The pressure loss Δp through a rectangular gap is calculated from the flow Q, the gap-width bg and the 3rd power of the gap-height hg, the overflow length lg of the gap as well as the density ρ and the kinematic viscosity of the medium.
The equation is valid, for gaps where the width is considerably larger than the height, and the gap-length is more than 100 times the gap-height.

Calculate the pressure loss through a gap directly and easily in our hydraulic calculator.