New Computational Methods for the Prediction and Analysis of Helicopter Noise

New Computational Methods for the Prediction and Analysis of Helicopter Noise
Author: Roger C. Strawn
Publisher:
Total Pages: 18
Release: 1996
Genre: Fluid dynamics
ISBN:

Abstract: "This paper describes several new methods to predict and analyze rotorcraft noise. These methods are: 1) a combined computational fluid dynamics and Kirchhoff scheme for far-field noise predictions, 2) parallel computer implementation of the Kirchhoff integrations, 3) audio and visual rendering of the computed acoustic predictions over large far-field regions, and 4) acoustic tracebacks to the Kirchhoff surface to pinpoint the sources of the rotor noise. The paper describes each method and presents sample results for three test cases. The first case consists of in-plane high-speed impulsive noise and the other two cases show idealized parallel and oblique blade-vortex interactions. The computed results show good agreement with available experimental data but convey much more information about the far-field noise propagation. When taken together, these new analysis methods exploit the power of new computer technologies and offer the potential to significantly improve our prediction and understanding of rotorcraft noise."

Army RD & A.

Army RD & A.
Author:
Publisher:
Total Pages: 380
Release: 1997
Genre: Military research
ISBN:

Professional publication of the RD & A community.

Principles of Helicopter Aerodynamics with CD Extra

Principles of Helicopter Aerodynamics with CD Extra
Author: Gordon J. Leishman
Publisher: Cambridge University Press
Total Pages: 860
Release: 2006-04-24
Genre: Science
ISBN: 9780521858601

Written by an internationally recognized teacher and researcher, this book provides a thorough, modern treatment of the aerodynamic principles of helicopters and other rotating-wing vertical lift aircraft such as tilt rotors and autogiros. The text begins with a unique technical history of helicopter flight, and then covers basic methods of rotor aerodynamic analysis, and related issues associated with the performance of the helicopter and its aerodynamic design. It goes on to cover more advanced topics in helicopter aerodynamics, including airfoil flows, unsteady aerodynamics, dynamic stall, and rotor wakes, and rotor-airframe aerodynamic interactions, with final chapters on autogiros and advanced methods of helicopter aerodynamic analysis. Extensively illustrated throughout, each chapter includes a set of homework problems. Advanced undergraduate and graduate students, practising engineers, and researchers will welcome this thoroughly revised and updated text on rotating-wing aerodynamics.

Aerodynamic Noise

Aerodynamic Noise
Author: Tarit Bose
Publisher: Springer Science & Business Media
Total Pages: 175
Release: 2012-11-09
Genre: Technology & Engineering
ISBN: 1461450195

Aerodynamic Noise extensively covers the theoretical basis and mathematical modeling of sound, especially the undesirable sounds produced by aircraft. This noise could come from an aircraft’s engine—propellers, fans, combustion chamber, jets—or the vehicle itself—external surfaces—or from sonic booms. The majority of the sound produced is due to the motion of air and its interaction with solid boundaries, and this is the main discussion of the book. With problem sets at the end of each chapter, Aerodynamic Noise is ideal for graduate students of mechanical and aerospace engineering. It may also be useful for designers of cars, trains, and wind turbines.

Calculation of Complex Turbulent Flows

Calculation of Complex Turbulent Flows
Author: George Tzabiras
Publisher: Witpress
Total Pages: 424
Release: 2000
Genre: Science
ISBN:

A selection of invited chapters focusing on developments in the application of Computational Fluid Dynamics (CFD) to compressible or incompressible flows dominated by turbulence effects. These may be applied to complex geometrical configurations or flow-fields in simpler geometries requiring higher-order turbulence modelling, or suitably modified low-order models, to calculate crucial parameters such as instabilities, transition, separation, accurate description of velocity and scalar fields, and local and total forces.