A Steady-State and Hydroelastic Analysis of Towed Line Arrays for ASW target Applications
Abstract
The three-dimensional static and dynamic configurations of towed line arrays such as those used for mobile targets are of extreme importance. It has been found through towing tank tests of a 200-ft array that it assumes a statically deformed shape over its entire length. In addition, under certain conditions dynamic oscillations of the drogue end occur. This is in contract to the design requirement of overall neutral buoyancy, which would result in an essentially straight array under tow. Three mathematical and numerical computer models have been developed to study and analyze this behavior. These include (1) a three-dimensional steady state model that is sensitive to array weight and/or buoyance distribution, (2) a two-dimensional (horizontal plane) hydroelastic model that will predict static and dynamic configuration instabilities, and (3) a two-dimensional (horizontal or vertical plane) dynamic response model that will predict response to tow-vehicle maneuvers. The three computer models have been used to study the characteristics of the 200-ft array tested in the towing tank. It was found that the 'as built' nonuniform weight distribution, in conjunction with the uniform buoyancy distribution due to the constant diameter array, results in static deflections. These deflections may in turn initiate hydrostatic instabilities. Dynamic instabilities were found to be confined to the drogue end of the array, where the tension is at a minimum.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1983
- Accession Number
- ADA247901
Entities
People
- D. E. Calkins
Organizations
- University of Washington