Modeling of vortices in straight-line wind simulators

Abstract

A vortex is an important feature for wind engineering. This paper presents an experimentally validated technique to create vortices in straight-line wind simulators, advancing the study of transient flow features in traditional boundary layer wind tunnels. Repeatable translating vortices can be created in traditional atmospheric boundary layer wind tunnels by partially blocking off the tunnel's flow introducing horizontal shear instability. The technique is initially explored using computational fluid dynamics (CFD) simulations, followed by experimental validation at the University of Florida boundary layer wind tunnel. Findings validating the premise are observed concerning the radial profiles of (a) pressure, (b) velocity, and (c) vertical profile of velocity, which demonstrate the ability to create vortex characteristics comparable to that of specialized vortex simulators and field observations. This technique enables a realistic ratio of translation to tangential speed and swirl ratio of the vortices that conform well with full-scale measurements.