二维机翼混合相结冰数值模拟

近年来冰晶引发的飞机结冰问题逐渐引起人们的重视。针对冰晶和过冷水滴同时存在的混合相结冰问题，通过数值模拟的方法实现结冰冰形预测。空气流场和对流换热的计算中采用了转捩剪切应力输运（SST）湍流模型，基于欧拉法计算冰晶和水滴收集系数。在Messinger结冰热力学模型基础上进行扩展，分析了二维结冰部件表面在混合相气象条件下的传热传质过程，建立了适用于混合相的结冰热力学模型，同时考虑冰晶的黏附效应，添加黏附效率经验公式。利用FLUENT的用户自定义函数（UDF）编程求解混合相热力学模型，计算了霜冰和明冰条件下NACA0012翼型表面结冰情况，与国外风洞试验结果进行比较，验证了计算模型和方法的有效性。结果表明，冰晶黏附效应对混合相结冰量及冰形有很大影响，明冰条件结冰形状偏向楔形。

Numerical simulation of mixed phase icing on two-dimensional airfoil

In recent years, the problem of aircraft icing caused by ice crystals has attracted wide attention. For the mixed phase (ice crystals and supercooled droplets coexisting) icing problem, the numerical simulation method is used to predict the ice shape. The transition Shear-Stress Transport (SST)turbulence model is adopted in the calculation of air flow field and convective heat transfer. The ice crystal and droplet collection coefficients are calculated based on the Eulerian method. Based on the classical Messinger icing model, the heat and mass transfer process on a two-dimensional surface under the mixed phase icing condition is analyzed, and the icing thermodynamic model suitable for the mixed phase icing is established. Meanwhile, considering the adhesion effect of ice crystals, an empirical formula of adhesion efficiency is added. The mixed phase icing thermodynamic model is solved based on FLUENT and its User Defined Function (UDF). The rime ice and glaze ice conditions are simulated on NACA0012 airfoil. The computational results are compared with foreign wind tunnel experimental results and show agreement. The results show that the effect of ice crystal adhesion has a significant influence on the amount and the shape of ice. Ice accumulation tends to be wedge-shaped under glaze ice condition.