Extended model for single-blow transient testing method in evaluating thermal performance of heat transfer surfaces

The present study is aimed to extend the theoretical model of the maximum-slope single-blow transient testing method[4,5,8], which is frequently used in evaluating the thermal performance of heat transfer surfaces in heat exchangers, by additionally considering the effects of longitudinal diffusion and thermal capacity of fluid. Energy equations are solved by the finite-difference methods to examine the transient variation of the solid and fluid temperatures within the solid matrix. Results show that the neglect of these fluid properties in the earlier models may cause a considerable error in the evaluation of thermal performance of surfaces and hence, limits the accuracy and applicability of this testing method.