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It is often desired to reduce sound radiated from cylindrical shells. Active structural acoustic control (ASAC) provides a means of controlling the structural vibration in a manner to efficiently reduce the radiated sound. Previous work has often required a large number of error sensors to reduce the radiated sound power, and the control performance has been sensitive to the location of error sensors. The ultimate objective is to provide global sound power reduction using a minimal number of local error measurements, while also minimizing any dependence on error sensor locations. Recently, a control metric referred to as weighted sum of spatial gradients (WSSG) was developed for ASAC. Specific features associated with WSSG make this method robust under a variety of conditions. In this work, the WSSG control metric is extended to curved structures, specifically a simply supported cylindrical shell. It is shown that global attenuation of the radiated sound power is possible using only one local error measurement. It is shown that the WSSG control metric provides a solution approximating the optimal solution of attenuating the radiated sound power, with minimal dependence on the error sensor location. Numerical and experimental results are presented to demonstrate the effectiveness of the method.

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There are a number of applications involving cylindrical shells where it is desired to attenuate the acoustic power radiated from the shell, such as from an aircraft fuselage or a submarine. In this paper, a new active control approach is outlined for reducing radiated sound power from structures using a weighted sum of spatial gradients (WSSG) control metric. The structural response field associated with the WSSG has been shown to be relatively uniform over the surface of both plates and cylindrical shells, which makes the control method relatively insensitive to error sensor location. It has also been shown that minimizing WSSG is closely related to minimizing the radiated sound power. This results in global control being achieved using a local control approach. This paper will outline these properties of the WSSG control approach and present control results for a simply supported cylindrical shell showing the attenuation of radiated sound power that can be achieved.