Flow pattern improvement in nozzle-rotor axial gap in impulse turbine

Abstract

Purpose

This paper is concerned with improving the flow pattern in the nozzle-rotor axial gap in impulse turbines using a genetic algorithm (GA) and 3D numerical analysis. The paper aims to discuss these issues.

Design/methodology/approach

The appropriate model was used to estimate the turbine performance introduced in the beginning of the work. Then, the nozzle design parameters that are effective in the axial gap flow pattern are optimized using a non-linear optimization code. This code works based on the GA theory. Since the GA results are not conclusive, the selected cases were evaluated using 3D numerical analysis. For a detailed comparison of the flow pattern in initial and improved cases, a transient analysis was done. Experimental tests were performed in order to validate the work. For this purpose, the characteristic curves of the turbines were studied and compared with each other.

Findings

Improving the nozzle-rotor axial gap flow pattern leading to increase in the total-to-total efficiency of the turbine by more than two points.

Research limitations/implications

Partially injected flow forced to use the full model computational analysis.

Practical implications

Weight reduction in a feeding system.

Originality/value

New loss modeling method presented for partial admission condition.

Citation

Aghaei tog, R. and Mesgarpoor Tousi, A. (2014), "Flow pattern improvement in nozzle-rotor axial gap in impulse turbine", Aircraft Engineering and Aerospace Technology, Vol. 86 No. 2, pp. 108-116. https://doi.org/10.1108/AEAT-09-2012-0146