Il est offert ici en HTML pour votre commodit , mais nous vous conseillons d'utiliser plut t la version officielle, soit en format PDF , soit en format PostScript . The performance of computer codes in simulating the velocity, Reynolds stress and surface pressure fields for time-periodic and stationary turbulent flows is to be assessed. When this bluff body is sufficiently far from the wall, the wake flow is time-periodic due to von Karman vortex shedding. For small separations, shedding is suppressed and the turbulent wake flow is stationary.
Contributions are welcome to either or both cases.
S. The flow around a square cylinder immersed in a uniform stream is independent of Reynolds number, based on side dimension D, in the range 10000 to 100000. The formation and shedding of these vortices is related to the flow separation at the leading edges giving rise to intense shear layers over each of the lateral faces which oscillate at a nearly constant phase difference of 180 o . If the cylinder is mounted close to the wall below a critical gap height, vortex shedding can be completely suppressed. The mechanism causing suppression is still unclear, but appears to be related to opposing effects due to the production of counter-rotating vorticity in the wall boundary layer and the increased circulation produced on the lower cylinder face. The experimental geometry is defined in Figure 1.