ABSTRACT
Highly efficient turbine at high expansion ratio is required with the expanded application of the Miller cycle to automotive engines. At high expansion ratio, turbine diffuser plays an important role in turbine efficiency because of the increased leaving loss. In addition, since the turbine operates under engine exhaust pulsation, the diffuser's performance is required to be robust over a wide operating range of velocity ratio. Therefore, internal flow in a turbine diffuser is experimentally investigated under several velocity ratio conditions.
