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The Noise Of A Forward Swept Fan
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Author :National Aeronautics and Space Administration (NASA) Publisher :Createspace Independent Publishing Platform ISBN 13 :9781721023172 Total Pages :32 pages Book Rating :4.0/5 (231 download)
Book Synopsis The Noise of a Forward Swept Fan by : National Aeronautics and Space Administration (NASA)
Download or read book The Noise of a Forward Swept Fan 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 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: A forward swept fan, designated the Quiet High Speed Fan (QHSF), was tested in the NASA Glenn 9-by 15-foot Low Speed Wind Tunnel to investigate its noise reduction relative to a baseline fan of the same aerodynamic performance. The objective of the Quiet High Speed Fan was a 6 decibel reduction in the Effective Perceived Noise relative to the baseline fan at the takeoff condition. The intent of the Quiet High Speed Fan design was to provide both a multiple pure tone noise reduction from the forward sweep of the fan rotor and a rotor-stator interaction blade passing tone noise reduction from a leaned stator. The tunnel noise data indicted that the Quiet High Speed Fan was quieter than the baseline fan for a significant portion of the operating line and was 6 dB quieter near the takeoff condition. Although reductions in the multiple pure tones were observed, the vast majority of the EPNdB reduction was a result of the reduction in the blade passing tone and its harmonics. The baseline fan's blade passing tone was dominated by the rotor-strut interaction mechanism. The observed blade passing tone reduction could be the result of either the redesign of the Quiet High Speed Fan Rotor or the redesigned stator. The exact cause of this rotor-strut noise reduction, whether from the rotor or stator redesign, was not discernable from this experiment.Dittmar, James H. and Elliott, David M. and Fite, E. BrianGlenn Research CenterAERODYNAMIC NOISE; LOW SPEED WIND TUNNELS; FAN BLADES; AIRCRAFT DESIGN; AEROACOUSTICS; ROTOR STATOR INTERACTIONS; VANES; AIRCRAFT WAKES; SUPERSONIC SPEED; PROPELLER NOISE; STRUTS
Author :National Aeronautics and Space Administration (NASA) Publisher :Createspace Independent Publishing Platform ISBN 13 :9781721777457 Total Pages :34 pages Book Rating :4.7/5 (774 download)
Book Synopsis Flow Measurements and Multiple Pure Tone Noise from a Forward Swept Fan by : National Aeronautics and Space Administration (NASA)
Download or read book Flow Measurements and Multiple Pure Tone Noise from a Forward Swept Fan written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-24 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: A forward-swept fan, designated the Quiet High Speed Fan (QHSF), was tested in the NASA Glenn 9- by 15-foot Low Speed Wind Tunnel to investigate its noise reduction relative to a baseline fan of the same aerodynamic performance. The objective of the Quiet High Speed Fan was a 6-dB reduction in the Effective Perceived Noise Level relative to the baseline fan at the takeoff condition. The intent of the Quiet High Speed Fan design was to provide both a multiple pure tone noise reduction from the forward sweep of the fan rotor and a rotor-stator interaction blade passing tone noise reduction from a leaned stator. The tunnel noise data indicted that the Quiet High Speed Fan was quieter than the baseline fan for a significant portion of the operating line and was 6 dB quieter near the takeoff condition. Although reductions in the multiple pure tones were observed, the vast majority of the EPNdB reduction was a result of the reduction in the blade passing tone and its harmonics. Laser Doppler Velocimetry (LDV) and shroud unsteady pressure measurement data were obtained upstream of the QHSF and baseline rotors to improve the understanding of the shocks which propagate upstream of the two fans when they are operated at high speeds. The flow phenomena that produce multiple pure tone noise is discussed and compared to measurements of the fan acoustic inlet modes and the far field noise signature of the fan. Weir, Donald S. and Podboy, Gary G. Glenn Research Center NASA/TM-2005-213413, AIAA Paper 2005-1200, E-14931
Book Synopsis Noise Reduction of Short Ducted Fan by Using Forward Swept and Inclided Blade by : Katsuhisa Ohtsuta
Download or read book Noise Reduction of Short Ducted Fan by Using Forward Swept and Inclided Blade written by Katsuhisa Ohtsuta and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Comparison of Tone Mode Measurements for a Forward Swept and Baseline Rotor Fan by :
Download or read book Comparison of Tone Mode Measurements for a Forward Swept and Baseline Rotor Fan written by and published by . This book was released on 2003 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author :National Aeronautics and Space Administration (NASA) Publisher :Createspace Independent Publishing Platform ISBN 13 :9781721577835 Total Pages :32 pages Book Rating :4.5/5 (778 download)
Book Synopsis Comparison of Tone Mode Measurements for a Forward Swept and Baseline Rotor Fan by : National Aeronautics and Space Administration (NASA)
Download or read book Comparison of Tone Mode Measurements for a Forward Swept and Baseline Rotor Fan written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-20 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: A forward swept fan, designated the Quite High Speed Fan (QHSF), was tested in the NASA Glenn 9- by 15-foot Low Speed Wind Tunnel to investigate its noise reduction relative to a baseline fan of the same aerodynamic performance. The design objective of the QHSF was a 6 dB reduction in Effective Perceived Noise Level relative to the baseline fan at the takeoff condition. The design noise reduction was to be a result of lower levels of multiple pure tone noise due to the forward swept rotor, and lower rotor/stator interaction tone noise from a leaned stator. Although the design 6 dB reduction was observed in far-field measurements, the induct mode measurements revealed the reasons for goals. All of the noise reduction was from the blade passing tone and its harmonics and most of this was unexpectedly from rotor/strut interaction modes. The reason for large differences in rotor/strut noise sources could not be determined with certainty. The reductions in the multiple pure tone noise for the forward swept rotor were not observed. this reduction were not the ones related to the design Heidelberg, Laurence J. Glenn Research Center NASA/TM-2003-212378, E-13953, NAS 1.15:212378, AIAA Paper 2003-3293
Author :National Aeronautics and Space Administration (NASA) Publisher :Createspace Independent Publishing Platform ISBN 13 :9781726187411 Total Pages :50 pages Book Rating :4.1/5 (874 download)
Book Synopsis Aerodynamic Performance Measurements for a Forward Swept Low Noise Fan by : National Aeronautics and Space Administration (NASA)
Download or read book Aerodynamic Performance Measurements for a Forward Swept Low Noise Fan written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-29 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: One source of noise in high tip speed turbofan engines, caused by shocks, is called multiple pure tone noise (MPT's). A new fan, called the Quiet High Speed Fan (QHSF), showed reduced noise over the part speed operating range, which includes MPT's. The QHSF showed improved performance in most respects relative to a baseline fan; however, a partspeed instability discovered during testing reduced the operating range below acceptable limits. The measured QHSF adiabatic efficiency on the fixed nozzle acoustic operating line was 85.1 percent and the baseline fan 82.9 percent, a 2.2 percent improvement. The operating line pressure rise at design point rotational speed and mass flow was 1.764 and 1.755 for the QHSF and baseline fan, respectively. Weight flow at design point speed was 98.28 lbm/sec for the QHSF and 97.97 lbm/sec for the baseline fan. The operability margin for the QHSF approached 0 percent at the 75 percent speed operating condition. The baseline fan maintained sufficient margin throughout the operating range as expected. Based on the stage aerodynamic measurements, this concept shows promise for improved performance over current technology if the operability limitations can be solved.Fite, E. BrianGlenn Research CenterAERODYNAMIC CHARACTERISTICS; TURBOFAN ENGINES; FAN BLADES; NOISE GENERATORS; AERODYNAMIC NOISE; ACOUSTIC DELAY LINES; MASS FLOW; VORTICES; TIP SPEED...
Book Synopsis Fluid Machinery and Fluid Mechanics by : Jianzhong Xu
Download or read book Fluid Machinery and Fluid Mechanics written by Jianzhong Xu and published by Springer Science & Business Media. This book was released on 2010-07-05 with total page 445 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Fluid Machinery and Fluid Mechanics: 4th International Symposium (4th ISFMFE)" is the proceedings of 4th International Symposium on Fluid Machinery and Fluid Engineering, held in Beijing November 24-27, 2008. It contains 69 highly informative technical papers presented at the Mei Lecture session and the technical sessions of the symposium. The Chinese Society of Engineering Thermophysics (CSET) organized the First, the Second and the Third International Symposium on Fluid Machinery and Fluid Engineering (1996, 2000 and 2004). The purpose of the 4th Symposium is to provide a common forum for exchange of scientific and technical information worldwide on fluid machinery and fluid engineering for scientists and engineers. The main subject of this symposium is "Fluid Machinery for Energy Conservation". The "Mei Lecture" reports on the most recent developments of fluid machinery in commemoration of the late professor Mei Zuyan. The book is intended for researchers and engineers in fluid machinery and fluid engineering. Jianzhong Xu is a professor at the Chinese Society of Engineering Thermophysics, Chinese Academy of Sciences, Beijing.
Book Synopsis Recent Advances in Fluid Dynamics by : Jyotirmay Banerjee
Download or read book Recent Advances in Fluid Dynamics written by Jyotirmay Banerjee and published by Springer Nature. This book was released on 2022-09-24 with total page 507 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents select proceedings of the International Conference on Advances in Fluid Flow and Thermal Sciences (ICAFFTS 2021) and summarizes the modern research practices in fluid dynamics and fluid power. The content of the book involves advanced topics on turbulence, droplet deposition, oscillating flows, wave breaking, spray structure and its atomization and flow patterns in mini and micro channels. Technological concerns relevant to erosion of steam turbine blade due to droplets, influence of baffle cut and baffle pitch on flow regime, bubble formation and propagation in pool boiling, design optimization of flow regulating valves are included in the book. In addition, recent trends in small-scale hydropower plant and flow stability issues in nanofluids, solar water heating systems and closed-loop pulsating heat pipes are discussed. Special topics on airflow pattern in railway coach and vortex tube are also included. This book will be a reliable reference for academicians, researchers and professionals working in the areas of fluid dynamics and fluid power.
Download or read book Research & Technology 2002 written by and published by DIANE Publishing. This book was released on with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Fundamentals of Aeroacoustics with Applications to Aeropropulsion Systems by : Xiaofeng Sun
Download or read book Fundamentals of Aeroacoustics with Applications to Aeropropulsion Systems written by Xiaofeng Sun and published by Elsevier. This book was released on 2020-10-14 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamentals of Aeroacoustics with Applications to Aeropropulsion Systems from the Shanghai Jiao Tong University Press Aerospace series, is the go-to reference on the topic, providing a modern take on the fundamental theory and applications relating to prediction and control of all major noise sources in aeropropulsion systems. This important reference compiles the latest knowledge and research advances, considering both the physics of aerodynamic noise generation in aero-engines and related numerical prediction techniques. Additionally, it introduces new vortex sound interaction models, a transfer element method, and a combustion instability model developed by the authors. Focusing on propulsion systems from inlet to exit, including combustion noise, this new resource will aid graduate students, researchers, and R&D engineers in solving the aircraft noise problems that currently challenge the industry. Updates the knowledge-base on the sound source generated by aeropropulsion systems, from inlet to exit, including combustion noise Covers new aerodynamic noise control technology aimed at the low-noise design of next generation aero-engines, including topics such as aerodynamic noise and aero-engine noise control Includes new, cutting-edge models and methods developed by an author team led by the editor-in-chief of the Chinese Journal of Aeronautics and Astronautics Considers both the physics of aerodynamic noise generation in aero-engines and related numerical prediction techniques
Download or read book Green Aviation written by Emily S. Nelson and published by CRC Press. This book was released on 2018-06-12 with total page 493 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aircraft emissions currently account for ~3.5% of all greenhouse gas emissions. The number of passenger miles has increased by 5% annually despite 9/11, two wars and gloomy economic conditions. Since aircraft have no viable alternative to the internal combustion engine, improvements in aircraft efficiency and alternative fuel development become essential. This book comprehensively covers the relevant issues in green aviation. Environmental impacts, technology advances, public policy and economics are intricately linked to the pace of development that will be realized in the coming decades. Experts from NASA, industry and academia review current technology development in green aviation that will carry the industry through 2025 and beyond. This includes increased efficiency through better propulsion systems, reduced drag airframes, advanced materials and operational changes. Clean combustion and emission control of noise, exhaust gases and particulates are also addressed through combustor design and the use of alternative fuels. Economic imperatives from aircraft lifetime and maintenance logistics dictate the drive for "drop-in" fuels, blending jet-grade and biofuel. New certification standards for alternative fuels are outlined. Life Cycle Assessments are used to evaluate worldwide biofuel approaches, highlighting that there is no single rational approach for sustainable buildup. In fact, unless local conditions are considered, the use of biofuels can create a net increase in environmental impact as a result of biofuel manufacturing processes. Governmental experts evaluate current and future regulations and their impact on green aviation. Sustainable approaches to biofuel development are discussed for locations around the globe, including the US, EU, Brazil, China and India.
Book Synopsis Unsteady Aerodynamics, Aeroacoustics and Aeroelasticity of Turbomachines by : Kenneth C. Hall
Download or read book Unsteady Aerodynamics, Aeroacoustics and Aeroelasticity of Turbomachines written by Kenneth C. Hall and published by Springer Science & Business Media. This book was released on 2006-05-11 with total page 605 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook is a collection of technical papers that were presented at the 10th International Symposium on Unsteady Aerodynamics, Aeroacoustics, and Aeroelasticity of Turbomachines held September 8-11, 2003 at Duke University in Durham, North Carolina. The papers represent the latest in state of the art research in the areas of aeroacoustics, aerothermodynamics, computational methods, experimental testing related to flow instabilities, flutter, forced response, multistage, and rotor-stator effects for turbomachinery.
Book Synopsis Blade-To-Blade Variations in Shocks Upstream of Both a Forward-Swept and an Aft-Swept Fan by : Gary G. Podboy
Download or read book Blade-To-Blade Variations in Shocks Upstream of Both a Forward-Swept and an Aft-Swept Fan written by Gary G. Podboy and published by BiblioGov. This book was released on 2013-06 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Detailed laser Doppler velocimeter (LDV) flow field measurements were made upstream of two fans, one forward-swept and one aft-swept, in order to learn more about the shocks which propagate upstream of these rotors when they are operated at supersonic tip speeds. The blade-to-blade variations in the flows associated with these shocks are thought to be responsible for generating Multiple Pure Tone (MPT) noise. The measured blade-to-blade variations are documented in this report through a series of slideshows which show relative Mach number contours computed from the velocity measurements. Data are presented for the forward-swept fan operating at three speeds (corresponding to tip relative Mach numbers of 0.817, 1.074, and 1.189), and for the aft-swept fan operating at two (tip relative Mach numbers of 1.074 and 1.189). These LDV data illustrate how the perturbations in the upstream flow field created by the rotating blades vary with axial position, radial position and rotor speed. As expected, at the highest tested speed the forward-swept fan swallowed the shocks which occur in the tip region, whereas the aftswept fan did not. This resulted in a much smaller flow disturbance just upstream of the tip of the forward-swept fan. Nevertheless, further upstream the two fan flows were much more similar.
Download or read book Inter-noise 93 written by Pierre Chapelle and published by . This book was released on 1993 with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Reference Publication written by and published by . This book was released on 1977 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Aeroacoustics of Flight Vehicles by : Harvey H. Hubbard
Download or read book Aeroacoustics of Flight Vehicles written by Harvey H. Hubbard and published by . This book was released on 1991 with total page 620 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Patent Interference Practice Handbook by : Jerome Rosenstock
Download or read book Patent Interference Practice Handbook written by Jerome Rosenstock and published by Wolters Kluwer. This book was released on 1998-01-01 with total page 5514 pages. Available in PDF, EPUB and Kindle. Book excerpt: One procedural misstep in patent interference practice can put an invention at risk. Patent Interference Practice Handbook is the only book that leads you step by step through proper procedure at every stage of the interference process, before and after declaration. Covering practice before the U.S. Patent Office, the District Courts and the Court of Appeals for the Federal Circuit, this intensely practical guide shows you exactly how to: Assess elements such as anticipation, use or sale, obviousness, abandonment, suppression, concealmentEstablish patentabilityDetermine priorityMeet reduction-to-practice standardsMeet all burden of proof requirementsAvoid export license violationsFile preliminary statements and motionsBring civil actions or appeals after interference.At every stage of his p
