A bibliographical review of the main technologies employed for the mitigation of aircraft
noise is presented. According to a component-based approach, analytical and semi …

8.1 Regular Perturbations 8.1. 1 Webster's horn equation 8.2 Multiple scales......... 8.3
Helmholtz resonator with non-linear dissipation 8.4 Slowly varying ducts......... 8.5 Reflection …

There exist a number of good textbooks on both the analytical and the numerical aspects of
PDEs. So why another book on PDEs, then? Well, most existing texts deal with either …

For the relatively high frequencies relevant in a turbofan engine duct, the modes of a lined
section may be classified in two categories: genuine acoustic 3D duct modes resulting from …

Sound transmission through ducts of constant cross-section with a uniform inviscid mean
flow and a constant acoustic lining (impedance wall) is classically described by a modal …

Over-the-rotor liner exhibits the potential to further attenuate turbofan noise, but the physics
involved remain to be explored. In this paper, a three-dimensional coupled singularity …

COMPUTATIONALLY it is inefficient, and as yet practically impossible, to describe the sound
field that is produced within a turbofan aeroengine duct, by rotor–stator interaction of fan and …

Although explicit time integration schemes require small computational efforts per time step,
their efficiency is severely restricted by their stability limits. Indeed, the multi-scale nature of …

The propagation of unsteady disturbances in a slowly varying cylindrical duct carrying mean
swirling flow is described. A consistent multiple-scales solution for the mean flow and …

The objective of this paper is to expose the computational aeroacoustics (CAA) community
to the current unresolved issues in modeling and predicting fan noise. The paper includes a …