Structure of Two Dimensional Vortex behind a Highly Heated Cylinder

Abstract

Two dimensional vortex structure behind a highly heated cylinder has been studied experimentally. The air velocity is set as 1.0 m/s. The surface temperature of the heated cylinder is set at up to 600°C. A particle image velocimetry (PIV) is used to measure two dimensional instantaneous and average velocity. At just downstream of the heated cylinder, the vortex is intensified by increasing wall temperature of heated cylinder. The vortex frequency decreases when the wall temperature is increased. This indicates that the local kinematic viscosity plays a key role in the vortex structure. As a result, the vortex frequency of the heated cylinder can be expressed as a function of Strouhal number and Reynolds number, when the local kinematic viscosity is reasonably estimated by taking into account the effect of the wall heating.