Shape Optimization of Vertical Profiler using Computational Fluid Dynamics

Autonomous underwater vertical profiler is a free-drifting profiling drifter that measures the temperature and salinity of the upper 2000 m of the ocean depth and is used to continuously monitor the climatic state of the ocean. The main objective is to determine the hull resistance for a given boundary conditions using computational fluid dynamics techniques. The hull resistance is an important factor in determining the speed of the system. In the present work, the numerical simulation of flow past the vertical profiler has been performed by using ANSYS Fluent 14.5 with Reynolds-Averaged Navier-Stokes based k-epsilon turbulence model. The turbulent flow has been simulated to investigate the drag force coefficient, the velocity vector and the vortex formation over the vertical profiler for its ascending and descending motions in ocean for its present shape. The flow simulation without stability disc has been carried out to see how the stability disc affects the flow and the drag. Then the work deals with the shape optimization of the vertical profiler under the limitation of manufacturing feasibility, without altering the weight and volume. The bladder cover and the stability disc have been modified to reduce the drag coefficient for the descending and ascending motion of the vertical profiler.