Visualization and Simulation of Near-Body Hydrodynamics Using the Semi-Lagrangian Fluid Simulation Method

Efficient numerical techniques developed in the field of computer graphics are able to simulate compellingly realistic simulations of interactions between solids and fluids. These techniques are less used for engineering applications due to errors inherent in the systemic approximations. The errors, manifesting as excessive damping, are expected to change the nature of steady-state fields and nullify the typical engineering static flow analysis. On the other hand, near-body solid/fluids interaction are affected to a lesser degree since errors originating from dissipation are more severe when accumulated over time. Although it is generally not possible to numerically validate unsteady, high-velocity vector fields, our investigations show that near- body solid/fluid dynamics converges with respect to parametric refinements. Though far from a correctness proof, the numerical convergence of near-body quantities suggests the applicability of the method to certain classes of analysis and visualization where near-body characteristics are of greater concern. This article applies the semi-Lagrangian stable fluids method to biomechanical hydrodynamics visualization. The near-body surface dynamics provide meaningful information for rendering visuals that are intuitive to the streamlined flow characteristics surrounding the body. The techniques are applied to the visualization of active and passive resistive forces on the body in a video-based capture of an immersed dolphin kick.