Computation of the Sound Generated by Isotropic Turbulence

Computation of the Sound Generated by Isotropic Turbulence
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
Total Pages: 34
Release: 2018-06-30
Genre:
ISBN: 9781722116750

The acoustic radiation from isotropic turbulence is computed numerically. A hybrid direct numerical simulation approach which combines direct numerical simulation (DNS) of the turbulent flow with the Lighthill acoustic analogy is utilized. It is demonstrated that the hybrid DNS method is a feasible approach to the computation of sound generated by turbulent flows. The acoustic efficiency in the simulation of isotropic turbulence appears to be substantially less than that in subsonic jet experiments. The dominant frequency of the computed acoustic pressure is found to be somewhat larger than the dominant frequency of the energy-containing scales of motion. The acoustic power in the simulations is proportional to epsilon (M(sub t))(exp 5) where epsilon is the turbulent dissipation rate and M(sub t) is the turbulent Mach number. This is in agreement with the analytical result of Proudman (1952), but the constant of proportionality is smaller than the analytical result. Two different methods of computing the acoustic power from the DNS data bases yielded consistent results. Sarkar, S. and Hussaini, M. Y. Langley Research Center NAS1-19480; RTOP 505-90-52-01...

New Trends in Fluid Mechanics Research

New Trends in Fluid Mechanics Research
Author: F. G. Zhuang
Publisher: Springer Science & Business Media
Total Pages: 764
Release: 2009-04-24
Genre: Science
ISBN: 3540759956

This volume is the proceedings of the Fifth International Conference on Fluid Mechanics (ICFM-V), the primary forum for the presentation of technological advances and research results in the fields of theoretical, experimental, and computational Fluid Mechanics. Topics include: flow instability and turbulence, aerodynamics and gas dynamics, industrial and environmental fluid mechanics, biofluid mechanics, geophysical fluid mechanics, plasma and magneto-hydrodynamics, and others.

Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports
Author:
Publisher:
Total Pages: 456
Release: 1995
Genre: Aeronautics
ISBN:

Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Handbook of Noise and Vibration Control

Handbook of Noise and Vibration Control
Author: Malcolm J. Crocker
Publisher: John Wiley & Sons
Total Pages: 1594
Release: 2007-10-05
Genre: Technology & Engineering
ISBN: 0471395994

Two of the most acclaimed reference works in the area of acoustics in recent years have been our Encyclopedia of Acoustics, 4 Volume set and the Handbook of Acoustics spin-off. These works, edited by Malcolm Crocker, positioned Wiley as a major player in the acoustics reference market. With our recently published revision of Beranek & Ver's Noise and Vibration Control Engineering, Wiley is a highly respected name in the acoustics business. Crocker's new handbook covers an area of great importance to engineers and designers. Noise and vibration control is one largest areas of application of the acoustics topics covered in the successful encyclopedia and handbook. It is also an area that has been under-published in recent years. Crocker has positioned this reference to cover the gamut of topics while focusing more on the applications to industrial needs. In this way the book will become the best single source of need-to-know information for the professional markets.

Acoustics, Aeroacoustics and Vibrations

Acoustics, Aeroacoustics and Vibrations
Author: Fabien Anselmet
Publisher: John Wiley & Sons
Total Pages: 528
Release: 2016-01-07
Genre: Technology & Engineering
ISBN: 1119178401

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.).

Computational Fluid Dynamics

Computational Fluid Dynamics
Author: T. J. Chung
Publisher: Cambridge University Press
Total Pages:
Release: 2010-09-27
Genre: Technology & Engineering
ISBN: 1139493299

The second edition of Computational Fluid Dynamics represents a significant improvement from the first edition. However, the original idea of including all computational fluid dynamics methods (FDM, FEM, FVM); all mesh generation schemes; and physical applications to turbulence, combustion, acoustics, radiative heat transfer, multiphase flow, electromagnetic flow, and general relativity is still maintained. The second edition includes a new section on preconditioning for EBE-GMRES and a complete revision of the section on flowfield-dependent variation methods, which demonstrates more detailed computational processes and includes additional example problems. For those instructors desiring a textbook that contains homework assignments, a variety of problems for FDM, FEM and FVM are included in an appendix. To facilitate students and practitioners intending to develop a large-scale computer code, an example of FORTRAN code capable of solving compressible, incompressible, viscous, inviscid, 1D, 2D and 3D for all speed regimes using the flowfield-dependent variation method is made available.

Computational Aeroacoustics

Computational Aeroacoustics
Author: Jay C. Hardin
Publisher: Springer Science & Business Media
Total Pages: 525
Release: 2012-12-06
Genre: Science
ISBN: 1461383420

Computational aeroacoustics is rapidly emerging as an essential element in the study of aerodynamic sound. As with all emerging technologies, it is paramount that we assess the various opportuni ties and establish achievable goals for this new technology. Essential to this process is the identification and prioritization of fundamental aeroacoustics problems which are amenable to direct numerical siIn ulation. Questions, ranging from the role numerical methods play in the classical theoretical approaches to aeroacoustics, to the correct specification of well-posed numerical problems, need to be answered. These issues provided the impetus for the Workshop on Computa tional Aeroacoustics sponsored by ICASE and the Acoustics Division of NASA LaRC on April 6-9, 1992. The participants of the Work shop were leading aeroacousticians, computational fluid dynamicists and applied mathematicians. The Workshop started with the open ing remarks by M. Y. Hussaini and the welcome address by Kristin Hessenius who introduced the keynote speaker, Sir James Lighthill. The keynote address set the stage for the Workshop. It was both an authoritative and up-to-date discussion of the state-of-the-art in aeroacoustics. The presentations at the Workshop were divided into five sessions - i) Classical Theoretical Approaches (William Zorumski, Chairman), ii) Mathematical Aspects of Acoustics (Rodolfo Rosales, Chairman), iii) Validation Methodology (Allan Pierce, Chairman), iv) Direct Numerical Simulation (Michael Myers, Chairman), and v) Unsteady Compressible Flow Computa tional Methods (Douglas Dwoyer, Chairman).

Applications of Computational Fluid Dynamics Simulation and Modeling

Applications of Computational Fluid Dynamics Simulation and Modeling
Author: Suvanjan Bhattacharyya
Publisher: BoD – Books on Demand
Total Pages: 240
Release: 2022-10-26
Genre: Science
ISBN: 1839682477

This book provides well-balanced coverage of computational fluid dynamics analysis for thermal and flow characteristics of various thermal and flow systems. It presents the latest research work to provide insight into modern thermal engineering applications. It also discusses enhanced heat transfer and flow characteristics.

Numerical Simulation of Turbulent Flows and Noise Generation

Numerical Simulation of Turbulent Flows and Noise Generation
Author: Christophe Brun
Publisher: Springer Science & Business Media
Total Pages: 344
Release: 2009-03-07
Genre: Technology & Engineering
ISBN: 3540899561

Large Eddy Simulation (LES) is a high-fidelity approach to the numerical simulation of turbulent flows. Recent developments have shown LES to be able to predict aerodynamic noise generation and propagation as well as the turbulent flow, by means of either a hybrid or a direct approach. This book is based on the results of two French/German research groups working on LES simulations in complex geometries and noise generation in turbulent flows. The results provide insights into modern prediction approaches for turbulent flows and noise generation mechanisms as well as their use for novel noise reduction concepts.