Scaling of the wall-normal turbulence component in high-Reynolds-number pipe flow

Streamwise and wall-normal turbulence components are obtained in fully developed turbulent pipe over a Reynolds number range from 1.1 × 105to 9.8 × 106. The streamwise intensity data are consistent with previous measurements in the same facility. For the wall-normal turbulence intensity, a constant region inv'r.m.s.is found for the region 200 ≤ y+≤ 0.1R+for Reynolds numbers up to 1.0 × 106. An increase inv'r.m.s.is observed below abouty+∼ 100, although additional measurements will be required to establish its generality. The wall-normal spectra collapse in the energy-containing region with inner scaling, but for the low-wavenumber region ay/Rdependence is observed, which also indicates a continuing influence from the outer flow on the near-wall motions.