APPLICATION OF COMPUTATIONAL FLUID TECHNIQUE WITH HIGH ACCURACY AND CONSERVATION PROPERTY TO THE WIND RESISTANT PROBLEMS OF BUILDINGS AND STRUCTURES : Part 2 Vortex structures and aerodynamic characteristics around a three-dimensional square prism on a ground plane

Abstract

It is generally thought that the vortices shed from a three-dimensional square prism on a ground plane become to have a three-dimensional structure because of the free end. These vortices differ from those in case of a two-dimensional prism, and these are known to evolve into Karman type or Arch type behind a three-dimensional prism according to the aspect ratio of the prism or the Reynolds numbers. These phenomena are highly affected by the downwash over the free end. Here, we numerically simulate the flows around a three-dimensional square prism on a ground plate by use of the interpolation method. First, we estimate the accuracy for the prediction of the flows through the comparison with the previous experimental data. Second, the local aerodynamic characteristics determined by these vortex structures are discussed.