Aerodynamic design and performance investigation of an axial turbocharger turbine for automotive application

Abstract

In recent years, developments of vehicle downsizing promote the developers to improve the performance of current turbocharging technology. Due to drawbacks transient response of conventional radial turbine used in turbocharging techniques, preliminary design of axial turbine was proposed, in order to achieve highest performance of turbocharger axial turbine. In this study, the optimal design methodology, based NACA profile blade of a single stage axial turbine for turbocharger system. Therefore, simulation analysis of steady state three dimensional flow carried out by highly reliable for calculation, computational fluid dynamic (CFD), using ANSYS CFX, to be evaluated the stage overall aerodynamic performance of the axial turbine stage. Analysis results, gave a more details of flow behaviour such as, flow separation, vortexes and performance characteristics. Moreover, it is found the pressure load for less blades, it's too low on each blade, and a reasonable pressure blade load on a single blade was therefore seen to be too high for more blades, resulting in loss of Boundary layer of the blade, flow of tip leakage and Secondary flow. Hence, noticeably, it was observed that the aerodynamic performance of turbocharger axial turbine model were predicted numerically such as, total-total Polytropic efficiency (84.64) % and shaft output power (187) kW at (80k) rpm.