An improved enthalpy-thickness model for predicting heat transfer of a free rotating disk using an integral method

摘要

An integral method has been developed for predictions of heat transfer near a free rotating disk for the Prandtl numbers less or equal to unity including the case of Pr tending to zero. An improved semi-empirical enthalpy-thickness model has been proposed, which is valid both for the laminar and turbulent flow cases. Special attention is paid to the asymptotic case of Pr→0. The proposed integral method allowed obtaining an approximate analytical solution for the Nusselt number for both flow regimes. This solution is significantly more accurate than known Dorfman's formula and other known relationships, especially at almost zero or negative gradients of the wall temperature.