The effect of pore size distribution on the fractal evaporative interface in porous media

Abstract

This article aims to comprehensively analyze the heat and mass transfer and fractal evaporative interface in porous media with different pore size distribution through experiments and simulations of water. Weierstrass-Mandelbrot(W-M) function is used to establish a fractal evaporative interface based on fractal dimension and scaling parameter, which are determined by parameters of pore. The evaporative interface at the pore level is observed in the experiment with aluminum and nickel porous media, which shows reliability of model. The simulation results reveal that when the mass flow rate enlarges, the average Nusselt number, RMS and STD gradually grow, and the average temperature, vapor volume fraction, and velocity reduce, which indicates better thermal protection. As the initial temperature of the bottom improves, the trends in these variables are opposite except for STD, which means more irregular of evaporative interface. These findings have potential applications in transpiration cooling with high temperature in aerospace field and technologies requiring a stable evaporative interface, such as seawater desalination.