Parametric CFD investigation of ALS technique on reduction in drag of bulk carrier

ABSTRACT

Development has been made in the field of Naval Architecture to enhance the fuel efficiency of ships by using techniques which reduces pressure drag at higher speeds. However, for slower moving vessels, the major concern is higher percentage of frictional drag. It is well-known fact that, frictional drag depends on the wetted surface area of a ship, viscosity and density of fluid flowing around it. Applications to change the viscosity and/or density and/or wetted surface area of the ship is need of an hour. In the Air lubrication system technique, alteration of above is possible by injecting air bubbles below the hull. In this study, numerical investigations into frictional drag reduction by injection of air bubbles were carried out in Star CCM+ for a 1:23 scaled model of a Bulk Carrier for two speeds and for different air injection rates using different diameters of series of injection holes.

KEYWORDS:

• Bubble drag reduction
• air lubrication system
• frictional drag reduction
• BDR
• ALS

Acknowledgements

The authors would like to acknowledge the Ministry of Shipping, India and SIEMENS Ltd formerly known as CD ADAPCO for funding the project. Authors express their sincere gratitude for their support. Moreover, authors sincerely express warm gratitude towards Mr Sangmeshwar Biredar of SIEMENS for his invaluable inputs during the investigation using Multiphase flow in Star CCM +.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Mr Sudhir Sindagi is currently doing his PhD from Department of Ocean Engineering of IIT Madras in external category and is working as Sr. Assistant Professor at Tolani Maritime Institute, Pune, India. In last two years, he has presented/published more than 10 Research papers in the International Journals/Conferences. After completion of his Post Graduation from IIT Kharagpur, he joined Marine Engineering Centre of Larsen & Toubro Ltd as Naval Architect and worked there for 5 yrs and was member of the design team who designed and constructed high Speed Interceptor Boat for Indian Coast Guard which moves at a speed of 45 knots. His Research work and papers have been awarded by Institution of Engineers, India Division and by Springer in an International Conference of Ocean Engineering (ICOE-18) organised by IIT Madras. Recently, he has been awarded by the Department of Science and Technology, Govt of India for his article in AWSAR Scheme. He is a member of RINA and SNAME.

Cdr (Dr) R. Vijayakumar is a assistant Professor at the Ocean Engineering Department at Indian Institute of Technology, Madras since 2016. He is a graduate of Naval Architecture from the Cochin University of Science and Technology. He has completed his PG Diploma in Naval Construction from Indian Institute of Technology, Delhi, MTech in Ocean Engineering from Indian Institute of Technology, Madras and Ph.D. from Indian Institute of Technology, Delhi. At IIT Madras he teaches the subjects of Ship Hydrodynamics, Ship Dynamics and Advanced Marine Vehicles. He has served in the Indian Navy for period of 21 years, in dockyards and design directorate. During his tenure in the Navy, besides many other appointments, he has also served as Adjunct Faculty at the Naval Construction Wing, Department of Applied Mechanics at Indian Institute of Technology, Delhi. He has published a total of 45 technical papers in refereed Journals and Proceedings of international/National Conferences. He is a member of the Institution of Naval Architects, India. His fields of interest include Warship Design, Ship Hydrodynamics, Ship Dynamics and Computational Fluid Dynamics (CFD).

Dr Brijendra K. Saxena, is the retired Principal of Tolani Maritime Institute, Pune and the Immediate Past President of the Institute of Marine Engineers (India). He has been with the Shipping Corporation of India for over 30 years, both in fleet as well on shore appointments. He completed two-year full-time post graduate course in shipping management from the prestigious World Maritime University, Malmo, Sweden. He was also the first graduate of the WMU to be invited to teach there on full-time basis. On his return he was at MTI and then joined the first private sector marine engineering collage Tolani Maritime Institute as Principal in 1999 and has been working there since then. He is a Senior Member of American Society for Quality, USA and is actively involved in international study groups developing standards for quality in education. Recognising his contribution to Maritime Education & Training internationally, he was given the Lifetime achievement award by GlobalMET, the international organisation of maritime institutes. He was also conferred with an award for ‘Outstanding Contribution to maritime education and training’ at the National Maritime Day function this year. He is a Fellow of the Narottam Morarjee Institute of Shipping; Member of the Institute of Chartered Shipbrokers, London; International Maritime Lecturers Association, Sweden; and the Indian Council of Arbitration.

ORCID

Sudhir Sindagi http://orcid.org/0000-0002-7752-6196

R. Vijayakumar http://orcid.org/0000-0002-7696-0740

Additional information

Funding

This research is well supported by the Ministry of Shipping, India and SIEMENS Ltd formerly known as CD ADAPCO.