飞机除冰冲击射流多相流耦合模型研究

Study on multiphase flow coupling model of aircraftdeicing impact jet

以飞机除冰喷洒作业为研究对象,对冲击射流与冲击壁面进行建模和数值模拟,分析了冲击壁面的速度压力分布特性。用相场函数φ解释了相场和水平集模型模拟出的射流偏转现象,探讨了冲击射流周围压强分布梯度不均匀的原因,以Realizable k-ε湍流模型为基础对比了不同多相流数值模型的模拟结果。发现冲击射流的截面沿着中心轴线呈锥状发展,在滞点处流速迅速衰减为0,压强达到最大值。壁面射流在偏离滞点0.15~0.2 m的位置逐渐获得最大流动速度。最后对比了实验常用的紊流系数与不同多相流模型的模拟结果。综合考虑模型模拟出的速度、压力分布特性及射流紊流系数得出结论:混合物模型和相传递混合模型比较适合进行飞机除冰射流以及类似的大流速、多流体微团类的流动研究。

This paper studies the modeling and numerical simulation of the impact jet and impact wall in aircraft deicing spray operations,and analyzes the velocity and pressure distribution characteristics of the impact wall.The phase field functionφis employed to explain the jet deflection phenomenon simulated by the phase field and level set models.The reason for the uneven pressure distribution gradient around the impact jet is explored,and the simulation results of different multiphase flow numerical models are compared based on the Realizable k-εturbulence model.Our research results show the cross-section of the impact jet develops conically along the central axis,with the flow velocity rapidly decreasing to zero at the stagnation point and the pressure reaching its maximum value.The wall jet gradually gains maximum flow velocity when it deviates from the stagnation point by 0.15~0.2 m.The simulation results of different multiphase flow models are compared with the commonly used turbulence coefficient in experiments.Considering the velocity,pressure distribution characteristics and jet turbulence coefficients simulated by the models,it is concluded that the mixture model and the phase-transfer mixing model are more suitable for the study of aircraft deicing jets and other similar large-flow,multi-fluid microcluster-like flows.