Active control of structurally radiated sound from an elastic cylindrical shell

Abstract

A numerical and experimental study was presented on active control of structurally radiated sound from an elastic cylindrical shell. An analytical model was developed for the active structural acoustic control (ASAC) of the cylindrical shell. Both global and local control strategies were considered. The optimal control forces corresponding to each control strategy were obtained by using the linear quadratic optimal control theory. Numerical simulations were performed to examine and analyze the control performance under different control strategies. The results show that global sound attenuation of the cylindrical shell at resonance frequencies can be achieved by using point force as the control input of the ASAC system. Better control performance can be obtained under the control strategy of minimization of the radiated sound power. However, control spillover may occur at off-resonance frequencies with the control strategy of structural kinetic energy minimization in terms of the radiated sound power. Considerable levels of global sound attenuation can also be achieved in the on-resonance cases with the local control strategy, i.e., minimization of the mean-square velocity of finite discrete locations. An ASAC experiment using an FXLMS algorithm was implemented, agreement was observed between the numerical and experimental results, and successful attenuation of structural vibration and radiated sound was achieved.

Keywords

cylindrical shell / radiated sound power / active structural acoustic control (ASAC) / FXLMS algorithm

References

[1] Brevart B.J., Fuller C.R. Active control of coupled wave propagation in fluid-filled elastic cylindrical shells. Journal of Acoustical Society of America, 1993, 94: 1467-1475

[2] Bullmore A.J., Nelson P.A., Elliott S.J. Theoretical studies of the active control of propeller-induced cabin noise. Journal of Sound and Vibration, 1990, 140(2): 191-217

[3] Caresta M. Active control of sound radiated by a submarine in bending vibration. Journal of Sound and Vibration, 2011, 330: 615-624

[4] Clark R.L., Fuller C.R. Active control of structurally radiated sound from an enclosed finite cylinder. Journal of Intelligent Material Systems and Structures, 1994, 5(3): 379-391

[5] Fuller C.R., Elliott S.J., Nelson P.A. Active control of vibration, 1996, London: Academic Press, 1-120

[6] Hansen C.H., Snyder S.D. Active control of noise and vibration, 1997, Cambridge: Cambridge University Press

[7] Jin G., Chen H., Du J., Yang T., Li W. The influence of edge restraining stiffness on the transverse vibrations of rectangular plate structures. Journal of Marine Science and Application, 2010, 9(4): 393-402

[8] Jin G., Liu Z., Du J., Yang T. Experimental study on active structural acoustic control based on distributed structural volume velocity sensor. Acta Acustica, 2009, 34(4): 342-349

[9] Jin G., Liu Z., Yang T. Active control of sound transmission into an acoustic cavity surrounded by more than one flexible plate. Noise Control Engineering Journal, 2009, 57(3): 210-220

[10] Jin G., Yang T.J., Liu Z. A Simultaneous equation method-based online secondary path modeling algorithm for active noise control. Journal of Sound and Vibration, 2007, 303: 455-474

[11] Leissa AW (1973). Vibration of Shells. NASA-SP-288, NASA, 1–49.

[12] Maillard J.P., Fuller C.R. Advanced time domain wave-number sensing for structural acoustic systems. I. Theory and design. Journal of the Acoustical Society of America, 1994, 95: 3252-3261

[13] Pan X., Tso Y., Juniper R. Active control of low-frequency hull-radiated noise. Journal of Sound and Vibration, 2008, 313: 29-45

[14] Zhang J., Li T., Ye W., Zhu X. Acoustic radiation of damped cylindrical shell with arbitrary thickness in the fluid field. Journal of Marine Science and Application, 2010, 9(4): 431-438