A Novel Transient Heater-Foil Technique for Liquid Crystal Experiments on Film-Cooled Surfaces

Abstract

A novel transient measurement technique has been developed for determining the heat transfer characteristics in the presence of film cooling (heat transfer coefficient and adiabatic film-cooling effectiveness). The method is based on a transient heater foil technique, where a non-homogeneous surface heat flux is applied to the test surface. A regression analysis of multiple transient liquid crystal experiments is used to obtain the heat transfer characteristics. The method introduced here has the advantage that the (often not known) heat flux distribution at the surface is not needed for the analysis of the measured data. The method is used to study the influence of several heater foil configurations on a flat plate with film cooling, elucidating the effect of different thermal boundary conditions on film-cooling performance. The obtained data is also compared to results presented in literature and good agreement is found.