An experimental program has been developed by which one may non-intrusively measure the heat transfer coefficient of highly porous metal/ceramic foams. Under steady one-dimensional flow conditions, the solid phase is subjected to a step change in heat generation rate via induction heating. By measurement of the gas phase temperature response, one may determine the heat transfer coefficient based upon the volume-averaged equations for gas and solid phase energy. These equations are developed and solved numerically to determine the heat transfer coefficient from the gas phase temperature response.
The media in question is a highly porous (0.75–0.90) reticulated structure that, due to small gas pathways (25–160 pores per linear inch) and narrow solid ligaments, makes direct temperature measurement impractical, intrusive and inaccurate. Not only does this technique alleviate the need for complicated gas and solid phase temperature measurements, the heat generation rate does not require determination. Therefore, at no point is the fluid/solid porous media interaction disturbed by the presence of temperature sensors and the experimentalist avoids the calibration difficulty of an inductively-coupled, sample specific, heat generation system.