NATIONAL AERONAUTICS AND SPACE ADMINISTRATION WASHINGTON DC
Measurements were made of the cooling on the fronts of model cylinders in a conventional cowling for cooling at both ground and cruising conditions. The mechanisms of front and rear cooling are essentially different. Cooling on the rear baffle part of the cylinders increases with increasing fin width. For the front of the cylinder, an optimum fin width was found to exist beyond which an increase in width reduced the heat transfer. The heat transfer coefficient on the front of the cylinders was larger on the side of the cylinder facing the propeller swirl than on the opposite side, and this effect became more pronounced with increasing fin width.