Assessment of the propulsion qualities of a ship in the open water after dismantling the bulbous bow

Authors: A.A. Petrov, A.A. Ryabova, Ph.S. Ryabov

 

Abstract

 

Recently, among shipowners operating Arc4 — Arc5 or IA — IA Super ice-class ships on the Northern Sea Route, projects for dismantling the bow bulb have seen increase in demand. The purpose of such projects is to ensure the possibility of icebreaker close towing and, as a result, year-round operation in the Arctic. Since the main function of the bulb is to reduce the wave resistance in open water, after such a modernization (while maintaining the propulsion system and ship dimensions), a deterioration in the speed and, as a consequence, an increase in fuel costs is inevitable. With the help of CFD-analysis, it is possible to estimate the change in resistance to the movement of the ship rather quickly and with high accuracy, and if there are reliable data on fuel consumption before modernization, it is possible to predict an increase in fuel consumption. The article provides an example of a completed project for dismantling the bulb and the corresponding CFD-analysis of the resistance to the movement of the ship. The proposed approach can be used for practical assessment of the ship's propulsion qualities at the stage of developing a modernization project for the purpose of long-term planning of the economic activity of a shipping company.

 

Keywords: bulb, bulb dismantling, ship modernization, close towing, propulsion qualities, CFD analysis, resistance to the movement of the ship.

 

References

1. Bronnikov A.V. Proektirovanie sudov [Ship design]. Leningrad, Sudostroenie, 1991. 320 p.
2. Ovchinnikov K.D. Analiz polnogo soprotivleniya korpusa sudna na razlichnykh skorostyakh khoda [Analysis of total resistance for different ship speeds]. Trudy ISP RAN/Proc. ISP RAS, vol. 31, issue 6, 2019. pp. 195 — 202.
3. Kiryanto, Deddy Chrismianto and Ahmad Firdhaus. Analysis of Total Ships Resistance with Variation of Hull Bow Types, Ulstein X-Bow, Spherical and Tapering Bulbous Bow using CFD Method. In Proceedings ofthe 6th International Seminar on Ocean and Coastal Engineering, Environmental and Natural Disaster Management (ISOCEEN 2018), pages 60-64. DOI: 10.5220/0008374400600064.
4. Woochan Seok, Gwan Hoon Kim, Jeonghwa Seo, and Shin Hyung Rhee. Application ofthe Design ofExperiments and Computational Fluid Dynamics to Bow Design Improvement. Journal of Marine Science and Engineering 2019, 7, 226. DOI:10.3390/jmse7070226
5. Shahid Mahmood, Debo Huang. Computational Fluid Dynamics Based Bulbous Bow Optimization Using a Genetic Algorithm. Journal of Marine Science and Application. 11. 10.1007/s11804-012-1134-1.
6. Rules for the Classification and Construction of Sea-Going Ships, RS, 2020 326 p. (In Russian)
7. Voytkunsky Ia.I. Spravochnikpo teorii korablia [Ship theory handbook], Leningrad, Sudostroenie, 1985. 786 p.
8. Rami Ali, Nikita V. Tryaskin. Study the influence of the relative position of two vessels moving in parallel on their hydrodynamic characteristics. Marine intellectual technologies, No. 4, Part 3, 2020. pp. 59 — 65. DOI: 10.37220/MIT.2020.50.4.042
9. Ansys Fluent, Release 2021 R1, Help System, Fluent help, user manual, 26.3.5 Modeling Open Channel Flows, ANSYS, Inc.

 

About authors:

 

A.A. Petrov - PhD, JSC CNIIMF, St. Petersburg

A.A. Ryabova - JSC CIFRA, St. Petersburg

Ph.S. Ryabov - JSC CADFEM CIS, St. Petersburg

Issue: 64/65 (2021)

For citation: A.A. Petrov, A.A. Ryabova, Ph.S. Ryabov. Assessment of the propulsion qualities of a ship in the open water after dismantling the bulbous bow. Research Bulletin by Russian Maritime Register of Shipping. 2021, No. 64/65, pp. 27-36.

UDC 656.6; 629.5.083.7

Pp: 27-36