Heat-Transfer Distribution Around a Cylinder in Pulsating Crossflow

Abstract

The effects of sinusoidal flow pulsations on the heat transfer from a cylinder to a crossflow at Re = 50,000 were investigated. A range of different pulsation amplitudes of up to 25% and frequencies both above and below the natural shedding frequency were used. The pulsating flow was clean and well organized. It had greater than 95% of the power at the fundamental frequency with a low turbulence level (less than 0.5%). The time-averaged local heat transfer was experimentally measured for a constant-temperature surface-boundary condition using a small heat flux gage in the cylinder wall. Distributions were obtained by rotating the cylinder through 180 deg. The experiments showed no significant increase of heat transfer due to the flow pulsation in either the wake or attached boundary layer region. Small local increases were found near the separation point.