Competent, compact, comparative visualization of a vortical flow field

In computational fluid dynamics, visualization is a frequently used tool for data evaluation, understanding of flow characteristics, and qualitative comparison to flow visualizations originating from experiments. Building on an existing visualization software system that allows for a careful selection of state-ofthe- art visualization techniques and some extensions, it became possible to present various features of the data in a single image. The visualization shows vortex position and rotation as well as skin-friction lines, experimental oil-flow traces, shock-wave positions, and time surfaces. Animation provides natural perception of flow in combination with abstract representation of phenomena. By adding experimental flow visualization, a comparison between numerical simulation and wind-tunnel flow becomes possible up to a high level of detail. Since some of the underlying algorithms are not yet described in detail in the visualization literature, some experiences gained from the implementation are illustrated. The dedicated techniques which are illustrated here address specific properties of vector quantities in the flow field, such as the velocity vector or the friction vector. Image complexity is reduced by employing complex visualization methods. Thus, the room is created which is necessary to study the interaction of various phenomena.