In this paper, a numerical study is performed to investigate the effects of thermal shrinkage on the deposition of molten particles on a substrate in a thermal spray process using the Volume-of-Fluid (VOF) method. Thermal shrinkage is a phenomenon caused by the variation of density during cooling and solidification of a molten metal. The Navier-Stokes equations along with the energy equation including phase change are solved using a 2D/axisymmetric mesh. The VOF method is used to track the free surface of molten particles, and an enthalpy-porosity formulation is used to modelsolidification. For the normal impact of tin particles in the order of 2 mm in diameter and 1 m/s in impact velocity, the final splat had a single cavity inside due to shrinkage. For cases with the scales of a typical thermal spray process, the effect of shrinkage appeared as a reduction in the droplet splashing on the substrate.
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机译：在本文中，进行了数值研究，以使用流体体积（VOF）方法研究热收缩对热喷涂过程中基材上熔融颗粒沉积的影响。热收缩是由熔融金属的冷却和凝固期间的密度变化引起的现象。使用2D /轴对称网格求解Navier-Stokes方程以及包括相位变化的能量方程。 VOF方法用于跟踪熔融颗粒的自由表面，而焓-孔隙度公式用于模型化凝固。对于直径2 mm左右，冲击速度1 m / s左右的锡颗粒的正常冲击，由于收缩，最终的splat内部只有一个空腔。对于具有典型热喷涂工艺水垢的情况，收缩的效果表现为飞溅在基材上的液滴飞溅减少。
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