Performance of the Wide-Angle Two-Dimensional Diffusers with Various Inlet Shear Flows (2nd Rept. In case of Wake Type Inlet Shear Flows)

摘要

Experimental study of the two-dimensional diffusers with wake-type inlet velocity profiles in the parallel walls was carried out. The purpose of this study is to investigate the effects of nonuniform inlet velocity profiles on flow regime and performance.In general, a diffuser performance is affected by the relative location of the low velocity core-flow region in the inlet velocity profile. For the wide-angle diffuser with wake-type inlet shear flows, the favorable effects of mixing result in velocity profile flattening and hence the pressure-recovery performance is increased relative to the performance obtained for diffusers with uniform inlet core velocity profiles. However, for small angle diffuser the performance is decreased below that measured for diffusers with uniform inlet velocity profiles.A centerline stall develops in the core region of the flow for diffusers with severe inlet profile distortion. However, the central stall may not affect the diffuser performance than the wall stall.