열선 풍속계 에 의한 진동하는 익형 의 후류 측정

Abstract

Results of invesbgabon of the wake downstream of a sinusoidally pitching airfoil using single hot~wire probe me reported. The experimental data are reduced by ensemble average technique for 150 consecutive measurement with 48 sampling points distributed evenly during the period of oscillation. The measurements are caried out for wake velocity And turbulence intensity profiles at several downstream locations for the case of reduced frequencies, K=ωC/2U∞=0.09, 0.13 And 0.2. The corresponding Reynold number, Re=U∞C/ν are 47,000, 40,000 and 27,000.It is observed that with increase of K-value, the wake flow thickness also increases And a second dominant peak is present in turbulence intensity at certain instantaneous angle of attack. Also, the clearly visible vortices region with distinct large male is identified by flow visualization using smoke-wire technique.