Numerical Investigation for a Vanned Mixed Flow Turbine Volute Under Steady Conditions

For automotive applications, a turbocharger which consists essentially of a radial turbine and a centrifugal compressor is used to get more available output torque for internal combustion engines. The volute is also an important component for a turbocharger turbine. It transforms a part of the engine exhaust gas energy into kinetic energy and guides the flow toward the rotor inducer at a suitable flow angle value. This chapter presents our numerical model in order to capture the flow fields within a vanned volute under steady conditions. Numerical simulations were conducted using the CFX 17.0 package to solve Navier–Stokes equations by means of a finite volume discretization method. The good agreement between the experimental and numerical results of the turbine performance confirms the validation of our numerical model. Then, many computed flow discharge parameters such as the averaged volute exit flow angle were plotted to understand the behavior of the volute under different turbine expansion ratios. Furthermore, several loss coefficient distribution and entropy contours were plotted to characterize the occurring losses. In addition, pressure distributions, velocity, and turbulence parameters as well as streamlines were numerically obtained to analyze the flow behavior within the turbine volute.