【作者】 范训；

【导师】 吉洪湖；

【作者基本信息】 南京航空航天大学 ， 热能工程， 2009， 硕士

【摘要】 目前在航空发动机进口部件积冰的数值模拟中,一般都是将大气参数作为发动机进口截面上的结冰参数,而实际情况下,由于进气道对气流的调节作用,发动机进口处的结冰参数是不同于其在大气环境中的分布的。针对这个问题,本文以FLUENT商业软件为平台,数值模拟了空气-过冷水滴两相流在经过进气道沿程时,结冰参数的变化过程,为发动机进口部件的结冰数值模拟提供了较准确的结冰参数分布。在研究过程中,首先了解了两相流数值计算时常用的两种基本计算方法:拉格朗日法和欧拉法。而后针对本研究所模拟工况下稀疏两相流动的特点,分析FLUENT软件中几个多相流模型的适用条件、控制方程,计算过程,并进行了探索计算,通过对计算结果的分析对比,最终确定了基于拉格朗日法的计算模型作为本文研究中所采用的模型。在应用该模型计算时,为了满足过冷水滴在大气中的分布状态,对模型中喷射源类型、喷射源数量、边界条件、颗粒轨道数量等设置条件进行了大量的探索性研究,总结出一套利用该模型模拟大气结冰状态下两相流动的方法。然后针对二维进气道支板模型,计算了不同结冰参数变化对颗粒运动轨迹、水滴浓度场分布以及局部水收集系数的影响,并将计算结果与参考文献进行了定性的对比,验证了该方法的可行性。在二维计算方法的基础上,针对复杂的三维S弯进气道模型,计算了空气-过冷水滴两相流的运动,并分析了喷射源、边界条件等的设定方法。得到了包括温度,速度,过冷水滴浓度场等主要结冰参数在进气道沿程的变化过程。更多还原

【Abstract】 At present, the atmospheric icing parameters have been direct used for the icing accretion numerical simulation of the Aeroengine entrance parts. Actually, the icing parameters of the engine entrance is different from the atmospheric icing parameters due to the inlet effect. The purpose of this thesis is to find an effective method for simulate the two phase flow of the air-supercooled water droplet and get the outlet icing parameters by the use of FLUENT software.Firstly, we were known that there are two kinds of basic models for the multiphase flow, i.e. Lagrangian model and Euler model. According to the characteristic of the sparse two-phase flow, we analyse the conditions, governing equations and computational process of the different multiphase models in FLUENT. Through the compare of the calculation results, we determine to use the model which is based on the Lagrangian method for numerical simulation. In order to find an effective method to simulate the two-phase flow by the Lagrangian model, we did much research on the effects of various jet sources, number of jet sources, boundary conditions and number of particle trajectories. We found the relationship between particle trajectories, droplet concentration and the local water collection efficiency through a 2D simulation. At last, we thought that the Lagrangian method is feasible to simulate the two-phase flow in this thesis..For a three-dimensional S-Duct inlet model, according to the numerical simulation methods of 2D model, we use discrete-phase model to solve the air flow field firstly, then calculate the supercooled water droplets movement along the inlet, At last, we get the parameters variation along the inlet which including temperature, velocity and concentration of supercooled water droplets.更多还原