Flow Characteristics and Convection Heat Transfer in Microporous Media

Abstract

The flow characteristics of water and air in micro porous tubes with average diameters of 200 μm ∼ 10 μm were studied experimentally and numerically. The results showed that compressibility significantly influence the air flow in porous media with the particle diameters of 200 μm ∼ 10 μm, which increases the friction factor in porous media. Rarefaction effects occur in air flows in the microporous media with particle diameters less than 90 μm. New correlations for K and F were proposed with consideration of Kn. The numerically predicted friction factors for the slip-flow regime in the micro-porous media with 90 μm ∼ 10 μm diameter particles were less than the known correlation and close to the experimental data. The internal convection heat transfer coefficients between particles and fluid in the micro porous media were determined experimentally and numerically. The experimental data for the micro porous media with particle diameters of 20 and 10 μm are much lower than the previously published results. A new correlation for Nusslet number was proposed with consideration of the influence of Kn. Numerical calculation with consideration of slip-flow and temperature jump in micro porous media can properly simulate internal convection heat transfer.