Numerical Analysis of Steam Flow in Steam Turbine Nozzle Blade Cascade

Abstract

Condensation phenomenon is observed in the stationary and rotating blades of low-pressure steam turbine. In the present paper, computational fluid dynamics (CFD) method was employed to simulate the flow path and condensation phenomenon of steam within the linear blade cascade. Initially, 2D cascade results were validated with the available published experimental data. The comparative study of flow field characteristics such as pressure distribution, Mach number distribution, and wetness fraction is presented with two-phase and IAPWS IF-97 fluid properties in the ANSYS Fluent and ANSYS CFX simulation. Also, the parametric analysis has been carried out to determine the stage exit pressure of cascade. The Eight cases were simulated by the variation in boundary conditions. The cases 1 to 4 were simulated in the ANSYS Fluent and the cases 5 to 8 were simulated in ANSYS CFX. The results of CFX simulation can be used to predict the uneven stage exit pressure. Furthermore, using the Mach number distribution, the shock wave formation due to the condensation of vapours was visualized at the trailing edge of the blade.