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).

Inhalt

Keynote Address.- A General Introduction to Aeroacoustics and Atmospheric Sound.- Classical Theoretical Approaches.- Classical Theoretical Approaches to Computational Aeroacoustics.- Computational Aeroacoustics for Low Mach Number Flows.- A Multiple Scales Approach to Sound Generation by Vibrating Bodies.- On the Noise Radiated from a Turbulent High Speed Jet.- A Study of the Short Wave Components in Computational Acoustics.- Mathematical Aspects of Acoustics.- The Acoustic Analogy as a Tool of Computational Aeroacoustics.- Problems with Different Time Scales and Acoustics.- Validation Methodology.- Validation Methodology: Review and Comments.- Wall Pressure and Radiated Noise Generated by 3 Line Vortices in Chaotic Motion Close to a Solid Surface.- Acoustic Scattering by an Elastic Window in a Rigid Duct: Numerical Approaches.- Calculation of Noise Produced by High Mach Number Jets.- Regarding Numerical Considerations for Computational Aeroacoustics.- Observed and Computed Waves of Aerodynamic Sound.- Validation of Computational Aeroacoustics Algorithms.- Model Problems Associated with the Prediction of Noise by High Speed Shear Layers.- Direct Simulation.- Direct Simulation: Review and Comments.- Time-Dependent Jet Noise Computation Techniques.- A Consideration of Energy from the Viewpoint of Computational Aeroacoustics.- Direct Computation of Aerodynamic Noise.- Computation of the Acoustic Radiation from Bounded Homogeneous Flows.- On the Development of a Time Domain Method for CAA "The Successes and Failures".- Unsteady Compressible Flow Computational Methods.- CFD Methods Development Considerations for Unsteady Aerodynamic Analysis.- Numerical Study of Flow/Structure Interaction over a Flexible Plate.- Navier-Stokes Simulations of Blade-Vortex Interaction using High-Order-Accurate Upwind Schemes.- Contributed Papers.- Scattering of Sound by Rigid Bodies in Arbitrary Flows.- Application of Geometrical Acoustics to Propagation of High Frequency Jet Noise.- Application of a CFD Code for Unsteady Transonic Aerodynamics to Problems in Aeroacoustics.- Report on Final Panel Discussion.- The Final Panel Discussion.