A Steady-State Analysis of Candidate Towing Cables for a Deep-Towed Geophysical Array System

摘要

The relative performance of two candidate towing cables for the proposed Deep-Towed Geophysical Array System is examined. A preliminary design of this ship-towed system is presented. It includes a description of the candidate towing cables and a towed body, which is composed of an instrumented fish and a long, nearly neutrally buoyant seismic streamer. Using a two-dimensional steady-state analysis, towing cable geometry and tensions are predicted for the body depths specified and for a series of towing speeds. Results of the analysis are presented graphically and shown not only the effects of body depth and towing speed, but the effects of cable drag coefficients and body downforce as well. These results are then used in conjunction with constraints on cable length and design tension to predict maximum towing speeds. Although based on a particular design, the information contained in this report provides useful guidance to further assist in the engineering development of the overall system. (Author)