Visualization of Flow past Aerodynamically Vibrating Cross Sections by k-εmodel

Abstract

This paper introduces the numerically simulated flow patterns which are formed around bluff bodies with various cross sections. The numerical procedure consists of the modified k-ε model proposed by Kato & Launder and two-layer model. Computations were carried out for rectangular cylinders at rest, at vortex-induced vibration, at torsional vibration and at flutter. When the motion velocity is larger than wind speed, flow patterns are quite different from the one at rest. Aerodynamically, this case corresponds to the vortex induced vibration in which a very strong concentration of the vortices and its convection along the surface of the cross sections are observed.When the motion velocity is smaller than wind speed, Flow patter is rather simple and similar to the one at rest. Although the numerical procedure is simple two-dimensional analysis, the results were compared with wind tunnel experiments and the satisfactory agreement were demonstrated.