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Generation of Long Water Waves by Moving Disturbances


Lee, Seung-Joon (1985) Generation of Long Water Waves by Moving Disturbances. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/EG1N-VZ69.


Several theoretical models are developed to study generation of nonlinear dispersive long waves by moving disturbances. All these models belong to the same class as the original Boussinesq or KdV model. The newly developed models, now with external forcing functions added to the KdV equation and the pair of coupled Boussinesq equations, have been chosen for numerical investigations. A predictor-corrector method is adopted to develop the numerical schemes employed here. In order to make the region of computation reasonably small for the case with moving disturbances, a pseudo-moving frame and the sufficiently transparent open boundary conditions are devised. The numerically obtained surface elevations exhibit a series of positive waves running ahead of the disturbance over a wide range of transcritical speeds of the disturbance. The numerical results show that, for speeds close to the critical value, the generation of such waves appears to continue indefinitely. The numerically obtained wave resistance coefficient is compared to the results given by linear dispersive theory. Numerical solutions have been obtained using the KdV and Boussinesq models with surface pressure and bottom bump as forcing functions. Comparisons are made between these results for various cases. Experiments were conducted for a two-dimensional bottom bump moving steadily in shallow water of a towing tank. Experimental results so attained are compared with the numerical solutions, and the agreement between them is good in terms of both the magnitude and the phase of the waves for the range of parameters used in the current study.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Water Waves
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Engineering
Awards:Richard Bruce Champman Memorial Award
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Wu, Theodore Yao-tsu
Thesis Committee:
  • Wu, Theodore Yao-tsu (chair)
  • Caughey, Thomas Kirk
  • Whitham, Gerald Beresford
  • Keller, Herbert Bishop
  • Raichlen, Fredric
Defense Date:17 May 1985
Non-Caltech Author Email:sjoonlee (AT)
Funding AgencyGrant Number
Korean Ministry of EducationUNSPECIFIED
Office of Naval Research (ONR)UNSPECIFIED
Record Number:CaltechETD:etd-04012008-151918
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:1242
Deposited By: Imported from ETD-db
Deposited On:08 Apr 2008
Last Modified:02 Dec 2022 23:44

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