Full-Scale Measurement and Prediction of the Dynamics of High-Speed Helicopter Tow Cables
Abstract
LONG-TERM GOALS: To provide the Navy with a non-invasive measurement technique and a numerical simulation tool for analyzing the vibration response of high-speed towed cables using a helicopter. The non-invasive measurement technique is based on fiber Bragg gratings, which measure the tensions and transverse vibrations of a high-speed tow cable at multiple sites along the cable. The numerical tool is based on combining two software applications, WHOI CABLE for calculating tow cable shape and an updated version of MIT's VIVA for calculating hydro-elastic multi-mode vibration response and variable drag coefficient of a cable in arbitrary current. OBJECTIVES: To construct and test in at sea trials a prototype electro-optical test cable with the same dimensions as that of the OAMCM tow cable. We are using the test cable to demonstrate, through full-scale measurements, that fiber Bragg gratings can measure the vibrational amplitudes and frequencies along the length of the cable under high speed towing conditions. The results from the full-scale measurements are used to verify the numerical simulation tool for predicting tow cable strumming and flutter. A numerical simulation that accurately models these processes will increase NSWC's ability to design tow cables with the proper distribution of ribbon and hard-nose fairing and to do mission planning. In addition, we are developing alternative designs to suppress strumming and at the same time avoid galoping and significant side curvatures.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 14, 2014
- Accession Number
- ADA602610
Entities
People
- Michael S Triantafyllou
- Rockwell Geyer
Organizations
- Massachusetts Institute of Technology