Download or read book Noise Generation by Fans with Supersonic Tip Speeds 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 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fan noise continues to be a significant issue for commercial aircraft engines and there still exists a requirement for improved understanding of the fundamental issues associated with fan noise source mechanisms. At the present time, most of the prediction methods identify the dominant acoustic sources to be associated with the stator vanes or blade trailing edges which are downstream of the fan face. However recent studies have shown that acoustic waves are significantly attenuated as they propagate upstream through a rotor, and if the appropriate corrections are applied, sound radiation from the engine inlet is significantly underpredicted. The prediction models can only be applied to fans with subsonic tip speeds. In contrast, most aircraft engines have fan tip speeds which are transonic and this implies an even higher attenuation for upstream propagating acoustic waves. Consequently understanding how sound propagates upstream through the fan is an important, and not well understood phenomena. The objective of this study is to provide improved insight into the upstream propagation effects through a rotor which are relevant to full scale engines. The focus of this study is on broadband fan noise generated by boundary layer turbulence interacting with the trailing edges of the fan blades. If this source mechanism is important upstream of the fan, the sound must propagate upstream through a transonic non uniform flow which includes large gradients and non linearities. Developing acoustic propagation models in this type of flow is challenging and currently limited to low frequency applications, where the frequency is of the same order as the blade passing frequency of the fan. For trailing edge noise, much higher frequencies are relevant and so a suitable approach needs to be developed, which is not limited by an unacceptably large computational effort. In this study we are in the process of developing a computational method which applies for the high frequencies of

Download or read book NASA Technical Note written by and published by . This book was released on 1977 with total page 642 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fluid Mechanics Acoustics and Design of Turbomachinery written by B. Lakshminarayana and published by . This book was released on 1974 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NASA Technical Paper written by and published by . This book was released on 1985 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 1572 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 1985 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Aerothermodynamics of Aircraft Gas Turbine Engines written by and published by . This book was released on 1978 with total page 770 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Federal Aircraft Noise Abatement Plan written by United States. Office of Noise Abatement and published by . This book was released on 1969 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Federal Aircraft Noise Abatement Plan written by and published by . This book was released on 1969 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book First Federal Aircraft Noise Abatement Plan FY 1969 70 written by United States. Office of Noise Abatement and published by . This book was released on 1970 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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:

Download or read book Fluctuating Pressures on Fan Blades of a Turbofan Engine Flight Test Investigation written by James A. Schoenster and published by . This book was released on 1985 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aerothermodynamics of Aircraft Engine Components written by Gordon C. Oates and published by AIAA. This book was released on 1985 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: Annotation Design and R & D engineers and students will value the comprehensive, meticulous coverage in this volume. Beginning with the basic principles and concepts of aeropropulsion combustion, chapters explore specific processes, limitations, and analytical methods as they bear on component design.

Download or read book Aircraft Engine Noise and Sonic Boom written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Fluid Dynamics Panel and published by . This book was released on 1969 with total page 604 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Shock and Vibration Digest written by and published by . This book was released on 1983 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Transportation Noise and Noise from Equipment Powered by Internal Combustion Engines written by Wyle Laboratories and published by . This book was released on 1972 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1976 with total page 990 pages. Available in PDF, EPUB and Kindle. Book excerpt: