基于低雷诺数κ-ε模型冲击射流传热的数值模拟

Numerical Simulation of Impact Jet Heat Transfer Based on Low Reynolds Number κ-ε Model

冲机射流在机翼除霜、电子元器件散热等工程领域应用广泛,为进一步研究其传热机理,利用两种低雷诺数κ-ε模型对单股冲击射流的传热进行数值模拟,并与标准κ-ε模型及雷诺应力模型的计算结果进行对比。结果表明,低雷诺数κ-ε模型在两种工况下的计算结果均优于其他模型。湍流热扩散系数作为求解温度场最重要的参数,对传热的计算结果影响极大,通常用湍流普朗特数作为常数求解。在低雷诺数κ-ε模型的基础上,分别通过湍流普朗特数函数求解和t2-εt方程直接求解进行改进,并将计算结果进行比较。结果表明,使用湍流普朗特数函数形式求解湍流热扩散系数能给出更好的预测结果,直接求解仍需进一步改进。

Impact jet is widely used in wing defrosting,electronic components heat dissipation and other engineering fields.In this paper,two different low-Reynolds Number κ-ε models are used to simulate the heat transfer of single impact jet,and the results are compared with the standard κ-ε model and Reynolds stress model.The results show that the low-Reynolds Number κ-ε model is better than other models in two experimental conditions.As the most important parameters to solve the temperature field,the turbulent thermal diffusion coefficient has a great influence on the calculation results of heat transfer.Usually,it is solved by the turbulent Prandlt number used as a constant.Based on the Low Reynolds Number κ-ε models,turbulent Prandlt number function form and the t2-εtequation are used to improve the solution.The results show that using the turbulent Prandlt number function to solve the turbulent thermal diffusion coefficient can give more satisfactory results,but the t2-εtequation still needs further improvement.