Abstract
Large scale structures in outer layer of wall-bounded shear flows, that is, a zero-pressure-gradient boundary layer and plane wall jet above flat plates, were investigated experimentally. Our objective is to clarify mean properties of the large scale structures in the intermittent region. Measurements were made by using I-type and X-type hot-wire probes, and an I-type rake probe with 16 hot wires along the spanwise direction. Turbulent/non-turbulent intermittency factor was calculated, and then from these distributions, a center position and width of the intermittent region were estimated. And also, RMS values of the streamwise velocity fluctuation at the center position were defined as a velocity scale. Wavenumber spectra were transformed from the measured velocity data by the rake probe, and spanwise length scales were estimated from these spectra. Reynolds number dependencies of scales of length and velocity were examined.
