Mechanical Engineering - Theses

Permanent URI for this collection

http://hdl.handle.net/11343/360

Filters

1983 1
1
1
Reset filters

Settings
Statistics
Citations
Start date: 1980 × End date: 1999 × Subject: fluid dynamics × Subject: pipe ×

Search Results

Now showing 1 - 1 of 1
  • Item
    Thumbnail Image
    The structure of turbulent pipe flow
    HENBEST, SIMON ( 1983)
    A brief literature survey of the modelling of wall turbulence is presented. In addition, a recent development in the modelling of wall turbulence (Perry & Chong 1982) is annotated. The structure of fully-developed turbulent flow in a smooth-walled pipe and in a rough-walled pipe are investigated experimentally over the Reynolds number range of 75,000 to 200,000. Each pipe had a nominal length of 400 diameters. The turbulence intensity results were measured using dynamically calibrated normal and crossed-wires. A dynamic calibration mechanism was built that enabled the wires to be calibrated inside the test section of either pipe. The longitudinal and transverse broad-band turbulence intensity results and their spectral distributions, in the turbulent wall region of both the smooth-walled and rough-walled pipes, show encouraging support for Townsend’s (1976) attached-eddy hypothesis and Perry & Chong’s (1982) model of wall turbulence. Using the spectral similarity laws proposed, the asymptotic longitudinal broad-band turbulence intensity distribution in the turbulent and viscous wall regions of the smooth-walled pipe are predicted with reasonable accuracy. In the core region of both pipes, the longitudinal and transverse spectral results show support for the existence of an inertial-subrange and hence of “locally isotropic” small scale motions. In the smooth-walled pipe, Townsend’s (1956) Reynolds number similarity hypothesis is found to be valid in the asymptotic limit with Reynolds number, while in the rough-walled pipe, the extended version of Townsend’s Reynolds number similarity hypothesis (Perry & Abell, 1977) is not upheld, at least for the results presented in this thesis.