Numerical and Experimental Investigation of the Stators Overlapping Degree on Partially Admitted Supersonic Turbine Performance

This paper presents experimental and numerical evaluations of convergent-divergent stators overlapping degree effects on an impulse supersonic turbine performance. The studied model is a small turbine with a large pressure ratio that is being used to produce high specific work output in the liquid propellant engine. Because of a low-mass flow rate, the turbine is used in partial admission condition. The turbine stator is a group of convergence-divergence nozzles that provide the supersonic flow. Five stators with different NAA are modeled and tested. In the turbine performance prediction code, an empirical efficiency relationship is used. This relationship is corrected in the turbine test rig that is designed by the author. The results of prediction code and numerical and experimental tests show that the NAA has a significant impact on the three-dimensional distribution of the flow in the stator downstream. The flow loss distribution and the turbine performance are changed as a result of the flow pattern changing.