阵列空气射流传热均匀性问题的数值研究

Numerical Study on Array Air Jet Heat Transfer Uniformity

针对用于飞行器地面降温模拟试验的喷嘴阵列空气射流的传热均匀性问题,开展了数值模拟研究,用以指导相关降温试验装置的设计和试验方案的制定。首先,对降温试验装置建立了相关模型,通过对比发现SST k-ω湍流模型适用于阵列空气射流冷却模拟;进而分别研究了喷嘴数量、喷嘴高度等因素对阵列空气射流传热均匀性的影响规律,分析了其中的原因,并通过正交实验获得了研究范围内传热均匀性最优的参数匹配方案,数值计算出相应的表面对流传热系数h的变异系数为0.201;最后,研究了空气横流对阵列空气射流传热均匀性的影响。发现在最优结构参数下,通过添加挡板将最小横向流动形式改为中等横向流动形式后,试件表面的对流换热系数h变异系数减小了39.7%,试件局部表面传热均匀性得到了大幅的提高。

The uniformity of multiple air jet impingement heat transfer which is used in the aircraft cooling simulation is numerically studied to guide the design of the thermal simulation equipment and the experiment. A model of cooling simulation is established, and the result shows that SST k - ω turbulence model can be used to simulate the air jet impingement heat transfer. Then the influences of the nozzle number, nozzle height, nozzle diameter and jet velocity on air jet impingement heat transfer are studied and the related reasons are discussed. The optimal match of the parameters has been obtained through the orthogonal test, and the coefficient of variation of the convective heat transfer coefficient h is 0.201. At last, an attempt to improve the uniformity of air jet impingement heat transfer has been made through changing the cross-flow scheme, which proves to be effective, and the coefficient of variation of h can be reduced by 39.7%.