The prediction of vibration and noise has long been a problem in many fields. It has become increasingly important because of safety and environmental legislation, and its study has benefited from increasingly powerful computer technology. This thesis concentrates on acoustically generated vibrations in ship hulls, particularly those of cruise liners. These vibrations must be predicted and understood so that passenger comfort can be ensured and operational restrictions met. In order to analyse vibration one needs to bring together an acoustic model appropriate to the form of the propeller, hull and operating environment, a numerical technique that can reliably solve the resulting equations and an effective and accurate way of representing the complex hull shapes involved. Because of the complexity of the problem, progress on understanding vibration in real situations needs computational analysis. A numerical method must be established which has the potential to be used for optimal design of the shapes involved in such structures. The acoustic model is based upon the Helmholtz wave equation with a distribution of sources representing the propellers and hull. The numerical technique used is the boundary element method. The value of the boundary element method compared with other common techniques lies in the fact that it reduces the dimension of the problem and hence simplifies the boundary conditions required as input. The partial differential equation (PDE) method is used to represent the hull. The advantage of this method is that it can represent and manipulate real ship geometries in an effective efficient and accurate way. This thesis proposes an approach to predicting the propeller-induced vibration. The work is novel in its application of boundary elements together with the partial differential equation (PDE) surface method to vibration problems. The work has already been used to predict vibration on <I>Aurora</I>, the latest P&O cruise ship, prior to its launch.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:596728 |
| Date | January 2002 |
| Creators | Bloor, C. |
| Publisher | University of Cambridge |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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