Application and benchmark of SPH for modeling the impact in thermal spraying

Abstract

The properties of a thermally sprayed coating, such as its durability or thermal conductivity depend on its microstructure, which is in turn directly related to the particle impact process. To simulate this process, we present a 3D smoothed particle hydrodynamics (SPH) model, which represents the molten droplet as an incompressible fluid, while a semi-implicit Enthalpy-Porosity method is applied for modeling the phase change during solidification. In addition, we present an implicit correction for SPH simulations, based on well-known approaches, from which we can observe improved performance and simulation stability. We apply our SPH method to the impact and solidification of Al$$_2$$ 2 O$$_3$$ 3 droplets onto a substrate and perform a comprehensive quantitative comparison of our method with the commercial software Ansys Fluent using the volume of fluid (VOF) approach, while taking identical physical effects into consideration. The results are evaluated in depth, and we discuss the applicability of either method for the simulation of thermal spray deposition. We also evaluate the droplet spread factor given varying initial droplet diameters and compare these results with an analytic expression from the previous literature. We show that SPH is an excellent method for solving this free surface problem accurately and efficiently.

Ray tracing method with implicit surface detection for smoothed particle hydrodynamics‐based laser beam welding simulations

“…This includes having direct access to the neighborhood search needed for an efficient evaluation of the ray tracer. Additionally, since SPlisHSPlasH has already been used in the process simulations of tungsten inert gas welding (TIG) and thermal spraying, the temperature and fluid simulation can be leveraged for a full process simulation in future [9][10][11].…”

“…For the subsequent process simulation, smoothed particle hydrodynamics has been shown to be well applicable to the simulations of heat and mass transfer needed in welding engineering [6][7][8][9][10][11]. Due to the meshless, Lagrangian nature of smoothed particle hydrodynamics, it conserves mass by construction and eases the treatment of topological changes.…”

SPH simulation of YSZ and stainless-steel droplet impact for thermal spray process

“…As a result, the gridbased method induces expensive computational time and imprecision outcomes [17][18][19]. To resolve these issues, the particle-based Smoothed Particle Hydrodynamics (SPH) method has been employed to simulate the thermal spray process [20][21][22][23][24][25]. The SPH method is a mesh-free Lagrangian method for simulating fluid flows and natural phenomena that involve complex deformations, free surface flows, and moving particles.…”

“…The SPH method is a mesh-free Lagrangian method for simulating fluid flows and natural phenomena that involve complex deformations, free surface flows, and moving particles. Because of its advantage, the SPH method has been applied to study various multiphase fluid problems [18,[20][21][22][23][24][25][39][40][41][42][43][44]. The SPH method was applied to investigate the effects of contact angle and surface tension on the outcome of the YSZ droplet impact [20]; they found that the impact angle is less than 44°, and the droplet splash occurred.…”

“…But it has a severe mesh distortion and causes expensive computational time due to numerous problems in dealing with a free surface and moving interface [17][18][19]. To resolve these issues, the Smooth Particle Hydrodynamics (SPH) method is used to investigate the thermal spray process, and its applicability has been demonstrated in natural phenomena: complex deformation, free-surface movement, and fluid flow [20][21][22][23][24][25].…”