论文部分内容阅读
通过对青藏铁路沿线砾石方格内风速特征、固沙效率的风洞模拟实验研究发现,当气流运行至砾石方格前缘,水平风速迅速降低,砾石方格对风速的削弱作用非常显著,达到50%左右。气流在沿砾石方格向下风向移动过程中,水平梯度风速逐渐减小,但其减小幅度比较缓慢。砾石方格中风速随高度的分布遵循对数规律,各方格间风速变化趋势相对稳定。砾石方格地表粗糙度在5.2cm左右,摩阻速度为2.4 cm/s。砾石方格中固沙量随着进口风速的增加而增加,在相同风速下,固沙量随离沙源距离的增加呈指数关系递减。
Through the wind tunnel simulation experiment on the wind speed and sand fixation efficiency along the Qinghai-Tibet Railway, it is found that when the airflow runs to the front edge of the gravel, the horizontal wind speed decreases rapidly, and the gravitational chelation effect on wind speed is very significant, reaching 50 %about. During the movement of gravel checkered downwind, the air velocity of horizontal gradient gradually decreased, but the decrease was slower. The distribution of the wind speed with the height of gravel squares follow the law of logarithm, and the trend of wind speed among the squares is relatively stable. Gravel surface roughness of about 5.2cm, friction velocity of 2.4 cm / s. The volume of sand in the gravel squares increases with the increase of the inlet wind speed. At the same wind speed, the amount of sediment decreases exponentially with the increase of the distance from the sand source.