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 Green Aviation written by Ramesh Agarwal and published by John Wiley & Sons. This book was released on 2016-10-17 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: Green Aviation is the first authoritative overview of both engineering and operational measures to mitigate the environmental impact of aviation. It addresses the current status of measures to reduce the environmental impact of air travel. The chapters cover such items as: Engineering and technology-related subjects (aerodynamics, engines, fuels, structures, etc.), Operations (air traffic management and infrastructure) Policy and regulatory aspects regarding atmospheric and noise pollution. With contributions from leading experts, this volume is intended to be a valuable addition, and useful resource, for aerospace manufacturers and suppliers, governmental and industrial aerospace research establishments, airline and aviation industries, university engineering and science departments, and industry analysts, consultants, and researchers.
Download or read book Air Transport and Operations written by R. Curran and published by IOS Press. This book was released on 2012 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the proceedings of the joint conference held in Delft, the Netherlands inJune 2012, incorporating the 3rd International Air Transport Operations Symposium ATOS, the 3rd Association of Scientific Development in Air Traffic Management in Europe ASDASeminar, the 6th International Meeting for Aviation Products Support Processes IMAPP and the 2012Complex World Seminar. The book includes the majority of academic papers presented at the conference, and provides a wide overview of the issues currently of importance in the world of air transport.pIOS Press is an international science, technical and medical publisher
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 NASA SP written by and published by . This book was released on 1988 with total page 520 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 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 International Aerospace Abstracts written by and published by . This book was released on 1979 with total page 1072 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 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 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 Aeronautical Engineering written by and published by . This book was released on 1988 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt: A selection of annotated references to unclassified reports and journal articles that were introduced into the NASA scientific and technical information system and announced in Scientific and technical aerospace reports (STAR) and International aerospace abstracts (IAA).
Download or read book Flight Effects on Exhaust Noise for Turbojet and Turbofan Engines Comparison of Experimental Data with Prediction written by and published by . This book was released on 1976 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Forward Acoustic Performance of a Model Turbofan Designed for a High Specific Flow QF 14 written by James G. Lucas and published by . This book was released on 1982 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Forward Acoustic Performance of a Model Turbofan Designed for a High Specific Flow QF 14 written by and published by . This book was released on 1982 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Forward Velocity Effects on Fan Noise and the Suppression Characteristics of Advanced Inlets as Measured in the NASA Ames 40 by 80 Foot Wind Tunnel written by and published by . This book was released on 1980 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
