The excitation of waves on a flexible panel in a uniform flow
UNSPECIFIED. (1998) The excitation of waves on a flexible panel in a uniform flow. PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY OF LONDON SERIES A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, 356 (1749). pp. 2999-3039. ISSN 1364-503XFull text not available from this repository.
The wave-bearing behaviour of a finite flexible plate in a uniform flow is studied when a source of continuous oscillatory excitation is present. The method of numerical simulation is employed so that any prescription of response is avoided. A series of numerical experiments is carried out and analysed using methods similar to those applicable to a physical experiment. It is found that the plate can respond at frequencies other than that of the driver; these frequencies may either be present in the start-up procedure or be generated by wave conversions at the panel edges. At early times in the response evolution, two types of behaviour are evident. These may be separately characterized as response to low-frequency excitation and response to high-frequency excitation. The former is dominated by spatially growing waves and the latter by absolute stability. The long-time behaviour of the flexible panel shows disturbance amplitude growth at all locations for flow speeds that approach zero in the limit of an infinitely long flexible plate. For parameters corresponding to a realistic flexible panel, the long-time growth of the deformation is found to be attributable to a combination of low-frequency unstable waves which are capable of convecting wall energy and thus disturbance growth to all parts of the flexible panel; the mechanism for this features repeated wave conversions at the panel ends. This convective mechanism predominates despite the presence of an absolute instability found in the system studied here. In the later stages of the flexible-panel response, the line excitation is largely insignificant. An attempt is made to reconcile the observations of the present numerical experiments with the predictions of hydroelastic boundary-value studies of an infinitely long flexible plate and the rigorous structural-acoustics approach to the problem in which causality is a key element.
|Item Type:||Journal Article|
|Journal or Publication Title:||PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY OF LONDON SERIES A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES|
|Publisher:||ROYAL SOC LONDON|
|Date:||15 December 1998|
|Number of Pages:||41|
|Page Range:||pp. 2999-3039|
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