Surface shear stress sensitive film sensing technology and its validation experiments in a low-speed wind tunnel

A new surface shear stress sensitive film sensing technology was introduced, including the basic conceptual features, principles, technical approaches and the current development status at home and abroad. The main advantages of the surface shear stress sensitive film were analyzed, and the applications of the surface shear stress sensitive film were shown through typical cases in the water tunnel, low-speed wind tunnel and high-speed wind tunnel. We optimized the measurement method and data processing method of this technology, and carried out validation experiments of the homemade surface shear stress-sensitive film with a scaled-down model of the high-speed train in the 0.8 m × 0.6 m Low-speed Wind Tunnel of China Aerodynamic Research and Development Center (CARDC). The cloud maps of surface shear stress distributions at several velocities were obtained, whose characteristics and repeatability were analyzed. The results show that the homemade simplified surface shear stress sensitive film, whose shear modulus is 1224.82 Pa, can accurately measure the surface shear stress distribution in the local region, and the repeatability is better than 0.4% in the range of 3～13 Pa. The optimized surface shear stress sensitive film sensing technology is verified to have excellent stability and repeatability in a certain range.