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Cavity ripple dynamics after pinch-off

Published online by Cambridge University Press:  06 July 2018

Jean-François Louf
Affiliation:
Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, USA
Brian Chang
Affiliation:
Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, USA
Javad Eshraghi
Affiliation:
Department of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA
Austin Mituniewicz
Affiliation:
Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, USA
Pavlos P. Vlachos*
Affiliation:
Department of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA
Sunghwan Jung*
Affiliation:
Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24061, USA Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA
*
Email addresses for correspondence: [email protected], [email protected]
Email addresses for correspondence: [email protected], [email protected]

Abstract

During water entry, a projectile can entrain an air cavity that trails behind it. Most previous studies focus on the formation and pinch-off dynamics of the air cavity, but only a few have investigated the long-term cavity dynamics after pinch-off. In this study, we examine the ripple formation following the pinch-off of an air cavity generated by a cone, with different cone angles and impact velocities. The amplitude and wavelength of these ripples are measured, and the force on the cone is experimentally determined. It was observed that the ripple amplitude and wavelength increase linearly with the cone impact velocity, which is predicted by our acoustic model of the compressible air cavity. In addition, the measured force exhibits distinct amplitudes and wavelengths. By measuring the length of the cavity, the resulting pressure variation was averaged inside the air cavity leading to a theoretical force amplitude, which matched our observations. We noted that the force wavelength also follows the same acoustic model, which agrees very well with the wavelength of the ripples.

Type
JFM Papers
Copyright
© 2018 Cambridge University Press 

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References

Abelson, H. I. 1970 Pressure measurements in the water-entry cavity. J. Fluid Mech. 44, 129144.Google Scholar
Abrate, S. 2013 Hull slamming. Appl. Mech. Rev. 64, 060803.Google Scholar
Bergmann, R., Van Der Meer, D., Gekle, S., Van Der Bos, A. & Lohse, D. 2009 Controlled impact of a disk on a water surface: cavity dynamics. J. Fluid Mech. 633, 381409.Google Scholar
Bergmann, R., Van Der Meer, D., Stijnman, M., Sandtke, M., Prosperetti, A. & Lohse, D. 2006 Giant bubble pinch-off. Phys. Rev. Lett. 96, 154505.Google Scholar
Bodily, K. G., Carlson, S. J. & Truscott, T. T. 2014 The water entry of slender axisymmetric bodies. Phys. Fluids 26, 072108.Google Scholar
Chang, B., Croson, M., Straker, L., Gart, S., Dove, C., Gerwin, J. & Jung, S. 2016 How seabirds plunge-dive without injuries. Proc. Natl Acad. Sci. USA 113, 12006.Google Scholar
Duclaux, V., Caillé, F., Duez, C., Ybert, C., Bocquet, L. & Clanet, C. 2007 Dynamics of transient cavities. J. Fluid Mech. 591, 119.Google Scholar
Epstein, D. & Keller, J. B. 1972 Expansion and contraction of planar, cylindrical, and spherical underwater gas bubbles. J. Acoust. Soc. Am. 52, 975980.Google Scholar
Franc, J.-P. & Michel, J.-M. 2006 Fundamentals of Cavitation, vol. 76. Springer Science & Business Media.Google Scholar
Gaudet, S. 1998 Numerical simulation of circular disks entering the free surface of a fluid. Phys. Fluids 10, 2489.Google Scholar
Gekle, S., Gordillo, J. M., Van der Meer, D. & Lohse, D. 2009a High-speed jet formation after solid object impact. Phys. Rev. Lett. 102, 034502.Google Scholar
Gekle, S., Snoeijer, J. H., Lohse, D. & Van der Meer, D. 2009b Approach to universality in axisymmetric bubble pinch-off. Phys. Rev. E 80, 036305.Google Scholar
Glasheen, J. W. & McMahon, T. A. 1996 Vertical water entry of disks at low Froude numbers. Phys. Fluids 8, 2078.Google Scholar
Grumstrup, T., Keller, J. B. & Belmonte, A. 2007 Cavity ripples observed during the impact of solid objects into liquids. Phys. Rev. Lett. 99, 114502.Google Scholar
Knapp, R. T., Daily, J. W. & Hammitt, F. G. 1970 Cavitation. McGraw-Hill.Google Scholar
Mansoor, M. M., Marston, J. O., Vakarelski, I. U. & Thoroddsen, S. T. 2014 Water entry without surface seal: extended cavity formation. J. Fluid Mech. 743, 295326.Google Scholar
May, A. 1952 Vertical entry of missiles into water. J. Appl. Phys. 23, 1362.Google Scholar
May, A.1975 Water entry and the cavity-running behavior of missiles. Rep. NAVSEA hydrodynamics advisory committee.Google Scholar
Truscott, T. T., Epps, B. P. & Beden, J. 2014 Water entry of projectiles. Annu. Rev. Fluid Mech. 46, 355378.Google Scholar
Truscott, T. T. & Techet, A. H. 2009 Water entry of spinning spheres. J. Fluid Mech. 625, 135165.Google Scholar
Vincent, L., Xiao, T., Yohann, D., Jung, S. & Kanso, E. 2018 Dynamics of water entry. J. Fluid Mech. 846, 508535.Google Scholar