McCabe, A. P. and Aggidis, George A. and Stallard, T. J. (2006) A time-varying parameter model of a body oscillating in pitch. Applied Ocean Research, 28 (6). pp. 359-370.
Full text not available from this repository.Abstract
Among the assumptions upon which linear time-invariant models of floating bodies are based is that the body motions are so small that any change in the body’s angular position can be disregarded. However, it is often a major design requirement of a wave energy conversion device that the response amplitude is large, thereby invalidating one of the assumptions of the linear model. In particular, the immersed geometry of a body undergoes considerable variation when it is moved in pitch. With regard to this we investigate the difference in performance between a quasi-linear model in which the change of immersed surface is modelled by time-varying parameters and a basic linear model in which the immersed surface is time-invariant. The time-varying parameter model is realized by interpolation between the appropriate parameter values of a set of linear time-invariant (LTI) models derived for the different immersed surfaces that occur at discrete body displacements. It is shown that the responses predicted using the time-varying parameter model are closer to those measured experimentally than those of a standard frequency-domain model. Particular improvement occurs when the responses are large, such as at or near the resonance frequency. A problem which may limit the general use of the model is also discussed.
| Item Type: | Article |
|---|---|
| Journal or Publication Title: | Applied Ocean Research |
| Uncontrolled Keywords: | Time-varying parameter model ; Time-domain model ; Potential-flow hydrodynamics |
| Subjects: | T Technology > TC Hydraulic engineering. Ocean engineering |
| Departments: | Faculty of Science and Technology > Engineering |
| ID Code: | 33754 |
| Deposited By: | Mrs Yaling Zhang |
| Deposited On: | 24 Jun 2010 09:17 |
| Refereed?: | Yes |
| Published?: | Published |
| Last Modified: | 30 Aug 2012 17:28 |
| Identification Number: | |
| URI: | http://eprints.lancs.ac.uk/id/eprint/33754 |
Actions (login required)
| View Item |
