Numerical Simulation of 3D Viscous Flow in Exhaust Casing of a Low-Pressure Steam Turbine

Numerical results of a 3D viscous flow in an exhaust casing of a low-pressure steam turbine were obtained with the 3D Navier-Stokes solver Fine/Turbo. Good agreements with the available experimental data in velocity, static and total pressure coefficients were exhibited. The computational results revealed a complex vortex system within the casing model, including a passage vortex, a separation vortex and an endwall vortex. Of all the vortices, most portion of energy losses within the casing is contributed by the passage vortex. The calculated overall mass averaged total pressure loss in the casing is nearly 47.8%, very close to the experimental value of 40.9%.