ANALYZING SURFACE FLOW BEHAVIOR BY OPTICAL-FLOW ALGORITHM AND AN APPLICATION FOR FLOW ON DELTA WING

Abstract

Surface flow visualization around flying objects plays an important role in evaluating the efficiency of the design process. In previous studies, traditional oil flow visualization technique was mainly used for visualizing flow. In this approach, oil is mixed with pigments, such as titanium dioxide is pained on the surface. The flow phenomenons on the surface are discussed based on the image taken after the wind tunnel test and no data processing technique is applied. This study presents a data processing algorithm for visualizing flow on the surface. Experimental setup, evaluation, and the algorithm are presented. The algorithm is applied for analyzing surface flow on a low-aspect-ratio wing and a delta wing. The processing results indicate that the method shows high efficiency in extracting flow on the surface of models. The locations of separation, reattachment, and secondary separation are presented. The difference in flow between the two models is also shown in detail. The results of the present study provide a good reference for further numerical simulation.