为了解风蚀风沙运动规律，提高旋风分离式集沙仪集沙效率。该文在Fluent 平台中建立了旋风分离式集沙仪有限元模型，基于RNG k-ε模型和雷诺应力模型对旋风分离式集沙仪进行数值分析，并对3种不同结构参数旋风分离式集沙仪进行风洞试验。通过有限元分析，得到了其内部气相运动规律，观察到集沙仪升气管附近气流强度较大，其内部有“短路流”存在。同时，通过对3种不同结构参数旋风分离式集沙仪进行数值模拟，得到结构参数为：筒体直径50 mm；锥体段高度125 mm 的旋风分离式集沙仪集沙盒底部具有较小的湍动能和向上轴向速度，其大小分别为0.99 m2/s2和1.48 m/s。另外，分别对3种不同结构参数旋风分离式集沙仪进行风洞试验，得到了改变筒体直径与锥体段高度引起集沙盒底部湍流强度的改变，从而对集沙效率有一定影响，相比较筒体直径而言，锥体段高度对集沙效率影响更明显；集沙盒底部湍动能和向上轴向速度较小的集沙仪，集沙效率较高，具有良好的分离性能。结合数值模拟和风洞试验确定了集沙盒底部湍动能、向上轴向速度为目标函数，根据目标函数，优化设计了集沙盒直管的长度，确定了集沙盒直管长16 mm的旋风分离式集沙仪可以降低集沙盒底部湍动能和向上轴向速度，理论上可以提高旋风分离式集沙仪集沙效率。该文研究结果可为进一步提高旋风分离式集沙仪性能提供依据。%For the purpose of knowing the motion law of sand erosion and improving the efficiency of cyclone separation sand sampler, the finite element model of cyclone separation sand sampler is built by using the software of Fluent. There is a two-phase movement inside the cyclone separation sand sampler, including air and soil particles. The cyclone separation sand sampler mainly separates the soil particles from the air. Since the concentration of the soil particles is not too high, its movement inside the sand sampler depends largely on the gas phase (air) movement, and a majority of the particles flow with the air. Due to the above-mentioned reasons, it is necessary to make further analysis on the air flow inside the cyclone separation sand sampler. Boundary conditions are of great importance to the simulation of the gas flow inside the cyclone separation sand sampler, and the gas phase has been simplified: the gas in the sand sampler is air, with a density of 1.225 kg/m3 and a viscosity of 18.1×10-6;it is treated as incompressible gas, and its flow is treated as in steady state;the exit is set for free outflow;the wall surface is set as no skidding and no moving surface;the 2 surfaces overlapped by the ascension pipe and the barrel of the sand sampler are set respectively as Interface for data exchange;the upper part of the sand sampler and the sandbox are sealed well, without gas flowing out;the straight pipe connecting the cone-shaped part and the sandbox is 10 mm long;the hydraulic diameter is 0.015 mm, the Reynolds number is 1.02×104 and the turbulent intensity is 5.1%. Based on the RNG k-εmodel and the Reynolds stress model, numerical analysis is carried out for the cyclone separation sand sampler. Besides, some wind tunnel tests are made for 3 cyclone separation sand samplers with different structure parameters. The internal motion law of the gas phase is found through the finite element analysis;current field intensity near the gas exit tube of the sand sampler is stronger and the “shunting flow” exist inside. At the same time, by the numerical simulation of 3 cyclone separation sand samplers with different structure parameters, the results show that the sand sampler with cylinder diameter of 50 mm, and cone height of 125 mm has the smaller turbulent kinetic energy 0.99 m2/s2 and the maximum upward axial velocity 1.48 m/s in sandbox bottom. In addition, the wind tunnel test is done with 3 different structural parameters of the cyclone separation sand sampler, and the experimental results show the turbulent kinetic energy of sandbox bottom which has certain impact on the trapping efficiency is changed with cylinder diameter and cone segment height. Compared to cylinder diameter, cone segment height has greater influence on the efficiency of the cyclone separation sand sampler. The cyclone separation sand sampler has better separation performance and higher trapping efficiency when the turbulent kinetic energy and the upward axial velocity of sandbox bottom are lesser. Through numerical simulation and wind tunnel test, the objective function is determined by the turbulent kinetic energy and the upwards axial velocity of the bottom of sandbox. The length of the straight tube of sandbox is optimally designed through the objective function. The efficiency of cyclone separation sand sampler can be improved while the straight pipe of sandbox is 16 mm. The results can provide the basis for further enhancing the performance of cyclone separation sand sampler.
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