EXPERIMENTS IN FLUIDS



July 2008, Volume 45, Issue 1, pp 123-129

"The laminar hole pressure for Newtonian fluids"

Vasileios Symeonidis and Bruce Caswell




Abstract: For flows with wall turbulence the hole pressure, P H , was shown empirically by Franklin and Wallace (J Fluid Mech, 42, 33–48, 1970) to depend solely on R +, the Reynolds number constructed from the friction velocity and the hole diameter b. Here this dependence is extended to the laminar regime by numerical simulation of a Newtonian fluid flowing in a plane channel (gap H) with a deep tap hole on one wall. Calculated hole pressures are in good agreement with experimental values, and for two hole sizes are well represented by: (P H P HS )/τ w = √(k 2 + c 2 R +2)−k, where the Stokes hole pressure P HS w s (b/H)3, k, c, s are fitted constants, and τ w is the wall shear stress.