Realistic and stable simulation of turbulent details behind objects in smoothed-particle hydrodynamics fluids

This paper presents a novel realistic and stable turbulence synthesis method to simulate the turbulent details generated behind objects in smoothed particle hydrodynamics (SPH) fluids. Firstly, by approximating the boundary layer theory on the fly in SPH fluids, we propose a vorticity production model to identify which fluid particles shed from object surfaces and which are seeded as vortex particles. Then, we employ an SPH-like summation interpolant formulation of the Biot-Savart law to calculate the fluctuating velocities stemming from the generated vorticity field. Finally, the stable evolution of the vorticity field is achieved by combining an implicit vorticity diffusion technique and an artificial dissipation term. Moreover, in order to efficiently catch turbulent details for rendering, we propose an octree-based adaptive surface reconstruction method for particle-based fluids. The experiment results demonstrate that our turbulence synthesis method provides an effect way to model the obstacle-induced turbulent details in SPH fluids and can be easily added to existing particle-based fluid-solid coupling pipelines.