POD Analysis of Flow around Torpedo-Like Geometry with a Hemispherical Nose

Abstract

There has been an increased interest in underwater vehicles for a wide range of applications over the past decade. In the current study, flow characteristics around a common, torpedo-like geometry with a Myring profile were investigated at a length-based Reynolds number of Re=20000 using the Particle Image Velocimetry (PIV). As a result of PIV and Proper Orthogonal Decomposition (POD) analyzes in this study; instantaneous streamline topology Ψ, instantaneous vorticity ωL⁄U_∞ contours, instantaneous streamwise velocity component u⁄U_∞ graphs, cross-streamwise velocity component v⁄U_∞ graphs, instantaneous vorticity ωL⁄U_∞ graphs, perpendicular to the flow direction, instantaneous vortex graphs and time-averaged TKE graphs were evaluated and compared. At the same time, as a result of PIV analysis, time-average streamline topology <Ψ> and Time-averaged vorticity <ωL⁄U_∞ > contours values are given. When the flow characteristics were compared by using the obtained POD method of the PIV results, it was determined that although the POD data were generally quite similar to the PIV results, the POD analysis results had a more uniform flow structure and vortex turbulence was lessened.