Clone particles: A simplified technique to enforce solid boundary conditions in SPH

A simplified technique for the enforcement of boundary conditions along solid profiles is proposed in the framework of the Smoothed Particle Hydrodynamics. The main idea relies on a local definition of the normal and tangent vectors to the solid body, along with a local mirroring of the flow fields. This compound approach allows for a robust and accurate modelling of the fluid-solid interaction close to acute angles and sharp profiles. Numerical benchmarks at increasing complexity are considered to prove the reliability of the proposed technique: hydrostatic test cases, flow past cylinders with elliptic, triangular and spiked circular profile and, finally, a roto-translating motion of a spiked cylinder. The results are compared and validated with other numerical methods.