A simplified model of low Re, immiscible, gas-liquid flow, and heat transfer in porous media numerical solution with experimental validation

This study investigates the thermohydraulic characteristics of immiscible two-phase downward flow and heat transfer through porous media in a vertical, cylindrical, and homogeneous porous medium numerically and experimentally. The test section is exposed to a constant wall temperature after filled with spherical beads. Numerical solution of the model is achieved by the finite volume method and applied to a single-phase flow model. The numerical results are experimentally validated according to air/water downward flow, spherical beads, a ratio of particle diameter to pipe radius is 0.412, 0.396 porosity, 0.01 <= Re <= 500, water to air volume ratio range from 0 to infinity, and saturation ratio from 0 to 1. The results show that the average Nu is nearly constant up to Re = 40. At Re > 100, it is recommended to take inertia and friction effects into account by means of Forchheimer-Brinkman's equation. For single-phase flow (water or air) and two-phase flow mixtures, the local Nu has higher values at the entrance section and decreases as the axial distance increases until it reaches its fully developed value of 4.37 at the end of the thermal entrance length. The comparison between numerical, experimental, and other available previous results shows good agreement and validates the numerical model.