PIV解析を用いたオイルフィルム干渉法による翼負圧面に作用する壁面せん断応力の計測

抄録

In this study, we evaluated the analysis algorithm and control window with standard deviation and non-detection vector rate to find the appropriate analysis conditions in PIV analysis of the interference fringe images by OFI (Oil Film Interferometry) adapted to the suction surface of a two-dimensional airfoil in high lift conditions with Reynolds number around 8×10⁴. As a result, X/C=0.75 where the flow was relatively simple showed a similar trend to the PIV analysis using particle images, and the analysis conditions were suitable for the control window of 32×32 pixels using the Direct Spatial Domain Correlation method or WIDIM. Near the reattachment point with secondary flow at X/C=0.17 to 0.25, the analysis conditions were suitable for the control window of 128×128 pixels using the Direct Spatial Domain Correlation method, and if higher resolution was required, the use of WIDIM to reduce the non-detection vector rate was suitable. The velocity vector data obtained from the PIV analysis was used in the OFI analysis to successfully measure the wall shear stress and friction velocity in areas with secondary flow.