Study on Flow Field Characteristics in Sandstorm Conditions Using Wind Tunnel Test

Abstract

To study the sandstorm resistance design of civil structures and transportation infrastructures, the sandstorm flow fields with various grain concentrations were simulated by the windblown sand tunnel. The results show that the grain concentration profile presents an exponential decay form before the critical wind speed; as the test speed increases, the grain concentration decreases initially and increases afterwards with height, and the characteristic height of moving grain increases while the creep percentage decreases. Moving sand grains reduce wind speed and increase turbulence intensity, and the whole process is affected by grain concentration. The moving grain and the turbulence of the sandstorm flow field form a mutual feedback mechanism, which affects the wind-induced response and impact response to structures. The variation of kinetic energy with height is similar to that of total energy with height in the sandstorm flow fields. Specifically, the grain energy increases with increasing concentration and wind speed, but decreases initially and increases afterwards with height. Furthermore, the critical heights of the grain energy and concentration profile are both about 0.2 m, which has little impact on structures.