Generation, propagation and breaking of an internal gravity wave beam

• Author / Creator

  Clark, Heather A

• We report upon an experimental study of internal gravity waves generated
  by the large-amplitude vertical oscillations of a circular cylinder
  in uniformly stratified fluid. Quantitative
  measurements are performed using a modified synthetic schlieren technique
  for strongly stratified solutions of NaCl or NaI.
  Oscillatory turbulent patches that develop around the cylinder
  are found to be the primary source of the observed quasi-monochromatic
  wave beams whose characteristics differ from theoretical predictions and
  experimental investigations of waves generated by small-amplitude
  cylinder oscillations. Over long times the waves break down into
  turbulence that is examined quantitatively through conductivity
  probe measurements and qualitatively through unprocessed synthetic
  schlieren images. Based on observations of the location of wave
  breakdown we determine that the likely mechanism for breakdown is through
  parametric subharmonic instability. This conclusion is supported
  by fully nonlinear numerical simulations of the evolution of a
  temporally monochromatic internal wave beam.

• Subjects / Keywords

  • Internal
  • Experiments
  • Waves
  • Instability
  • Turbulence

• Graduation date

  Spring 2010

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3MP4V

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.