Acoustic Performance Of An Advanced Model Turbofan In Three Aeroacoustic Test Facilities

Author : National Aeronaut Administration (Nasa)
Publisher :
ISBN 13 :
Total Pages : 64 pages
Book Rating : 4.23/5 ( download)

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Download or read book Acoustic Performance of an Advanced Model Turbofan in Three Aeroacoustic Test Facilities written by National Aeronaut Administration (Nasa) and published by . This book was released on 2020-08-11 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: A model advanced turbofan was acoustically tested in the NASA Glenn 9- by 15-Foot-Low-Speed Wind Tunnel (LSWT), and in two other aeroacoustic facilities. The Universal Propulsion Simulator (UPS) fan was designed and manufactured by the General Electric Aircraft Engines (GEAE) Company, and featured active core, as well as bypass, flow paths. The reference test configurations were with the metal, M4, rotor with hardwall and treated bypass flow ducts. The UPS fan was tested within an airflow at a Mach number of 0.20 (limited flow data were also acquired at a Mach number of 0.25) which is representative of aircraft takeoff and approach conditions. Comparisons were made between data acquired within the airflow (9x15 LSWT and German-Dutch Wind Tunnel (DNW)) and outside of a free jet (Boeing Low Speed Aero acoustic Facility (LSAF) and DNW). Sideline data were acquired on an 89-in. (nominal 4 fan diameters) sideline using the same microphone assembly and holder in the 9x15 LSWT and DNW facilities. These data showed good agreement for similar UPS operating conditions and configurations. Distortion of fan spectra tonal content through a free jet shear layer was documented, suggesting that in-flow acoustic measurements are required for comprehensive fan noise diagnostics. However, there was good agreement for overall sound power level (PWL) fan noise measurements made both within and outside of the test facility airflow. Woodward, Richard P. and Hughes, Christopher E. Glenn Research Center NASA/TM-2012-217608, E-18189 ACOUSTIC MEASUREMENT; AEROACOUSTICS; LOW SPEED WIND TUNNELS; TEST FACILITIES; TURBOFANS; WIND TUNNEL TESTS; AIRCRAFT MODELS; SIMULATORS; NOISE REDUCTION; SHEAR LAYERS; FREE JETS; FAN BLADES; AIR FLOW

Author : Richard P. Woodward
Publisher :
ISBN 13 :
Total Pages : 57 pages
Book Rating : 4.34/5 ( download)

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Download or read book Acoustic performance of an advanced model turbofan in three aeroacoustic test facilities written by Richard P. Woodward and published by . This book was released on 2012 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Author : National Aeronautics and Space Administration (NASA)
Publisher : Createspace Independent Publishing Platform
ISBN 13 : 9781726187763
Total Pages : 38 pages
Book Rating : 4.64/5 ( download)

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Download or read book Aerodynamic Performance of Scale-Model Turbofan Outlet Guide Vanes Designed for Low Noise written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-27 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: The design of effective new technologies to reduce aircraft propulsion noise is dependent on an understanding of the noise sources and noise generation mechanisms in the modern turbofan engine. In order to more fully understand the physics of noise in a turbofan engine, a comprehensive aeroacoustic wind tunnel test programs was conducted called the 'Source Diagnostic Test.' The text was cooperative effort between NASA and General Electric Aircraft Engines, as part of the NASA Advanced Subsonic Technology Noise Reduction Program. A 1/5-scale model simulator representing the bypass stage of a current technology high bypass ratio turbofan engine was used in the test. The test article consisted of the bypass fan and outlet guide vanes in a flight-type nacelle. The fan used was a medium pressure ratio design with 22 individual, wide chord blades. Three outlet guide vane design configurations were investigated, representing a 54-vane radial Baseline configuration, a 26-vane radial, wide chord Low Count configuration and a 26-vane, wide chord Low Noise configuration with 30 deg of aft sweep. The test was conducted in the NASA Glenn Research Center 9 by 15-Foot Low Speed Wind Tunnel at velocities simulating the takeoff and approach phases of the aircraft flight envelope. The Source Diagnostic Test had several acoustic and aerodynamic technical objectives: (1) establish the performance of a scale model fan selected to represent the current technology turbofan product; (2) assess the performance of the fan stage with each of the three distinct outlet guide vane designs; (3) determine the effect of the outlet guide vane configuration on the fan baseline performance; and (4) conduct detailed flowfield diagnostic surveys, both acoustic and aerodynamic, to characterize and understand the noise generation mechanisms in a turbofan engine. This paper addresses the fan and stage aerodynamic performance results from the Source Diagnostic Test.Hughes, Christopher E.Glenn Research Cente...

Author : National Aeronautics and Space Administration (NASA)
Publisher : Createspace Independent Publishing Platform
ISBN 13 : 9781726184670
Total Pages : 34 pages
Book Rating : 4.76/5 ( download)

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Download or read book Aeroacoustic Analysis of Fan Noise Reduction with Increased Bypass Nozzle Area written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-27 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: An advanced model turbofan was tested in the NASA Glenn 9-by 15-Foot Low Speed Wind Tunnel (9x15 LSWT) to explore far field acoustic effects of increased bypass nozzle area. This fan stage test was part of the NASA Glenn Fan Broadband Source Diagnostic Test, second entry (SDT2) which acquired aeroacoustic results over a range of test conditions. The baseline nozzle was sized to produce maximum stage performance at cruise condition. However, the wind tunnel testing is conducted near sea level condition. Therefore, in order to simulate and obtain performance at other operating conditions, two additional nozzles were designed and tested one with +5 percent increase in weight flow (+5.4 percent increase in nozzle area compared with the baseline nozzle), sized to simulate the performance at the stage design point (takeoff) condition, and the other with a +7.5 percent increase in weight flow (+10.9 percent increase in nozzle area) sized for maximum weight flow with a fixed nozzle at sea level condition. Measured acoustic benefits with increased nozzle area were very encouraging, showing overall sound power level (OAPWL) reductions of 2 or more dB while the stage thrust actually increased by 2 to 3 percent except for the most open nozzle at takeoff rotor speed where stage performance decreased. Effective perceived noise levels for a 1500 ft engine flyover and 3.35 scale factor showed a similar noise reduction of 2 or more EPNdB. Noise reductions, principally in the level of broadband noise, were observed everywhere in the far field. Laser Doppler Velocimetry measurements taken downstream of the rotor showed that the total turbulent velocity decreased with increasing nozzle flow, which may explain the reduced rotor broadband noise levels.Woodward, Richard P. and Hughes, Christopher E. and Podboy, Gary G.Glenn Research CenterAEROACOUSTICS; FAN BLADES; LOW SPEED WIND TUNNELS; NOZZLE FLOW; WIND TUNNEL TESTS; NOISE REDUCTION; AIRCRAFT ENGINES; BYPASSES; NOZZLE DESIGN; EFFECTIVE...

Author :
Publisher :
ISBN 13 :
Total Pages : 492 pages
Book Rating : 4.5X/5 ( download)

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Download or read book NASA Technical Memorandum written by and published by . This book was released on 1994 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Author : T. J. Mueller
Publisher : Springer Science & Business Media
ISBN 13 : 9783540417576
Total Pages : 344 pages
Book Rating : 4.75/5 ( download)

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Download or read book Aeroacoustic Measurements written by T. J. Mueller and published by Springer Science & Business Media. This book was released on 2002-08-07 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book describes recent developments in aeroacoustic measurements in wind tunnels and the interpretation of the resulting data. The reader will find the latest measurement techniques described along with examples of the results.

Author :
Publisher :
ISBN 13 :
Total Pages : 978 pages
Book Rating : 4.98/5 ( download)

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Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1975 with total page 978 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Author : Richard P. Woodward
Publisher :
ISBN 13 :
Total Pages : 161 pages
Book Rating : 4.70/5 ( download)

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Download or read book In-flight Near- and Far-field Acoustic Data Measured on the Propfan Test Assessment (PTA) Testbed and with an Adjacent Aircraft written by Richard P. Woodward and published by . This book was released on 1993 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Author : Lewis Research Center
Publisher :
ISBN 13 :
Total Pages : 356 pages
Book Rating : 4.87/5 ( download)

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Download or read book Bibliography of Lewis Research Center Technical Publications Announced in 1977 written by Lewis Research Center and published by . This book was released on 1978 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: This compilation of abstracts describes and indexes over 780 technical reports resulting from the scientific and engineering work performed and managed by the Lewis Research Center in 1977. All the publications were announced in the 1977 issues of STAR (Scientific and Technical Aerospace Reports) and/or IAA (International Aerospace Abstracts). Documents cited include research reports, journal articles, conference presentations, patents and patent applications, and theses.

Author : National Aeronautics and Space Administration (NASA)
Publisher : Createspace Independent Publishing Platform
ISBN 13 : 9781719500500
Total Pages : 80 pages
Book Rating : 4.09/5 ( download)

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Download or read book Acoustic Performance of the Geae Ups Research Fan in the NASA Glenn 9- By 15-Foot Low-Speed Wind Tunnel written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-05-22 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: A model advanced turbofan was acoustically tested in the NASA Glenn 9- by 15-Foot Low-Speed Wind Tunnel in 1994. The Universal Propulsion Simulator fan was designed and manufactured by General Electric Aircraft Engines, and included an active core, as well as bypass, flow paths. The fan was tested with several rotors featuring unswept, forward-swept and aft-swept designs of both metal and composite construction. Sideline acoustic data were taken with both hard and acoustically treated walls in the flow passages. The fan was tested within an airflow at a Mach number of 0.20, which is representative of aircraft takeoff/approach conditions. All rotors showed similar aerodynamic performance. However, the composite rotors typically showed higher noise levels than did corresponding metal rotors. Aft and forward rotor sweep showed at most modest reductions of transonic multiple pure tone levels. However, rotor sweep often introduced increased rotor-stator interaction tone levels. Broadband noise was typically higher for the composite rotors and also for the aft-swept metal rotor. Transonic MPT generation was reduced with increasing fan axis angle of attack (AOA); however, higher downstream noise levels did increase with AOA resulting in higher overall Effective Perceived Noise Level. Woodward, Richard P. and Hughes, Christopher E. Glenn Research Center ACOUSTIC PROPERTIES; NOISE INTENSITY; AERODYNAMIC CHARACTERISTICS; MACH NUMBER; ANGLE OF ATTACK; AIR FLOW; WIND TUNNEL MODELS; WIND TUNNEL TESTS