Revision as of 09:24, 16 February 2021

Abstract

Advanced concepts for aero-structures with multifunctional capabilities are investigated within the EU-project ACASIAS. In work package 3 of ACASIAS, components of an active noise reduction system are structurally integrated into a curved sandwich panel by means of 3D printed inserts. This so-called smart lining is intended for application in aircraft as a modular and lightweight interior noise treatment in propeller-driven aircraft. The broad application scenario of smart linings ranges from retro-fitting of current regional aircraft such as ATR 42, ATR 72, DHC-8 Q400 to the application in new short-range aircraft with energy efficient counter rotating open rotor (CROR) engines or with distributed electric propellers. A key feature of the smart lining with integrated active components is its modularity, facilitating a flexible application in the aircraft cabin. This requires a fully self-contained sensing mechanism based on structurally integrated accelerometers. Using the normal surface vibration data from the integrated sensors, the smart lining is able to predict the sound field in front of it. The so-called virtual microphone method with remote sensors and observer filter allows to get rid of real microphones and wiring in the aircraft cabin. This makes retro-fitting easier because it reduces wiring effort and costs which is beneficial for future aircraft as well. However, the use of virtual instead of real microphones might deteriorate the performance or even the stability of the active noise reduction system because it relies on accurate plant models. Laboratory experiments in a sound transmission loss facility are conducted to assess the behavior of the smart lining with virtual microphones and compare it to a smart lining with real microphones. The sensitivity of the smart lining to environmental changes and the noise reduction performance and control system stability are investigated in this study.

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References

[1] S. J. Elliott, P. A. Nelson, I. M. Stothers, and C. C. Boucher, “In-flight experiments on the active control of propeller-induced cabin noise,” Journal of Sound and Vibration, vol. 140, no. 2, pp. 219–238, 1990.

[2] C. R. Fuller and J. D. Jones, “Experiments on reduction of propeller induced interior noise by active control of cylinder vibration,” Journal of Sound and Vibration, vol. 112, no. 2, pp. 389–395, Jan. 1987.

[3] K. H. Lyle and R. J. Silcox, “A study of active trim panels for interior noise reduction in an aircraft fuselage,” in SAE Technical Paper. SAE International, 05 1995. [Online]. Available: https://doi.org/10.4271/951179

[4] M. Misol, S. Algermissen, M. Rose, and H. P. Monner, “Aircraft lining panels with low-cost hardware for active noise reduction,” in Joint ConferenceACOUSTICS 2018, 2018. [Online]. Available: https://elib.dlr.de/122049/

[5] M. Misol, “Full-scale experiments on the reduction of propeller-induced aircraft interior noise with active trim panels,” Applied Acoustics, vol. 159, p. 107086, 2020. [Online]. Available: https://elib.dlr.de/129910/

[6] A. Roure and A. Albarrazin, “The remote microphone technique for active noise control,” in PROCEEDINGS OF ACTIVE 99: THE INTERNATIONAL SYMPOSIUM ON ACTIVE CONTROL OF SOUND AND VIBRATION, VOLS 1 & 2, 1999, pp. 1233–1244.

[7] J. Cheer and S. Daley, “Active structural acoustic control using the remote sensor method,” Journal of Physics: Conference Series, vol. 744, no. 1, 2016.

[8] S. Algermissen and M. Misol, “Experimental Analysis of the ACASIAS Active Lining Panel,” in Proc. of European Conference on Multifunctional Structures (EMuS), X. Martinez and H. Schippers, Eds., 2020, online event, November 17–18.

[9] M. Misol, “Active Sidewall Panels with Virtual Microphones for Aircraft Interior Noise Reduction,” Applied Sciences, vol. 10, no. 6828, pp. 1–13, 2020. [Online]. Available: https://elib.dlr.de/136353/

[10] S. J. Elliott, Signal Processing for Active Control. London: Academic Press, 2001.