Hostname: page-component-586b7cd67f-2brh9 Total loading time: 0 Render date: 2024-11-24T23:51:53.279Z Has data issue: false hasContentIssue false

The Flow and Pressure Losses in Smooth Pipe Bends of Constant Cross Section

Published online by Cambridge University Press:  04 July 2016

A. J. Ward Smith*
Affiliation:
Technical Department, Royal Aeronautical Society

Summary

Incompressible turbulent flow in smooth pipe bends of circular-arc curvature and constant cross section is discussed. The effects of bend angle, radius ratio, duct cross-sectional shape and Reynolds number are considered. Particular attention is paid to the influence of the tangents on the flow and losses in a bend. In addition consideration is given to the definition and measurement of the bend loss.

A correlation of experimental pressure loss data is made. It is shown that large variations in experimental results, which cannot be ascribed to the effects of geometrical parameters or Reynolds number, are accounted for by the effects of the downstream tangent and position at which the pressure measurements were made. The inadequacy of existing experimental information is an obstacle to the presentation of comprehensive data on the effect of geometrical parameters on bend losses.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society 1963

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1.Patterson, G. N. Note on the Design of Corners in Duct Systems. R. and M. 1773, 1937.Google Scholar
2.Henry, J. R. Design of Power Plant Installations. Pressure- Loss Characteristics of Duct Components. NACA ARR L4F26, NACA/TIL/703, 1944.Google Scholar
3.Gray, S. A Survey of Existing Information on the How in Bent Channels and the Losses Involved. Power Jets Report No. R.1 104, 1945.Google Scholar
4.Anderson, A. G. Fluid Flow Diversion. St. Anthony Falls Hydraulic Laboratory, Project Report No. 1, 1947.Google Scholar
5.Ito, H.Pressure Losses in Smooth Pipe Bends. Transactions of the American Society of Mechanical Engineers, Series D, p. 131, March 1960.Google Scholar
6.Martin, moira, E. and Deverson, E. C. The Effect of Bend Outlet Conditions on the Pressure Losses in Bent Circular Pipes. ARC CP 505, 1960.Google Scholar
7. Royal Aeronautical Society Aerodynamics Data Sheet 00.02.04. Friction Factor for Straight Ducts of Constant Cross Section Including Effects of Surface Roughness, Non- circularity and Compressibility. 1961.Google Scholar
8.Hofmann, A.Der Verlust in 90°-Rohrkrümmern mit gleich- bleibendem Kreisquerschnitt. Mitteilungen des Hydraulischen Instituts der Technischen Hochschule, München. Bulletin 23, p. 45, 1929. (This bulletin was also published as a translation by the American Society of Mechanical Engineers, 1935).Google Scholar
9.Wasielewski, R.Verluste in glatten Rohrkrümmern mit kreisrundem Querschnitt bei weniger als 90° Ablenkung. Mitteilungen des Hydraulischen Instituts der Technischen Hochschule, Miinchen. Bulletin 5, p. 53, 1932.Google Scholar
10.Yarnell, D. L. and Nagler, F. A.Flow of Water Around Bends in Pipes. Transactions of the American Society of Civil Engineers, Vol. 100, p. 1018, 1935.Google Scholar
11.Keulegan, G. H. and Beij, K. H.Pressure Losses for Fluid Flow in Curved Pipes. Journal of Research, National Bureau of Standards, Vol. 18, pp. 89144, 1937.Google Scholar
12.Eichenberger, H. P. Shear Flow in Bends. Office of Naval Research Technical Report No. 2, 1952.Google Scholar
13.(a) Eastwood, W. and Sarginson, E. J.The Effect of a Transition Curve on the Loss of Head at a Bend in a Pipeline. Proceedings of the Institution of Civil Engineers, p. 129, June 1960. (b) Discussion, Proceedings of the Institution of Civil Engineers, p. 199, September 1961.Google Scholar
14.Weske, J. R. Pressure Loss in Ducts with Compound Elbows. NACA/TIL/384, February 1943.Google Scholar
15.Higginbotham, J .T., Wood, C. C. and Valentine, E. F. A Study of the High Speed Performance Characteristics of 90° Bends in Circular Ducts. NACA TN 3696, 1956.Google Scholar
16.Wilbur, S. W. An Investigation of Flow in Circular and Annular 90° Bends with a Transition in Cross Section. NACA TN 3995, 1957.Google Scholar
17.Young, A. D., Green, G. L. and Owen, P. R. Tests of High-speed Flow in Right-angled Pipe Bends of Rectangular Cross-Section. R. and M. 2066, 1943.Google Scholar
18.Madison, R. D. and Parker, J. R.Pressure Losses in Rectangular Elbows. Transactions of the American Society of Mechanical Engineers, p. 137, 1936.Google Scholar
19.Edwards, A. R. The Effects of High Mach Number Flow on Bend Losses in Square Section Constant Area Ducting. Armstrong Siddeley Motors Ltd., Aerodynamics Department Report No. A180, 1956.Google Scholar
20.Weske, J. R. Experimental Investigation of Velocity Distribu tions Downstream of Single Duct Bends. NACA TN 1471, 1947.Google Scholar
21.Detra, R. W. The Secondary Flow in Curved Pipes. Mit teilungen aus dem Institut fur Aerodynamik, E.T.H. Zurich Nr. 20, 1953.Google Scholar
22. Royal Aeronautical Society Aerodynamics Data Sheet 00.02.07. The Pressure Loss for Incompressible Turbulent Flow in Smooth Circular-Arc Bends. Constant Rectangular or Circular Cross Section. (To be published).Google Scholar
23.Ward Smith, A. J. Subsonic Adiabatic Flow in a Duct of Constant Cross-Sectional Area. (To be published).Google Scholar