Wire-Screen Head Loss
Calculates the pressure-drop loss coefficient and pressure drop across a circular metallic wire-mesh screen fitted inside a pipe or duct.
Free Area Ratio
FAR=Total AreaFree AreaThe free area ratio must be entered directly. For a standard woven wire mesh, FAR is determined from the wire diameter and mesh pitch.
Loss Coefficient
For Reynolds numbers Re > 10³ (turbulent regime):
K=1.3(1−FAR)+(FAR1−FAR)2The first term represents viscous drag on the wires; the second is the contraction-expansion inertial loss through the mesh openings.
Pressure Drop
Δp=K⋅21ρV2where ρ is the air density at the specified temperature and V is the mean flow velocity in the duct upstream of the screen.
Validity
- Pipe (duct) Reynolds number Re > 10³.
- Circular metallic wire mesh inside a circular or rectangular duct.
- FAR must be in the range (0, 1).
References
- Idel'chik, I.E. and Fried, E., Flow Resistance, a Design Guide for Engineers, Taylor & Francis, Washington D.C., 1989, p. 265.