复杂地形下的近地层风沙运动模拟

Simulation of wind-blown sands near surface layer over complex microtopography

本文利用FLUENT软件模拟了奇华胡安沙漠复杂微地形的流场,发现风速模拟精度优于QUIC软件的结果。为了进一步研究复杂地形下的沙粒运动规律,在甘肃民勤某沙丘迎风面上测量了脉动风速、输沙强度和输沙量,并模拟计算了沙丘风场、沙丘不同位置处的单宽输沙率及输沙量,结果表明沿着沙丘基线的输沙率从沙丘的右角开始逐渐增加,在沙丘纵剖面与丘基线的交点处达到最大,而后又逐渐减小。

It is simulated by FLUENT software the wind field over a complex microtopography in Chihuahuan Desert where wind speed and direction are fluctuating with time.Compared with the Bowker’s(2006) measured wind speed,the maximal error of simulated wind speed is within ±1.0m/s,which is more accurate than the QUIC software's result.To further study the regularities of sand transport under the complex terrain,the fluctuate wind speed,saltation intensity and sand mass flux were meansured in the windward dune in Minqin field.Then wind field of sand dune were simulated by FLUENT software,and sand mass flux were calculated on some positions of sand dune.It is found that sand flux increases from the right horn of dune,gets the maximum at point of intersection of dune longitudinal section and brink,and decreases to the left horn of dune.