Large Eddy Simulations of a Self-Propelled Tuna

This study numerically investigates the swimming characteristics of a self-propelled virtual Bluefin Tuna. The self-propelled Tuna is simulated using Curvilinear Immersed Boundary (CURVIB) method, and the turbulence is modeled using a dynamic Smagorinsky Model for Large Eddy Simulations (LES) at various Reynolds numbers. The body kinematics are prescribed based on experimental observations provided by the Hopkins Marine Station at Stanford University and the swimming velocity is computed based on the forces on the fish body. An over-set mesh is used to increase the grid resolution near the fish body for High Reynolds number flows to reduce the computational costs. The simulations demonstrate that as the Reynolds number of the Tuna decreases, Strouhal number increases, swimming efficiency decreases, and wake spreading increases. At the initial time, the swimming velocity is zero, and as time progresses, the fish gets accelerated until it reaches the steady swimming speed. The computational resources are provided by the High-Performance Research Computing (HPRC) at Texas A&M University.