为考察溶液注入热等离子体喷涂过程中喷雾参数对涂层质量的影响,本文建立了溶液液滴在热等离子体中运动蒸发的数学模型。模拟了液滴在不同参数下的运动和蒸发的过程,考虑了液滴、热等离子气流及液滴表面气体混合物随温度及组分的物性变化以及斯蒂芬流的影响,得到液滴的运动轨迹,蒸发速率以及半径和表面温度的变化。结果表明在一定范围内增大液滴的尺寸或提高入射速度,使液滴获得较大的初始动量,可使液滴进入射流高温区得到充分加热强化蒸发。
To investigate the effect of spray parameter on the performance of the coating in solution plasma spraying, a model of the evaporation and motion of individual ceramic solution droplets in the plasma jet is presented in this paper. The influence of Stefan flow and the variable physical properties of droplets and environment gases are considered, the droplet motion and the heat and mass transfer of the droplet are simulated. The trajectory, temporal droplet surface temperature, as well as droplet radius variation are predicted. The effect of droplet size and injection velocity on droplet motion and evaporation are investigated. The results indicate that increasing the initial size or the injection velocity of the droplet in a certain range could enhance the heat and mass transfer between the droplet and the jet.