A passive flow separation approach for reducing slamming loads on large catamarans: experimental investigation

Ahmed Abdel Wahab Swidan, Giles Thomas


This paper reports on experimental and numerical simulations conducted on a high-speed catamaran’s bow section during water entry using both water impact device. The water impact facility allows the water/model interaction to occur at relatively highvelocities up to 10m/s and with two angles of trim, e.g. 0° and 5°. The tested model was constructed with two interchangeable centrebows to study the influence of flow separation prior to slam events. The present work aims at addressing the issue of disconnect between impact pressure peak magnitudes and slam force peaks. It was found that limited pressure transducers that are localized in space and time are important for validating numerical techniques but should not be used as a basis for structural design.


Water impact loads on large catamarans

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Davidson G, Roberts T, Thomas G. Global and slam loads for a large wavepiercing catamaran design. Australian Journal of Mechanical Engineering. 2006;3:155-64.

Faltinsen O. Hydrodynamic features of high-speed vessels. Ships and Offshore Structures. 2006;1:13-23.

Rothe F, Sames PC, Schellin TE. Catamaran wetdeck structural response to wave impact. In: SNAME, editor. International Conference of Fast Sea Transportation (FAST'01). Southampton, England2001. p. 125-33.

Steinmann P, Fach K, Menon B. Global and Slamming Sea Loads Acting on an 86m High Speed Catamaran Ferry. In: SNAME, editor. 5th International Conference on Fast Sea Transportation. Seattle, USA, 1999.

Thomas G, Davis M, Holloway D, Roberts T. Extreme asymmetric slam loads on large high speed catamarans. In: RINA, editor. 6th Symposium of High Speed Marine Vessels. Naples, Italy2002. p. 15-23.

Wang S, Guedes Soares C. Slam induced loads on bow-flared sections with various roll angles. Ocean Engineering. 2013;67:45-57.

Thomas G. Wave Slam Response of Large High Speed Catamarans: University of Tasmania; 2003.

Cummings TR, Roden PJ. A summary of the IMO HighSpeed Craft (HSC) Code and its impact on the First US vessel built to this standard. Marine Technology and SNAME News. 1998;35:183.

LR. Rules and regulations for the classification of special service craft. LIoyd's Register; 2019.

DNV-GL. Rules for Classification of High Speed and Light Craft. Design Principles, Design Loads: DNV-GL; 2018.

ABS. Rules for building and classing high-speed craft. American Bureau of Shipping; 2016.

Davis MR, Whelan JR. Computation of wet deck bow slam loads for catamaran arched cross sections. Ocean Engineering. 2007;34(17):2265-76.

Swidan A, Thomas G, Ranmuthugala D, Penesis I, Amin W. Numerical investigation of water slamming loads on wavepiercing catamaran hull model. In: RINA, editor. 10th Symposium on High Speed Marine Vessels (HSMV). Naples, Italy2014. p. 1-9.

Swidan A, Amin W, Ranmuthugala D, Thomas G, Penesis I. Numerical Prediction of Symmetric Water Impact Loads on Wedge Shaped Hull Form Using CFD. World Journal of Mechanics. 2013;3:1-8.

Swidan A, Thomas G, Ranmuthugala D, Amin W, Penesis I, Allen T, et al. Experimental drop test investigation into wetdeck slamming loads on a generic catamaran hullform. Ocean Engineering. 2016;117:143-53.

Swidan A, Thomas G, Penesis I, Ranmuthugala D, Amin W, Allen T, et al. Wetdeck slamming loads on a developed catamaran hullform–experimental investigation. Ships and Offshore Structures. 2017;12:653-61.

Payne PR. A discussion of the design pressures appropriate to the bottom of a planing boat. Ocean Engineering. 1988;15:471-93.

Cooker MJ, Peregrine D. Pressure-impulse theory for liquid impact problems. Journal of Fluid Mechanics. 1995;297:193-214.

Faltinsen OM, Kvålsvold J, Aarsnes JV. Wave impact on a horizontal elastic plate. Journal of Marine Science and Technology. 1997;2:87-100.

Dobrovol'Skaya Z. On some problems of similarity flow of fluid with a free surface. Journal of Fluid Mechanics. 1969;36:805-29.

Zhao R, Faltinsen O. Water entry of two-dimensional bodies. Journal of Fluid Mechanics. 1993;246:593-612.

Zhao.R FO, Aarsnes.J,. Water entry of arbitrary two dimensional sections with and without flow separation. 21st Symposium on Naval Hydrodynamics. Trondheim, Norway.1996.

Yettou E-M, Desrochers A, Champoux Y. Experimental study on the water impact of a symmetrical wedge. Fluid Dynamics Research. 2006;38:47-66.

Lewis SG, Hudson DA, Turnock SR, Taunton DJ. Impact of a free-falling wedge with water: synchronized visualization, pressure and acceleration measurements. Fluid Dynamics Research. 2010;42(3):035509

DOI: https://dx.doi.org/10.21622/mrt.2022.01.1.017


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Maritime Research and Technology
E-ISSN: 2812-5622
P-ISSN: 2812-5614 

Published by:

Academy Publishing Center (APC)
Arab Academy for Science, Technology and Maritime Transport (AASTMT)
Alexandria, Egypt