Performance Comparison of Straight and Curved Diffusers

Experimental studies have been carried out to compare the performance of two dimensional straight and curved diffusers of same area ratio and effective divergence angle in the Reynolds number range of 7.8 X 10(5) to 1.29 X 10(6). Free stream turbulence effects have also been studied at the increased turbulence level to 3.4 per cent. The results indicate that straight diffuser pressure recovery is slightly higher as compared to the curved diffusers. However, stream turbulence, which improves the pressure recovery in both cases, has been observed to have greater effect in case of curved diffuser. Boundary layer velocity profiles on the diffuser surfaces have also been presented at various streamwise stations. It is observedthat the growth of inner surface boundary layer has a major effects on losses in case of a curved diffuser