Fluid Flow through Various Plain Square Screens and Comparison of the Resistance Coefficient

The fluid flow through woven screens in a circular pipe was measured to evaluate the resistance coefficient of those screens. Three kinds of screens, stainless steel, brass and polyethylene, made of round wire forming a square mesh, were used in this study. The Reynolds number based on the pipe diameter was kept constant at 9×104. Results show that after the flow passes through the three kinds of screens, the velocity profiles show three different patterns due to the coefficient of porosity. In particular, the velocity profile for the polyethylene screen is different from those for the stainless and the brass screens. The resistance coefficient K vs the wire diameter Reynolds number can be classified into three categories according to the patterns of the velocity profile. The value of K for the polyethylene screen is larger than those of both the stainless and brass screens because the streamwise gradient of the streamline through the polyethylene screen shows the maximum value. The use of average velocity Ue/β and pore spacing l as a characteristic velocity and scale enables a more general correlation between the resistance coefficient and the Reynolds number.