We perform a scaling analysis of the terms composing Ffowcs-Williams and Hawkings (FWH) equation, which rules propagation noise generated by rigid body in motion. Our extends seminal work Lighthill ( Proc. R. Soc. Lond. A, vol. 211, 1952, pp. 564–587) dimensional classical sources (monopole, dipole quadrupole) considering all FWH integral terms. Scaling properties are analysed light perfect/imp...

Aerodynamic noise produced by aerodynamic interaction between a cylinder (rod) and an airfoil in tandem arrangement is investigated using large eddy simulations. Wake from the rod convects with the flow, impinges of the airfoil to produce unsteady force which acts as a sound source. This rod-airfoil interaction problem is a model problem for noise generation due to inflow or upstream-generated ...

A new approach to accelerating the evaluation of monopole and dipole source integrals via fast multipole method (FMM) in time domain for general three-dimensional (3-D) aeroacoustic problems is presented this paper. In approach, field predicted a hybrid that uses computational fluid dynamics (CFD) near-field flow calculations Ffowcs Williams–Hawkings (FW-H) acoustic analogy far-field sound pred...

The study numerically investigated the noise dissipation, cavitation, output power, and energy produced by marine propellers. A Ffowcs Williams–Hawkings (FW–H) model was used to determine effects of three different propellers with five blades a fixed advancing ratio. large-eddy Simulations best predicted turbulent structures’ spatial temporal variation, which would better illustrate flow physic...

Despite almost 60 years of active research on jet noise, the noise generated by expulsion of hot gases at the exhaust of aircraft engines remains an important part of the total aircraft noise. This is particularly true in the case of supersonic aircrafts, where the high speed of the exhaust gases yields extremely high noise. In the framework of the development of future civil supersonic aircraf...

Although the Lighthill–Curle acoustic analogy theory is formally exact, presence of linear source terms related to viscous stresses and non-isentropic density changes makes it unsuitable for studying aerodynamic sound generation in low Reynolds number thermoviscous flows. Here we use an extension Ffowcs Williams Hawkings formulation, with effects explicitly included, find analytical solution ca...

As the main noise source in hydrogen fuel cell system, level of centrifugal air compressor greatly affects comfort vehicle, and can be effectively reduced by optimizing trailing edge sweep angle blade. In this paper, computational fluid dynamics model was used to study influence on aerodynamic performance flow characteristics a for vehicle cells. The Ffowcs Williams–Hawkings equation dynamics–b...

This paper presents the broadband noise analysis of a Counter Rotating Open Rotor (CROR) configuration. The numerical study is based on hybrid approach: Large Eddy Simulation (LES) code solves near-flow field CROR configuration and near-to-far-field propagation then predicted by Ffowcs Williams–Hawkings analogy either solid or porous formulation. LES solver uses phase-lagged assumption with pro...

In appreciation of Ffowcs-Williams and Hawkings’ seminal contribution on describing the sound radiation from moving objects, this article discusses a concept taking into account local non-trivial flow effects propagation. The approach is motivated by fact that numerical simulation propagation complete full scale aircraft means volume-discretizing (CAA = Computational AeroAcoustics) methods proh...