A comparison of postprocessing methods for hot film sensors for the heat transfer analysis of impinging jet flows

Abstract The aim of this investigation is to optimise the data post-processing techniques associated with hot film sensors when intended to be used as a means of accurate, high-resolution heat flux measurement. More specifically, this project focuses on the performance of hot film sensors operated in a constant temperature anemometer bridge, used in conjunction with impinging jet air flows. The characteristic heat transfer behaviour in this impinging jet flow provides the reference against which the heat flux data attained using the hot film sensor is compared. As part of this investigation, three hot film calibration methods are examined for a range of sensor overheat values: (A) a wall shear correction method, (B) a physical quasi 1-D conduction model and (C) a physical quasi 2-D fin conduction model. The results show that the method C, when used in conjunction with a 5 K sensor overheat, best replicated that of the reference heat flux sensor for the jet configurations investigated.