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从两相流的基本理论和输运方程出发,建立超音速火焰喷涂过程的气固两相流场的数学模型,以FLUENT软件为计算平台,采用k-ε湍流模型模拟湍流流动,采用非预混燃烧模型设置反应过程,模拟气态流场的流动特性,研究喷涂过程中燃烧反应、燃烧物质含量比等参数对气态流场的影响;采用离散相模型中颗粒随机跟踪轨道模型计算喷涂颗粒的动力学飞行行为,研究颗粒大小与颗粒注射速度对颗粒动力学行为的影响,为以后喷涂工艺参数的选取和FLUENT在喷涂模拟中的广泛应用提供有用信息。结果表明:当煤油与氧气含量比为3时,焰流速度与温度场最好;随颗粒直径的增大,颗粒的加速度减小;速度为25 m/s以上的颗粒出现了与壁面的撞击行为。
Based on the basic theory and transport equation of two-phase flow, the mathematical model of gas-solid two-phase flow field in supersonic flame spraying process was established. Using FLUENT software as the calculation platform, k-ε turbulence model was used to simulate turbulent flow, The mixed combustion model was set up to simulate the flow characteristics of the gaseous flow field. The influences of combustion parameters, combustion mass ratio and other parameters on the gas flow field were studied. The kinetics of the spray particles was calculated using the particle random tracking orbit model in the discrete phase model The flight behavior was studied to study the effects of particle size and particle injection velocity on particle dynamic behavior, which provided useful information for future selection of spray process parameters and the wide application of FLUENT in spray simulation. The results show that when the content ratio of kerosene and oxygen is 3, the flame velocity and temperature field are the best. As the particle diameter increases, the acceleration of the particles decreases. At the velocity of 25 m / s, the particles collide with the wall behavior.