Document Type : Original Manuscript

Authors

Department of Naval Architecture and Marine Engineering, Faculty of Marine Engineering, Khorramshahr University of Marine Science and Technology, Khorramshahr, Iran.

Abstract

The prediction of ship resistance is the most important part of the ship's hydrodynamic design. Nowadays, computational methods are used as a common tool for this purpose. Ship total resistance calculation by using two phase numerical method based on the Reynolds-averaged Naiver–Stokes solution requires high computational power. The idea of total resistance decomposition based on the physical cause is a basic principle in the ship hydrodynamic. In the proposed hybrid method, wave making resistance part is calculated by using Michell Integral and viscous part is computed by numerical solution of one phase viscous flow for double body condition. Computations are performed for 10 velocities from Fn = 0.06-0.62 and at each velocity the percentage of every component calculated. Hybrid method reduce computational time.  To investigate the results, tow phase simulations are performed for a SWATH vessel. On average, there are 7% difference between the results obtained from hybrid and two phase method and computational time in hybrid method is 97% less than two phase method.

Keywords

Main Subjects

Bertram, V. 2012. Practical Ship Hydrodynamics. Butterworth-Heinemann.
Brizzolara, S, Curtin, T, Bovio, M, Vernengo, G. 2012. Concept design and hydrodynamic optimization of an innovative SWATH USV by CFD methods. Ocean Dynamics. 62: 227–237.
Brizzolara, S, Vernengo, G. 2011. Automatic Optimization Computational Method for Unconventional SWATH Ships Resistance. International Journal of Mathematical Models and Methods in Applied Sciences. 5(5): 882-889.
Ferziger, J. H. and Peric, M. 1996. Computational Methods for Fluid Dynamics. Berlin etc., Springer-Verlag.
Kim, J., Kwang-Soo, K., Gun-Do, K., Il-Ryong, P. and Suak-Ho, V. 2006. Hybrid RANS and Potential Based Numerical Simulation for Self-Propulsion Performances of the Practical Container Ship. Journal of Ship and Ocean Technology. 10(4): 1-11.
Larsson, L., Raven, H. C. and Paulling, J. R. 2010. Ship resistance and flow. Jersey City, N.J. Society of Naval Architects and Marine Engineers.
Larsson, L., Stern, K. and Visonneau, M. 2011. CFD in Ship Hydrodynamics—Results of the Gothenburg 2010 Workshop. IV International Conference on Computational Methods in Marine Engineering.
Molland, A. F., Turnock, S. R. and Hudson, D. A. 2011. Ship resistance and propulsion: practical estimation of ship propulsive power. Cambridge, GB, Cambridge University Press.
Raven, H. C. and Starke, A. R. 2002. Effi cient methods to compute ship viscous flow with a free surface. In 24th Symposium on Naval Hydrodynamics. Fukuoka, Japan.
Raven, A, Ploeg, A., Strake, A. R. 2008. Towards a CFD-Based prediction of ship performance progress in predicting full-scale resistance and scale effects. RINA MARINE CFD conference.
Raven H. C. 2017. Numerical and Hybrid Prediction Methods for Ship Resistance and Propulsion. Encyclopedia of Maritime and Offshore Engineering.
Regnström, B. and Bathfi eld, N. 2006. Drag and wake prediction for ships with appendages using an overlapping grid method. 26th Symposium on Naval Hydrodynamics (pp. 243–258). Rome,Italy.
Rotte, G. M. 2015. Analysis of a Hybrid RaNS-BEM Method for Predicting Ship Power. MSc Thesis Delft University.
STAR CCM+ Programm Help. 2013.
Tuck, E, O, 1989. The wave resistance formula of J.H. Michell and Its significance to recent research in ship hydrodynamics. J. Austral. Math. Soc. Ser. B. 30(1989): 365-377.
Visonneau, M. 2005. A Step Towards the Numerical Simulation of Viscous Flows Around Ships at Full Scale Recent Achievements Within the European Union Project Effort. Marine CFD, Southampton, UK.
Wang, T., Sun, W. and Yao, X. M. 2012. Numerical Simulation of Flow Field around Amphibious Vehicle Based on CFD. Applied Mechanics and Materials. 138-139: 99-103.