Wyniki wyszukiwania - BazTech

1

Modernisation of the last stage in the low- pressure cylinder of a steam turbine using CFD and optimisation techniques

Rusanov A. V., Paschenko N. V., Yakovlev V. A., Yershov S. V.

Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka

|

2008

|

nr 133

291--298

EN

The results of gas dynamic improvement of the last stage in the low-pressure cylinder of a steam turbine are presented. The turbine stage performance and the 3D flow patterns were obtained with the CFD solver FlowER. Stage modernisation was carried out in two ways. First, stage blade sections were renovated, and then the 3D blade shape was optimised using the CFD and optimisation techniques. The optimised stage has stator blades with a compound lean at the hub and a compound sweep at the tip. The efficiency of the improved stage is higher by roughly 2 percent at nominal flow conditions and is up to 10 percent for low flow rate conditions as compared to that of the original stage.

2

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

EN

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.

3

Numerical simulation of 3D viscous turbomachinery flow with high-resolution ENO scheme and modern turbulence model

Yershov S. V., Rusanov A. V.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

|

2001

|

Vol. 5, No 4

459-476

EN

This paper presents the basic principles of construction of numerical models for 3D viscous turbulent flows through multi stage turbomachines. The great attention is given to such properties of the methods as accuracy, linear and non-linear stability, robustness and computational efficiency. It is shown that these properties can be guaranteed if the implicit Godunov’s type ENO scheme is used. A 3D code FLOWER has been developed within this concept. Using the code the numerical results are obtained for flows through high loaded compressor cascades, a turbine stage, a low-pressure multi stage turbine and a centrifugal compressor stage. The results of optimisation of a low-pressure turbine last stage are presented.

4

Preliminary investigations of the effect of stator-rotor interaction on the characteristics of an HP turbine stage

Lampart P., Rusanov A. V., Yershov S. V., Świrydczuk J., Gardzilewicz A.

Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka

|

1999

|

nr 115

285--296

EN

A numerical study is conducted to estimate the effect of stator-rotor interaction on the performance of an HP turbine stage. The results obtained from a steady-state mixingplane analysis are compared with those of unsteady simulation based upon generalised time-space periodicity conditions and sliding mesh technique. The most important outcome of this numerical experiment is the comparison of stage reaction and losses obtained from these two methods of calculation. The calculations are performed with the help of a 3D NS solver - Flow ER.

5

Numerical method and code flower for calculation of 3D viscous unsteady flows within axial and radial turbomachines

Yershov S. V., Rusanov A. V.

Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka

|

1999

|

nr 115

479--488

EN

The numerical method of the 3D compressible unsteady viscous flow through axial and radial turbomachine is developed. The approach is based on numerical integration of the Reynolds-averaged Navier-Stokes equations with implicit high-resolution ENO scheme. To demonstrate the power of the method the following results are presented: 3D flows through straight test cascades; 3D viscous flows in turbine and compressor (axial and radial) stages unsteady wake propagation through blade-to-blade passages of downstream row; unsteady blade cooling effects.

6

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

EN

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.