基于FLUENT的直流漏沙式风沙风洞研究

目前的风沙风洞大多适用于风沙地貌、风沙环境的研究以及防护治理，而用于结构风工程的风沙风洞很少,因为其需要在一定高度处能够实现风速和风沙浓度可调的均匀稳定段.为了研究直流漏沙式风沙风洞中风沙流的分布规律，运用FLUENT建立风洞模型，通过对已有的漏沙风洞试验进行数值模拟，验证了模型的正确性.进一步基于风洞风速、漏沙体积分数、漏沙速度等参数对风洞风沙流的影响规律，提出了一种新型的水平多口风洞漏沙装置.对该风沙风洞的分析表明:在试验模拟浓度的范围内，风洞风速越大，同一位置的沙粒分布高度越高；漏沙体积分数和漏沙速度主要影响单位时间内进入风洞的沙粒质量，且试验位置沙粒浓度的峰值与单位时间进入风洞的沙粒质量成正比；该风沙风洞可以得到约1/2风洞高度的沙粒浓度均匀试验段，并可以通过调节漏沙体积分数、漏沙速度和试验位置可得到试验所需的试验风速及对应的沙粒浓度，使其能很好地完成风工程中的风沙定量试验. 

Numerical Simulation of Direct-Current Sand Leakage Wind Tunnel Based on FLUENT

Currently wind-sand tunnels are mainly used for research, protection and management of wind-sand landscape and wind-sand environment, and rarely adopted in structural wind engineering because the stable sections with adjustable wind speeds and wind-sand concentrations at a certain height are difficult to achieve. In order to study the distribution of wind-sand two-phase flow field in the direct-current sand leakage wind tunnel, in this work a wind tunnel model was built using the commercial software FLUENT, and then verified by simulating the existing sand leakage wind tunnel test. Based on the influence of wind speed, sand leakage volume fraction, sand leakage speed, and other parameters on wind-sand flow in the wind tunnel, a new type of sand leakage device for horizontal multi-port wind tunnel was further proposed. Simulation results of the wind-sand tunnel show that the distribution height of sand particles in the same location is higher at a larger wind speed. The quality of the sand particles entering the wind tunnel in unit time is mainly affected by volume fraction and velocity of the sand particles, and is directly proportional to the peak value of the sand particle concentration in the test location. Besides, a test section of about 1/2 wind tunnel height with uniform sand concentration has been realized in the wind-sand tunnel. The required test wind speed field and corresponding sand concentration can be achieved by adjusting the sand leakage volume fraction, sand leakage speed, and test position to complete the wind-sand quantitative tests for wind engineering well.