降雨条件下飞机尾涡演化数值模拟研究

Numerical Simulation of Aircraft Wake Vortices in Rainy Conditions

降雨作为一种气象条件,与飞机尾涡相互作用,改变自身与尾涡的动力学特性。高强度的尾涡导致后机难以着陆、复飞甚至坠机等后果,因此尾涡的演化进程对评估后机的飞行安全有重要意义。为了分析尾涡与降雨的相互干扰,基于欧拉-欧拉多相流模型,研究了降雨条件下的尾涡演化特性。对于多相流模型中的空气相模拟,采用大涡模拟湍流模型,雨相通过两个标量方程控制其动力学输运,两相间的耦合利用动量源项实现能量的传递。分析了降雨对环量、涡量和涡核附近速度分布、下沉速度等尾涡演化特征量的影响。结果表明:降雨加速了环量的衰减,减小了涡心最大涡量,使速度分布趋于平滑,改变了尾涡下沉规律。另外,尾涡也影响了雨滴的下降轨迹和浓度分布。

The interaction between rainfall and aircraft wake vortices changes their dynamic characteristics,and the dynamic evolution of wake vortices,which has an important impact on the safety of wake encounters.Aiming at the interaction between wake vortices and rainfall,this study investigates the evolution characteristics of wake vortices in rainy conditions based on the Euler-Euler multiphase flow model.For the air phase simulation in the multiphase flow model,the large eddy simulation turbulence model is used.The dynamic transport of rain phase is controlled by two scalar equations.The two phases are coupled through the momentum source term to realize the energy transfer.The influence of rainfall rate on the evolution characteristics of wake vortices,such as circulation,vorticity,velocity distribution near the vortex core and sinking velocity,is analyzed.The results show that rainfall accelerates the decay of the circulation,reduces the maximum vorticity of the vortex core,smooths the velocity distribution,and affects the descent process of wake vortices.In addition,the presence of wake vortices also affects the trajectory and concentration distribution of rain.