Download or read book Broadband fan noise prediction system for turbofan engines written by Bruce L. Morin and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Broadband Fan Noise Prediction System for Turbofan Engines written by National Aeronautics and Space Administration (NASA) and published by . This book was released on 2010-11-01 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pratt & Whitney has developed a Broadband Fan Noise Prediction System (BFaNS) for turbofan engines. This system computes the noise generated by turbulence impinging on the leading edges of the fan and fan exit guide vane, and noise generated by boundary-layer turbulence passing over the fan trailing edge. BFaNS has been validated on three fan rigs that were tested during the NASA Advanced Subsonic Technology Program (AST). The predicted noise spectra agreed well with measured data. The predicted effects of fan speed, vane count, and vane sweep also agreed well with measurements. The noise prediction system consists of two computer programs: Setup_BFaNS and BFaNS. Setup_BFaNS converts user-specified geometry and flow-field information into a BFaNS input file. From this input file, BFaNS computes the inlet and aft broadband sound power spectra generated by the fan and FEGV. The output file from BFaNS contains the inlet, aft and total sound power spectra from each noise source. This report is the first volume of a three-volume set documenting the Broadband Fan Noise Prediction System: Volume 1: Setup_BFaNS User's Manual and Developer's Guide Volume 2: BFaNS User's Manual and Developer's Guide Volume 3: Validation and Test Cases The present volume begins with an overview of the Broadband Fan Noise Prediction System, followed by step-by-step instructions for installing and running Setup_BFaNS. It concludes with technical documentation of the Setup_BFaNS computer program.

Download or read book Broadband Fan Noise Prediction System for Turbofan Engines written by National Aeronautics and Space Administration (NASA) and published by . This book was released on 2010-11-01 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pratt & Whitney has developed a Broadband Fan Noise Prediction System (BFaNS) for turbofan engines. This system computes the noise generated by turbulence impinging on the leading edges of the fan and fan exit guide vane, and noise generated by boundary-layer turbulence passing over the fan trailing edge. BFaNS has been validated on three fan rigs that were tested during the NASA Advanced Subsonic Technology Program (AST). The predicted noise spectra agreed well with measured data. The predicted effects of fan speed, vane count, and vane sweep also agreed well with measurements. The noise prediction system consists of two computer programs: Setup_BFaNS and BFaNS. Setup_BFaNS converts user-specified geometry and flow-field information into a BFaNS input file. From this input file, BFaNS computes the inlet and aft broadband sound power spectra generated by the fan and FEGV. The output file from BFaNS contains the inlet, aft and total sound power spectra from each noise source. This report is the first volume of a three-volume set documenting the Broadband Fan Noise Prediction System: Volume 1: Setup_BFaNS User's Manual and Developer's Guide Volume 2: BFaNS User's Manual and Developer's Guide Volume 3: Validation and Test Cases The present volume begins with an overview of the Broadband Fan Noise Prediction System, followed by step-by-step instructions for installing and running Setup_BFaNS. It concludes with technical documentation of the Setup_BFaNS computer program.

Download or read book Broadband Fan Noise Prediction System for Turbofan Engines written by National Aeronautics and Space Administration (NASA) and published by . This book was released on 2010-11-01 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pratt & Whitney has developed a Broadband Fan Noise Prediction System (BFaNS) for turbofan engines. This system computes the noise generated by turbulence impinging on the leading edges of the fan and fan exit guide vane, and noise generated by boundary-layer turbulence passing over the fan trailing edge. BFaNS has been validated on three fan rigs that were tested during the NASA Advanced Subsonic Technology Program (AST). The predicted noise spectra agreed well with measured data. The predicted effects of fan speed, vane count, and vane sweep also agreed well with measurements. The noise prediction system consists of two computer programs: Setup_BFaNS and BFaNS. Setup_BFaNS converts user-specified geometry and flow-field information into a BFaNS input file. From this input file, BFaNS computes the inlet and aft broadband sound power spectra generated by the fan and FEGV. The output file from BFaNS contains the inlet, aft and total sound power spectra from each noise source. This report is the first volume of a three-volume set documenting the Broadband Fan Noise Prediction System: Volume 1: Setup_BFaNS User's Manual and Developer's Guide Volume 2: BFaNS User's Manual and Developer's Guide Volume 3: Validation and Test Cases The present volume begins with an overview of the Broadband Fan Noise Prediction System, followed by step-by-step instructions for installing and running Setup_BFaNS. It concludes with technical documentation of the Setup_BFaNS computer program.

Download or read book UHB Engine Fan Broadband Noise Reduction Study written by and published by . This book was released on 1995 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Broadband Fan Noise Generated by Small Scale Turbulence written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-17 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the development of prediction methods for broadband fan noise from aircraft engines. First, experimental evidence of the most important source mechanisms is reviewed. It is found that there are a number of competing source mechanism involved and that there is no single dominant source to which noise control procedures can be applied. Theoretical models are then developed for: (1) ducted rotors and stator vanes interacting with duct wall boundary layers, (2) ducted rotor self noise, and (3) stator vanes operating in the wakes of rotors. All the turbulence parameters required for these models are based on measured quantities. Finally the theoretical models are used to predict measured fan noise levels with some success. Glegg, Stewart A. L. Langley Research Center FAN BLADES; NOISE (SOUND); TURBULENCE; WAKES; NOISE REDUCTION; NOISE INTENSITY; AERODYNAMIC NOISE; MATHEMATICAL MODELS; WALLS; VANES; ROTOR AERODYNAMICS; PREDICTION ANALYSIS TECHNIQUES; DUCTS; BOUNDARY LAYERS; AIRCRAFT ENGINES...

Download or read book Improved Nasa Anopp Noise Prediction Computer Code for Advanced Subsonic Propulsion Systems written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-18 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent experience using ANOPP to predict turbofan engine flyover noise suggests that it over-predicts overall EPNL by a significant amount. An improvement in this prediction method is desired for system optimization and assessment studies of advanced UHB engines. An assessment of the ANOPP fan inlet, fan exhaust, jet, combustor, and turbine noise prediction methods is made using static engine component noise data from the CF6-8OC2, E(3), and QCSEE turbofan engines. It is shown that the ANOPP prediction results are generally higher than the measured GE data, and that the inlet noise prediction method (Heidmann method) is the most significant source of this overprediction. Fan noise spectral comparisons show that improvements to the fan tone, broadband, and combination tone noise models are required to yield results that more closely simulate the GE data. Suggested changes that yield improved fan noise predictions but preserve the Heidmann model structure are identified and described. These changes are based on the sets of engine data mentioned, as well as some CFM56 engine data that was used to expand the combination tone noise database. It should be noted that the recommended changes are based on an analysis of engines that are limited to single stage fans with design tip relative Mach numbers greater than one. Kontos, K. B. and Janardan, B. A. and Gliebe, P. R. Glenn Research Center NOISE PREDICTION; TURBOFAN ENGINES; ENGINE NOISE; SUBSONIC FLOW; COMPUTER PROGRAMS; NOISE SPECTRA; AIRCRAFT NOISE; PREDICTION ANALYSIS TECHNIQUES; ENGINE INLETS; GAS JETS; BLADE TIPS; MACH NUMBER; COMBUSTION CHAMBERS...

Download or read book Noise Predictions of a High Bypass Turbofan Engine Using the Lockheed Near Field Noise Prediction Program written by and published by . This book was released on 1986 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Models for the Prediction of Rear arc and Forward arc Fan Broadband Noise in Turbofan Engines written by G. Jenkins and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Source Methodology for Turbofan Noise Prediction Source3d Technical Documentation written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-11 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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

Download or read book Modular Engine Noise Component Prediction System McP Technical Description and Assessment Document written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-03 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes an empirical prediction procedure for turbofan engine noise. The procedure generates predicted noise levels for several noise components, including inlet- and aft-radiated fan noise, and jet-mixing noise. This report discusses the noise source mechanisms, the development of the prediction procedures, and the assessment of the accuracy of these predictions. Finally, some recommendations for future work are presented.Herkes, William H. and Reed, David H.Langley Research CenterNOISE PREDICTION (AIRCRAFT); JET AIRCRAFT NOISE; AERODYNAMIC NOISE; ENGINE NOISE; JET MIXING FLOW; TURBOFAN ENGINES; ENGINE PARTS; ACCURACY; FAN BLADES; AEROACOUSTICS; NOISE INTENSITY

Download or read book Interim Prediction Method for Turbine Noise written by Eugene A. Krejsa and published by . This book was released on 1976 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Theory for Broadband Noise of Rotor and Stator Cascades with Inhomogeneous Inflow Turbulence Including Effects of Lean and Sweep written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-11 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: The problem of broadband noise generated by turbulence impinging on a downstream blade row is examined from a theoretical viewpoint. Equations are derived for sound power spectra in terms of 3 dimensional wavenumber spectra of the turbulence. Particular attention is given to issues of turbulence inhomogeneity associated with the near field of the rotor and variations through boundary layers. Lean and sweep of the rotor or stator cascade are also handled rigorously with a full derivation of the relevant geometry and definitions of lean and sweep angles. Use of the general theory is illustrated by 2 simple theoretical spectra for homogeneous turbulence. Limited comparisons are made with data from model fans designed by Pratt & Whitney, Allison, and Boeing. Parametric studies for stator noise are presented showing trends with Mach number, vane count, turbulence scale and intensity, lean, and sweep. Two conventions are presented to define lean and sweep. In the "cascade system" lean is a rotation out of its plane and sweep is a rotation of the airfoil in its plane. In the "duct system" lean is the leading edge angle viewing the fan from the front (along the fan axis) and sweep is the angle viewing the fan from the side (, perpendicular to the axis). It is shown that the governing parameter is sweep in the plane of the airfoil (which reduces the chordwise component of Mach number). Lean (out of the plane of the airfoil) has little effect. Rotor noise predictions are compared with duct turbulence/rotor interaction noise data from Boeing and variations, including blade tip sweep and turbulence axial and transverse scales are explored.Hanson, Donald B.Glenn Research CenterINTERACTIONAL AERODYNAMICS; ROTORS; STATORS; CASCADE FLOW; TURBOFAN ENGINES; HOMOGENEOUS TURBULENCE; NOISE PREDICTION; ENGINE NOISE; POWER SPECTRA; LEADING EDGES; DUCTS; BROADBAND; BLADE TIPS; AIRFOILS; BOUNDARY LAYERS; MACH NUMBER; SWEEP ANGLE

Download or read book The Jet Engine written by Rolls Royce and published by John Wiley & Sons. This book was released on 2015-07-20 with total page 291 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Jet Engine provides a complete, accessible description of the working and underlying principles of the gas turbine. Accessible, non-technical approach explaining the workings of jet engines, for readers of all levels Full colour diagrams, cutaways and photographs throughout Written by RR specialists in all the respective fields Hugely popular and well-reviewed book, originally published in 2005 under Rolls Royce’s own imprint

Download or read book Towards Computational Aeroacoustics Prediction of Realistic Turbofan Broadband Noise Using Synthetic Turbulence Modeling written by Adrian Sescu and published by . This book was released on 2011 with total page 271 pages. Available in PDF, EPUB and Kindle. Book excerpt: The prediction of broadband noise radiating from realistic turbulent flows interacting with complex geometries, using nonlinear time-domain algorithms, is still in infancy. The main obstacle is related to the computational efficiency--both in terms of processing time and storage capacity--but equally important is the accuracy of imposing realistic turbulence superposed on deterministic vortical gusts at the inflow boundary, or the initiation of the solution with a realistic turbulent flow. The main objective of this thesis is to derive a divergence-free synthetic turbulence model, and to impose turbulent wakes at the inflow boundary, for the prediction of broadband noise radiating from the interaction between rotor wakes and stator vanes in a realistic bypass turbofan engine. The tool is an advanced Computational Aeroacoustics code, NASA Broadband Aeroacoustic Stator Simulation (BASS) code, which employs state-of-the-art spatial and temporal schemes, and accurate boundary conditions. A number of synthetic turbulence models have been implemented in BASS code, including a new divergence free model based on the assumption that turbulence can be considered as a superposition of random eddies satisfying certain conditions. The divergence free condition is satisfied by using a streamfunction which is a scalar in two dimensions and a vector in three dimensions, and the momentum equations linearized about the mean flow. The synthetic turbulence model uses the statistics from the experimental turbulent data taken from NASA Source Diagnostic Test rig. The thesis also includes the derivation and analysis of the multidimensional finite difference schemes designed to improve the isotropy of waves propagating in multidimensions. The dispersion properties of the schemes in multidimensions are analyzed using Fourier analysis, and the isotropy error is found to be very low. The stability of the multidimensional schemes in combination with either linear multistep time marching methods and Runge-Kutta schemes are extensively analyzed. Various test cases in two or three dimensions show that the multidimensional schemes have low isotropy error, and perform more efficiently when compared to corresponding conventional schemes. The thesis begins with a thorough introduction on turbofan broadband noise prediction techniques, including a comprehensive literature review on turbofan noise and synthetic turbulence modeling. In chapter 2, an overview of Computational Aeroacoustics is included, with a description of actual fields of research, and available tools and techniques. Here, the derivation and analysis of multidimensional finite difference schemes in terms of isotropy error and stability are also included. In chapter 3, the nonlinear time-domain analysis tool, BASS code, is described, and the description and derivation of the new synthetic turbulence model are included. Chapter 4 is reserved to various results from different tests cases, and chapter 5 to comments, conclusions and remarks on future directions related to the research in this thesis.

Download or read book Modular Engine Noise Component Prediction System Technical Description and Assessment Document written by William H. Herkes and published by BiblioGov. This book was released on 2013-06 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes an empirical prediction procedure for turbofan engine noise. The procedure generates predicted noise levels for several noise components, including inlet- and aft-radiated fan noise, and jet-mixing noise. This report discusses the noise source mechanisms, the development of the prediction procedures, and the assessment of the accuracy of these predictions. Finally, some recommendations for future work are presented.

Download or read book Acoustic and Aerodynamic Performance of a 6 foot diameter Fan for Turbofan Engines written by Arthur W. Goldstein and published by . This book was released on 1970 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: Low noise turbofan engine without aerodynamic blade loading.