SIMULATION STUDIES OF THE RESPONSE OF A DEEPLY TOWED VEHICLE TO VARIOUS TOWING SHIP MANEUVERS
The behavior of a long cable towed at slow speeds through the ocean depends in a complex fashion on the path followed by the towing ship relative to the water. A cable simulation program was used to characterize the response of the cable by using idealized towing ship maneuvers as input to the program. The response of the cable was noted and it was found that the behavior of the cable was strongly dependent on the fundamental period of the towing vessel maneuvers. Sinusoidal deviations of the towing ship from a straight towing track resulted in delayed and reduced excursions of the towed vehicle from the track; the estimated response ratio varied from 0.002 to 0.800, depending both on the period of the deviation (periods ranged from 0.5 to 4.0 hr) and on the towing depth (2 or 6 km). The ship's speed was 3 km/hr. The time lag between ship motion and vehicle response was approximately 0.5 hr for the shallow case and 1.3 hr for the deep case. Simulation runs of a low drag (faired) cable showed that the behavior of the vehicle when towed at a depth of 6 km was similar to that obtained with a conventional cable at 2 km depth. The response of the towed vehicle to a right- angle turn of the towing ship was investigated and a generalized model of the response developed. The effects of a controllable side force on the towed vehicle were also simulated and it was noted that a deviation (2-hr period) of the towed vehicle from a straight-line track could be reduced from 40 to 2 m by impressing a side force on the vehicle with an average magnitude of 150 newtons (30 lb). (Author)
- Also published in Ocean Engineering, V3, pp 37-46, 1975.
Scripps Institution of OceanographyCalifornia Marine Physical Laboratory
San Diego, CA United States
- Mudie, J D
- Ivers, W D
- Publication Date: 1975
- Pagination: 14 p.
- TRT Terms: Cables; Hydrodynamics; Simulation; Towing devices
- Old TRIS Terms: Simulated towing; Towed bodies; Towing cables; Towline hydrodynamics
- Subject Areas: Hydraulics and Hydrology; Marine Transportation; Vehicles and Equipment;
- Accession Number: 00134624
- Record Type: Publication
- Source Agency: National Technical Information Service
- Report/Paper Numbers: MPL-U-66/74 Summ. Rpt.
- Contract Numbers: N00014-69-A0200-6002, NSF-DES-74-03690
- Files: TRIS
- Created Date: Jun 9 1976 12:00AM