Separated Flow in Lee of Solid and Porous Fences

The mean flow characteristics immediately downstream of solid and porous fences submerged in turbulent boundary layers have been studied using two‐dimensional fences of different porosities. The flow downstream of the fence within and above the standing eddy was found to be well described by Goertler's half‐jet model. The dimensionless spread parameter σ was found to vary systematically with X/δ0 and the porosity of the fence. The intrinsic axis from which the coordinates are measured was found to follow a similarity law. The scaling parameters used in such similarity analysis are shown to be functions of U*0H/ν and porosity. The model developed in this paper has been found to be applicable to the flow past both solid wedges and quadrant‐edged roughness. A method of predicting the mean velocity field downstream of solid and porous bodies has been proposed as a result of the analysis presented in the paper.