Steady and pulsating flow efficiency of a waste-gated turbocharger radial flow turbine for automotive application

In the paper the results of an experimental investigation developed on a small turbocharger turbine for automotive application are presented, including the effect of the waste-gate valve opening. The study was focused on the evaluation of turbine efficiency, especially under unsteady flow conditions typically occurring in automotive turbocharged engines. Turbine efficiency values measured under steady and pulsating flow conditions are compared, also considering a quasi-steady flow approach.