Hydrodynamic optimization of performance of blunt ships
- 1 Downloads
Various research works on hydrodynamic performance of the general streamlined ships in the domain of ship fluid mechanics have been implemented during the past several decades. However, as to those special types of ship, say, the blunt ship, relevant investigative work is never put on the top of the agenda. This paper and the subsequent work would like to deal with a representative kind of blunt ship, the dumb barge. It is expected that the research work can supply a gap in the weakness of study on the blunt ships.
The drags and flow fields of the dumb barge models are numerically calculated by solving the RANS (Reynolds Averaged Navier-Stokes) equations associated with the RNG (ReNormalization Group) k-ε turbulence model and the VOF (Volume Of Fluid) model. The comparison of the calculated drags with that of experimental data from towing tank shows that hydrodynamic performance of the dumb barge can accurately be predicted by numerical calculations. On the basis of the aforementioned numerical calculations, the work turns to the hydrodynamic stability of the barge. Theoretically speaking, the faster the barge moves on the water surface, the greater the trim angle. This means the barge would lose its hydrodynamic stability when it goes faster and faster. To overcome this difficulty, it occurs to us that the hydrodynamic stability of the barge at high speed may be improved by some appendages on the hull. Then two experiments are carried out, respectively, for two styles of hydrofoils with the same profile. The first twin hydrofoils are symmetrically put on the two sides of the hull and the second single hydrofoil below the bottom of the hull. At a series of steady speeds of the barge, every group of experiments includes two aspects of information, the drags and the trim angles. The experimental results indicate that the hydrofoils effectively control the flow fields around the appendaged barges.
Key wordsblunt ship dumb barge hydrodynamic performance numerical calculations hydrofoil experiments
Unable to display preview. Download preview PDF.
- Jonnalagadda, Ramanadham. Reynolds averaged navier-stokes computation of forces and moments for appended suboff configurations at incidence[D] M.S. Thesis, Department of Aerospace Engineering, Mississippi State University, May 1996Google Scholar
- Allison Nicole Cash. Computational Studies of Fully Submerged Bodies, Propulsors, and Body/Propulsor Interactions [D], Mississippi State: Mississippi State University, 2001Google Scholar
- GAO Qiu-xin, SHU Lei. Numerical Simulation of Free Surface Flow around Frigate Model 5415 [J], Journal of Ship Mechanics, 2002, 6(6): 1–9Google Scholar
- CHANG Yu, ZHANG Zhi-rong, ZHAO Feng. Application of multi-block structured grid to computation of viscous flow around a ship with appendage[J]. Journal of Ship Mechanics, 2004, 8(1):19–25 (in Chinese)Google Scholar
- Doctors L J, Day A H. Hydrodynamically optimal hull forms for river ferries. II Symposium on High-Speed Vessels, Royal Institute of Naval Architechture, London, England. 1995.Google Scholar
- TAO Wen-quan. Numerical Heat Transfer (2nd Edition) [M]. Xian: Xian Transportation University Publishing House, 2000 (in Chinese)Google Scholar
- H. K. Versteeg & W. Malalasekera. An introduction to computational fluid dynamics: The finite volume method [M]. Edinburgh Gate: Addison Wesley Longman Limited, England, 1998Google Scholar
- Wang Xian-fu. Theory of Shipborne Hydrofoil [M]. Beijing: National Defence Industry Publishing House, 1998:26 (in Chinese)Google Scholar