高速电弧喷枪流场模拟研究

Studies of Computational Fluid Dynamics in the Flow Field of a High Velocity Wire Arc Spray Gun

电弧喷枪流场特性是影响电弧喷涂质量的关键因素之一。文中运用 CFD 软件 Fluent,对高速电弧喷枪头部及枪外射流进行了模拟计算,通过分析可以看出,枪外射流可以分为射流核心区、射流卷吸区和射流湍流区。受欠膨胀激波反射和相交的影响,枪外射流的速度分布具有不均匀性,其轴线射流速度存在剧烈波动,同时呈现先递增后衰减的规律。受丝材的影响,枪外射流速度分布呈现空间不对称性,其丝材所在平面流场的发散性大于丝材垂直平面的发散性。为了保证涂层质量,提高沉积率,喷涂距离控制以及喷嘴封闭气帽形状的合理设计显得非常重要。

The fluid dynamics in the jet field of a high velocity wire arc spray gun is one of the key factors to coating qualities. With the application of Fluent, the jet flow dynamics of a spray gun is simulated and computed, which concludes that the jet field could be characterized by three regions: the core region, the entrainment region, and the fully turbulent region. Influenced by the intersecting and reflecting of shock waves, the velocity distribution of the jet is non-homogeneous and asymmetric, and the axis velocity is severely fluctuated. Moreover, The flow in the wire plane is more divergent than that in the wires’ vertical plane. Therefore, it’s an important way to improve spray quality with appropriate spray distance and a special designed cap.