Parallel adaptive weakly-compressible SPH for complex moving geometries

Abstract

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. Program summaryProgram Title: Parallel adaptive EDAC-SPHCPC Library link to program files:https://doi.org/10.17632/62rhbb9p4t.1Developer's repository link:https://gitlab.com/pypr/asph_motion.Code Ocean capsule:https://codeocean.com/capsule/4785489Licensing provisions: BSD 3-clauseProgramming language: PythonExternal routines/libraries:: PySPH (https://github.com/pypr/pysph), matplotlib (https://pypi.org/project/matplotlib/), NumPy (https://pypi.org/project/numpy/), automan (https://pypi.org/project/automan/), compyle (https://pypi.org/project/compyle/).Nature of problem: Simulating fluid flow around multiple moving bodies requires the local resolution to be automatically adapted in order to capture all the necessary flow features. If a single resolution is used throughout the domain, the number of particles would be excessively large.Solution method: We validate and demonstrate the accuracy of the adaptive particle refinement algorithm in simulating flow past moving multiple geometries. Our algorithm is fully parallel, and we provide an open-source implementation.