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Saturday, July 11, 2020 | History

3 edition of Cruise noise of counterrotation propeller at angle of attack in wind tunnel found in the catalog.

Cruise noise of counterrotation propeller at angle of attack in wind tunnel

Cruise noise of counterrotation propeller at angle of attack in wind tunnel

  • 106 Want to read
  • 38 Currently reading

Published by National Aeronautics and Space Administration, For sale by the National Technical Information Service in [Washington, D.C.], [Springfield, Va .
Written in English

    Subjects:
  • Propellers.,
  • Noise -- Measurement.

  • Edition Notes

    StatementJames H. Dittmar.
    SeriesNASA technical memorandum -- 88869
    ContributionsUnited States. National Aeronautics and Space Administration.
    The Physical Object
    FormatMicroform
    Pagination1 v.
    ID Numbers
    Open LibraryOL17090594M

    Get this from a library! Noise of a simulated installed model counter rotation propeller at angle-of-attack and takeoff/approach conditions. [Richard P Woodward; United States. National Aeronautics and Space Administration.]. The effect of angle-of-attack or sideslip on noise radiation by a propeller is considered, (Fig. 3). For a single propeller, neglecting installation effects, the angles of attack .

    American Institute of Aeronautics and Astronautics Sunrise Valley Drive, Suite Reston, VA Experimental results from tests at both takeoff/approach and cruise conditions are reviewed with emphasis on: (1) single and counterrotation model tests in the NASA Lewis 9 by 15 (low speed) and 8 by 6 (high speed) wind tunnels, and (2) full scale flight tests of a 9 ft ( m) diameter single rotation wing mounted tractor and a ft (

      Mach 1 is the speed of sound, which varies with the air density. See the following I.C.A.O. chart (chart A) below. Mach 2 is twice the speed of sound, Mach 3 is three times the speed of sound. Use the Velocity Relationship Curve Graph chart below, Chart B, to find the appropriate CL from the given angle of attack. Far-field noise measurements have been taken at a single observer location and with a microphone array in the Virginia Tech Stability Wind Tunnel for a wall-mounted finite airfoil with aspect.


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Cruise noise of counterrotation propeller at angle of attack in wind tunnel Download PDF EPUB FB2

The noise of a counterrotation propeller at angle of attack was measured in the NASA Lewis 8- by 6-Foot Supersonic Wind Tunnel at cruise conditions. Noise increases of as much as 4 dB were measured at positive angles of attack on the tunnel side wall, which represented an airplane : J.

Dittmar. Get this from a library. Cruise noise of counterrotation propeller at angle of attack in wind tunnel. [James H Dittmar; United States. National Aeronautics and Space Administration.].

To evaluate how angle of attack affects the noise from a counterrotation advanced propeller at cruise, the F7-A7 counterrotation propeller model was tested in the Lewis 8- by 6-Foot Supersonic Wind Tunnel at 2" and 4" angles of.

Add to Book Bag Remove from Book Bag. Saved in: a Cruise noise of the SR-2 propeller model in a wind tunnel |h [electronic resource] / |c James H. Dittmar. |a a Dittmar, James H. |t Cruise noise of the SR-2 propeller model in a wind tunnel. A model high-speed advanced counterrotation propeller, F7/A7, was tested in the NASA Lewis Research Center's 9- by Foot Anecholc Wind Tunnel at simu- lated takeoff/approach conditions of Mach number.

were taken with fixed floor microphones, an axially translating microphone. The aeroacoustics of advanced, high speed propellers (propfans) are reviewed from the perspective of NASA research conducted in support of the Advanced Turboprop Program. Aerodynamic and acoustic components of prediction methods for near and far field noise are summarized for both single and counterrotation propellers in uninstalled and configurations.

The Effect of Front-to-Rear Propeller Spacing on the Interaction Noise at Cruise Conditions of a Model Counterrotation Propeller Having a Reduced Diameter Aft Propeller.

Technical report, NASA TM CD Figure h. - SR-7A propeller model in 9- by Foot Anechoic Wind Tunnel, SOUND PRESSURE LEVEL AT BLADE FUNDAMENTAL TONE, dB PROPELLER AXIS ANGLE OF ATTACK, deg O D 5 O 10 A 15 20 40 60 80 ft SIDELINE ANGLE. 9-ft (m) diameter SR-7L propeller to the scaled 8- by 6-ft tunnel data obtained on the 2-ft (m) diameter model of the SR Agree-ment is quite good for this flight condition where the angle-of-attack into the propeller was nearly zero corresponding to the zero angle-of-attack of the wind tunnel model.

Broadband noise prediction methods are also described and it is noted that further development and validation of the current models is required. The paper concludes with a discussion of the analytical methods which are used to assess the acoustic data collected during the high-speed wind-tunnel testing of a model scale advanced open rotor rig.

Takeoff/approach noise for a model counterrotation propeller with a forward-swept upstream rotor has been tested in the NASA Lewis 9- by Foot Anechoic Wind Tunnel. This paper presents.

Agree- ment is quite good for this flight condition where the angle-of-at tack into the propeller was nearly zero corresponding to the zero angle-of- attack of the wind tunnel model. Model data at low speed conditions represen- tative of takeof f /approach were obtained in the Lewis 9- by ft Anechoic Wind Tunnel shown in Fig.

Low-speed wind tunnel performance of high-speed counterrotation propellers at angle-of-attack. CHRISTOPHER HUGHES and Measurements and predictions of turboprop noise at high cruise speed.

METZGER; 8th Aeroacoustics Conference August An illustration of an open book. Books. An illustration of two cells of a film strip. Video. An illustration of an audio speaker.

Audio. An illustration of a " floppy disk. Software. An illustration of two photographs. Full text of "NASA advanced propeller research". A fixed pitch cruise prop will have a steeper pitch with the goal being to have the most efficient angle of attack reached near cruising speed.

If you have been able to follow along with this discussion then you may have realized that both the climb and cruise props will be flying at nearly the same angle of attack when they are most efficient. Low-speed wind tunnel performance of high-speed counterrotation propellers at angle-of-attack.

Comparative acoustic wind-tunnel measurements and theoretical correlations on subsonic aircraft propellers at full-scale and model-scale. 7th Aeroacoustics Conference August   Wind Tunnel Simulation of Propeller Effects in the AM FLA-4 Model.

Low-speed wind tunnel performance of high-speed counterrotation propellers at angle-of-attack. Summary of low-speed wind tunnel results of several high-speed counterrotation propeller configurations.

“Cruise Noise of the SR-2 Propeller Models of such propellers were tested for acoustics in the Lewis 8-byfoot wind tunnel. One of these propeller models, SR-3, was tested in flight on the. The results highlight the potential of humpy designs to reduce noise in cruise conditions with a small loss of efficiency.

[1] Low-speed wind tunnel performance of high-speed counterrotation propellers at angle-of-attack. Summary of low-speed wind tunnel results of several high-speed counterrotation propeller configurations. Angle of attack α 0 Angle of “Noise of Counter-rotation Propellers,” Journal of Aircraft, Vol.

22, No. 7,Initial wind tunnel experiments for a high speed propeller (M =. This banner text can have markup. web; books; video; audio; software; images; Toggle navigation.the airplane at cruise. The cruise noise of a number of single-rotation pro- peller models has previously been measured in the NASA Lewis 8- by 6-Foot Wind Tunnel (refs.

3 to 7). Noise measurements are presently being conducted on a counterrotation propeller for a pusher airplane (fig. 1). A generalized noise.A model high-speed advanced counterrotation propeller, F7/A3, was tested in the NASA Lewis Research Center's 9- by FOOt Anechoic Wind Tunnel at simu- lated takeoff/approach conditions of Mach number.

were taken with an axially translating microphone probe, and with a "polar".