Journal ArticleDOI
Modern Challenges Facing Turbomachinery Aeroacoustics
Nigel Peake,Anthony B. Parry +1 more
TLDR
In this paper, the authors describe current scientific and technological issues in the quest to reduce aeroengine noise, in the face of predicted rapid increases in the volume of air traffic, and increasingly strict environmental regulation.Abstract:
In this review we describe current scientific and technological issues in the quest to reduce aeroengine noise, in the face of predicted rapid increases in the volume of air traffic, on the one hand, and increasingly strict environmental regulation, on the other. Alongside conventional ducted turbofan designs, new open-rotor contra-rotating power plants are currently under development, which present their own noise challenges. The key sources of tonal and broadband noise, and the way in which noise propagates away from the source, are surveyed in both cases. We also consider in detail two key aspects underpinning the flow physics that continue to receive considerable attention, namely the acoustics of swirling flow and unsteady flow-blade interactions. Finally, we describe possible innovations in open-rotor engine design for low noise.read more
Citations
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Journal ArticleDOI
Combustion and Engine-Core Noise
TL;DR: In this paper, the authors review the fundamental understanding, experimental analysis, and modeling of engine-core noise; address limitations of current techniques; and identify opportunities for future research, and identify core-noise contributions from the combustor, turbomachinery, nozzles, and jet exhaust.
Journal ArticleDOI
Turbulent boundary layer trailing-edge noise: Theory, computation, experiment, and application
TL;DR: In this paper, the authors discuss a hierarchy of numerical approaches that range from semi-empirical schemes that estimate the wall pressure spectrum using mean flow and turbulence statistics to high-fidelity unsteady flow simulations such as Large Eddy Simulation (LES) or Direct Numerical Simulation (DNS) that resolve the sound generation and scattering process based on the first-principles flow physics.
Journal ArticleDOI
Large Eddy Simulation of a scale-model turbofan for fan noise source diagnostic
TL;DR: In this paper, a wall-modelled statistically converged Large Eddy Simulation (LES) of the turbulent flow in the NASA Source Diagnostic Test turbofan has been successfully performed for the first time.
Journal ArticleDOI
Turbomachinery Noise Predictions: Present and Future
TL;DR: In this paper, a review of analytical models and numerical methods to yield both tonal and broadband contributions of such noise sources is presented, which rely on hybrid methods coupling gust response over very thin flat plates of finite chord length, either isolated or in cascade.
Journal ArticleDOI
A second golden age of aeroacoustics
TL;DR: This review traces the progress in large-scale computations to resolve the noise-source processes and the methods devised to predict the far-field radiated sound using this information, and concludes that suitable theoretical formulations and reduced models will be even more important in future.
References
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Journal ArticleDOI
Aerodynamic sound generation by turbulent flow in the vicinity of a scattering half plane
J. E. Ffowcs Williams,L. H. Hall +1 more
TL;DR: In this paper, the presence of the edge of a half plane in a turbulent fluid results in a large increase in the noise generated by that fluid at low Mach numbers, and the farfield sound has the same features as would be predicted by geometrical acoustics.
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A note on an algebraic instability of inviscid parallel shear flows
TL;DR: In this paper, it was shown that all parallel inviscid shear flows of constant density are unstable to a wide class of initial infinitesimal three-dimensional disturbances in the sense that, according to linear theory, the kinetic energy of the disturbance will grow at least as fast as linearly in time.
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Some Aspects of Non-Stationary Airfoil Theory and Its Practical Application
TL;DR: In this paper, the lift and moment of a rigid airfoil passing through a vertical-gust pattern having a sinusoidal distribution of intensity were derived for two-dimensional thin airfoils in non-uniform motion.
Journal ArticleDOI
Linear Acoustic Formulas for Calculation of Rotating Blade Noise
TL;DR: In this paper, a unified approach is used to derive many of the current formulas for calculation of discrete frequency noise of helicopter rotors and propellers, both compact and non-compact results are derived.