Three-component, time-resolved velocity statistics in the wall region of a turbulent pipe flow

Three-component, coincident, time-resolved velocity measurements were obtained in the near wall region, y⁺ < 100, of a fully developed turbulent pipe flow. The measurements were conducted in the ARL/PSU glycerin tunnel at a Reynolds number (Re_h), based on pipe radius and centerline velocity, of 6436 and an Re_θ of approximately 730. The reported data include velocity statistics up to fourth order, Reynolds stresses and three component, coincident turbulent velocity spectral estimates. The current data are generally in quite good agreement with the fully developed channel flow direct numerical simulation (DNS) results of Antonia et al. (1992) at Re_θ ≃ 700 ∼- 700. The accuracy of the current experimental data and the very good agreement with the DNS results provides evidence for the accuracy of the DNS solutions and thus Antonia's conclusions of very near wall, y⁺ < 20, Re dependence on turbulent velocity statistics. The very good agreement between the low Re rectangular channel flow DNS results and the low Re_θ flat plate turbulent boundary layer statistics of Karlsson and Johansson (1988) suggests that for y⁺ < 30 statistics of similar flows of differing geometry may be compared on the basis of equal Re_θ. The current data are available on disk or by anonymous ftp by the first author.