Proposed Method for Measuring Local Heat Transfer Coefficients of Isothermal Surfaces

A method has been proposed for measuring local heat transfer coefficients. The method uses the change of a wet surface temperature by radiation heating and can be applied to isothermal conditions and with large variations of the local heat transfer coefficients along the surface of a body. The present method is based on the heat balance equation, which expresses a simple relationship between humidity and wet-bulb temperatures. An experiment was devised to measure the local heat transfer coefficient along a flat plate. The results confirmed the effectiveness of the present method to measure local and overall heat and mass transfer coefficients with reasonable accuracy.