Accession Number:

AD0729728

Title:

Scattering and Radiation of Gravity Waves by an Elliptical Cylinder.

Descriptive Note:

Final rept. 1970-1971,

Corporate Author:

MASSACHUSETTS INST OF TECH CAMBRIDGE RALPH M PARSONS LAB FOR WATER RESOURCES AND HYDRODYNAMICS

Personal Author(s):

Report Date:

1971-08-01

Pagination or Media Count:

152.0

Abstract:

Theoretical results of scattering and radiation of simple-harmonic gravity waves by a vertical cylinder of elliptical cross-section are worked out in this report. The cylinder extends from the free surface to the bottom of the sea of constant depth. Linearized theory for small amplitude waves is adopted. The question of flow separation is not treated. The mathematical solution leads to Mathieus equations and the computer program by Clemm is used. Physical quantities calculated include the wave forces and moments in various directions on, and the scattering amplitude around, a stationary cylinder due to a plane incident wavetrain. Also calculated are the damping coefficients representing radiation energy losses due to various modes of oscillation of a cylinder in the absence of incident waves. By the method of images the scattering of plane incident wave by a semi-elliptical peninsula is studied. Extensive numerical results are presented for various degrees of ellipticity, angles of incidence, and for wave-lengths ranging from very long to comparable to the horizontal dimensions of the cylinder. These results should provide useful information for the design of large ocean structures. Author

Subject Categories:

  • Physical and Dynamic Oceanography
  • Structural Engineering and Building Technology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE