ON THE PERMEABILITY OF POROUS MATERIALS

The effects on porous-material permeability characteristics of the absolute pressure level (and associated scale effects), choking of the flow, bending the material ^ and other factors have been investigated. Samples of rolled 30-by 250-mesh Dutch weave Monel metal cloth and l/l6-inch-thick sintered bronze were calibrated with constant upstream pressures of 1 atmosphere and 2 — atmospheres (varying downstream pressure) and with constant downstream pressure of 1 atmosphere (varying upstream pressure). Experiments showed permeability characteristics to be appre-ciably affected by absolute pressure level, flow choking, and thickness of the material. Moderate bending of the material caused no noticeable change in the permeability. Simple calculation and correlation proce-dures are presented for determining permeability characteristics with reasonable accuracy when experimental data are limited