Numerical simulation of low speed flows past under water vehicles

Currently there is a renewed interest in the area related to the design of robotic underwater sea vehicles, ship's hulls, and submarines. Exploration under water vehicles are widely used for sunken ships and monuments, oceanographic research, environmental monitoring, tourist site seeing submarines and military mine countermeasures. The objective of this work is the development of a numerical and visualization method for low speed flow simulation around and past under water vehicles. The flow-simulation method is based on the numerical solution of the three-dimensional incompressible Navier-Stokes equations. The developed solution algorithm features: 1. A finite volume approach, 2. A new combination of spatial derivatives discretization using upwind flux splitting, 3. A novel approach that implements artificial compressibility method on unstructured grids, 4. A new preconditioning method to remove numerical stiffness associated with incompressible flow conditions. 5. Local time stepping and artificial dissipation for numerical algorithm acceleration, and finally 6. A flexible multi-stage Runge-Kutta algorithm. The code was validated through comparison with a well documented bench mark cases.