Accession Number : AD0690796

Title :   DIRECTIONAL SPECTRA MODELS FOR DESIGN USE,

Corporate Author : CALIFORNIA UNIV BERKELEY HYDRAULIC ENGINEERING LAB

Personal Author(s) : Borgman,L. E.

Report Date : JUN 1969

Pagination or Media Count : 58

Abstract : The directional spectrum for ocean waves has not been widely used in design computations, although it is generally acknowledged that the directional distribution is a major and significant feature of waves in the ocean. This lack of use is largely due to the absence of reliably measured directional data for waves and the resulting unavailability of 'design' versions of severe wave directional spectra. The first problem, measuring the directional spectrum can be treated quite satisfactorily with techniques based on Fourier series analysis of cross-spectrum data from an array of wave recorders. The co- and quadrature-spectral densities are represented in terms of the direction and length of the line between the wave recorders, and the Fourier series coefficients for the directional spectrum. The Fourier coefficients are then extracted by solving a system of n equations in n unknowns. Complete formulas are given for a four-gauge array. The method is computationally checked against a set of computer-simulated wave records having a known theoretical directional spectrum and is shown to have satisfactory precision. (Author)

Descriptors :   (*OCEAN WAVES, MATHEMATICAL MODELS), DISTRIBUTION FUNCTIONS, FOURIER ANALYSIS, SURFACE PROPERTIES, POLYNOMIALS, SERIES(MATHEMATICS)

Subject Categories : Physical and Dynamic Oceanography

Distribution Statement : APPROVED FOR PUBLIC RELEASE