Convective heat transfer inside a rotating cylinder with an axial air flow

This article presents an experimental identification technique for the convective heat transfer coefficient inside a rotating cylinder with an axial airflow. The method consists in heating the outer face of the cylinder using infrared lamps, and acquiring the evolution of the external surface temperature versus time using an infrared camera. Heat transfer coefficients are identified via three methods. The first one is based on an inverse model, the second one assumes the wall of the cylinder as a thermally thin wall and the third one is based on an analytical method permitting to obtain the temperature field within the whole cylinder. The experiments were carried out for a rotational speed ranging from 4 to 880 rpm corresponding to rotational Reynolds numbers varying from 1.6 x 10(3) to 4.7 x 10(5) and an air flow rate varying from 0 to 530 m(3) h(-1) which corresponds to an axial Reynolds numbers ranging from 0 to 3 x 10(4). Correlations connecting the Nusselt number to the axial and rotational Reynolds numbers are also proposed. (C) 2006 Elsevier Masson SAS. All rights reserved.