Transition to Turbulence in the Wake of a Sphere

Experimental investigation of the wake of a sphere is reported, namely, the change from steady to periodic flow in the Reynolds number range [100, 360]. First, visualizations have been carried out in a water channel to make precise the geometry of downstream bubble and shedding vortices behind the sphere. Thereafter, measurements have been performed in a wind tunnel and results have been compared successfully to the predictions of the Landau model.