Research on the windproof efficiency of polygonal straw sand barrier

To understand the windproof benefit of triangular sand barrier, square sand barrier and hexagonal sand barrier, we studied respectively the windproof efficiency, wind speed profile characteristics and roughness of ground surface of straw sand barrier, whose single mesh grid was 1 m² by measuring the wind speeds in different heights in three straw sand barrier types. Results showed that wind speed efficiency could be reduced by triangular sand barrier and hexagonal sand barrier significantly than square sand barrier. The windproof efficiency of square sand barrier was 12% and 8% lower than triangular sand barrier and hexagonal sand barrier respectively at 0.2 m height, and was 11% and 10% lower than triangular sand barrier and hexagonal sand barrier respectively at 0.3 m height. The difference of windproof efficiency in triangular and hexagonal sand barrier was not obvious at he height between 0.2-0.3 m. The variation of roughness with wind speed was linear when the wind speed was less than 6 m/s. When wind speed was 4 m/s at 1 m height above bare sand, the roughness of bare sand was 0.166 cm, and the roughness of triangular sand barrier, square sand barrier and hexagonal sand barrier was 11.5, 9.3 and 10.4 cm, respectively, and was 69.3, 56 and 62.7 times of bare sand. The roughness of triangular sand barrier was 23.7% and 10.5% higher than that of square sand barrier and hexagonal sand barrier, respectively. Consequently, the roughness of triangular straw sand barrier is the highest.