Theory of Ocean-Array Interaction. Phase I Report.
Abstract
This report discusses a linear model that describes the transverse dynamics of a cable/towed array system driven by oceanic crosscurrents. Solutions of the governing momentum equation show the characteristics of transverse dynamics of the system. The cable/towed array system attempts to align locally with the fluid flow axis but is impeded by the tension stiffness of the system. The result is that the transverse displacement response of the system is proportional to the local fluid angle and the ratio of normal to transverse hydrodynamic drag, and is inversely proportional to a power of the oceanic alongtrack wavenumber (k to the nth power), where n = 0 for small wavenumbers and n = 2 for large wavenumbers. Diminishing longitudinal tension near the free end creates the appearance of a 'tail wagging' which is more pronounced at high wavenumbers. The actual response to oceanic forcing is determined by the Fourier Bessel spectra of a function of the spatial distribution of crosstrack ocean current structure that determines which 'modes' of behavior are excited. A numerically efficient solution to the governing equation using the 'method of lines' and 'generalized Adams-Bashforth methods' was developed and examples were run. Keywords; Towed arrays; Hydrodynamics.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 21, 1983
- Accession Number
- ADA163550
Entities
People
- Ding Lee
- Robert M. Kennedy
Organizations
- Naval Underwater Systems Center