Application of Optical Measurement for Skin Friction Field around Tires of a Simplified Vehicle Model

The objective of this study is to apply the Global Luminescent Oil-Film Skin-Friction (GLOF) meter, which optically observes the skin friction vectors on the object surface, to reveal the fluid structure around the wheelhouse. The image analysis results show characteristic longitudinal vortices on the side surface of the front wheel and the wheelhouse. In contrast, the separation line at the rear end of the side near the rear wheelhouse is curved significantly upstream, and the separation area expands in the lower half of the rear end, probably due to the suction flow generated between the wheel and the wheelhouse.