In order to establish the dynamic control system of turbulent heat transfer using active vortex generators (AVGs), it is necessary to understand heat transfer and flow behavior of longitudinal vortices generated by AVGs. In this study, we measure surface temperatures on the heated wall by thermochromic liquid crystal sheets. The neural network method is applied to conversion of the colors of the liquid crystal sheet images into the temperatures. The AVG is characterized by the angle of attack and the driving cycle. It is found that longitudinal vortices generated by the AVGs enhance the heat transfer through downwash motion toward the wall.
