後向きステップ流れにおける再付着点付近の流れと熱伝達挙動の相関に関する研究

抄録

In this study, the mechanism of heat transfer enhancement near the reattachment point behind a backward facing step is experimentally investigated at a Reynolds number of 5400. The unsteady fluctuations of the velocity and temperature were simultaneously measured by using two-dimensions and three-components (2D-3C) Particle Image Velocimetry (PIV) in the reattachment region in the xy plane at z/H = 0 and the high-speed infrared (IR) thermograph on the heated wall. To discuss the thermal and flow structure near the reattachment point, three-components of the velocity and heat transfer coefficient were measured. The fluctuations of the velocity and heat transfer appear near the reattachment point, and the cross-correlation coefficient of fluctuations of each velocity and heat transfer coefficient was calculated. As a result, the downwash flow in the transverse direction corresponds to the increasing of the heat transfer coefficients in the reattachment region. Also, there is the time delay between the fluctuations of the flow and heat transfer.