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
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
The paper presents shortly current state of numerical simulation of turbomachinery flows. The choice of flow model, turbulence modelling and numerical technique is considered by the example of CFD solver FlowER. The numerical results for turbomachinery flows concerning unsteady effects, flow leakages, film-cooling and blade shape optimization are shown.
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
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
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
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
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.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.