Measurements of Turbulent Heat Transfer on the Leading and Trailing Surfaces of a Square Duct Rotating About an Orthogonal Axis

Abstract

This paper presents the results of an experimental investigation of local heat transfer on the trailing and leading surfaces of a square-sectioned duct rotating about an axis orthogonal to its central axis. The flow geometry has application to the cooling of gas turbine rotor blades. It is demonstrated that Coriolis induced secondary flows enhance local heat transfer over the trailing surface in relation to the corresponding non rotating case. Little effect of rotation on the leading surface was detected over the range of experiments covered to date. Rotational buoyancy is shown to have a slight effect only at the lowest Reynolds number tested. The conditions under which buoyancy may be neglected in the real engine range of parameters is still uncertain. Simple correlations for the present data are given as design aids.