09:00   Invited lecture by Prof. A.J. Smits, "Spectral scaling in very high Reynolds number wall-bounded flows" Chair: Detlef Lohse 09:00 60 mins SPECTRAL SCALING IN VERY HIGH REYNOLDS NUMBERWALL-BOUNDED FLOWS Alexander Smits Abstract: We present measurements of one-dimensional spectra in pipe and boundary layer flows at Reynolds numbers up to Re =72500. The results indicate that in the inertial region the spectra follow closely a k􀀀3=2 dependence rather than the expected k􀀀5=3. Inthe energy-containing range, an approximate region of k􀀀1 variation is seen to emerge at very high Reynolds numbers, connected with the appearance of the log-law for the streamwise turbulence intensity, but it is not an overlap region in the sense of [13]. The location of the outer spectral peak displays only a weak dependence on Reynolds number. The k􀀀1 x region seems to occur when there is sufficient scale separation between the locations of the outer spectral peak and the outer edge of the log region. The extent of k􀀀1 x region depends on the wavelength of the outer spectral peak, which appears to emerge as a new length scale for the log region.

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