## Proceedings of the International Conference
on Coastal Engineering, No 22 (1990)

###

### SCALE
EFFECTS IN BREAKING WAVES

*A.D. **Toumazis**, K. Anastasiou*

#### Abstract

A breaking wave model, which is partly physical and partly
analytical, is proposed. This model is based on observations
that up to a certain moment the wave presents a long, smooth,
horizontal, cylindrical edge, which then segments due to surface tension
effects. A disturbance on a cylindrical surface, withdrawn from the influence
of gravity, becomes unstable when its wavelength exceeds the circumference of
the cylinder. The rate of growth of the instability,
is a function of the radius of the cylinder and the wavelength of the
disturbance. Using the theory describing the evolution of the assumed
hyperbolic shape of the tip of a breaking wave, the radius of the cylindrical
edge is approximated to the radius of curvature of the hyperbola. The model
describes the three-dimensional evolution of the curling wave crest. Scale
effects are then derived which show good agreement with experimental results.

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