YF-12 inlet suppression of compressor noise - First results

Bangert, L. H.; Burcham, Frank W.; Mackall, K. G.

doi:10.2514/6.1980-99

Cited by 6 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Woodward et al (1984) is the only known work to present the acoustic effects of open versus closed auxiliary inlet doors. Also, Bangert et al (1980) and Bangert et al (1981) report full scale inlet acoustic testing conducted on the YF-12 aircraft.…”

Section: Previous Researchmentioning

confidence: 99%

Fan Noise Reduction From a Supersonic Inlet During Simulated Aircraft Approach

Nuckolls

1993

Volume 3B: General

View full text Add to dashboard Cite

A series of experiments was conducted to investigate the radiation of fan noise from a supersonic inlet during a simulated aircraft approach. A scaled-down model of an axisymmetric, mixed-compression, supersonic inlet (P-inlet) was used in conjunction with a 10.4 cm (4.1 in) diameter turbofan engine simulator as the noise source. The tests were conducted at an outdoor facility under static conditions. The main goal of the experiment was to reduce the forward radiating fan noise by modifying the auxiliary inlet doors. The modified doors are designed to reduce the inlet distortion to the fan face. In addition, the new door design also uses a converging flow passage in order to take advantage of the noise attenuation due to the choking effect at the auxiliary door. The simulator was tested at 60% design speed in an attempt to match the simulator noise source to that of a real aircraft engine on approach. Both aerodynamic and acoustic measurements were taken in the experiments. The results show that when compared to the original design, the modified auxiliary inlet doors reduced the circumferential inlet distortion to the fan face by a factor of two. The key result is that the blade passing frequency tone has been decreased by an average of 6 dB in the forward sector for the modified door design. Results from the closed auxiliary inlet door case are also presented to provide additional comparisons.

show abstract

Section: Previous Researchmentioning

confidence: 99%

Fan Noise Reduction From a Supersonic Inlet During Simulated Aircraft Approach

Nuckolls

1993

Volume 3B: General

View full text Add to dashboard Cite

show abstract

“…Previous studies on supersonic inlets under static conditions by Bangert et al [1] and by Trefny and Wasserbauer [2] at low-speed forward flight have shown that the forward-propagated fan noise forms a significant portion of the takeoff and landing noise. Woodward et al [3] acoustically tested a supersonic P-type inlet in simulated low-speed flight at up to Mach 0.2 and concluded that the auxiliary doors significantly increased the fundamental tone of the fan noise.…”

Section: Introductionmentioning

confidence: 99%

Forward Flight Effects on Fan Noise from Supersonic 2-D Inlets

Venkatakrishnan

Krothapalli

2006

Journal of Aircraft

View full text Add to dashboard Cite

Engineering Notes ENGINEERING NOTES are short manuscripts describing new developments or important results of a preliminary nature. These Notes should not exceed 2500 words (where a figure or table counts as 200 words). Following informal review by the Editors, they may be published within a few months of the date of receipt. Style requirements are the same as for regular contributions (see inside back cover).

show abstract

“…Earlier investigators (see Ref. 1) have shown that the installation of a supersonic inlet may reduce the fan noise levels relative to those for a CTOL inlet. However, in Ref.…”

Section: Flight Effectmentioning

confidence: 99%