Numerical Investigation of Flow Around Finite Height Rectangular

Abstract

Three-dimensional flow features of the slender rectangular prism with cross-section height (H) to streamwise depth (D) ratio or side ratio (D/H = 0.5) were investigated numerically using the Large-eddy simulations (LES) turbulence model with Reynolds number Re = 22000. Four different aspect ratios (L/H = 2.5 – 10) were employed in this research to study the effect of the spanwise variation of the prism model on the flow pattern around the prism. Moreover, the instability-induced motion of the prism was modeled to predict the alteration of flow characteristics of stationary to vibrating states of the test model. The global quantities such as drag force, pressure coefficient, and Strouhal frequency characteristics are presented, which suggests that the structure end tip effect plays an essential role in the dependency of flow features variation. The velocity vector variations at streamwise and spanwise positions are also demonstrated. The prism model with a small aspect ratio (L/H = 2.5) exhibited Karman vortex suppression at the prism's vicinity, and the streamwise vortices region shrank. The flow features of the vibrating prism show different behaviors from the stationary prism model