The Numerical Study Of Three Dimensional Viscous Flow Of Multi-Blade Rows In Turbomachinery

To meet the requirements for 3D viscous flow computational software in steam turbine design, the time marching method and explicit finite volume difference scheme have been employed to simulate rapidly the flow in multi-blade row steam turbines based on the works of predecessor. This paper presents the governing equations of three dimensional viscous flow in the rotating coordinate system. This paper presents four kinds of viscous body force which was used to simulate the viscous effects. The mixing plane model was used to exchange parameters between the blade rows. The multi-grid scheme, and local time stepping and residual smoothing were also used to accelerate the convergence.Due to the difference of geometry and flow parameters form the high pressure cylinder to low pressure cylinder for the steam turbine, it is necessary to calculate respectively. To evaluate the accuracy and reliability, the four kinds of viscous body force were employed to simulate the flow fields for the multi-blade row turbines of the high pressure, and intermediate pressure and low pressure cylinders as six examples. The calculated mass flow rate and efficiency were compared with the design ones, and the distributions of some parameters and secondary flow were shown. The results have shown that the numerical method presented in this paper can get the performance of 3D viscous flow field rapidly, and the precision of the computational results should be acceptable in steam turbine applications. Because of the simple viscous body force and steam as working fluid used here, the models should be further improved. Otherwise, an interface to generate the computational grid and control the calculation was designed by using C# and FORTRAN languages.