Vortical structures over rectangular cavities at low speed

Experiments have been performed to acquire qualitative and quantitative flow-field data for an open cavity flow using the particle image velocimetry technique. The study focuses on the time-mean and instantaneous development of the turbulent flow structures in the cavity shear layer. The effects of geometry (length-to-depth ratio) and flow speed on these structures are investigated. The shear layers are found to be characterized by coherent vortical structures whose size and rate of growth vary with geometry. The smaller scales of the flow are investigated using a large-eddy decomposition method. Results show these stochastic structures to predominate primarily in the shear layer and aft wall regions. (C) 2005 American Institute of Physics.