplified H-type multi-grid approach and delta -form implicit step. Turbulent effects are simulated with the help of a modified algebraic model of Baldwin-Lomax (1978). This method was at the foundation of a computer code-a complex software package to calculate 3D flow in multi-stage turbomachines that allows us to obtain local characteristics, like temperature, pressure, density or velocity distributions, as well as global characteristics, such as flow rates, stage reaction, flow efficiency for the considered turbine/compressor stage. The paper also gives selected results of computation of a number of turbomachinery cascades, showing that these results agree reasonably well with the available experimental data.