Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-29T01:30:55.510Z Has data issue: false hasContentIssue false
  • English
  • Français

Experimental investigation of the water entry of a rectangular plate at high horizontal velocity

Published online by Cambridge University Press:  28 June 2016

A. Iafrati
A. Iafrati*
Affiliation:
CNR-INSEAN, Marine Technology Research Institute, Rome 00128, Italy
*
†Email address for correspondence: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

The water entry of a rectangular plate with a high horizontal velocity component is investigated experimentally. The test conditions are representative of those encountered by aircraft during emergency landing on water and are given in terms of three main parameters: horizontal velocity, approach angle, i.e. vertical to horizontal velocity ratio, and pitch angle. Experimental data are presented in terms of pressure, spray root shape, pressure peak propagation velocity and total loads acting on the plate. A theoretical solution of the plate entry problem based on two-dimensional and potential flow assumptions is derived and is used to support the interpretation of the experimental measurements. The results indicate that, as the plate penetrates and the ratio between the plate breadth and the wetted length measured on the longitudinal plane diminishes, the role of the third dimension becomes dominant. The increased possibility for the liquid to escape from the lateral sides yields a reduction of the pressure peak propagation velocity and, consequently, of the corresponding pressure peak intensity. In particular, it is shown that, at the beginning of the entry process, the pressure peak moves much faster than the geometric intersection between the body and the free surface, but at a later stage the two points move along the body at the same speed. Furthermore, it is shown that the spray root develops a curved shape which is almost independent of the specific test conditions, even though the initial growth rate of the curvature is higher for larger pitch angles. The loads follow a linear increase versus time, as predicted by the theoretical model, only in a short initial stage. Next, for all test conditions examined here, they approach a square-root dependence on time. It is seen that, if the loads are scaled by the square of the velocity component normal to the plate, the data are almost independent of the test conditions.

JFM classification

Multiphase and Particle-laden Flows: Multiphase flow Waves/Free-surface Flows: Waves/Free-surface Flows
Type
Papers
Information
Journal of Fluid Mechanics , Volume 799 , 25 July 2016 , pp. 637 - 672
Check for updates
Copyright
© 2016 Cambridge University Press 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Battistin, D. & Iafrati, A. 2003 Hydrodynamic loads during water entry of two-dimensional and axisymmetric bodies. J. Fluids Struct. 17, 643–664.Google Scholar
Battistin, D. & Iafrati, A. 2004 A numerical model for the jet flow generated by water impact. J. Engng Maths 48, 353–374.Google Scholar
Brennen, C. E. 2005 Fundamentals of Multiphase Flow. Cambridge University Press.Google Scholar
Chuang, S. L. 1967 Experiments on slamming of wedge-shaped bodies. J. Ship. Res. 11, 190–198.Google Scholar
Climent, H., Benitez, L., Rosich, F., Rueda, F. & Pentecote, N. 2006 Aircraft ditching numerical simulation. In Proceedings of the 25th International Congress of the Aeronautical Sciences, 3–8 September 2006, Hamburg, Germany.Google Scholar
Cointe, R. & Armand, J.-L. 1987 Hydrodynamic impact analysis of a cylinder. J. Offshore Mech. Arctic. Engng 109, 237–243.Google Scholar
Faltinsen, O. M. & Semenov, Y. A. 2008 Nonlinear problem of flat-plate entry into an incompressible liquid. J. Fluid Mech. 611, 151–173.Google Scholar
Guo, B., Liu, P., Qu, Q. & Wang, J. 2013 Effect of pitch angle on initial stage of a transport airplane ditching. Chinese J. Aeronaut. 26, 17–26.Google Scholar
Howison, S. D., Ockendon, J. R. & Wilson, S. K. 1991 Incompressible water-entry problems at small deadrise angles. J. Fluid Mech. 222, 215–230.Google Scholar
Iafrati, A. 2015 Fluid–structure interactions during the high speed water entry of a plate. In Proceedings of the 18th International Conference on Ships and Shipping Research, 24–26 June 2015, Lecco, Italy.Google Scholar
Iafrati, A. & Battistin, D. 2003 Hydrodynamics of water entry in presence of flow separation from chines. In Proceedings of the 8th International Conference on Numerical Ship Hydrodynamics, 22–25 September 2003, Busan, Korea.Google Scholar
Iafrati, A. & Calcagni, D. 2013 Numerical and experimental studies of plate ditching. In Proceedings of the 28th International Workshop Water Waves Floating Bodies, 7–10 April 2013, Marseille, France, available online at www.iwwwfb.org.Google Scholar
Iafrati, A., Grizzi, S., Siemann, M. & Benítez Montañés, L. 2015 High-speed ditching of a flat plate: experimental data and uncertainty assessment. J. Fluids Struct. 55, 501–525.Google Scholar
Iafrati, A. & Korobkin, A. 2004 Initial stage of flat plate impact onto liquid free surface. Phys. Fluids 16, 2214–2227.Google Scholar
Iafrati, A. & Korobkin, A. 2008 Hydrodynamic loads during early stage of flat plate impact onto water surface. Phys. Fluids 20, 082104.Google Scholar
Kapsenberg, G. K. 2011 Slamming of ships: where are we now? Phil. Trans. R. Soc. Lond. A 369, 2892–2919.Google Scholar
Korobkin, A. A. & Pukhnachov, V. V. 1988 Initial stage of water impact. Annu. Rev. Fluid Mech. 20, 159–185.Google Scholar
Korobkin, A. A. & Scolan, Y.-M. 2006 Three-dimensional theory of water impact. Part 2. Linearized Wagner problem. J. Fluid Mech. 549, 343–373.Google Scholar
McBride, E. E. & Fisher, L. J.1953 Experimental investigation of the effect of rear-fuselage shape on ditching behavior. Tech. Note 2929. National Advisory Council for Aeronautics (NACA), Langley Field, VA, USA.Google Scholar
Moghisi, M. & Squire, P. T. 1981 An experimental investigation of the initial force of impact on a sphere striking a liquid surface. J. Fluid Mech. 108, 133–146.Google Scholar
Okada, S. & Sumi, Y. 2000 On the water impact and elastic response of a flat plate at small impact angles. J. Mar. Sci. Technol. 5, 31–39.Google Scholar
Reinhard, M., Korobkin, A. A. & Cooker, M. J. 2013 Water entry of a flat elastic plate at high horizontal speed. J. Fluid Mech. 724, 123–153.Google Scholar
Seddon, C. M. & Moatamedi, M. 2006 Review of water entry with applications to aerospace structures. Intl J. Impact Engng 32, 1045–1067.Google Scholar
Semenov, Yu. A. & Iafrati, A. 2006 On the nonlinear water entry problem of asymmetric wedges. J. Fluid Mech. 547, 231–256.Google Scholar
Siemann, M. H. & Groenenboom, P. H. L. 2014 Modeling and validation of guided ditching tests using a coupled SPH–FE approach. In Proceedings of the 9th International SPHERIC Workshop, 3–5 June 2014, Paris, France.Google Scholar
Siemann, M. H., Kohlgruber, D., Benítez Montañés, L. & Iafrati, A. 2014 Numerical simulation and experimental validation of guided ditching tests. In Proceedings of the 11th World Congress on Computational Mechanics (WCCM XI), 20–25 July 2014, Barcelona, Spain.Google Scholar
Smiley, R. F.1950 A study of water pressure distribution during landings with special reference to a prismatic model having a heavy beam loading and a $30^{\circ }$ angle of dead rise. Tech. Note 2111, National Advisory Council for Aeronautics (NACA), Langley Field, VA, USA.Google Scholar
Smiley, R. F.1951 An experimental study of water-pressure distributions during landings and planing of a heavily loaded rectangular flat-plate model. Tech. Note 2453, National Advisory Council for Aeronautics (NACA), Langley Field, VA, USA.Google Scholar
Smiley, R. F.1952 A theoretical and experimental investigation of the effects of yaw on pressures, forces, and moments during seaplane landings and planing. Tech. Note 2817, National Advisory Council for Aeronautics (NACA), Langley Field, VA, USA.Google Scholar
Smith, A. G., Warren, C. H. E. & Wright, D. F.1957 Investigations of the behaviour of aircraft when making a forced landing on water (ditching). Reports and Memoranda 2917, Aeronautical Research Council, Ministry of Supply.Google Scholar
Stenius, I., Rosèn, A., Battley, M. & Allen, T. 2013 Experimental hydroelastic characterization of slamming loaded marine panels. Ocean Engng 74, 1–15.Google Scholar
Streckwall, H., Lindenau, O. & Bensch, L. 2007 Aircraft ditching: a free surface/free motion problem. Arch. Civil Mech. Engng 3, 178–190.Google Scholar
Van Nuffel, D., Vepa, K. S., De Baere, I., Degrieck, J., De Rouck, J. & Van Paepegem, W. 2013 Study on the parameters influencing the accuracy and reproducibility of dynamic pressure measurements at the surface of a rigid body during water impact. Exp. Mech. 53, 131–144.Google Scholar
Zhang, T., Li, S. & Dai, H. 2012 The suction force effect analysis of large civil aircraft ditching. Sci. China Technol. Sci. 55, 2789–2797.Google Scholar
Zhao, R., Faltinsen, O. M. & Aarsnes, J. 1996 Water entry of arbitrary two-dimensional sections with and without flow separation. In Proceedings of the 21st Symposium on Naval Hydrodynamics, 24–28 June 1996, Trondheim, Norway.Google Scholar
Zhao, R., Faltinsen, O. M. & Haslum, H. A. 1997 A simplified nonlinear analysis of a high-speed planing craft in calm water. In Proceedings of the Fourth International Conference on Fast Sea Transportation, FAST’97, 21–23 July 1997, Sydney, Australia.Google Scholar