UNSTEADY FLOW IN TUBES AND TUNNELS

A theory is presented for the attenuation and dispersion of small sinusoidal waves superimposed on gross turbulent flow in cylindrical tubes. Three frequency bands are distinguished: a low-frequency band in which a constant-inertance-resistance-compliance model applies, a high-frequency band in which a time-invariant-eddy-viscosity model applies, and an intermediate transition band for which no complete theory is given. Experiment corroborates the theory, and reveals dramatic resonances in the transistion band associated with nonequilibrium turbulence. A quasi method of characteristics is presented in general and in detail for the case of fluid transients with history-dependent properties such as occur at intermediate and high frequencies. Historetic weighting functions are the key to the method, and are found for laminar flow and several different turbulent flows. Results are extended to include the effects of heat transfer in a perfect gas contained by isothermal walls.

• Corporate Authors:

  Massachusetts Institute of Technology

  Engineering Projects Laboratory
  Cambridge, MA  United States 
• Authors:
  • Brown, F T
  • Knebel, G
  • Margolis, D
• Publication Date: 1971-8

Media Info

• Pagination: 327 p.

Subject/Index Terms

• TRT Terms: Computer programming; Equations of motion; Flow; Fluid mechanics; Frequency (Electromagnetism); Heat transfer; Laminar flow; Liquids; Mathematical models; Tubing; Tunnels; Turbulence; Unsteady flow; Vehicular tunnels
• Old TRIS Terms: Liquid flow; Tube systems; Tunnel flow
• Subject Areas: Bridges and other structures; Railroads;

Filing Info

• Accession Number: 00039293
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: DSR-76107-4 Final Rpt, FRA-RT-72-22
• Contract Numbers: DOT-C-85-65
• Files: TRIS
• Created Date: Nov 24 1973 12:00AM