Methodology for prediction of time-varying heat flux during pulsed spray cooling

Surface heat flux plays a crucial role in the evaluation of heat transfer performance during pulse spray cooling. This paper employed direct and indirect methods to measure transient surface temperature of epoxy resin.A new transfer function was constructed, and thus the Green function method was extended to solve multi layer, semi-infinite inverse heat conduction problems. The accuracy of several algorithms, i.e. Duhamel's theorem, sequential function specification method (SFSM) and Green function method were analyzed under different temperature measurement methods. It was found that all algorithms were able to predict surface heat flux well based on the direct measurement of surface temperature. However, Duhamel's theorem was unsuitable for predicting surface heat flux under condition of in direct measurement of surface temperature, since it did not take into consideration of heat dissipation between measurement point and surface layer. The result predicted by SFSM appeared a noticeable discrepancy during the period when surface temperature changed extremely fast. Green function method can always predict an accurate surface heat flux.