Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 74
Book Description
Noise Predictions of a High Bypass Turbofan Engine Using the Lockheed Near-Field Noise Prediction Program
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 960
Book Description
Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 960
Book Description
Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Scientific and Technical Information Output of the Langley Research Center for Calendar Year 1986
Author: Langley Research Center. Research Information and Applications Division
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 270
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 270
Book Description
NASA SP.
Near Field Noise Prediction for a Linear Array of Turbojet Engines
Author: D. L. Smith
Publisher:
ISBN:
Category :
Languages : en
Pages : 77
Book Description
A computer program is presented for calculating the sound pressure level (SPL) in the jet near field which accounts for ground reflection and multiple engine operation. The prediction method is a modification of the semi-empirical technique presented in AFFDL TR-67-43 'Near Field Noise Analysis of Aircraft Propulsion Systems with emphasis on Prediction Techniques for Jets'. The modifications in addition to accounting for ground reflection allow the prediction of the SPL for the overall and three octave bands at any point in the field and require data inputs of jet exit temperature, Mach number and diameter. A brief description is presented of a noise measurement program conducted on the XB-70 aircraft during which one-third octave band noise spectra were obtained for a range of engine conditions and for various combinations of linear arrays of engines.
Publisher:
ISBN:
Category :
Languages : en
Pages : 77
Book Description
A computer program is presented for calculating the sound pressure level (SPL) in the jet near field which accounts for ground reflection and multiple engine operation. The prediction method is a modification of the semi-empirical technique presented in AFFDL TR-67-43 'Near Field Noise Analysis of Aircraft Propulsion Systems with emphasis on Prediction Techniques for Jets'. The modifications in addition to accounting for ground reflection allow the prediction of the SPL for the overall and three octave bands at any point in the field and require data inputs of jet exit temperature, Mach number and diameter. A brief description is presented of a noise measurement program conducted on the XB-70 aircraft during which one-third octave band noise spectra were obtained for a range of engine conditions and for various combinations of linear arrays of engines.
NASA Technical Memorandum
Improved Nasa-Anopp Noise Prediction Computer Code for Advanced Subsonic Propulsion Systems. Volume 2; Fan Suppression Model Development
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722485368
Category :
Languages : en
Pages : 80
Book Description
The Aircraft Noise Predication Program (ANOPP) is an industry-wide tool used to predict turbofan engine flyover noise in system noise optimization studies. Its goal is to provide the best currently available methods for source noise prediction. As part of a program to improve the Heidmann fan noise model, models for fan inlet and fan exhaust noise suppression estimation that are based on simple engine and acoustic geometry inputs have been developed. The models can be used to predict sound power level suppression and sound pressure level suppression at a position specified relative to the engine inlet. Kontos, Karen B. and Kraft, Robert E. and Gliebe, Philip R. Glenn Research Center...
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722485368
Category :
Languages : en
Pages : 80
Book Description
The Aircraft Noise Predication Program (ANOPP) is an industry-wide tool used to predict turbofan engine flyover noise in system noise optimization studies. Its goal is to provide the best currently available methods for source noise prediction. As part of a program to improve the Heidmann fan noise model, models for fan inlet and fan exhaust noise suppression estimation that are based on simple engine and acoustic geometry inputs have been developed. The models can be used to predict sound power level suppression and sound pressure level suppression at a position specified relative to the engine inlet. Kontos, Karen B. and Kraft, Robert E. and Gliebe, Philip R. Glenn Research Center...
Government reports annual index
Aircraft Engine Noise and Sonic Boom
Author: North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Fluid Dynamics Panel
Publisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 604
Book Description
Publisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 604
Book Description
Source Methodology for Turbofan Noise Prediction (Source3d Technical Documentation)
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781720954941
Category :
Languages : en
Pages : 82
Book Description
This report provides the analytical documentation for the SOURCE3D Rotor Wake/Stator Interaction Code. It derives the equations for the rotor scattering coefficients and stator source vector and scattering coefficients that are needed for use in the TFANS (Theoretical Fan Noise Design/Prediction System). SOURCE3D treats the rotor and stator as isolated source elements. TFANS uses this information, along with scattering coefficients for inlet and exit elements, and provides complete noise solutions for turbofan engines. SOURCE3D is composed of a collection of FORTRAN programs that have been obtained by extending the approach of the earlier V072 Rotor Wake/Stator Interaction Code. Similar to V072, it treats the rotor and stator as a collection of blades and vanes having zero thickness and camber contained in an infinite, hardwall annular duct. SOURCE3D adds important features to the V072 capability-a rotor element, swirl flow and vorticity waves, actuator disks for flow turning, and combined rotor/actuator disk and stator/actuator disk elements. These items allow reflections from the rotor, frequency scattering, and mode trapping, thus providing more complete noise predictions than previously. The code has been thoroughly verified through comparison with D.B. Hanson's CUP2D two- dimensional code using a narrow annulus test case.Meyer, Harold D.Glenn Research CenterAPPLICATIONS PROGRAMS (COMPUTERS); NOISE PREDICTION; ROTORS; STATORS; TURBOFAN ENGINES; WAKES; ROTOR AERODYNAMICS; DOCUMENTATION; ACOUSTIC SIMULATION; VORTICITY; FORTRAN; UPWASH; SCATTERING COEFFICIENTS
Publisher: Createspace Independent Publishing Platform
ISBN: 9781720954941
Category :
Languages : en
Pages : 82
Book Description
This report provides the analytical documentation for the SOURCE3D Rotor Wake/Stator Interaction Code. It derives the equations for the rotor scattering coefficients and stator source vector and scattering coefficients that are needed for use in the TFANS (Theoretical Fan Noise Design/Prediction System). SOURCE3D treats the rotor and stator as isolated source elements. TFANS uses this information, along with scattering coefficients for inlet and exit elements, and provides complete noise solutions for turbofan engines. SOURCE3D is composed of a collection of FORTRAN programs that have been obtained by extending the approach of the earlier V072 Rotor Wake/Stator Interaction Code. Similar to V072, it treats the rotor and stator as a collection of blades and vanes having zero thickness and camber contained in an infinite, hardwall annular duct. SOURCE3D adds important features to the V072 capability-a rotor element, swirl flow and vorticity waves, actuator disks for flow turning, and combined rotor/actuator disk and stator/actuator disk elements. These items allow reflections from the rotor, frequency scattering, and mode trapping, thus providing more complete noise predictions than previously. The code has been thoroughly verified through comparison with D.B. Hanson's CUP2D two- dimensional code using a narrow annulus test case.Meyer, Harold D.Glenn Research CenterAPPLICATIONS PROGRAMS (COMPUTERS); NOISE PREDICTION; ROTORS; STATORS; TURBOFAN ENGINES; WAKES; ROTOR AERODYNAMICS; DOCUMENTATION; ACOUSTIC SIMULATION; VORTICITY; FORTRAN; UPWASH; SCATTERING COEFFICIENTS