Force on the Top Layers of a Porous Medium Subjected to Surface Pressure Oscillation.
J Appl Phys 1975 Jul; 46(7):2976-2980
The fluid-mechanical force acting on the top layers of porous dust beds is analyzed and a new interpretation made when the beds constitute the walls in turbulent gas streams. The nonlinear differential equation governing the pressure distribution in the medium is solved numerically. When a sinusoidal pressure oscillation is applied at the surface of a porous medium, direct calculations show that there may occur a net upward force, for a duration within one cycle, on the top layers of the medium. By using the present results, a possible mode for the initiation of erosion of an erodible granular bed in a turbulent gas stream is examined. This mechanism may have significance in connection with dust explosions and soil erosion.
J. Appl. Phys., V. 46, No. 7, July 1975, PP. 2976-2980