Average wavelength of organised structures in the turbulent far wake of a cylinder

The average wavelength of organised structures in the far wake of a circular cylinder is inferred from several different estimates based primarily on wind tunnel measurements. Spectra of the lateral velocity fluctuation and cross-spectra between this fluctuation and the temperature fluctuation, at either the same point or at a different point in space, provide relatively unambiguous estimates of the average wavelength of the structures. Dye photographs in a water tunnel provide a less accurate estimate of the average wavelength of the structures. However, all estimates indicate that the average wavelength increases with streamwise distance, at a rate consistent with the self-preserving growth of the wake.