"On the large scale organization of a turbulent boundary layer disturbed by a circular cylinder "

by
De Souza, F., Delville, J., Lewalle, J. and Bonnet, J.P.

ABSTRACT

The three conditional analysis techniques, applied to multi-point measurements obtained with a rake of x-wires, have provided valuable insight into the large scale organization of the turbulent boundary layer disturbed by a cylinder. The WAG approach is the most easily implemented, although the least objective, of the three techniques. Nevertheless, it led to fairly accurate estimations of average structure characteristics. Information on the instantaneous dynamics of the organized flow was made available by the two filtering techniques (spectral and wavelet techniques). In particular, the time-frequency filter based on wavelet analysis permitted to extract and analyze particular coherent events most objectively. We conclude from these analyses that the domination of the upper vortices shed from the cylinder is the key to the observed dissimilarity between momentum and heat transfer in the disturbed boundary layer.