Evaluation on Shelter Effect of Porous Windbreak Fence through Wind Tunnel Test

The flow field of a large storage yard with windbreak was investigated in the wind tunnel under three dominant wind directions. The wind speed was measured by the so-called “omnidirectional surface wind sensor", and the qualitative flow pattern was visualized by tuft method. According to the experimental results, the shelter effect of the porous windbreak fence was evaluated. It was found that the wind speed significantly decreased behind the windbreak, by 80% at most. However, at some wind direction a large bubble appeared behind the fence due to the low porosity of 30%. Thus it's necessary to improve the design of the windbreak fence. In addition, it was verified that the shelter effect for a certain storage yard was related to the local terrain and accordingly the given conditions should be taken in consideration.