Computational Aeroacoustics


Book Description

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).







Computational Aeroacoustics


Book Description

Both a textbook for graduate students with exercises and a reference with code for researchers in computational aeroacoustics (CAA).




Computational Aeroacoustics


Book Description

Computational aeroacoustics (CAA) is a relatively new research area. CAA algorithms have developed rapidly and the methods have been applied in many areas of aeroacoustics. The objective of CAA is not simply to develop computational methods but also to use these methods to solve practical aeroacoustics problems and to perform numerical simulation of aeroacoustic phenomena. By analysing the simulation data, an investigator can determine noise generation mechanisms and sound propagation processes. This is both a textbook for graduate students and a reference for researchers in CAA and as such is self-contained. No prior knowledge of numerical methods for solving partial differential equations (PDEs) is needed, however, a general understanding of partial differential equations and basic numerical analysis is assumed. Exercises are included and are designed to be an integral part of the chapter content. In addition, sample computer programs are included to illustrate the implementation of the numerical algorithms.




Computational Aeroacoustics in Low Mach Number Flows


Book Description

This work studies a flexible methodology to predict radiated noise. The main contributions of this work are focused on the way flow parameters are acquired in fluid dynamics simulations are synthesised, stored and later used to predict radiated noise, but also on the procedure considered in the radiation calculations. The methodology has been restricted to low Mach number flows where the noise generation is dominated by the interaction of the flow with a surface at least one of whose typical dimensions is short compared to the wavelength of intereset, known as a compact source. The radiation calculations may employ purely analytical methods or numerical methods, depending on the application. Finally, the requirements in data storage and transfer are significantly reduced by using this method. Besides, if the flow remains essentially the same, the Computational Fluid Dynamics simulation should not need to be repeated in case different acoustic scenarios should be studied.







Aeroacoustics of Low Mach Number Flows


Book Description

Aeroacoustics of Low Mach Number Flows: Fundamentals, Analysis and Measurement, Second Edition provides a detailed introduction to sound radiation from subsonic flow over moving surfaces. This phenomenon is the most widespread cause of flow noise in engineering systems, including fan noise, rotor noise, wind turbine noise, boundary layer noise, airframe noise and aircraft noise. This fully updated new edition includes additional problems, illustrations and summary materials to support readers. New content covers Rapid Distortion theory (RDT), boundary layer wall pressure fluctuations, and flow induced sound at surfaces. Themes addressing non-compressible flows have also been added, offering coverage of hydroacoustic as well as aeroacoustic applications. New support materials for this edition include course outlines, problem sets, sample MATLAB codes and experimental data to be found at www.aeroacoustics.net. - Addresses, in detail, sound from rotating blades, ducted fans, airframes, boundary layers, and more - Presents theory in such a way that it can be used in computational methods and calculating sound levels - Includes coverage of different experimental approaches to this subject







AIAA Journal


Book Description