Experimental analysis of strut's effect on annular diffuser performance

This paper presents the experimental investigations carried out to compare the turbulence and velocity distribution with and without struts in a diffuser. The research has also been carried out to investigate the effect of baseline struts on the flow structure and the performance of the diffuser. A typical exhaust diffuser of an industrial gas turbine is annular with structural members, called struts, which extend radially from the inner to the outer annulus wall. An annular diffuser model, primarily intended for fundamental research, has been tested on a wind tunnel. Similar conditions that prevail in an industrial gas turbine have been generated in the diffuser. During the experimental work, hot wire measurements were taken at a number of radial positions across the annulus and at some circumferential positions at each axial location along the diffuser. The results indicate that the performance characteristics of a diffuser are influenced by the presence of baseline struts. The Measurements were performed at different circumferential and radial locations for different axial stations to make an investigation on the effect of struts and to advance design tools for gas turbine exhaust diffusers.