Sina Alavi, Mohammad Passandideh-Fard

Frontiers in Heat and Mass Transfer (FHMT) 2 - 023007 (2011)

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 model
solidification. 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.