A particle accelerated computational fluid dynamics (CFD) boundary element method (BEM) technique is proposed that allows the total sound pressure field produced by low Mach number flow past a rigid body to be predicted. An incompressible CFD solver is used to calculate the transient hydrodynamic flow field. The CFD/BEM coupling technique is then used to compute the acoustic pressure and pressu...

In recent years, an increasing number of pioneering studies have been carried out in the field of acoustic metamaterials, following the path of electromagnetic metamaterials. These artificial engineered materials are designed in such a way so as to achieve new macroscopic properties , like negative refraction, that are not readily present in nature. While the design and the fabrication of these...

Aerodynamic noise becomes significant for high-speed trains and its prediction in an industrial context is hard to achieve. The aerodynamic and aeroacoustic behaviour of the flow past a highspeed train wheelset, one of the main components of a bogie, are investigated at a scale 1:10 using a two-stage hybrid method of computational fluid dynamics and acoustic analogy. The near-field unsteady flo...

Current text-to-speech systems do not support the effective provision of the semantics and the cognitive aspects of the documents’ typographic cues (e.g., font type, style, and size). A novel approach is introduced for the acoustic rendition of text font based on the emotional analogy between the visual (text font cues) and the acoustic (speech prosody) modalities. The methodology is based on: ...

There are many approaches to determine the sound propagated from turbulent flows.  In hybrid methods, the turbulent noise source field is computed or modeled separately from the far-field calculations.  To have an initial and quick estimation of the sound propagation, less computationally intensive methods can be developed using stochastic models of the turbulent fluctuations.   In this paper, ...

Combined variable rotor speed and active blade twist helicopter technologies have the potential to reduce environmental acoustic impact of modern rotorcraft. This paper explores aeroacoustics, ground noise combined rotors, optimized for simultaneous mitigation source NOx emissions. An integrated approach is employed including free-wake aeroelastic modeling time-domain aeroacoustic formulations ...

The paper proposes a design method of periodic acoustic structures composed filters. Based on acoustic-electric analogy, the second-order Butterworth filter is first designed, which comprises main pipe, Helmholtz resonator, short tube and an expansion cavity. Second, are constructed by taking as original unit cell or modifying to obtain modified cell, periodically arraying cells along axial dir...

In this paper, the DBEM/Hybrid LES（Directly Boundary Element Method/Hybrid Large Eddy Simulation）technique is applied to predict aerodynamic noise generated by tandem circular cylinders immersed in a three-dimensional turbulent flow. Utilizing Lighthill's Acoustic Analogy, flow pressure fluctuation near surface of cylinder converted into acoustic dipole sources. Taking sound sources as actual s...

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