Journal of the Korean Society of Marine Environment & Safety (해양환경안전학회지)

The Korean Society of Marine Environment and safety (해양환경안전학회)
권호 표지
DOI QR코드

DOI QR Code

A Study on the Self-Propulsion CFD Analysis for a Catamaran with Asymmetrical Inside and Outside Hull Form

안팎 형상이 비대칭인 쌍동선의 자항성능 CFD 해석에 관한 연구

  • Jonghyeon Lee (Shipbuilding & Marine Simulation Center, Tongmyong University) ;
  • Dong-Woo Park (Department of Marine Mobility, Tongmyong University)
  • 이종현 (동명대학교 조선해양시뮬레이션센터) ;
  • 박동우 (동명대학교 해양모빌리티학과)
  • Received : 2023.11.27
  • Accepted : 2024.02.23
  • Published : 2024.02.28
Download PDF
⟨ Previous Next ⟩

Abstract

In this study, simulations based on computational fluid dynamics were performed for self-propulsion performance prediction of a catamaran that has asymmetrical inside and outside hull form and numerous knuckle lines. In the simulations, the Moving Reference Frame (MRF) or Sliding Mesh (SDM) techniques were used, and the rotation angle of the propeller per time step was different to identify the difference using the analysis technique and condition. The propeller rotation angle used in the MRF technique was 1˚ and those used in the SDM technique were 1˚, 5˚, or 10˚. The torque of the propeller was similar in both the techniques; however, the thrust and resistance of the hull were computed lower when the SDM technique was applied than when the MRF technique was applied, and higher as the rotation angle of the propeller per time step in the SDM technique was smaller in the simulations for several revolutions of the propeller to estimate the self-propulsion condition. The revolutions, thrust, and torque of the propeller in the self-propulsion condition obtained using linear interpolation and the delivered power, wake fraction, thrust deduction factor, and revolutions of the propeller obtained using the full-scale prediction method showed the same trend for both the techniques; however, most of the self-propulsion efficiency showed the opposite trend for these techniques. The accuracy of the propeller wake was low in the simulations when the MRF technique was applied, and slight difference existed in the expression of the wake according to the rotation angle of the propeller per time step when the SDM technique was applied.

본 연구에서는 너클 라인이 다수 존재하면서 안팎 형상이 비대칭으로 설계된 특이점을 갖는 쌍동선의 자항성능을 예측하기 위해 CFD 해석을 수행하였고, 해석 기법에 따른 차이를 파악하기 위해 MRF(Moving Reference Frame) 기법과 SDM(Sliding Mesh) 기법을 적용하였다. MRF 기법을 적용한 경우에는 time step당 프로펠러를 1˚ 회전시켰고, SDM 기법의 경우 10˚, 5˚, 1˚씩 회전시키며 각 기법별 예측된 자항성능을 비교하였다. 자항점 추정을 위한 몇 가지 프로펠러 회전수에서의 해석 결과 중 프로펠러의 토크는 기법에 따른 차이가 거의 없었지만 추력 및 선체가 받는 저항은 MRF 기법보다는 SDM 기법을 적용했을 때 더 낮게, SDM 기법의 time step당 프로펠러 회전각이 작을수록 높게 계산되었다. 선형 내삽을 통해 추정된 자항점의 프로펠러 회전수, 추력, 토크와 실선 확장법을 사용해 추정된 실선의 전달동력, 반류 계수, 추력 감소 계수 및 프로펠러 회전수도 동일한 경향을 보였으며, 대부분의 자항효율은 반대의 경향을 보였다. 프로펠러 후류의 경우 MRF 기법을 적용했을 때 정확도가 떨어졌고, SDM 기법의 time step당 프로펠러 회전각에 따라 표현되는 후류의 차이는 거의 없었다.

Keywords

Acknowledgement

이 연구는 한국산업기술진흥원의 부산 암모니아 친환경 에너지 특구 사업 중 암모니아 기반 연료전지 하이브리드 친환경 선박 실증(P0020619) 과제의 지원을 받아 수행되었습니다.

References

  1. CD-adapco(2018), STAR-CCM+ User Guide, Ver. 13.06.
  2. Cho, H. N., J. E. Choi, and H. H. Chun(2016), Parametric Designs of a Pre-Swirl Duct for the 180,000DWT Bulk Carrier Using CFD, Journal of the Society of Naval Architects of Korea, Vol. 53, No. 5, pp. 343-352. https://doi.org/10.3744/SNAK.2016.53.5.343
  3. Courant, R., K. Friedrichs, and H. Lewy(1967), On the Partial Difference Equations of Mathematical Physics, International Business Machines Corporation (IBM) Journal of Research and Development, Vol. 11, No. 2, pp. 215-234.
  4. Ferziger, J. H. and M. Peric(2002), Computational Methods for Fluid Dynamics, 3rd Edition, Springer, Germany, pp. 292-294.
  5. Guo C., X. Wang, C. Wang, Q. Zhao, and H. Zhang(2020), Research on Calculation Methods of Ship Model Self-Propulsion Prediction, Ocean Engineering, Vol. 203, 107232.
  6. Harvald, S. A.(1983), Resistance and Propulsion of Ships, John Wiley & Sons, USA, pp. 98-100.
  7. International Towing Tank Conference(ITTC)(1999), Performance, Propulsion, 1978 ITTC Performance Prediction Method, Recommended Procedures and Guidelines, 7.5-02-03-01.4, pp. 3-4.
  8. International Towing Tank Conference(ITTC)(2014a), Practical Guidelines for Ship CFD Applications, Recommended Procedures and Guidelines, 7.5-03-02-03, pp. 15.
  9. International Towing Tank Conference(ITTC)(2014b), Practical Guidelines for Ship Self-Propulsion CFD, Recommended Procedures and Guidelines, 7.5-03-03-01, pp. 3.
  10. International Towing Tank Conference(ITTC)(2014c), 1978 ITTC Performance Prediction Method, Recommended Procedures and Guidelines, 7.5-03-03-01, pp. 3-8.
  11. International Towing Tank Conference(ITTC)(2017), Uncertainty Analysis in CFD, Verification and Validation Methodology and Procedures, Recommended Procedures and Guidelines, 7.5-03-01-01, pp. 4-8.
  12. Kim, J. I., I. R. Park, J. Kim, K. S. Kim, and Y. C. Kim(2019), CFD Simulation of the Self-Propulsion of a Damaged Car Ferry in Waves, Journal of the Society of Naval Architects of Korea, Vol. 56, No. 1, pp. 34-46. https://doi.org/10.3744/SNAK.2019.56.1.034
  13. Kinaci, O. K., M. K. Gokce, A. D. Alkan, and A. Kukner (2018), On Self-Propulsion Assessment of Marine Vehicles, Brodogradnja, Vol. 69, No. 4, pp. 29-51. https://doi.org/10.21278/brod69403
  14. Lee, J. H., B. J. Park, and S. H. Rhee(2010), Ship Resistance and Propulsion Performance Test Using Hybrid Mesh and Sliding Mesh, Journal of Computational Fluids Engineering, Vol. 15, No. 1, pp. 81-87.
  15. Lee, J. H. and D. W. Park(2021), A Study on the Scale Effect and Improvement of Resistance Performance Based on Running Attitude Control of Small High-Speed Vessel, Journal of the Korean Society of Marine Environment & Safety, Vol. 27, No. 4, pp. 538-549. https://doi.org/10.7837/kosomes.2021.27.4.538
  16. Nyongesa, A. J., V. C. Pham, S. H. Yoon, W. S. Kwon, J. S. Kim, D. N. Ngo, J. H. Choi, Y. Y. Sul, and W. J. Lee(2022), Investigation of the Effect of Rope Cutter on Water Flow behind Ship Propellers Based on CFD Analysis, Machines, Vol. 10, No. 5, pp. 300-326. https://doi.org/10.3390/machines10050300
  17. Park, I. R.(2015), Numerical Analysis of the Flow around the Hull and the Propeller of a Ship Advancing in Shallow Water, Journal of Computational Fluids Engineering, Vol. 20, No. 4, pp. 93-101. https://doi.org/10.6112/kscfe.2015.20.4.093
  18. Suh, J. C. and C. S. Lee(1984), Polynomial Representation for MAU-Propeller Open Water Characteristics, Korea Institute of Machinery & Materials, Vol. 11, pp. 95-101.
  19. Todd, F. H.(1957), Skin Friction and Turbulence Stimulation, Proceedings of the 8th ITTC Conference, Madrid, September 1957, pp. 71-227.
  20. Yazaki A., E. Kuramochi, and T. Kumasaki(1960), Open Water Test Series with Modified AU-Type Four-Bladed Propeller Models, Journal of Zosen Kiokai, Vol. 108, pp. 99-104.  https://doi.org/10.2534/jjasnaoe1952.1960.108_99