DBPapers
DOI: 10.5593/SGEM2016/B32/S15.114

THE OSCILLATIONS ANALYSIS IN HEAD WAVES OF A TRACTOR-TUG MODEL BY EXPERIMENTAL AND NUMERICAL METHODS

C. Gasparotti, L. Domnisoru, D. Obreja
Wednesday 7 September 2016 by Libadmin2016

References: 16th International Multidisciplinary Scientific GeoConference SGEM 2016, www.sgem.org, SGEM2016 Conference Proceedings, ISBN 978-619-7105-62-9 / ISSN 1314-2704, June 28 - July 6, 2016, Book3 Vol. 2, 877-884 pp

ABSTRACT
The numerous accidents in the coastal areas in heavy weather conditions, with significant ecological disasters, have imposed the development of the specialized escort tug ships. The main objective of this paper is to assess the methods for the tractor-tug oscillations analysis that are used at the design process for ship’s seakeeping safety evaluation. A scaled 1:16 tractor-tug fiberglass model is considered for the experimental and numerical studies, with a total model length of 1.838 m. This tug is designed for maritime and harbor ships’ handling and safety operations. The experimental analyses were carried out at the Towing Tank from Galati Naval Architecture Faculty. The wave generator of the towing tank generates regular head waves, in the frequency range 0.3 to 1.0 Hz, which covers the model operation requirements. The heave and pitch motions were measured. Based on own program code DYN_OSC and the experimental waves characteristics, the heave and pitch coupled oscillations response of the tractor-tug model are computed. The results of this study are pointing out some differences between the experimental and numerical models. The physical phenomena leading to these differences are in detail analyzed.

Keywords: tractor-tug, experiment, numeric, oscillations, safety.