Effects of nozzle arrangement angle on the performance of partially admitted turbines

Abstract

This paper presents the experimental and numerical evaluations of the effects of a supersonic Nozzle arrangement angle (NAA) on the performance of an impulse axial turbine. The studied model is a small turbine with a large pressure ratio that is used to gain high specific work output. As a result of its low mass flow rate, the turbine is used under partial admission conditions. The turbine stator is a group of convergence–divergence nozzles that provide supersonic flow. Five stators with different NAAs are modeled and tested. Results show that NAA exerts considerable impact on the performance of the turbine. In this work, suggestions for achieving a decent design process for partly arranged nozzles are offered, and the proposed model and numerical analysis are validated using experimental tests.