Experimental Investigation of Vortex Shedding in High Reynolds Number Flow Over Compressor Blades in Cascade

摘要

An investigation of vortex shedding downstream of a cascade of compressor stator blades, at off-design inlet-flow angles of 35, 33 and 31 degrees and Reynolds numbers, based on chord length, of 625,000, 750,000 and 800,000 is reported. The objective of the study was to characterize the flow and vortex shedding through blade surface pressure measurements and hot-wire anemometry. Vortex shedding was determined to be a leading edge phenomenon as periodic shedding was only detected on the pressure side of the wake, The relationship between vortex shedding frequency and Reynolds number was nearly linear. The vortex shedding frequency at three incidence angles was observed to be quite similar at lower Reynolds number (i.e. 450,000 and below) but developed into a larger scatter at higher Reynolds number. Similarly, the Strouhal numbers were observed to be fairly consistent (0.22 to 0.24) at low Reynolds number and more scattered (0.18 to 0.25) with increasing Reynolds number. The result obtained was comparable to the experimental results obtained by Roshko Ref. 14, for vortex shedding behind a circular cylinder.