分流对冲与多级扩容组合式集沙仪内风沙分离规律研究  

Wind-Sand Separation Rules in Shunt-hedging and Multi-stage Expansion Combined Sand Sampler

作　　者：宋涛[1,2] 商晓彬 仇义 陈智[1] 边炳传[2] 刘海洋[1] 

机构地区：[1]内蒙古农业大学机电工程学院,呼和浩特010018 [2]泰山学院机械与工程学院,泰安271000

出　　处：《农业机械学报》2017年第3期113-118,共6页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家自然科学基金项目(41361058;41161045)

摘　　要：为揭示风沙在集沙仪内部的分离规律,以分流对冲与多级扩容组合式集沙仪风沙分离器为研究模型,通过Fluent数值模拟和微型风洞试验,对风沙分离器内单相流场和气固两相流场进行了分析。在阐释气流降速机理的基础上,进一步分析了气流降速和入口气流中沙尘所占体积分数对风沙分离的影响,并通过分析沙尘的运动规律,阐述了不同粒径沙尘受流场影响的情况。结果表明,气流大幅降速是实现风沙分离的最有效方法,而引起气流速度大幅降低的主要原因是较大值的湍动能场的大范围形成;对于风沙流,当沙尘含量增高时,降速效果变好,风沙分离效果也变好;当沙尘含量进一步增高时,降速及风沙分离效果则变化不大;对于分流对冲与多级扩容组合式集沙仪,当沙尘受强风以下风力影响时,粒径小于0.032 41 mm的沙尘较易受到流场的诱导,受惯性运动的影响较小,从排气口排出的可能性较大,是影响风沙分离效率和集沙效率的主要粒子。When wind speed, soil particle size distribution, collection time and inlet collection efficiency etc. are certain, separation efficiency of sand sampler is the main factor affecting collection efficiency, which is often affected by wind - sand separation rules. In order to reveal wind - sand separation rules in the sand sampler, a sand separator in the shunt-hedging and multi-stage expansion combined sand sampler was took as a study model, a analysis of single-phase flow field and gas - solid two-phase flow field in the sand separator was made through Fluent numerical simulation and micro wind-tunnel test. On the base of explaining reducing velocity mechanism of airflow, a further analysis of airflow reducing velocity and sand volume fraction effect on wind - sand separation was done, and the influencing situation of different particle size of sand was expounded. The results showed that reducing velocity substantially was the most effective method that achieving wind- sand separation, the main reason caused by substantial airflow speed reduction was the formation of a large value of turbulent kinetic energy field; for wind - sand flow, when the sand content was high, the wind - sand separation effect was going to be good with good velocity reducing effect, when sand was affected by strong winds, sand with particle size less than 0. 032 41 mm was easily induced by flow field, less affected by the motion of inertial, the possibility excreted from the exhaust port was large, which was the main part that affected sand separation efficiency and sand collection efficiency. The study provided a theoretical reference for the design of sand sampler, which had a good collection performance, and it further improved the theoretical system of sand sampler technology.

关 键 词：集沙仪 集沙效率 数值模拟 流场 

分 类 号：S237[农业科学—农业机械化工程]