Improved Nasa-Anopp Noise Prediction Computer Code for Advanced Subsonic Propulsion Systems. Volume 2; Fan Suppression Model Development
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

Published: 2018-07-08

Total Pages: 80

ISBN-13: 9781722485368

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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...

Improved Nasa-Anopp Noise Prediction Computer Code for Advanced Subsonic Propulsion Systems
Improved Nasa-Anopp Noise Prediction Computer Code for Advanced Subsonic Propulsion Systems

Author: National Aeronautics and Space Administration (NASA)

Publisher: Createspace Independent Publishing Platform

Published: 2018-07-18

Total Pages: 156

ISBN-13: 9781723178085

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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...

Green Aviation
Green Aviation

Author: Ramesh Agarwal

Publisher: John Wiley & Sons

Published: 2016-10-17

Total Pages: 528

ISBN-13: 1118866355

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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.

Combustion Noise
Combustion Noise

Author: Anna Schwarz

Publisher: Springer Science & Business Media

Published: 2009-06-17

Total Pages: 304

ISBN-13: 3642020380

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November, 2008 Anna Schwarz, Johannes Janicka In the last thirty years noise emission has developed into a topic of increasing importance to society and economy. In ?elds such as air, road and rail traf?c, the control of noise emissions and development of associated noise-reduction techno- gies is a central requirement for social acceptance and economical competitiveness. The noise emission of combustion systems is a major part of the task of noise - duction. The following aspects motivate research: • Modern combustion chambers in technical combustion systems with low pol- tion exhausts are 5 - 8 dB louder compared to their predecessors. In the ope- tional state the noise pressure levels achieved can even be 10-15 dB louder. • High capacity torches in the chemical industry are usually placed at ground level because of the reasons of noise emissions instead of being placed at a height suitable for safety and security. • For airplanes the combustion emissions become a more and more important topic. The combustion instability and noise issues are one major obstacle for the introduction of green technologies as lean fuel combustion and premixed burners in aero-engines. The direct and indirect contribution of combustion noise to the overall core noise is still under discussion. However, it is clear that the core noise besides the fan tone will become an important noise source in future aero-engine designs. To further reduce the jet noise, geared ultra high bypass ratio fans are driven by only a few highly loaded turbine stages.

Monster of the Week
Monster of the Week

Author:

Publisher:

Published: 2015-01-27

Total Pages:

ISBN-13: 9781613170922

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Most people don't believe in monsters, but you know the truth. They're real, and it's your task to bring them down. This revised edition of Monster of the Week brings that adventure to life.Monster of the Week is a standalone action-horror RPG for 3-5 people. Hunt high school beasties a la Buffy the Vampire Slayer, travel the country to bring down unnatural creatures like the Winchester brothers of Supernatural, or head up the government investigation like Mulder and Scully.This book contains everything you need to tackle Bigfoot, collar a chupacabra, and drive away demons. In this revised edition, you'll find:

Rotorcraft Aeromechanics
Rotorcraft Aeromechanics

Author: Wayne Johnson

Publisher: Cambridge University Press

Published: 2013-04-29

Total Pages: 949

ISBN-13: 1107355281

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A rotorcraft is a class of aircraft that uses large-diameter rotating wings to accomplish efficient vertical take-off and landing. The class encompasses helicopters of numerous configurations (single main rotor and tail rotor, tandem rotors, coaxial rotors), tilting proprotor aircraft, compound helicopters, and many other innovative configuration concepts. Aeromechanics covers much of what the rotorcraft engineer needs: performance, loads, vibration, stability, flight dynamics, and noise. These topics include many of the key performance attributes and the often-encountered problems in rotorcraft designs. This comprehensive book presents, in depth, what engineers need to know about modelling rotorcraft aeromechanics. The focus is on analysis, and calculated results are presented to illustrate analysis characteristics and rotor behaviour. The first third of the book is an introduction to rotorcraft aerodynamics, blade motion, and performance. The remainder of the book covers advanced topics in rotary wing aerodynamics and dynamics.

Principles of Ideal-fluid Aerodynamics
Principles of Ideal-fluid Aerodynamics

Author: Krishnamurty Karamcheti

Publisher: Krieger Publishing Company

Published: 1980

Total Pages: 664

ISBN-13:

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The prerequisite for the study of this book is a knowledge of matrices and the essentials of functions of a complex variable. It has been developed from courses given by the authors and probably contains more material than will ordinarily be covered in a one-year course. It is hoped that the book will be a useful text in the application of differential equations as well as for the pure mathematician.