Exterior noise on the fuselage of light propeller driven aircraft in flight

Šulc, J.; Hofr, J.; Benda, L.

doi:10.1016/0022-460x(82)90435-7

Cited by 12 publications

(12 citation statements)

References 8 publications

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“…Previous measurements on the same test airplane show the same trend, as indicated in Table 2. Measurements by Sulc et al 5 show overall levels lower than predicted by Ref. 8, but higher than predicted by Ref.…”

Section: Comparison With Predictionsmentioning

confidence: 63%

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Measurements of propeller noise in a light turboprop airplane

Wilby¹,

Wilby²

1989

Journal of Aircraft

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In-flight acoustic measurements have been made on the exterior and interior of a twin-engined turboprop airplane under controlled conditions to study data repeatability. It is found that the variability of the harmonic sound pressure levels in the cabin is greater than that for the exterior sound pressure levels, typical values for the standard deviation being +2.0 and -4.2 dB for the interior vs +1.4 and -2.3 dB for the exterior. When insertion losses are determined for acoustic treatments in the cabin, the standard deviations of the data are typically ±6.5 dB. It is concluded that factors such as accurate and repeatable selection of relative phase between propellers, controlled cabin air temperatures, installation of baseline acoustic absorption even for "untreated" configurations, and measurement of aircraft attitude should be considered in order to reduce uncertainty in the measured data.

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Section: Comparison With Predictionsmentioning

confidence: 63%

“…Measurements by Sulc et al 5 on a different high-wing, turboprop airplane also showed higher harmonic levels on the port side of the fuselage than on the starboard side. In that case, measurements were made at only one altitude (3000 m) and the difference varied from 3.8 to 0 dB as the propeller power increased.…”

Section: Measured Levelsmentioning

confidence: 82%

Measurements of propeller noise in a light turboprop airplane

Wilby¹,

Wilby²

1989

Journal of Aircraft

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“…An initial test was performed to check the results generated by the method against the experimental data of S[ ulc et al [36]. In this paper, results were presented for the noise generated by a three-bladed wing-mounted propeller in #ight.…”

Section: Resultsmentioning

confidence: 98%

“…In this paper, results were presented for the noise generated by a three-bladed wing-mounted propeller in #ight. A calculation was performed for the operating conditions of Figure 5(a) of reference [36] and the comparison is shown in Figure 1(a). Since the microphones used in the test were #ush-mounted in the aircraft fuselage, 6 dB has been added to the predictions to account for the pressure-doubling e!ect of the surface.…”

Section: Resultsmentioning

confidence: 99%

A Procedure for the Evaluation of Installed Propeller Noise

Marretta

Davi

Milazzo

et al. 2001

Journal of Sound and Vibration

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“…These conventional techniques are of limited use at low frequencies, however, particularly with the weight requirements in aircraft. From the classification of the main sources of interior noise ͑Bhat, 1999; Mixson et al, 1978;Pope et al, 1987a, b;Sulc et al, 1982͒ and the identification of the transmission paths of airborne noise and structure-borne noise ͑Mixson et al, 1978;Pope et al, 1987a, b;Unruh, 1988, the performance and limitations of the passive treatments are well-known ͑Barton and Mixson, 1981;Vaicatis, 1980͒. Passenger comfort is still influenced by noise at low frequencies, and several approaches have been investigated for controlling this low-frequency noise actively ͑Fuller et Gardonio and Elliott, 1999;Nelson and Elliott, 1992͒. This work started with active noise control ͑ANC͒ of the cabin, followed by active vibration control ͑AVC͒, and then active structural acoustic control ͑ASAC͒ of the fuselage and/or the trim panel.…”

Section: Introductionmentioning

confidence: 99%

Local feedback control of light honeycomb panels

Hong

Elliott

2007

The Journal of the Acoustical Society of America

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This paper summarizes theoretical and experimental work on the feedback control of sound radiation from honeycomb panels using piezoceramic actuators. It is motivated by the problem of sound transmission in aircraft, specifically the active control of trim panels. Trim panels are generally honeycomb structures designed to meet the design requirement of low weight and high stiffness. They are resiliently mounted to the fuselage for the passive reduction of noise transmission. Local coupling of the closely spaced sensor and actuator was observed experimentally and modeled using a single degree of freedom system. The effect of the local coupling was to roll off the response between the actuator and sensor at high frequencies, so that a feedback control system can have high gain margins. Unfortunately, only relatively poor global performance is then achieved because of localization of reduction around the actuator. This localization prompts the investigation of a multichannel active control system. Globalized reduction was predicted using a model of 12-channel direct velocity feedback control. The multichannel system, however, does not appear to yield a significant improvement in the performance because of decreased gain margin.

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Exterior noise on the fuselage of light propeller driven aircraft in flight

Cited by 12 publications

References 8 publications

Measurements of propeller noise in a light turboprop airplane

Measurements of propeller noise in a light turboprop airplane

A Procedure for the Evaluation of Installed Propeller Noise

Local feedback control of light honeycomb panels

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