Experimental study of the convective heat transfer from a rotating disc subjected to forced air streams

The convective heat transfer from a rotating disc subjected to forced streams of air has been investigated experimentally by means of an electrically heated disc in a wind tunnel. Mean heat transfer coefficients have been obtained for a wide range of air crossflow velocities and rotational speeds. The influence of finite disc thickness and incidence (angle of attack) on heat transfer has been investigated. The extreme conditions of a stationary disc in a crossflow and a rotating disc in still air have been considered, too. Concerning the onset of rotational heat transfer augmentation it is found that a universal ratio exists between the rotational and the crossflow Reynolds numbers.