Effect of a Bottom Gap on the Flow Characteristics behind Non-Planar Porous Fence

Abstract

The flow field behind non-planar porous fence of geometric porosity ε=0.273 with various bottom gaps (G) has been investigated by hot-wire anemometer velocity field measurement technique in a wind tunnel experiment. Seven gap ratios G/H=0.000, 0.025, 0.075, 0.125, 0.150, 0.175, 0.200 of non-planar porous fence were tested in this study with the free-stream velocity fixed at 10m/s. The experimental data were analyzed and the turbulence intensity and wind reduction ratios for different gaps of the porous fence were calculated to estimate the shelter effect of a non-planar porous fence model. The results show that the gap ratio G/H=0.150 gives the best shelter effect among the seven gaps of the non-planar porous fence tested in this study, having a better mean velocity and turbulence intensity as well as wind reduction ratio in a large area behind the non-planar porous fence.