Home Books eBooks Journals References & Proceedings Authors, Editors, Reviewers A-Z Product Index Awards
Turbulence and Shear Flow Phenomena -1 First International Symposium

ISBN:
1-56700-135-1 (Print)

NEAR-WALL STRUCTURE IN A FULLY DEVELOPED TURBULENT PIPE FLOW

Zhaoshun Zhang
Department of Engineering Mechanics, Tsinghua University, Beijing, China 100084

Guixiang Cui
Department of Engineering Mechanics, Tsinghua University, Beijing, China 100084

Guoqing Wang
Chemical Engineering Research Institute South China University of Technology, Guangzhou, 510641, China; Department of Engineering Mechanics, Tsinghua University Beijing 100084, CHINA

Michel Ayrault
LMFA, UMR CNRS 5509 Ecole Centrale de Lyon 69131 Ecully Cedex, France

Serge Simoens
Laboratoire de Mécanique des Fluides et d'Acoustique, URA 263 CNRS-ECL, BP 163-69131 Ecully Cedex, France

Abstract

This paper investigates the near wall structures of a turbulent pipe flow at Reynolds numbers ranged from 5000 to 10000. The LIF technique is used for the visualization of the flow patterns which are recorded by a CCD camera at the speed of 25 frames per second. The longitudinal vortices and bursting rates are evaluated from the time series of the images. The results show that both average spacing of the longitudinal vortices and mean time interval of the bursts are greater than those at plate wall of turbulent flows. The Fourier Descriptor technique is used for reconstruction of the vortical structures near the wall, it provides a new tool to explore the spatial evolution of the coherent structure.