Investigation of Step Sweep-Forward Angle Effects on the Hydrodynamic Performance of a Planing hull

Document Type : Research Article

Authors

Department of Maritime Engineering, Amirkabir University of Technology, Tehran, Iran

Abstract

One of the most effective methods to diminish the drag of the planning craft is using step at the bottom of the hull. Stepped hull causes to reduce the wet area and as a results reduce the drag. Shape of the step may be designed in a straight line through the entire width of the hull or it may be V-shape with a forward or backward sweep angle. In this paper, the effect of step sweep-forward angle on the hydrodynamic performance of a planning chine hull vessel is investigated by finite volume method. Reynolds-Averaged Navier-Stokes equations with standard k-ɛ turbulence model coupled with volume of fluid equations are solved in order to simulate transient turbulent surface flow around the hull with the help of Ansys CFX software. In order to predict the craft motions, equations of rigid body motions for two degrees of freedom are coupled with fluid flow governing equations. To validate presented numerical model, first the numerical results are compared with available experimental data and then obtained numerical results at different speeds and step angles are presented and discussed. The results show that the sweep-forward step angle up to 10 degrees have an insignificant effect on dynamic trim and sinkage, but its effect on the reduction of drag is significant.

Keywords

Main Subjects

References

[1] Stepped Hull vs. V-Hull, https://www.boatingmag.com/stepped-hull-vs-v-hull-0
[2] D. Savitsky, 1964. Hydrodynamic design of planing hulls, Marine Technology 1(1), 71–95.
[3] D. Savitsky, MF. Delorme, R. Datla, 2007. Inclusion of whisker spray drag in performance prediction method for high-speed planing hulls, Maine Technology, 44(1), 35-56.
[4] S. Brizzolara, F. Serra, 2007. Accuracy of CFD codes in the prediction of planing surfaces hydrodynamic characteristics. In: 2nd international conference on marine research and transportation, Naples
[5] H. Ghassemi, M. Ghiasi, 2007. A combined method for the hydrodynamic characteristics of planing crafts. Ocean Eng 35(3–4):310–322
[6] H. Ghassemi, S. Yumin, 2008. Determining the hydrodynamic forces on a planing hull in steady motion. J Mar SciAppl 7:147–156
[7] AR. Kohansal, H. Ghassemi, M. Ghiasi, 2010. Hydrodynamic characteristics of high speed planing hulls, including trim effects, Turkish. J Eng Environ Sci 34:1–16
[8] AR. Kohansal, H. Ghassemi, 2010. A numerical modeling of hydrodynamic characteristics of various planing hull forms. Ocean Eng 37(5–6):498–510
[9] I. Akkerman, J. Dunaway, J. Kvandal, J. Spinks, Y. Bazilevs,2012. Toward free-surface modeling of planing vessels: simulation of the Fridsma hull using ALE-VMS. Comput Mech 50(6):719–727
[10] S. Yumin, C. Qington, S. Hailong, L. Wei, 2012. Numerical simulation of a planing vessel at high speed. J Mar SciAppl11(2):178–183
[11] M. Ghassabzadeh, H. Ghassemi, 2014. Determining of the hydrodynamic forces on the multi-hull tunnel vessel in steady motion. Brazilian Soc Mech Sci Eng 36(4):1–12
[12] D. Svahn, 2009. Performance prediction of hulls with transverse step. Master thesis, Marina System Center for Naval Architecture, KTH, Stockholm Taunton et al.
[13] D. Savitsky, M. Morabito, 2010. Surface wave contours associated with the forebody wake of stepped planing hulls. Mar Technol 47(1):1–16
[14] D. Taunton, D. Hudson, R. Shenoi, 2010. Characteristics of a series of high speed hard chine planing hulls—Part 1: performance in calm water. Int J Small Craft Technol 152:55–75
[15] WR. Garland, KJA. Maki, 2012. Numerical study of a two-dimensional stepped planing surface. J Ship Prod Des 28(2):60–72
[16] S.T.G. Veysi ,M. Bakhtiari,H. Ghassemi, Ghiasi M. , 2014. Toward numerical modeling of the stepped and non stepped planing hull, Brazilian Soc Mech Sci Eng, 36:697–708.
[17] M. Bakhtiari, S.T.G. Veysi, H. Ghassemi, 2016. Numerical modeling of the stepped planning hull in calm water. International Journal of Engineering; Transactions B: Applications Vol. 29, No. 2, 236-245.
Amirkabir Journal of Mechanical Engineering
Volume 50, Issue 4
November and December 2018
Pages 903-912

Files

Share

How to cite

Statistics