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为明晰结冰风洞中液滴过冷特性,发展了基于欧拉法的气液两相耦合流动计算方法,模拟了结冰风洞中气液两相耦合流动过程。在此基础上,首先开展了参数影响研究,然后考察了典型结冰风洞构型中三维收缩效应对液滴过冷特性的影响,最后评估了该风洞试验段内液滴过冷状态。结果表明:结冰风洞中液滴过冷特性主要受液滴粒径和气流速度影响,增大液滴粒径和气流速度会显著增加两相温度平衡距离;结冰风洞中的液滴传热过程可以分为准一维传热和三维收缩传热两个阶段,三维收缩传热阶段对液滴过冷状态的影响显著强于准一维传热阶段,三维收缩效应对液滴过冷状态起决定性作用;在典型试验工况下,粒径小于40μm的小粒径液滴在试验段内均达到过冷状态(液滴气流温度差小于2℃),但粒径大于100μm的大粒径液滴在高风速条件下(试验段气流速度为157m/s)未达到过冷状态(液滴气流温度差大于5℃)。
In order to clarify the overcooling characteristics of liquid droplets in icing wind tunnel, a Eulerian-based method was developed to simulate the gas-liquid two-phase coupled flow in icing wind tunnel. On this basis, firstly, the influence of the three-dimensional shrinkage on the characteristics of droplet cooling in a typical icing wind tunnel was investigated. Finally, the droplet subcooled state in the wind tunnel test section was evaluated. The results show that the droplet supercooling characteristics in the icing wind tunnel are mainly affected by the droplet size and the airflow velocity. Increasing the droplet size and the airflow velocity will significantly increase the temperature equilibrium distance of the two phases. The droplet in the icing wind tunnel The heat transfer process can be divided into quasi-one-dimensional heat transfer and three-dimensional shrinkage heat transfer two stages, the three-dimensional shrinkage heat transfer phase on the droplet cooling state was significantly stronger than quasi-one-dimensional heat transfer stage, In the typical experimental conditions, the droplets with particle size less than 40μm reached the supercooled state in the experimental section (the temperature difference of the droplets was less than 2 ℃), but the particle size larger than 100μm Under the conditions of high wind speed (the velocity of airflow in the test section is 157m / s), the droplet of particle size did not reach the subcooled state (the droplet temperature difference is more than 5 ℃).