机舱通风口冲击射流湍流特征分析及验证

以机舱个性化通风口为背景,对自由射流加壁面冲击射流,采用几种湍流模型数值分析了10倍冲击高度、雷诺数为9,000的气流遇到冲击板后湍流脉动、流动转折等流动特征.探讨了湍流模型对冲击射流关键位置平均速度、脉动速度以及雷诺应力等流动参数特征的模拟能力,通过与实验测量结果的对比,确定了湍流模型在冲击射流中的适用性和局限性.综合来看,Relizable k-ε模型可以得到与实验值较好的符合度,但在近壁面区域会略有偏差.分析结果认为将RANS和LES组合将是开展实际机舱内通风口射流研究的最佳策略.

Numerical Analysis and Verification of Turbulent Characteristics for the Impinging Jet Flow in Air Vents of Aircraft Cabin

With individual vent in aircraft cabin as an investigation background, a classic model of free-jet and walljet was analyzed using numerical simulation method. Several turbulence models were applied to simulate the characteristics of turbulence fluctuation and flow turning direction for the impinging jet with an impinging height of 10 times of the exhaust nozzle diameter and an Re number was 9 000. The turbulent parameters of mean velocity, fluctuating velocity and Reynolds shear stress were compared to the experiment profiles, and the computing ability of the RANS method was confirmed for the impinging jet flow. Furthermore, by comparing the simulation result to the experiment data, the applicability and the limitation of turbulence models were made clear. On the whole, the turbulent characteristics of impinging jet could be accurately simulated by the Relizable k-ε turbulence model and agree well with experiment results in large regions but a little deviation near the wall area of jet flow. The results also give a proposal that the simulation method of RANS combined with LES would be an optimal strategy of numerical simulation for the impinging jet of vents in aircraft cabin.