5 research outputs found
Efficient and Accurate Adaptive Resolution for Weakly-Compressible SPH
In this paper we propose an accurate, and computationally efficient method
for incorporating adaptive spatial resolution into weakly-compressible Smoothed
Particle Hydrodynamics (SPH) schemes. Particles are adaptively split and merged
in an accurate manner while ensuring that the number of particles is not large
for a given resolution. Critically, the method ensures that the number of
neighbors of each particle is optimal, leading to an efficient algorithm. A set
of background particles is used to specify either geometry-based spatial
resolution or solution-based adaptive resolution. This allows us to simulate
problems using particles having length variations of the order of 1:250 with
much fewer particles than currently reported with other techniques. The method
is designed to automatically adapt when any solid bodies move. The algorithms
employed are fully parallel. We consider a suite of benchmark problems to
demonstrate the accuracy of the approach. We then consider the classic problem
of the flow past a circular cylinder at a range of Reynolds numbers and show
that the proposed method produces accurate results with a significantly reduced
number of particles. We provide an open source implementation and a fully
reproducible manuscript.Comment: 44 pages, 32 figures, 3 table
Parallel adaptive weakly-compressible SPH for complex moving geometries
The use of adaptive spatial resolution to simulate flows of practical
interest using Smoothed Particle Hydrodynamics (SPH) is of considerable
importance. Recently, Muta and Ramachandran [1] have proposed an efficient
adaptive SPH method which is capable of handling large changes in particle
resolution. This allows the authors to simulate problems with much fewer
particles than was possible earlier. The method was not demonstrated or tested
with moving bodies or multiple bodies. In addition, the original method
employed a large number of background particles to determine the spatial
resolution of the fluid particles. In the present work we establish the
formulation's effectiveness for simulating flow around stationary and moving
geometries. We eliminate the need for the background particles in order to
specify the geometry-based or solution-based adaptivity and we discuss the
algorithms employed in detail. We consider a variety of benchmark problems,
including the flow past two stationary cylinders, flow past different NACA
airfoils at a range of Reynolds numbers, a moving square at various Reynolds
numbers, and the flow past an oscillating cylinder. We also demonstrate
different types of motions using single and multiple bodies. The source code is
made available under an open source license, and our results are reproducible.Comment: 50 pages, 22 figures, 3 tables. Updated one figure (Fig. 9