Extension of Ergun equation for the calculation of the flow resistance in porous media with higher porosity and open-celled structure

Aiming to propose a correction of Ergun equation to expand its applicability into the flow resistance calculation of porous media with higher porosity and open-celled structure, this work numerically studied the flow field inside the rectangular channel partially filled with porous media and the average velocity in the zone adjacent to porous media against relative height, porosity and specific surface area using LBM both at REV scale together with Ergun equation and at pore scale. An equivalent resistance correction coefficient k(p) of Ergun equation is proposed to eliminate the significant difference in the simulated results of flow field between REV scale and pore scale. Moreover, a formula is presented to predict the value of k(p) by the parameters of porous media conveniently. By means of k(p), the flow field can be simulated at REV scale with lower cost of time and the same accuracy with that at pore scale.