Finding an optimal blade-profile to improving the performance of partially admitted turbines

Abstract

Purpose

This paper aims to present the designing and investigating various types of impulse blade profiles to find the optimal profile that has better performance than the first or original blade. The studied model is a turbine with an output power below 1 MW and a large pressure ratio up to 20, which is used to gain relatively high specific work output. As a result of its low mass flow rate, the turbine is used under partial-admission conditions. The turbine’s stator is a group of convergence–divergence nozzles that provide supersonic flow.

Design/methodology/approach

More than 10 types of two-dimensional blade profiles were designed using the developed preliminary design calculations and numerical analysis. The numerical results are validated using the existing experimental results. Finally, the case with improved performance is introduced as the final optimum case.

Findings

It was found that the performance parameters such as efficiency, power and torque are increased by more than 8% in the selected best model, in comparison with the original model. Moreover, the total pressure loss is 12% decreased for the selected model. Finally, the selected profile with superior performance is proposed.

Originality/value

Simultaneous numerical tests are conducted to examine the interaction of different supersonic blade profiles with the partially injected flow to the rotor.

Citation

Togh, R.A. and Karimi, M.M. (2020), "Finding an optimal blade-profile to improving the performance of partially admitted turbines", Aircraft Engineering and Aerospace Technology, Vol. 92 No. 6, pp. 863-877. https://doi.org/10.1108/AEAT-06-2019-0132