Measurement and correlation of friction characteristic of flow through foam matrixes

A correlation of friction characteristic was developed based on the measured pressure drop of air through foam matrixes. The pressure drops of seven types of aluminum foams with different porosities and pore densities were measured. The Reynolds number based on the equivalent spherical diameter of the foam ranged from 32.05 to 1289.32. The range of porosity was 0.87-0.958. A empirical equation was developed to correlate the dimensionless pressure drop with the dimensionless flow velocity for all seven types of aluminum foams. The empirical correlation agreed well with experimental data. According to the empirical correlation and the measured data, the pressure drop introduced by foam matrixes was much lower than that by granular matrixes at the same Reynolds number. The relationship between the friction factor and Re of foam matrixes follows the trend of granular matrixes and can be classified into three regimes: Re < 30: f(k) proportional to 1-epsilon/Re 30 < Re < 300; f(k) = 22 1-epsilon/Re + 0.22; Re > 300, the value of f(k) approaches 0.22. (C) 2005 Elsevier Inc. All rights reserved.