OPTICAL STUDIES OF LOCAL FLOW BEHAVIOR OF A NON-NEWTONIAN FLUID INSIDE A POROUS-MEDIUM

In this study the local flow of a polymeric solution inside a porous m edium is studied visually. While the flow is quite uniform for low vol ume flow rates it shows pronounced nonuniformity for higher volume flo w rates. That is to say, only certain preferred passages are taken and these passages change in time (they fluctuate). This flow irregularit y is the reason for increased resistance.