This paper is concerned with approximating arbitrarily shaped boundaries in SPH simulations. We model the boundaries by means of boundary particles which exert forces on a fluid. We show that, when these forces are chosen correctly, and the boundary particle spacing is a factor of 2 (or more) less than the fluid particle spacing, the total boundary force on a fluid SPH particle is perpendicular to boundaries with negligible error. Furthermore, the variation in the force as a fluid particle moves, while keeping a fixed distance from the boundary, is also negligible. The method works equally well for convex or concave boundaries. The new boundary forces simplify SPH algorithms and are superior to other methods for simulating complicated boundaries. We apply the new method to (a) the rise of a cylinder contained in a curved basin, (b) the spin down of a fluid in a cylinder, and (c) the oscillation of a cylinder inside a larger fixed cylinder. The results of the simulations are in good agreement with those obtained using other methods, but with the advantage that they are very simple to implement.

Item Type:	Refereed Article
Keywords:	SPH, fluid dynamics, boundaries
Research Division:	Mathematical Sciences
Research Group:	Numerical and computational mathematics
Research Field:	Numerical solution of differential and integral equations
Objective Division:	Expanding Knowledge
Objective Group:	Expanding knowledge
Objective Field:	Expanding knowledge in the mathematical sciences
UTAS Author:	Kajtar, JB (Dr Jules Kajtar)
ID Code:	137756
Year Published:	2009
Web of Science® Times Cited:	218
Deposited By:	Oceans and Cryosphere
Deposited On:	2020-03-03
Last Modified:	2020-04-17
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