An example of visualization of the kinematic structure around a single building

Summary The method of flow visualization with smoke allowed us to check the complexity of flow around an isolated building in a full-scale experiment. In the upstream zone the well established horseshoe vortex could be verified. Also the frontal separation point was clearly documented. Whether the flow reattaches to the sidewalls depends on the length of the building. Of special interest was the downstream region. In this region strong interaction of the different vortex structures was observed. The rising spiral vortices, which originated at the lateral edges, are important. Also an occasional breakdown and fast reorganization of the vortex is an interesting fact.This simple flow visualization experiment agrees well with the extensive laboratory experiments and topological criteria developed and used by Hunt (1978).NotesWith 6 Figures