Download or read book The Kirchhoff Formulas for Moving Surfaces in Aeroacoustics The Subsonic and Supersonic Cases written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-23 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the active areas of computational aeroacoustics is the application of the Kirchhoff formulas to the problems of the rotating machinery noise predictions. The original Kirchhoff formula was derived for a stationary surface. In 1988, Farassat and Myers derived a Kirchhoff Formula obtained originally by Morgans using modem mathematics. These authors gave a formula particularly useful for applications in aeroacoustics. This formula is for a surface moving at subsonic speed. Later in 1995 these authors derived the Kirchhoff formula for a super-sonically moving surface. This technical memorandum presents the viewgraphs of a day long workshop by the author on the derivation of the Kirchhoff formulas. All necessary background mathematics such as differential geometry and multidimensional generalized function theory are discussed in these viewgraphs. Abstraction is kept at minimum level here. These viewgraphs are also suitable for understanding the derivation and obtaining the solutions of the Ffowcs Williams-Hawkings equation. In the first part of this memorandum, some introductory remarks are made on generalized functions, the derivation of the Kirchhoff formulas and the development and validation of Kirchhoff codes. Separate lists of references by Lyrintzis, Long, Strawn and their co-workers are given in this memorandum. This publication is aimed at graduate students, physicists and engineers who are in need of the understanding and applications of the Kirchhoff formulas in acoustics and electromagnetics. Farassat, F. Unspecified Center KIRCHHOFF LAW; PIPE FLOW; SUBSONIC SPEED; AEROACOUSTICS; ELECTROMAGNETISM; SUPERSONIC FLOW; NOISE PREDICTION; DIFFERENTIAL GEOMETRY; ROTATION; ACOUSTICS...
Download or read book The Kirchhoff Formulas for Moving Surfaces in Aeroacoustics The Subsonic and Supersonic Cases written by and published by . This book was released on 1996 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustics Aeroacoustics and Vibrations written by Fabien Anselmet and published by John Wiley & Sons. This book was released on 2016-01-07 with total page 529 pages. Available in PDF, EPUB and Kindle. Book excerpt: This didactic book presents the main elements of acoustics, aeroacoustics and vibrations. Illustrated with numerous concrete examples linked to solid and fluid continua, Acoustics, Aeroacoustics and Vibrations proposes a selection of applications encountered in the three fields, whether in room acoustics, transport, energy production systems or environmental problems. Theoretical approaches enable us to analyze the different processes in play. Typical results, mostly from numerical simulations, are used to illustrate the main phenomena (fluid acoustics, radiation, diffraction, vibroacoustics, etc.).
Download or read book Lecture Notes on the Mathematics of Acoustics written by Matthew C. M. Wright and published by World Scientific. This book was released on 2005 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on lectures given at a one week summer school held at the University of Southampton, July 2003.
Download or read book Computational Fluid Dynamics written by T. J. Chung and published by Cambridge University Press. This book was released on 2002-02-07 with total page 1040 pages. Available in PDF, EPUB and Kindle. Book excerpt: Increasingly, computational fluid dynamics (CFD) techniques are being used to study and solve complex fluid flow and heat transfer problems. This comprehensive book ranges from elementary concepts for the beginner to state-of-the-art CFD for the practitioner. It begins with CFD preliminaries, in which the basic principles of finite difference (FD), finite element (FE), and finite volume (FV) methods are discussed and illustrated through examples, with step-by-step hand calculations. Then, FD and FE methods respectively are covered, including both historical developments and recent contributions. The next section is devoted to structured and unstructured grids, adaptive methods, computing techniques, and parallel processing. Finally, the author describes a variety of practical applications to problems in turbulence, reacting flows and combustion, acoustics, combined mode radiative heat transfer, multiphase flows, electromagnetic fields, and relativistic astrophysical flows. Students and practitioners - particularly in mechanical, aerospace, chemical, and civil engineering - will use this authoritative text to learn about and apply numerical techniques to the solution of fluid dynamics problems.
Download or read book NASA Technical Memorandum written by and published by . This book was released on 1997 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Acoustic Waves written by Marco G. Beghi and published by BoD – Books on Demand. This book was released on 2011-11-14 with total page 670 pages. Available in PDF, EPUB and Kindle. Book excerpt: The concept of acoustic wave is a pervasive one, which emerges in any type of medium, from solids to plasmas, at length and time scales ranging from sub-micrometric layers in microdevices to seismic waves in the Sun's interior. This book presents several aspects of the active research ongoing in this field. Theoretical efforts are leading to a deeper understanding of phenomena, also in complicated environments like the solar surface boundary. Acoustic waves are a flexible probe to investigate the properties of very different systems, from thin inorganic layers to ripening cheese to biological systems. Acoustic waves are also a tool to manipulate matter, from the delicate evaporation of biomolecules to be analysed, to the phase transitions induced by intense shock waves. And a whole class of widespread microdevices, including filters and sensors, is based on the behaviour of acoustic waves propagating in thin layers. The search for better performances is driving to new materials for these devices, and to more refined tools for their analysis.
Download or read book Development of Improved Surface Integral Methods for Jet Aeroacoustic Predictions written by Anthony Richard Pilon and published by . This book was released on 1997 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Combustion Noise written by Anna Schwarz and published by Springer Science & Business Media. This book was released on 2009-06-17 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book NASA Langley Scientific and Technical Information Output 1996 written by and published by . This book was released on 1997 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 43rd AIAA Aerospace Sciences Meeting Exhibit written by and published by . This book was released on 2005 with total page 598 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study on Optimized Upwind Schemesfor Computational Areoacoustics sic and Extension of a Fully Conservative Chimera to Finite Difference Schemes written by Rangfu Chen and published by . This book was released on 1998 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book AIAA Journal written by American Institute of Aeronautics and Astronautics and published by . This book was released on 2008 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computational Aero and Hydro acoustics 1993 written by R. R. Mankbadi and published by American Society of Mechanical Engineers. This book was released on 1993 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book 35th Aerospace Sciences Meeting Exhibit written by and published by . This book was released on 1997 with total page 654 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 International Aerospace Abstracts written by and published by . This book was released on 1998 with total page 980 pages. Available in PDF, EPUB and Kindle. Book excerpt:
