Heat transfer adjacent to the attached end of a cylinder in crossflow

Wind tunnel experiments were performed to determine heat transfer coefficients in the region of wall-cylinder interaction for a wall-attached cylinder in crossflow. Quasi-local transfer coefficients were measured with a small (one-quarter diameter long) disk-like sensing element positioned at various axial stations along the cylinder. The experiments spanned the Reynolds number range from 3500 to 23 000 and were supplemented by velocity profile measurements and flow visualization. It was found that the wall-cylinder interactions were confined to a length of the cylinder extending about one diameter from the wall. In the interaction region, the quasi-local coefficients were lower than those in the wall-unaffected region. The decreases were accentuated with decreasing distance from the wall, but this trend was reversed in the immediate neighborhood of the wall due to the presence of a compact, vigorous vortex. The largest decrease was in the 15% range, while the average decrease for the entire wall-affected region was about 9%.