Download or read book Jet Noise Modeling for Supersonic Business Jet Application written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-15 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: This document describes the development of an improved predictive model for coannular jet noise, including noise suppression modifications applicable to small supersonic-cruise aircraft such as the Supersonic Business Jet (SBJ), for NASA Langley Research Center (LaRC). For such aircraft a wide range of propulsion and integration options are under consideration. Thus there is a need for very versatile design tools, including a noise prediction model. The approach used is similar to that used with great success by the Modern Technologies Corporation (MTC) in developing a noise prediction model for two-dimensional mixer ejector (2DME) nozzles under the High Speed Research Program and in developing a more recent model for coannular nozzles over a wide range of conditions. If highly suppressed configurations are ultimately required, the 2DME model is expected to provide reasonable prediction for these smaller scales, although this has not been demonstrated. It is considered likely that more modest suppression approaches, such as dual stream nozzles featuring chevron or chute suppressors, perhaps in conjunction with inverted velocity profiles (IVP), will be sufficient for the SBJ. Stone, James R. and Krejsa, Eugene A. and Clark, Bruce J. Glenn Research Center NAS3-00178; WBS-22-781-30-12

Download or read book Jet Noise Modeling for Supersonic Business Jet Application written by James R. Stone and published by BiblioGov. This book was released on 2013-07 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: This document describes the development of an improved predictive model for coannular jet noise, including noise suppression modifications applicable to small supersonic-cruise aircraft such as the Supersonic Business Jet (SBJ), for NASA Langley Research Center (LaRC). For such aircraft a wide range of propulsion and integration options are under consideration. Thus there is a need for very versatile design tools, including a noise prediction model. The approach used is similar to that used with great success by the Modern Technologies Corporation (MTC) in developing a noise prediction model for two-dimensional mixer ejector (2DME) nozzles under the High Speed Research Program and in developing a more recent model for coannular nozzles over a wide range of conditions. If highly suppressed configurations are ultimately required, the 2DME model is expected to provide reasonable prediction for these smaller scales, although this has not been demonstrated. It is considered likely that more modest suppression approaches, such as dual stream nozzles featuring chevron or chute suppressors, perhaps in conjunction with inverted velocity profiles (IVP), will be sufficient for the SBJ.

Download or read book Large scale Simulation of Supersonic Jet Noise written by S. H. Shih and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Generation and Radiation of Supersonic Jet Noise written by Lockheed-Georgia Company and published by . This book was released on 1972 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Subsonic versus Supersonic Business Jets Full Concept Comparison considering Technical Environmental and Economic Aspects written by Michael Hans-Reichel and published by diplom.de. This book was released on 2012-01-19 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: Inhaltsangabe:Introduction: On the 26th of August 2010 the new ultra-large-cabin ultra-long-range Gulfstream G650 business jet reached Mach 0.995 during its flight test campaign (1). This is almost the speed of sound (Mach 1) and inspires one to say, why not fly faster than the speed of sound! Reduce travelling time in the commercial business aviation segment. This is, however not a completely new vision. Many companies and research facilities have already spent a lot of time and investment in studies to investigate the feasibility of supersonic flight. Entry Into Service (EIS) for the new Gulfstream G650 is scheduled for 2012. In the following the main performance parameter of the G650 aircraft will be summarised. The parameters range, cruise speed, MTOW, etc. have been selected and serve as a basis to allow an appropriate comparison between the G650 as the latest high end Subsonic Business Jet and potential in future Supersonic Business Jets (SSBJ) within this subject Master Thesis. With the impressive maximum range of nearly 13,000 km the G650 can connect Dubai with New York or London with Buenos Aires within almost 14 hours. Maximum Range @ Normal Cruise Speed: 7,000 nm/12,964 km. Normal Cruise Speed Mach: 0.85/904 km/h. Mmo (Maximum Operating Mach Number): Mach 0.925. Maximum Cruise Altitude: 51,000 ft/15,545 m. Maximum Takeoff Weight (MTOW): 99,600 lb/45,178 kg. Maximum Fuel Weight: 44,200 lb/20,049 kg. Passengers: 11 18. Price: appr. 60-70 million USD. Gulfstream business rival Bombardier Aerospace also announced in October 2010 two new high end models, the Global 7000 and 8000 with a maximum range of 7,300 nm (13,520 km) and 7,900 nm (14,631 km) at cruise speed Mach 0.85. Entry Into Service is scheduled for 2016 (Global 7000) and 2017 (Global 8000). A comprehensive overview of business jets in service and in development is given in attachment 13.1. A Supersonic Business Jet flying at Mach 2 cruise speed could virtually halve the travelling time, which would enormously enhance the mobility and flexibility. In order to achieve this ambition a paradigm shift is required. New technologies must be established, the impact on the environment must be understood and minimised, existing regulations must be changed to permit overland flight restrictions and the product still needs to be economically viable. All of the above aspects must be considered and will be subject for discussion within this Master Thesis (See also figure [...]

Download or read book A Fluid acoustic Coupled Simulation of Supersonic Jet Noise written by K. Viswanathan and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Supersonic Jet Exhaust Noise written by M. J. Benzakein and published by . This book was released on 1972 with total page 952 pages. Available in PDF, EPUB and Kindle. Book excerpt: The report summarizes the results obtained at General Electric during the first phase of the Air Force Supersonic Exhaust Noise - Velocity Model Program. The overall objective of the program is to develop the technology to significantly reduce supersonic aircraft propulsion system noise with minimum associated performance and weight penalties. To fulfill that objective, research is being carried out to develop the experimental techniques and the necessary theory to reveal the basic mechanisms of jet generated noise through the range of velocities and temperatures typical of present and future military and commercial supersonic aircraft propulsion systems. A comprehensive aerodynamic analytical model describing the flow mechanisms in supersonic jets is presented and compared with experimental data. A large number of theoretical models describing supersonic far field jet noise are evaluated. (Author).

Download or read book Simulation of Supersonic Jet Noise Reduction Using Fluid Inserts for Low Bypass Ratio Turbofans written by Chitrarth Prasad and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The design constraints on jet engines for high performance supersonic military aircraft require lower bypass ratios and supersonic exhaust velocities, which result in very high noise levels. This is a great concern to the US Navy as the noise generated from the jet exhaust of high performance supersonic military aircraft can affect the hearing and performance of personnel working in close proximity of the aircraft. There have been reports about the US Department of Veteran Affairs spending over hundreds of millions of dollars in disability payments for hearing loss compensation to former Navy personnel. In addition to this, jet noise is also a source of annoyance in communities in the vicinity of airbases and military training routes.Over the years, several noise reduction methods have been proposed with varying levels of success. The most effective noise reduction strategies include the installation of chevrons, and the use of corrugated seals, among many others. One primary disadvantage of these technologies is that they are passive technologies and cannot be switched off or modified after take-off and hence may reduce overall aircraft performance. An active, though steady, noise reduction technology is the use of fluid inserts in the divergent section of a converging-diverging nozzle. The fluid inserts consist of rows of injectors that inject a small amount of bypass air into the diverging section of the nozzle. It has been shown that by altering the configuration and operating conditions of the fluid inserts, noise reduction for both mixing and shock noise can be achieved. Since this blowing can be controlled, the fluid inserts can be switched off or modified after take-off to minimize any performance penalty to the aircraft.Although considerable experimental research has been performed to explore the effects of fluid inserts on the jet exhaust, the available data have been found to be insufficient to correlate the noise reduction with changes in the flow-field due to the noise reduction device. The present study is an extension to the previousresearch on fluid inserts that uses Large Eddy Simulation (LES) with the Ffowcs Williams-Hawkings (FWH) analogy for farfield noise prediction. The simulations are carried out using a commercially available CFD package, STAR-CCM+. The project aims to simulate and analyze the unsteady flow changes associated withthe noise reduction device to help understand the detailed mechanisms for the observed noise reductions.Different fluid insert configurations are used to analyze the effect of individual injector placement in a fluid insert on noise generation. It is observed that the changes in upstream noise correlate extremely well with the shock structure of the fluid insert jets downstream of the nozzle exit. Further insight into the noisereduction patterns is obtained by using two-point space time correlations and the use of the modal techniques such as Proper Orthogonal Decomposition on the near-field data on the FWH surface, which show that fluid inserts reduce the amplitude of the noise radiating coherent structures. Using Doaks Momentum Potential Theory, it is observed that the changes associated with fluid insertson the hydrodynamic and acoustic modes correlate well with the far-field noise reduction.

Download or read book The Generation and Radiation of Supersonic Jet Noise Future studies for definition of supersonic jet noise generation and reduction mechanisms written by and published by . This book was released on 1972 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Generation and Radiation of Supersonic Jet Noise Summary of supersonic jet noise studies written by and published by . This book was released on 1972 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Generation and Radiation of Supersonic Jet Noise Volume 1 Summary of Supersonic Jet Noise Studies written by and published by . This book was released on 1972 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a summary report of the results of a 13-month research program on the generation and reduction of supersonic jet noise. This program was planned as the first phase of a four-phase effort. Tasks compromising this Phase 1 program were as follows: reviews and evaluation of existing theoretical models for supersonic jet noise generation and radiation; development of the framework of a new, unified theory of aerodynamic noise; development of a new theoretical model of turbulent mixing region noise; development of a new theoretical model for calculating propagation and radiation of upstream noise; a preliminary review of combustion noise; tests on turbulent mixing region noise and shock-associated noise; review of the problems of jet flow measurement and analysis; development of new instrumentation for jet flow measurement; establishment of full facilities for the total program; formulation of the program for future studies.

Download or read book Aviation Noise Impact Management written by Laurent Leylekian and published by Springer. This book was released on 2022-03-15 with total page 321 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book provides a view into the state-of-the-art research on aviation noise and related annoyance. The book will primarily focus on the achievements of the ANIMA project (Aviation Noise Impact Management through Novel Approaches), but not exclusively. The content has a broader theme in order to encompass. regulation issues, the ICAO (International Civil Aviation Organization) balanced approach, progresses made on technologies and reduction of noise at source, impact of possible future civil supersonic aircraft, land-use planning issues, as well as the core topics of the ANIMA project, i.e. impact on human beings, annoyance, quality of life, health and findings of the project in this respect. This book differs from traditional research programmes on aviation noise as the authors endeavour, not to lower noise at source, but to reduce the annoyance. This book examines these non-acoustic factors in an effort to help those most affected by aviation noise – communities living close to airports, and also help airport managers, policy-makers, local authorities and researchers to deal with this issue holistically. The book concludes with some recommendations for EU, national and local policy-makers, airport and aviation authorities, and more broadly a scientifically literate audience. These recommendations may help to identify gaps for progress in terms of research but also genuine implementation actions for political and regulatory authorities.

Download or read book Acoustic Control of Turbulent Jets written by A.S. Ginevsky and published by Springer Science & Business Media. This book was released on 2004-01-22 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph presents recent results of experimental research relating to control of aerodynamic and acoustic characteristics of subsonic and supersonic turbulent jets by acoustic excitation of different intensity and frequency. Coherent structures in subsonic turbulent jets and their sensibility to harmonic acoustic excitation are studied, as well as the generation and suppression of turbulence in subsonic jets under acoustic excitation. The book covers active and passive methods of controlling supersonic non-isobaric jet characteristics and, in particular, suppression of discrete components of aerodynamic jet noise. Numerical simulation methods of subsonic turbulent jets are analyzed. Examples of practical realization of the presented methods are given in application to jet noise reduction of turbojet engines and to auto-oscillation suppression in wind tunnels with open test section.

Download or read book Simulation of Supersonic Jet Noise with the Adaptation of Overflow Cfd Code and Kirchhoff Surface Integral written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-19 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: An acoustic prediction capability for supersonic axisymmetric jets was developed on the basis of OVERFLOW Navier-Stokes CFD (Computational Fluid Dynamics) code of NASA Langley Research Center. Reynolds-averaged turbulent stresses in the flow field are modeled with the aid of Spalart-Allmaras one-equation turbulence model. Appropriate acoustic and outflow boundary conditions were implemented to compute time-dependent acoustic pressure in the nonlinear source-field. Based on the specification of acoustic pressure, its temporal and normal derivatives on the Kirchhoff surface, the near-field and the far-field sound pressure levels are computed via Kirchhoff surface integral, with the Kirchhoff surface chosen to enclose the nonlinear sound source region described by the CFD code. The methods are validated by a comparison of the predictions of sound pressure levels with the available data for an axisymmetric turbulent supersonic (Mach 2) perfectly expanded jet. Kandula, Max and Caimi, Raoul and Steinrock, T. (Technical Monitor) Kennedy Space Center NASA/TM-2001-210263, NAS 1.15:210263

Download or read book Jet Aeroacoustics written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2019 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: Progress associated with research in (1) physics and prediction of turbulent mixing noise from supersonic jets, and (2) numerical simulation of supersonic jet noise is reported. Tam, Christopher Langley Research Center NASA-CR-203579, NAS 1.26:203579 NAG1-1776...

Download or read book Numerical Simulation of Supersonic Jet Noise Phenomena written by L. N. Sankar and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advanced Jet Noise Exhaust Concepts in Nasa s N 2 Supersonics Validation Study and the Environmentally Responsible Aviation Project s Upcoming Hybrid written by Brenda S. Henderson and published by BiblioGov. This book was released on 2013-06 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: Acoustic and flow-field experiments were conducted on exhaust concepts for the next generation supersonic, commercial aircraft. The concepts were developed by Lockheed Martin (LM), Rolls-Royce Liberty Works (RRLW), and General Electric Global Research (GEGR) as part of an N+2 (next generation forward) aircraft system study initiated by the Supersonics Project in NASA s Fundamental Aeronautics Program. The experiments were conducted in the Aero-Acoustic Propulsion Laboratory at the NASA Glenn Research Center. The exhaust concepts presented here utilized lobed-mixers and ejectors. A powered third-stream was implemented to improve ejector acoustic performance. One concept was found to produce stagnant flow within the ejector and the other produced discrete-frequency tones (due to flow separations within the model) that degraded the acoustic performance of the exhaust concept. NASA's Environmentally Responsible Aviation (ERA) Project has been investigating a Hybrid Wing Body (HWB) aircraft as a possible configuration for meeting N+2 system level goals for noise, emissions, and fuel burn. A recently completed NRA led by Boeing Research and Technology resulted in a full-scale aircraft design and wind tunnel model. This model will be tested acoustically in NASA Langley's 14-by 22-Foot Subsonic Tunnel and will include dual jet engine simulators and broadband engine noise simulators as part of the test campaign. The objectives of the test are to characterize the system level noise, quantify the effects of shielding, and generate a valuable database for prediction method development. Further details of the test and various component preparations are described.