Abstract
Analysis of numerical model and experimental study on steady-state heat transfer characteristics of combined convection and radiation of the air transpiration cooling system using the open-cellular porous material was investigated. The Alumina-Cordierite (Al-Co) open – cellular plates, having porosity of 0.873 and pores per inch (PPI) of 6.0, was used as porous media. The upper surface of porous plate was heated by the heat flux (qR) of incoming radiation varying from 0.988 to 16.560 kW/m2 whereas air injection velocity fed into the lower surface was varied from 0.212 to 1.486 m/s. To report the results in the paper, the air velocity was rearranged as Reynolds number (Re). From study, the results showed that the temperature profile of both gas and solid phase increased when qR, increased and Re decreased. The temperature efficiency (T) increased first and then was taken to constant level about of 97% for Re > 70. The conversion efficiency (C) increased slightly with Re but depend strongly with qR. The agreement between theoretical and experiential data was satisfactory.
Keywords : Transpiration cooling system, Open-cellular porous materials, Raditive heat flux