Sage Journals: Discover world-class research

Abstract

A method has been developed for predicting unsteady turbulent friction in smooth, transitional, and rough pipe flows. For transitional and rough pipe flows the effective viscosity at the wall is varied depending on Reynolds number and roughness. An approximation has been made for the transition region using a cubic spline for the friction factor between the smooth and rough regions. This turbulence model can be implemented readily in several types of numerical model for pipe flow, including simple lumped parameter models, finite difference/finite element methods, and the method of characteristics. An approximate method for representing changes in turbulence energy is discussed. Using this, the method is suitable for small and large changes in flow, and for short and long time scales, but further validation is needed.

Keywords

turbulent flow unsteady flow rough pipes accelerating flow

Get full access to this article

View all access options for this article.

References

Johnston

D. N.

Numerical modelling of unsteady turbulent flow in smooth-walled pipes. Proc. IMechE, Part C: J. Mech. Engi. Sci.,, 2011 (Submitted).

Vardy

A. E.

Brown

J. M. B.

Transient turbulent friction in smooth pipe flows. J. Sound Vib., 2003, 259(5), 1011–1036.

Schlichting

Boundary layer theory, 1979 7th edition (McGraw Hill, New York).

Nikuradse

Strömungsgesetze in rauhen Rohren. Forschg. Arb. Ing.-Wes., 1933, 361, 1–22.

Bauer, B. and Galavics, F. Experimentelle und Theoretische Untersuchungen über die Rohrreibung von Heizwasserleitungen. Mitt. d. Fernheizkraftwerkes d. ETH, Zurich, 1939.

Moody

L. F.

Friction factors for pipe flow. Trans. ASME, 1944, 66, 671–684.

Colebrook

C. F.

Turbulent flow in pipes with particular reference to the transition region between the smooth and rough pipe laws. J. Inst. Civ. Eng., 1939, 11, 133–156.

Vardy

A. E.

Brown

J. M. B.

Transient turbulent friction in fully rough pipe flows. J. Sound Vib., 2004, 270, 233–257.

Brown

F. T.

Margolis

D. L.

Shah

R. P.

Small amplitude frequency behavior of fluid lines with turbulent flow. J. Basic Eng., Trans. ASME, 1969, 91, 678–692.

10.

Johnston, D. N. Pipeline models in Matlab Simulink, 2010, available from http://people.bath.ac.uk/ensdnj/models (accessed November 2010).

11.

Taylor, S. E. M., Johnston, D. N., and Longmore, D. K. Experimental validation of pipeline models for laminar and turbulent transient flow. In proceedings of the 1997 ASME International Mechanical Engineering Congress and Exposition, Dallas, TX, USA, 16–21 November 1997, Vol. 4, pp. 99–104 (The Fluid Power and Systems Technology Division (Publication) FPST, New York, NY).

12.

Jackson

J. D.

A study of turbulence under conditions of transient flow in a pipe. J. Fluid. Mech., 2000, 408, 1–38.

13.

Vítkovský, J., Stephens, M., Bergant, A., Lambert, M. and Simpson, A. Efficient and accurate calculation of Zielke and Vardy-Brown unsteady friction in pipe transients. In proceedings of 9th international conference on pressure surges, Chester, UK, 24–26 March 2004, pp. 405–419.

Numerical modelling of unsteady turbulent flow in tubes,including the effects of roughness and large changes in Reynolds number

Abstract

Keywords

Get full access to this article

References