A CAD-compatible body-fitted particle generator for arbitrarily complex geometry and its application to wave-structure interaction

Generating body-fitted particle distribution for arbitrarily complex geometry underpins the applications of particle-based method to engineering and bioengineering and is highly challenging, and thus hinders the potential of particle methods. In this paper, we present a new computer-aided design (CAD) compatible body-fitted particle generator, termed as CAD-BPG, for arbitrarily complex 3-D geometry. By parsing a CAD model, the present method can accurately tackle arbitrarily complex geometry representation and describe the corresponding geometry surface by constructing an implicit zero level-set function on Cartesian background mesh. To achieve a body-fitted and isotropic particle distribution, physics-driven relaxation process with surface bounding governed by the transport-velocity formulation of smoothed particle hydrodynamics (SPH) methodology is conducted to characterize the particle evolution. A set of examples, ranging from propeller, stent structures and anatomical heart models, show simplicity, accuracy and versatility of the present CAD-BPG for generating body-fitted particle distribution of arbitrarily complex 3-D geometry. Last but not least, the present CAD-BPG is applied for modeling wave-structure interaction, where wave interaction with an oscillating wave surge converter is studied, and the results show that the present method not only provides an efficient and easy-to-implement pre-processing tool for particle-based simulation but also improves the numerical accuracy compared with lattice particle distribution. Consequently, the propose CAD-BPG sheds light on simulating real-world applications by particle-based methods for researchers and engineers.