3 edition of Acoustic mode measurements in the inlet of a model turbofan using a continuously rotating rake found in the catalog.
Acoustic mode measurements in the inlet of a model turbofan using a continuously rotating rake
by National Aeronautics and Space Administration, For sale by the National Technical Information Service in [Washington, DC, Springfield, Va
Written in English
|Statement||David G. Hall and Laurence Heidelberg and Kevin Konno.|
|Series||NASA technical memorandum -- 105936.|
|Contributions||Heidelberg, Laurence J., Konno, Kevin E., United States. National Aeronautics and Space Administration.|
|The Physical Object|
Recently, research interests are increasing in mode detection methods based on compressed sensing, as it can reduce the number of sensors required by . acoustic enclosure with inner surface covered with sound absorbing material is used. The canopy absorbs noise and reduced the noise level to a permissible limit. This paper presents the formulation of a Field Data Based Multivariate (FDBM) regression model and an ANN model to estimate noise level outside canopy/acoustic enclosure.
The DLR department of engine acoustics performed acoustic measurements of a contra-rotating open-rotor (CROR) model with a linear microphone array in the T open wind-tunnel at TsAGI. The microphone data is corrected for shear-layer effects using the model of an infinitely thin shear layer by by: 6. This paper describes research involving an in-service failure of a variable pitch in motion fans blade bearing. Variable pitch in motion fans rotate at a constant speed, with the changing blade angle varying the load. A pitch-change mechanism facilitates the change in blade angle. A blade bearing supports each blade enabling it to rotate. The author Author: A. G. Sheard.
As a means to investigate the interactions of swirl distortion with turbofan engines, an experiment was designed to measure distorted flow profiles in an operating turbofan research engine. Three-dimensional flow properties were measured at discrete planes immediately upstream and immediately downstream of the fan rotor, isolating the component. To accomplish this, the outer source ring (r/R) was driven and the full mode measurement procedure was undertaken at several axial positions of the rake. The amplitude and phase of each radial order mode was plotted (Figure 12 and Figure 13) and a regression analysis was used to determine the wave number for each mode.
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Acoustic Mode Measurements in the Inlet of a Model Turbofan Using a Continuously Rotating Rake: Data Collection/ Analysis Techniques David G. Hall Sverdrup Technology, Inc. Brook Park, Ohio and Laurence Heidelberg and Kevin Konno Lewis Research Center Cleveland, Ohio Prepared for the 31st Aerospace Sciences MeetingFile Size: 7MB.
Acoustic mode measurements in the inlet of a model turbofan using a continuously rotating rake - Data collection/analysis techniques. DAVID HALL, LAURENCE HEIDELBERG and.
Turbofan Duct Mode Measurements Using a Continuously Rotating Microphone Rake 30 November | International Journal of Aeroacoustics, Vol.
6, No. 2 Optimisation of Sensor Arrays for Radial Mode Analysis in Flow DuctsCited by: Comprehensive measurements of the spinning acoustic mode structure in the inlet of the Advanced Ducted Propeller (ADP) have been completed.
These measurements were taken using a unique and previously untried method which was first proposed by T.G. Sofrin. A continuously rotating microphone system was : David G.
Hall and Laurence J. Heidelberg. Comprehensive measurements of the spinning acoustic mode structure in the inlet of the Advanced Ducted Propeller (ADP) have been completed. These measurements were taken using a unique and previously untried method which was first proposed by T.G. Sofrin.
A continuously rotating microphone system was employed. This Rotating Rake provides a complete map of the acoustic duct modes at fan harmonics in a ducted fan.
It has been used on a variety of test articles: from a low-speed, concept test fan rig, to a full-scale production turbofan engine. amplitude for m = 2 to the $’ sensor ring modal amplitude for m = 2.
turning off all of the rotor sources and running the model with only one actuator ring on at a time. The actuator sources of that ring are phased so as to excite the m = 2 mode. matrix which is used Author: Laralee G. Ireland, Scott D. Sommerfeldt. “Inlet Acoustic Mode Measurements Using a Continuously Rotating Rake.” JOURNAL OF AIRCR no.
4 (): MINNER, GL, GOLDMAN, RG, and HEIDELBERG, LJ. “Noise Suppression By an Acoustically Treated 3-Ring Inlet on a Tf Engine.” JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 58 (): S7-S7. of minimum gap between impeller and volute).
These pulsations do generate acoustic pressure waves that propagate through the pump towards both inlet and outlet. In order to study those two components, a simple acoustic model was considered for the volute, in which the interaction between the rotating jet-wake pattern behind the blades and the File Size: KB.
Heidelberg L J and Hall D G Inlet acoustic mode measurements using a continuously Rademaker E R, Sijtsma P and Tester B J Mode detection with an optimised array in a model turbofan engine intake at Sutliff D Turbofan duct mode measurements using a continuously rotating microphone rake Int.
Aeroacoust. 6 –Cited by: 8. Acoustic mode measurements in the inlet of a model turbofan using a continuously rotating rake. 30 p. (OCoLC) Material Type: Document, Government publication, National government publication, Internet resource: Document Type: Internet Resource, Computer File: All Authors / Contributors: Laurence J Heidelberg; David G Hall; United States.
The conical chamber muffler is characterised using the uniform piston-driven model in terms of the impedance [Z] matrix parameters (equivalently, the acoustic pressure response function) obtained by computing the average of the 3-D Green’s function over the surface area of the inlet/outlet ports modelled as rigid : Akhilesh Mimani.
The disadvantage is that the response of the mode detection algorithm to a single mode is distributed over all detectable modes, similarly to the Point Spread Function of Conventional Beamforming with microphone arrays. With multiple modes the response patterns interfere, leading to a relatively high “noise floor” Cited by: 4.
The system is a continuously rotating radial microphone rake that is inserted into the duct. This Rotating Rake provides a complete map of the acoustic duct modes present in a ducted fan and has been used on a variety of test articles: from a low-speed, concept test rig, to a full-scale production turbofan Size: 3MB.
Acoustic mode measurements in the inlet of a model turbofan using a continuously rotating rake - Data collection/analysis techniques. Rotating rake design for unique measurement of fan-generated spinning acoustic modes. [Washington, DC]: [Springfield, Va: National Aeronautics and Space Administration ; National Technical Information Service, distributor.
MLA Citation. Konno, Kevin E. and Hausmann, Clifford R. and United States. National Aeronautics and Space Administration. The system is a continuously rotating radial microphone rake that is inserted into the duct. This Rotating Rake provides a complete map of the acoustic duct modes present in a ducted fan and has been used on a variety of test articles: from a low-speed, concept test rig, to a full-scale production turbofan by: Acoustic Mode Measurements in the Inlet of a Turbofan Engine,” Rotating Rake Turbofan Duct Mode Measurement System/NASA,” Forschungsbericht, Paper No.
TM A 3D Compressible Flow Model for Weak Rotating Waves in Vaneless Diffusers—Part II: Detailed Results. Turbomach (July, Cited by: 3. Request this item to view in the Library's reading rooms using your library card.
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measure the wake characteristics and a microphone rake provides the acoustic spectra in the outlet duct. Table 1. Design parameters of the fan stage Volume flow rate at the inlet V in [m3/s] Rotor speed, N [rpm] Rotor diameter D A [m] Nr.
of rotor blades, B 18 Hub diameter D I [m] Nr. of stator vanes, V. An analytic radiation model can also be integrated with the mode-matching procedure in order to obtain far-ﬁeld directivity for tones and broadband multi-mode noise.
Validation results of the method using analytical results are presented. An application of particular interest to the acoustic design of turbofan.
A first-principles-based model of the generation of shock waves from a transonic rotor in nonuniform flow showed that the effects of nonuniform flow on acoustic wave propagation, which cannot be captured by the simplified model, are more dominant than those of inlet flow distortion on source noise.
Rotating Rake Turbofan Duct Mode Cited by: 4.AAIA A MODE DETECTION METHOD USING THE AZIMUTHAL DIRECTIVITY OF A TURBOFAN MODEL R. H. Thomas AIAA Senior Member, Research Associate Professor Mechanical Engineering Department, Virginia Tech Virginia Consortium (VCES), Butler Farm Road, SuiteHampton, Virginia F.
Farassat AIAA Associate Fellow, Sr. Research .