Drag Reduction and EEXI Compliance: Evaluating Air Lubrication for In-Service Ships via CFD

• Autorzy: Abbas Nawar , Hawa Rami , Hatem Wehad

Identyfikatory

DOI

10.2478/pomr-2025-0050

• Języki publikacji: EN

Abstrakty

EN

This research used CFD techniques to study the effect of air lubrication technology on the Energy Efficiency Existing Ship Index (EEXI), developed by the International Maritime Organization. The Unsteady RANS (Reynolds-Averaged Navier-Stokes Equation) and the k-ω SST turbulence model were used to solve the Navier-Stokes equations governing flows, while the Volume of Fluid (VOF) method was used to solve the two-phase (air-water) flow. The JBC bulk carrier was chosen for this study because its shape closely resembles that of bulk carriers and tankers currently operating in the merchant fleet. Initially, the ship model was studied alone, without any appendages, at a scale of 1:40. The MP687 propeller was used with this ship in a self-propulsion test. An Open Water Test was conducted, with the Verification and Validation procedure being applied to the CFD results obtained for the JBC alone, in order to verify the accuracy of the numerical grid and the equations and turbulence models used to complete these calculations. The wave effect and ship motions (pitch, heave, roll, etc.) were neglected and the calculations were carried out in calm water. Then, air flow directing strakes were added to the bottom of the parallel body of the ship to investigate the impact of air lubrication on the EEXI value. At this stage, air lubrication was used for the ship alone, without a propeller, and then again for the ship with a propeller. Several types of air flow-directing strakes were tested, to trap air beneath the parallel body of the hull. The implementation of air lubrication technology with the proposed strakes reduced total ship resistance, resulting in a 16.67% improvement in the attained EEXI value. This reduction directly correlates with lower CO₂ emissions per unit of transport work (measured in grams of CO₂ per ton × nautical mile), demonstrating the system’s potential to enhance compliance with IMO’s carbon intensity regulations, without compromising operational performance.

Słowa kluczowe

EN

Energy Efficiency Existing Ship Index; JBC; CFD; URANS; MP687; Air Injection; Drag Reduction

• Wydawca: Gdańsk University of Technology, Faculty of Ocean Engineering & Ship Technology
• Czasopismo: Polish Maritime Research
• Rocznik: 2025
• Tom: nr 4
• Strony: 59--77
• Opis fizyczny: Bibliogr. 54 poz., rys., tab.

Twórcy

autor

Abbas Nawar

• Latakia University, Department of Maritime Engineering, Latakia, Syria, Syrian Arab Republic

• https://orcid.org/0000-0003-3713-4806

autor

Hawa Rami

• Latakia University, Department of Maritime Engineering, Latakia, Syria, Syrian Arab Republic

• https://orcid.org/0009-0009-9212-4396

autor

Hatem Wehad

• Latakia University, Department of Maritime Engineering, Latakia, Syria, Syrian Arab Republic

• https://orcid.org/0009-0000-5876-3076

Bibliografia

• 1. Kanifolskyi O, “General Strength, Energy Efficiency (EEDI), and Energy Wave Criterion (EWC) of Deadrise Hulls for Transitional Mode,” Polish Marit. Res., vol. 29, no. 3, pp. 4–10, Sep. 2022, doi: 10.2478/POMR-2022-0021.
• 2. Mindykowski J, Wierzbicki Ł, Gorniak M, Piłat A, “Analysis and Experimental Verification of Improving the EEDI of a Ship using a Thruster Supplied by a Hybrid Power System,”Polish Marit. Res., vol. 31, no. 1, pp. 43–54, Mar. 2024, doi: 10.2478/POMR-2024-0005.
• 3. Ammar NR, Almas M, Nahas Q, “Economic Analysis and the EEXI Reduction Potential of Parallel Hybrid Dual-Fuel Engine Fuel Cell Propulsion Systems for LNG Carriers,”Polish Marit. Res., vol. 30, no. 3, pp. 59–70, Sep. 2023, doi: 10.2478/POMR-2023-0039.
• 4. IMO, “Resolution MEPC.212 (63)-Guidelines on the Method of Calculation of the Attained Energy Efficiency Design Index (EEDI) for New Ships,”IMO, London, UK., 2012, [Online]. Available: https://wwwcdn.imo.org/localresources/en/KnowledgeCentre/Indexof IMOResolut ions /MEPCDocument s /MEPC.212(63).pdf.
• 5. IMO, “Resolution MEPC.336 (76)-Guidelines on Operational Carbon Intensity Indicators and the Calculation Methods (CII Guidelines, G1),” IMO, London, UK., 2021, [Online]. Available: https://wwwcdn.imo.org/localresources/en/OurWork/Environment/Documents/Air pollution/MEPC.336(76).pdf.
• 6. IMO, “Resolution MEPC.337 (76)-Guidelines on the Reference Lines for Use with Operational Carbon Intensity Indicators (CII Reference Lines Guidelines, G2).,” IMO, London, UK., 2021, [Online]. Available: https://wwwcdn.imo.org/localresources/en/OurWork/Environment/Documents/Air pollution/MEPC.337(76).pdf.
• 7. Sinay, “Eco-Friendly Shipping: Transforming Maritime Sustainability.” https://sinay.ai/en/eco-friendly-shipping-transforming-maritimesustainability/(accessed Jun. 28, 2025).
• 8. IMO, “IMO’s work to cut GHG emissions from ships.”https://www.imo.org/en/MediaCentre/HotTopics/Pages/Cutting-GHG-emissions.aspx (accessed Jun. 28, 2025).
• 9. IMO, “Improving the energy efficiency of ships.” https://www.imo.org/en/OurWork/Environment/Pages/Improving the energy efficiency of ships.aspx (accessed Jun. 28, 2025).
• 10. Zhang D, Li Y, Gong J, “Study on the Effect of Air Injection Location on the Drag Reduction in SWATH with Air Lubrication,” J. Mar. Sci. Eng. Vol. 11, Page 667, vol. 11, no. 3, p. 667, Mar. 2023, doi: 10.3390/JMSE11030667.
• 11. Madavan NK, Deutsch S, Merkle CL, “Reduction of turbulent skin friction by microbubbles,” Phys. Fluids, vol. 27, no. 2, pp. 356–363, Feb. 1984, doi: 10.1063/1.864620.
• 12. Makiharju SA, Perlin M, Ceccio SL, “On the Energy economics of air lubrication drag reduction,” Int. J. Nav. Archit. Ocean Eng., vol. 4, no. 4, 2012, doi: 10.3744/jnaoe.2012.4.4.412.
• 13. Ceccio SL, “Friction drag reduction of external flows with bubble and gas injection,” Annual Review of Fluid Mechanics, vol. 42. 2010, doi: 10.1146/annurev-fluid-121108-145504.
• 14. Mizokami S, Kuroiwa R, “Installation of Air Lubrication System for Ro-Pax Ferry and Verification of its Effect in Actual Seas Based on Onboard Measurement Data,” J. Japan Soc. Nav. Archit. Ocean Eng., vol. 29, no. 0, pp. 1–9, 2019, doi: 10.2534/JJASNAOE.29.1.
• 15. Ship Universe, “Hull Optimization Strategies in 2025: What’s Hot and What’s Cold? – Ship Universe.” https://www.shipuniverse.com/hull-optimization-strategies-in-2025-whats-hot-and-whats-cold/ (accessed Jun. 28, 2025).
• 16. Mitsubishi Heavy Industries, “MHI Installs MALS (Mitsubishi Air Lubrication System) on a Ferry For First Time and Verifies Over 5% Fuel Efficiency Improvement-Sights On Expanded System Applications to High-speed, Slender Hull-form Ships - Mitsubishi Heavy Industries.”https://www.mhi.com/news/1210031580.html (accessed Jun. 29, 2025).
• 17. Jang J, Choi SH, Ahn SM, Kim B, Seo JS, “Experimental investigation of frictional resistance reduction with air layer on the hull bottom of a ship,” Int. J. Nav. Archit. Ocean Eng., vol. 6, no. 2, 2014, doi: 10.2478/IJNAOE-2013-0185.
• 18. Freitas FR, Moraes DEB, Warkentin S, Mais LA, Ivers JF, Taddei JAAC, “Maternal restrictive feeding practices for child weight control and associated characteristics,” Jornal de Pediatria (Versao em Portugues)., vol. 95, no. 2, pp. 201–208, Mar. 2019, doi: 10.1016/J.JPED.2017.12.009.
• 19. Pavlov GA, Yun L, Bliault A, He SL, “Air lubricated and air cavity ships: Development, design, and application,”Air Lubr. Air Cavity Ships Dev. Des. Appl., pp. 1–469, Jan. 2020, doi: 10.1007/978-1-0716-0425-0/COVER.
• 20. Silberschmidt N, Tasker D, Pappas T, Johannesson J, “SilverstreamR System – Air Lubrication Performance Verification and Design Development,” 10th Symp. High-Performance Mar. Veh., pp. 236–246, 2016, [Online]. Available: https://conferences.ncl.ac.uk/media/sites/conferencewebsites/scc2016/1.3.2.pdf.
• 21. Armada Technologies, “Home - Armada Technologies.”https://armada-technologies.com/ (accessed Jul. 11, 2025).
• 22. Alfa Laval, “OceanGlide- Air lubrication system, Alfa Laval.” https://www.alfalaval.com/products/processsolutions/fluidic-air-lubrication/oceanglide/ (accessed Jul. 11, 2025).
• 23. Menter FR, “Two-equation eddy-viscosity turbulence models for engineering applications,” AIAA J., vol. 32, no. 8, pp. 1598–1605, Aug. 1994, doi: 10.2514/3.12149.
• 24. Abbas N, Kornev N, Shevchuk I, Anschau P, “CFD prediction of unsteady forces on marine propellers caused by the wake nonuniformity and nonstationarity,” Ocean Eng., 2015, doi: 10.1016/j.oceaneng.2015.06.007.
• 25. Abbas N, Kornev N, “Study of unsteady loadings on the propeller under steady drift and yaw motion using URANS, hybrid (URANS-LES) and LES methods,” Sh. Technol. Res., vol. 63, no. 2, pp. 121–131, May 2016, doi:10.1080/09377255.2016.1211582.
• 26. Kornev N, Abbas N, “Numerical Simulation of the tip vortex behind a wing oscillated with a small amplitude,”J. Aircr., vol. 54, no. 2, 2017, doi: 10.2514/1.C033945.
• 27. Abbas N, Kornev N, “Validation of hybrid URANS/LES methods for determination of forces and wake parameters of KVLCC2 tanker at manoeuvring conditions,” Sh. Technol. Res., vol. 63, no. 2, pp. 96–109, May 2016, doi:10.1080/09377255.2016.1157275.
• 28. Abbas N, Barbahan M, Kabrial Y, Kabrial A, “A Novel Approach to Wave Energy Conversion Using CFD Technique,” Polish Marit. Res., vol. 31, no. 3, pp. 113–125, Sep. 2024, doi: 10.2478/POMR-2024-0041.
• 29. Hirt CW, Nichols BD, “Volume of fluid (VOF) method for the dynamics of free boundaries,” J. Comput. Phys., vol. 39, no. 1, pp. 201–225, Jan. 1981, doi: 10.1016/0021-9991(81)90145-5.
• 30.Wei Song K, Yu Guo C, Wang C, Sun C, Li P, Fan Zhong R, “Experimental and numerical study on the scale effect of stern flap on ship resistance and flow field,” Ships Offshore Struct., vol. 15, no. 9, 2019, doi:10.1080/17445302.2019.1697091.
• 31. Lee H, Rhee SH, “A dynamic interface compression method for VOF simulations of high-speed planing watercraft,” J. Mech. Sci. Technol., vol. 29, no. 5, pp. 1849–1857, May 2015, doi: 10.1007/S12206-015-0405-6/METRICS.
• 32. Queutey P, Visonneau M, “An interface capturing method for free-surface hydrodynamic flows,” Comput. Fluids, vol. 36, no. 9, pp. 1481–1510, Nov. 2007, doi: 10.1016/J.COMPFLUID.2006.11.007.
• 33. Rhee SH, Makarov BP, Krishinan H, Ivanov V, “Assessment of the volume of fluid method for free-surface wave flow,”J. Mar. Sci. Technol., vol. 10, no. 4, pp. 173–180, Dec. 2005, doi: 10.1007/S00773-005-0205-2/METRICS.
• 34. Tokyo 2015, “A Workshop on CFD in Ship Hydrodynamics.”Accessed: 28-Jun-2023. [Online]. Available: https://t2015.nmri.go.jp/jbc.html.
• 35. Hino T, Stern F, Larsson L, Visonneau M, Hirata N, Kim J, “Numerical Ship Hydrodynamics: An Assessment of the Tokyo 2015 Workshop,” Tokyo 2015, vol. 94, 2021, doi:10.1007/978-3-030-47572-7.
• 36. Tokyo 2015, “T2015 - jbc_Geometry.” https://www.t2015. nmri.go.jp/jbc_gc.html (accessed Nov. 10, 2024).
• 37. Tokyo 2015, “Open Water Tests for JBC (NMRI) MODEL PROPELLER NO.687.” 2015, Accessed: 28-Jun-2025. [Online]. Available: https://www.t2015.nmri.go.jp/Instructions_JBC/instruction_JBC_files/Open_Water_Tests_for_JBC_NMRI.txt.
• 38. ITTC, “International Towing Tank Conference. Recommended Procedures and Guidelines 7.5-03-02-03, Practical Guidelines for Ship CFD Applications,” 26th International Towing Tank Conference. 2011, [Online]. Available: http://ittc.info/media/1357/75-03-02-03.pdf.
• 39. ITTC, “International Towing Tank Conference. Recommended Procedures and Guidelines 7.5-03-02-03, Practical Guidelines for Ship CFD Applications,” 27th International Towing Tank Conference. 2014, [Online]. Available: https://www.ittc.info/media/8165/75-03-02-03.pdf.
• 40.Marine Environmental Protection Committee, “Mepc.350(78) - Guidelines On The Method Of Calculation Of The Attained Energy Efficiency Existing Ship Index (EEXI),” IMO Publ., vol. 304, no. June, pp. 1–11, 2022, [Online]. Available: https:// wwwcdn.imo.org/localresources/en/KnowledgeCentre/Indexof IMOResolut ions /MEPCDocument s /MEPC.350(78).pdf.
• 41. IMO, “Resolution MEPC.308 (73)-Guidelines on the method of calculation of the attained energy efficiency design index (EEDI) for new ships,” IMO, London, UK., 2018, [Online]. Available: https://wwwcdn.imo.org/localresources/en/OurWork/Environment/Documents/Air pollution/MEPC.308(73).pdf.
• 42. International Maritime Organization (IMO), “MARPOL - International Convention for the Prevention of Pollution from Ships - Annex VI - Regulations for the Prevention of Air Pollution from Ships - Chapter 4 - Regulations on Energy Efficiency for Ships - Regulation 25 – Required EEXI,” vol. 44, no. October, 2025, [Online]. Available: https://wwwcdn.imo.org/localresources/en/MediaCentre/HotTopics/Documents/Circular Letter No.5005 – Draft Revised Marpol Annex Vi (Secretariat).pdf.
• 43. International Maritime Organization (IMO), “MARPOL - International Convention for the Prevention of Pollution from Ships - Annex VI - Regulations for the Prevention of Air Pollution from Ships - Chapter 4 - Regulations on Energy Efficiency for Ships - Regulation 24 – Required EEDI,” vol. 44, no. October, 2025, [Online]. Available: https://wwwcdn.imo.org/localresources/en/MediaCentre/HotTopics/Documents/Circular Letter No.5005 – Draft Revised Marpol Annex Vi (Secretariat).pdf.
• 44. Stern F, Wilson RV, Coleman HW, Paterson EG, “Verification and validation of CFD simulations,” Proc. 1999 3rd ASME/JSME Jt. Fluids Eng. Conf. FEDSM’99, San Fr. California, USA, 18-23 July 1999.
• 45. Stern F, Wilson RV, Coleman HW, Paterson EG, “Comprehensive approach to verification and validation of CFD simulations—Part 1: Methodology and procedures,” J. Fluids Eng. Trans. ASME, vol. 123, no. 4, 2001, doi:10.1115/1.1412235.
• 46. Wilson RV, Stern F, Coleman HW, Paterson EG, “Comprehensive approach to verification and validation of CFD simulations—Part 2: Application for rans simulation of a cargo/container ship,” J. Fluids Eng. Trans. ASME, vol. 123, no. 4, 2001, doi: 10.1115/1.1412236.
• 47. Stern F, Wilson R, Shao J, “Quantitative V&V of CFD simulations and certification of CFD codes,” Int. J. Numer. Methods Fluids, vol. 50, no. 11, pp. 1335–1355, Apr. 2006, doi: 10.1002/FLD.1090.
• 48. ITTC, “Uncertainty Analysis in CFD Verification and Validation Methodology and Procedures,” 25th International Towing Tank Conference. pp. 1–12, 2008, [Online]. Available: https://www.ittc.info/media/8153/75-03-01-01.pdf.
• 49. Xing T, Stern F, “Factors of safety for Richardson extrapolation,” J. Fluids Eng. Trans. ASME, vol. 132, no. 6, pp. 614031–640313, Jun. 2010, doi: 10.1115/1.4001771/456309.
• 50.Mohamed Sukri Mat ALI CJD, Wheatley V, “Grid convergence study for a two-dimensional simulation of flow around a square cylinder at a low Reynolds number,” in Seventh International Conference on CFD in the Minerals and Process Industries, CSIRO, Melbourne, Australia, [Online]. Available: https://flair.monash.edu/intranet/proceedings/cfd2009/PDFs/136ALI.pdf.
• 51. Koo B, Yang J, Yeon SM, Stern F, “Reynolds and froude number effect on the flow past an interface-piercing circular cylinder,” Int. J. Nav. Archit. Ocean Eng., vol. 6, no. 3, pp. 529–561, Sep. 2014, doi: 10.2478/IJNAOE-2013-0197.
• 52. Tokyo 2015, “JBC-Case 1.3a,” 2015. https://www.t2015.nmri.go.jp/Instructions_JBC/Case_1-3a.html (accessed Nov. 03, 2024).
• 53. Tokyo 2015, “JBC Case 1.5a,” 2015. https://www.t2015.nmri.go.jp/Instructions_JBC/Case_1-5a.html (accessed Jul. 19, 2024).
• 54. Sorrentino V, Pigazzini R, De Luca F, Mancini S, Pensa C, “Experimental and numerical investigation of air lubrication on a planing hull with Double Interceptor System,” Ocean Eng., vol. 319, p. 120135, Mar. 2025, doi:10.1016/J.OCEANENG.2024.120135.