On the Prediction of Gas Flow Rates Through Round Wire Screens

A relatively simple expression is derived for the flow through round wire screens by considering the screen to be made up of a number of noninteracting cylinders and using classical data on the drag coefficient of a cylinder at various Reynolds numbers and Mach numbers. The theory is found to agree closely with the result of some recent experiments for low solidity screens (0.5 or less). At Knudsen numbers higher than 0.01 the screen passes more mass than would be predicted by the theory. This is attributed to slip.