Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-19T03:39:15.121Z Has data issue: false hasContentIssue false
  • English
  • Français

A stationary oblique breaking wave for laboratory testing of surfboards

Published online by Cambridge University Press:  11 April 2006

H. G. Hornung  and
P. Killen
H. G. Hornung
Affiliation:
Department of Physics, School of General Studies, Australian National University, Canberra
P. Killen
Affiliation:
Department of Physics, School of General Studies, Australian National University, Canberra
Get access Rights & Permissions [Opens in a new window]

Abstract

A surface gravity wave obliquely incident on a sloping beach is broken near the beach and has a smooth surface further out. Viewed in the frame of reference of the transition from the smooth to the broken part, the flow is steady, and the wave is oblique to the free stream. By placing a suitably shaped obstacle in a flume operated at high Froude number, such a wave can be generated. Experiments in which a wave of 18 cm height was generated are described and the wave shape and some of its characteristics presented. In particular, the dividing stream surface separating that part of the flow which curls over into the break from the part that flows smoothly over the obstacle is discussed.

Model surfboards can ride this wave unsupported, provided the correctly scaled weight loads them at the right centre-of-mass position. This makes it possible to determine the forces on the board without a balance. A comparison of the measured forces with estimates, particularly of the drag, indicate that viscous and surface-tension phenomena introduce only small scale effects in the Froude number modelling. While the results are not sufficiently accurate to draw definite conclusions about the effects of surf board shape, they indicate clearly that surf board flows may be modelled with quantitative success in the laboratory.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 78 , Issue 3 , 7 December 1976 , pp. 459 - 480
Copyright
© 1976 Cambridge University Press

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

Lamb, H. 1932 Hydrodynamics, $ 256. Cambridge University Press.
Paine, M. 1974 B.E. thesis, Mech. Engng Dept., Sydney University.
Savitsky, D., Prowse, R. E. & Lueders, D. H. 1958 N.A.C.A. Tech. Note, no. 4187.
Schlichting, H. 1965 Grenzschicht-Theorie. Braun.
Sedov, L. I. 1965 Two-dimensional Problems in Hydrodynamics and Aerodynamics. Interscience.
Stoker, J. J. 1957 Water Waves. Interscience.
Wagner, H. 1932 Z. angew. Math. Mech. 12, 193–215. (English trans. N.A.C.A. Tech. Memo. no. 1139.)
Wehausen, J. V. & Laitone, E. V. 1960 In Handbuch der Physik (ed. S. Flügge), vol. IX. Springer.
Weinstein, I. & Kapryan, W. J. 1953 N.A.C.A. Tech. Note, no. 2981.