Smoke is blown into the wind tunnel with corresponding devices placed upwind from the model, so that the air flows become visible. Peculiarities of the air flow alterations such as local vortices can then be recognized from the smoke (Figure 4/9).

	Fig. 4/9: Vertical flow field of a building in a wind tunnel, made visible by smoke, Source: Institute for Hydrology and Water Management (IHW), Karlsruhe Flow field as animation
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