Depth Enhancement of an Underwater Towed System using Hydrodynamic Depressor

P. Vinod; Roni Francis; P. Prabhasuthan; O.R. Nandagopan

doi:10.14429/dsj.66.9031

P. Vinod Naval Physical and Oceanographic Laboratory, Kochi
Roni Francis Naval Physical and Oceanographic Laboratory, Kochi
P. Prabhasuthan Naval Physical and Oceanographic Laboratory, Kochi
O.R. Nandagopan Naval Physical and Oceanographic Laboratory, Kochi

DOI: https://doi.org/10.14429/dsj.66.9031

Keywords: Towed system, hydrodynamic depressor, numerical analysis, towing tank tests, steady state theory of towing cables, sea trial

Abstract

The underwater towed system described here consists of tow cables, a towed body, an acoustic module and tail rope towed behind a surface ship. The required depth at a particular speed of the towing ship is obtained by paying out specified length of cable from the winch. However the excessive drag forces on the various components of the towed system results in impractically large values of cable length, especially at higher speeds. A hydrodynamic depressor is designed to improve the depth performance. The design is evolved based on numerical analysis and towing tank tests. Estimation of depth attained is carried out based on steady state theory of tow cables. Validation of the numerical analysis results is carried out through field evaluation of depressor performance during sea trial of the towed system.

Author Biographies

P. Vinod, Naval Physical and Oceanographic Laboratory, Kochi

Mr P. Vinod obtained his BTech (Mechanical Engineering) from College of Engineering, Trivandrum and MTech (Mechanical Engineering) from IIT, Madras. Presently he is heading the Ocean Engineering Division at Naval Physical and Oceanographic laboratory, Kochi. His areas of interest include: Design and development of sonar handling systems, underwater towed bodies and underwater housings. He has taken the lead role in this work and put forward the idea of augmenting the depth attained by the towed system through various possible hydrodynamic means. He has drawn up the design envelop within which the depressor has to operate.

Roni Francis, Naval Physical and Oceanographic Laboratory, Kochi

Mr Roni Francis, obtained his graduation in Naval Architecture from Cochin University of Science and Technology and MSc from Indian Institute of Technology, Madras. Presently he is working as scientist at Naval Physical and Oceanographic Laboratory, Kochi where he is involved in the design and development of underwater systems. His area of research includes: Hydrodynamics of towed systems and computational fluid dynamics. He has published 12 papers in national and international journals and conferences.

P. Prabhasuthan, Naval Physical and Oceanographic Laboratory, Kochi

Mr P. Prabhasuthan, obtained his BTech (Production Engineering) from Sree ChithraThirunal College of Engineering, Thiruvananthapuram. He is currently working as Scientist at Naval Physical and Oceanographic Laboratory (NPOL), Kochi. His significant contributions and interest are in the field of designing and developing SONAR towed bodies and handling systems.

O.R. Nandagopan, Naval Physical and Oceanographic Laboratory, Kochi

Dr O.R. Nandagopan, received BE (Mechanical Engineering) from Thiagarajar College of Engineering, Madurai, in 1983, ME (Production Engineering) from Anna University, Chennai, in 1985 and PhD (Structural Response of water backed Perforated plate for Underwater Non-contact Explosion) from Cochin University of Science & Technology, Kochi, in 2011. Presently he is the Director at Naval Science and Technological Laboratory (NSTL), DRDO, Kochi. He is Fellow of Institution of Engineers (India) and Member of Ocean Society of India.