A Radial Inflow Turbine Impeller for Improved Off-Design Performance

Abstract

Given the instantaneous operating conditions of the radial inflow turbine on a diesel engine and the possible requirement of a variable geometry turbine casing, an alternate approach was used to design an impeller which could accommodate the large variations in inlet states. Several impeller designs were generated and tested. Each was found to give a performance advantage in some portion of the turbine map. A blunt inlet shape design was found to give the best performance at all suspected inlet conditions. A final design turbine wheel was generated to cover the operating range of a variable geometry turbine casing. It was found that this impeller gave improved efficiencies at all operating conditions.