Skip to main content
Log in

Effects of elastic bed on hydrodynamic forces for a submerged sphere in an ocean of finite depth

  • Published:
Zeitschrift für angewandte Mathematik und Physik Aims and scope Submit manuscript

Abstract

In this paper, we consider a hydroelastic model to examine the radiation of waves by a submerged sphere for both heave and sway motions in a single-layer fluid flowing over an infinitely extended elastic bottom surface in an ocean of finite depth. The elastic bottom is modeled as a thin elastic plate and is based on the Euler–Bernoulli beam equation. The effect of the presence of surface tension at the free-surface is neglected. In such situation, there exist two modes of time-harmonic waves: the one with a lower wavenumber (surface mode) propagates along the free-surface and the other with higher wavenumber (flexural mode) propagates along the elastic bottom surface. Based on the small amplitude wave theory and by using the multipole expansion method, we find the particular solution for the problem of wave radiation by a submerged sphere of finite depth. Furthermore, this method eliminates the need to use large and cumbersome numerical packages for the solution of such problem and leads to an infinite system of linear algebraic equations which are easily solved numerically by any standard technique. The added-mass and damping coefficients for both heave and sway motions are derived and plotted for different submersion depths of the sphere and flexural rigidity of the elastic bottom surface. It is observed that, whenever the sphere nearer to the elastic bed, the added-mass move toward to a constant value of 1, which is approximately twice of the value of added-mass of a moving sphere in a single-layer fluid flowing over a rigid and flat bottom surface.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. Cadby, J.R., Linton, C.M.: Three-dimensional water-wave scattering in two-layer fluids. J. Fluid Mech. 423, 155–173 (2000)

    Article  MathSciNet  MATH  Google Scholar 

  2. Chiba, M., Watanabe, H., Bauer, H.F.: Hydroelastic coupled vibrations in a cylindrical container with a membrane bottom containing liquid with surface tension. J. Sound Vib. 251(4), 717–740 (2002)

    Article  Google Scholar 

  3. Das, D., Mandal, B.N.: Water wave radiation by a sphere submerged in water with an ice-cover. Arch. Appl. Mech. 78(8), 649–661 (2008)

    Article  MATH  Google Scholar 

  4. Das, D., Mandal, B.N.: Wave radiation by a sphere submerged in a two-layer ocean with an ice-cover. Appl. Ocean Res. 32, 358–366 (2010)

    Article  Google Scholar 

  5. Evans, D.V., Linton, C.M.: Active devices for the reduction of wave intensity. Appl. Ocean Res. 11, 26–32 (1989)

    Article  Google Scholar 

  6. Fox, C., Squire, V.A.: On the oblique reflection and transmission of ocean waves at shore fast sea ice. Philos. Trans. R. Soc. Lond. A 347, 185–218 (1994)

    Article  MATH  Google Scholar 

  7. Gray, E.P.: Scattering of a surface wave by a submerged sphere. J. Eng. Math. 12, 15–41 (1978)

    Article  MathSciNet  MATH  Google Scholar 

  8. Havelock, T.H.: Waves due to a floating sphere making periodic heaving oscillations. Proc. R. Soc. Lond. A 231, 443–463 (1955)

    Article  MathSciNet  MATH  Google Scholar 

  9. Linton, C.M.: Radiation and diffraction of water waves by a submerged sphere in finite depth. Ocean Eng. 18, 61–74 (1991)

    Article  Google Scholar 

  10. Linton, C.M., Chung, H.: Reflection and transmission at the ocean/sea-ice boundary. Wave Motion 38, 43–52 (2003)

    Article  MathSciNet  MATH  Google Scholar 

  11. Linton, C.M., Evans, D.V.: The radiation and scattering of surface waves by a vertial circular cylinder in a channel. Philos. Trans. R. Soc. Lond. A 338, 325–357 (1992)

    Article  MATH  Google Scholar 

  12. Mohapatra, S., Bora, S.N.: Water wave interaction with a sphere in a two-layer fluid flowing through a channel of finite depth. Arch. Appl. Mech. 79, 725–740 (2009)

    Article  MATH  Google Scholar 

  13. Mohapatra, S., Bora, S.N.: Radiation of water waves by a sphere in an ice-covered two-layer fluid of finite depth. J. Adv. Res. Appl. Math. 2, 46–63 (2010)

    Article  MathSciNet  Google Scholar 

  14. Mohapatra, S., Bora, S.N.: Exciting forces due to interaction of water waves with a submerged sphere in an ice-covered two-layer fluid of finite depth. Appl. Ocean Res. 34, 187–197 (2012)

    Article  Google Scholar 

  15. Mohapatra, S.C., Sahoo, T.: Surface gravity wave interaction with elastic bottom. Appl. Ocean Res. 33, 31–40 (2011)

    Article  Google Scholar 

  16. Srokosz, M.A.: The submerged sphere as an absorber of wave power. J. Fluid Mech. 95, 717–741 (1979)

    Article  MathSciNet  MATH  Google Scholar 

  17. Sturova, I.V.: Unsteady three-dimensional sources in deep water with an elastic cover and their applications. J. Fluid Mech. 730, 392–418 (2013)

    Article  MathSciNet  MATH  Google Scholar 

  18. Thorne, R.C.: Multipole expansions in the theory of surface waves. Proc. Camb. Philos. Soc. 49, 707–716 (1953)

    Article  MathSciNet  MATH  Google Scholar 

  19. Tkacheva, L.A.: Oscillations of a cylinderical body submerged in a fluid with ice-cover. J. Appl. Mech. Tech. Phys. 56, 1084–1095 (2015)

    Article  MathSciNet  MATH  Google Scholar 

  20. Ursell, F.: On the heaving motion of a circular cylinder on the surface of a fluid. Q. J. Mech. Appl. Math. 2, 218–231 (1949)

    Article  MathSciNet  MATH  Google Scholar 

  21. Ursell, F.: Surface waves on deep water in the presence of a submerged circular cylinder—I. Proc. Camb. Philos. Soc. 46, 141–152 (1950)

    Article  MathSciNet  MATH  Google Scholar 

  22. Wang, S.: Motions of a spherical submarine in waves. Ocean Eng. 13, 249–271 (1986)

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Smrutiranjan Mohapatra.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Mohapatra, S. Effects of elastic bed on hydrodynamic forces for a submerged sphere in an ocean of finite depth. Z. Angew. Math. Phys. 68, 91 (2017). https://doi.org/10.1007/s00033-017-0837-1

Download citation

  • Received:

  • Revised:

  • Published:

  • DOI: https://doi.org/10.1007/s00033-017-0837-1

Mathematics Subject Classification

Keywords

Navigation