Spectral wave attenuation by bottom friction: theory

Ole Secher Madsen, Ying Keung Poon, Hans C. Graber

Research output: Chapter in Book/Report/Conference proceedingConference contribution

267 Scopus citations


Based on the linearized form of the boundary layer equations and a simple eddy viscosity formulation of shear stress, the turbulent bottom boundary layer flow is obtained for a wave motion specified by its directional spectrum. Closure is obtained by requiring the solution to reduce, in the limit, to that of a simple harmonic wave. The resulting dissipation is obtained in spectral form with a single friction factor determined from knowledge of the bottom roughness and an equivalent monochromatic wave having the same root-mean-square near-bottom orbital velocity and excursion amplitude as the specified wave spectrum. The total spectral dissipation rate is obtained by integration and compared with the average dissipation obtained from a model considering the statistics of individual waves defined by their maximum orbital velocity and zero-crossing period. The agreement between the two different evaluations of total spectral dissipation supports the validity of the spectral dissipation model.

Original languageEnglish (US)
Title of host publicationTwenty First Coastal Eng Conf
PublisherPubl by ASCE
Number of pages13
ISBN (Print)0872626873
StatePublished - Dec 1 1988
Externally publishedYes
EventTwenty-First Coastal Engineering Conference - Costa del Sol, Malaga, Spain
Duration: Jun 20 1988Jun 25 1988

Publication series

NameTwenty First Coastal Eng Conf


OtherTwenty-First Coastal Engineering Conference
CityCosta del Sol, Malaga, Spain

ASJC Scopus subject areas

  • Engineering(all)


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