This page calculates
the head loss coefficient and head loss of a fluid in across a thin
perforated plate (plate thickness / hole hydraulic diameter < 0.015) inside a
pipe. It is assumed that Re is greater than 10^{5}.

The head loss *h _{L}* can be
calculated as:

hl = k_{loss} x (u_{m}^{2} / (2
x g) )

Where *k*_{loss}
is the head loss coefficient, *u _{m}* is the flow velocity in the pipe, and

k_{loss} =

Where *FAR* is the free area ratio. The free area ratio
must be entered directly by the user, but is defined as:

FAR = Free or Open Area / Total Area

**References**

Idel'chik, I E. and Fried, Erwin., *Flow Resistance, a
Design Guide for Engineers*, Taylor & Francis, Washington D.C. 1989. p
260.