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Experimental and Statistical Energy Analysis of the Structure-borne Noise in a Helicopter Cabin

Raffaella Di Sante(1*), Marcello Vanali(2), Elisabetta Manconi(3), Alessandro Perazzolo(4)

(1) Department of Industrial Engineering, University of Bologna, Italy
(2) Department of Industrial Engineering, University of Parma, Italy
(3) Department of Industrial Engineering, University of Parma, Italy
(4) Leonardo Helicopter Division, Italy
(*) Corresponding author


DOI: https://doi.org/10.15866/irease.v10i6.13120

Abstract


In this work, the mechanical power transferred from the main gearbox to the cabin of a helicopter is obtained experimentally and used as an input to the vibroacoustic model of the fuselage for interior noise prediction. The estimation of the transmitted mechanical power is based on the experimental evaluation of the coupled mechanical mobility and in-flight accelerations measured at the points connecting the main gearbox to the fuselage, i.e. the antitorque plate and struts. The predicted values, together with the airborne noise sources (upper deck cavity noise and aerodynamic excitation due to the turbulent boundary layer on the fuselage skin) are then fed into the vibroacoustic model of the fuselage/cabin, which is obtained using a Statistical Energy Analysis (SEA) approach. The reliability of the approach is finally demonstrated by comparing the SEA simulation results and in-flight noise measurements in terms of sound pressure level in the passenger cabin compartment.
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Keywords


Helicopter; Helicopter Gearbox; Helicopter Noise; Mechanical Power; Statistical Energy Analysis; Vibroacoustic Analysis

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References


F. J. Fahy, Statistical Energy Analysis: a Critical Overview, Philos. T. Roy. Soc. A 346 (1994), 431-447.
http://dx.doi.org/10.1098/rsta.1994.0027

B. Mace, Statistical Energy Analysis, Energy Distribution Models and System Modes, J. Sound Vib. 233 (2003), 391-409.
http://dx.doi.org/10.1016/s0022-460x(02)01201-4

R. J. Pinnington et al, Power Flow through Machine Isolators to Resonant and non-Resonant Beams, J. Sound Vib. 75 (1981), 179-197.
http://dx.doi.org/10.1016/0022-460x(81)90338-2

ISO7626, Vibration and shock—experimental determination of mechanical mobility—Part 1: basic definitions and transducers, 1986.
http://dx.doi.org/10.3403/30201353

ISO7626, Vibration and shock—experimental determination of mechanical mobility—Part2: measurements using single-point translation excitation with an attached vibration exciter, 1990.
http://dx.doi.org/10.3403/30284663u

ISO 7626, Vibration and shock—experimental determination of mechanical mobility—Part 5: measurement using impact excitation with an exciter which is not attached to the structure, 1994.
http://dx.doi.org/10.3403/00506324

P. Gardonio et al, Advanced Applications in Acoustics, Noise and Vibration (F. Fahy, J. Walker (Eds.), 2004, pp. 389–447).
http://dx.doi.org/10.4324/9780203645130

J. M. Mondot et al, Characterization of Structure-borne Sound Sources: the Source Descriptor and the Coupling Function, J. Sound Vib. 114 (3) (1987), 507–518.
http://dx.doi.org/10.1016/s0022-460x(87)80020-2

M. Lievens et al., Predicting the Interaction between Structure-borne Sound Sources and Receiver Structures from Independently Measured Quantities, Case Study of a Washing Machine on a Wooden Joist Floor, Acta Acust united Ac. 100(1) (2014), 79–92.
http://dx.doi.org/10.3813/aaa.918688

R. Di Sante et al, Frequency-response Coupling Technique for the Estimation of Power Transmission in Multi-point-connected Structures, Proc. Inst. Mech. Eng. Pt. I: J. Syst. Contr. Eng. 231 (3), (2017), 149-157.
http://dx.doi.org/10.1177/0959651816678501

R. Di Sante et al, Coupled Impedance for Power Transmission Characterisation in Multi-point-connected Structures, in Proceedings of the 22nd International Congress on Sound and Vibration, ICSV 22, 5354-5362 (2015).
http://dx.doi.org/10.1006/jsvi.1998.2256

R. Di Sante et al., Numerical and Experimental Evaluation of Mechanical Mobility in Multi-point-connected Structures for Power Transmission Prediction, in Proceedings of the 5th European Conference on Computational Mechanics ECCM V, (2014).
http://dx.doi.org/10.1002/bate.199900290

D. De Klerk et al, General framework for dynamic substructuring: history, review, and classification of techniques, AIAA J 46 (2008).
http://dx.doi.org/10.2514/1.33274

G. Pavic et al, Structure-borne Sound Characterization of Coupled Structures—Part I: Simple Demonstrator Model, J. Vib. Acoust. 132 (2010) 041008.
http://dx.doi.org/10.1115/1.4000980

G. De Sitter et al, Operational Transfer Path Analysis, Mech. Syst. Signal Pr. 24 (2010) 416–431.
http://dx.doi.org/10.1016/j.ymssp.2009.07.011

A.T. Moorhouse et al., In Situ Measurement of the Blocked Force of Structure-borne Sound Sources, J. Sound Vib. 325 (2009) 679–685.
http://dx.doi.org/10.1016/j.jsv.2009.04.035

A.T. Moorhouse et al., Some Relationships for Coupled Structures and their Application to Measurement of Structural Dynamic Properties in situ, Mech. Syst. Signal Pr. 25 (5) (2011) 1574–1584.
http://dx.doi.org/10.1016/j.ymssp.2010.12.016

A.T. Moorhouse et al., The Roundtrip Theory for Reconstruction of Green's Functions at Passive Locations, J. Acoust. Soc. Am. 134 (2013) 3605–3612.
http://dx.doi.org/10.1121/1.4821210

C. Holler et al., Indirect Determination of the Mobility of Structure-borne Sound Sources, J. Sound Vib. 344 (2015) 38-58.
http://dx.doi.org/10.1016/j.jsv.2015.01.011

H.K. Lai, Integrated Reception-plate Inverse-force Test Method for Commercial Airplane Equipment Structure-borne Noise Specification and Qualification, in Proceedings of the Inter-Noise 2012, (2012).
http://dx.doi.org/10.1121/1.3588024

H.K. Lay et al, Experimental Round-robin Evaluation of Structure-borne Sound Source Force-power Test Methods, Noise Control Eng. 64 (2) (2015) 170-180.
http://dx.doi.org/10.3397/1/376369

R. Di Sante et al., Experimental and numerical investigation of the structure-borne noise transmitted from the gearbox to fuselage of a helicopter, in Proceedings of The 27th International Conference on Noise and Vibration Engineering, ISMA 2016 and International Conference on Uncertainty in Structural Dynamics, USD2016; ISMA 2016, 1867-1874 (2016).

A. Brandt, Noise and Vibration Analysis: Signal Analysis and Experimental Procedures, (Wiley & Sons, 2010).
http://dx.doi.org/10.1002/9780470978160


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