切向流场影响下激光壁面加载特性

Numerical Simulation of Laser Wall Loading under the Influence of the Boundary Layer Flow Field

使用计算流体力学方法对激光壁面加载模型进行研究,重点分析受切向流场影响下,壁面出现熔池后所形成的两相流流场以及温度场。模拟结果表明:切向气流对激光壁面加载特性的影响不容忽略。激光加载初期,切向气流对壁面起气动冷却作用,随着熔池出现,熔池边界沿气流方向推移的速度快于向其反方向推移的速度。但随着熔池深度的增加,熔池的发展将呈现相反的趋势。随着加载过程不断持续,熔化边界向靶材内部推移的速度呈加速趋势。

In this paper,the computational fluid dynamics method is used to analyze the laser wall loading model ,which focuses on the two-phase flow field and temperature field under the influence of the boundary layer flow field when metal melting. The simulation results show that the thermal action of the laser load can be considered to act only on the irradiation spot position,and the influence of boundary layer flow to laser wall loading characteristics can not be ignored. In the subsonic speed range, the influence of the boundary layer flow mainly performs the pneumatic cooling effect. In the early stages of development of the molten pool, under the influence of pneumatic cooling effect, the movement speed of molten pool boundary to the downstream of the direction of airflow is faster than the speed to the upstream. However,with the increase of pool depth, the development of the molten pool will show the opposite trend. In the toading process ,the rate trend of melting boundary goes to the internal target is accelerating.