Measurement and Determination of Friction Characteristic of Air Flow through Porous Media

Abstract

Sintered metal porous media currently plays an important role in air bearing systems. When flowing through porous media, the flow properties are generally represented by incompressible Darcy-Forchheimer regime or Ergun regime. In this study, a modified Ergun equation, which includes air compressibility effects, is developed to describe friction characteristic. Experimental and theoretical investigations on friction characteristic are conducted with a series of metal-sintered porous media. Re = 10 is selected as the boundary for a viscous drag region and a form drag region. Experimental data are first used to determine the coefficient α in the viscous drag region, and then the coefficient β in the form drag region, rather than both simultaneously. Also, the theoretical mass flow rate in terms of the modified Ergun equation provides close approximations to the experimental data. Finally, it is also known that both the air compressibility and inertial effects can obviously enhance the pressure drop.

Parameter Sensitivity Analysis on Dynamic Coefficients of Partial Arc Annular-Thrust Aerostatic Porous Journal Bearings

“…The optimal governing equations required for porous air bearing analysis remain under discussion. Zhong et al [9] experimentally determined Ergun's equation coefficients for the pressure drop in sintered metal porous media for air bearings. Belforte et al [10] experimentally verified Forchheimer's law for porous air bearing applications.…”

Determination of Permeability and Inertial Coefficients of Sintered Metal Porous Media Using an Isothermal Chamber

“…The authors have developed theoretical equations and represented the pressure drop characteristic of sintered metal porous media in terms of experimentally determined property coefficients [28][29][30][31]. However, the measurements are conducted under steady flow condition and this inevitably lengthens the test time and consumes much energy.…”