Computation of Aerodynamic Sound around Complex Stationary and Moving Bodies

Seo, Jung-Hee; Mittal, Rajat

doi:10.2514/6.2011-1087

Cited by 2 publications

(2 citation statements)

References 41 publications

(68 reference statements)

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“…14 shows that the fluctuating pressure measured at (0, 60L) and (0, −60L) from present computation is also in a good agreement with the data from Ref. [63]. Good agreements of the root-mean-square of fluctuating pressure measured at a distance of 50L shown in Fig.…”

Section: Sound Generation By An Insect In Hovering Flightsupporting

confidence: 85%

“…Sound generation by an insect in hovering flight: comparison of the instantaneous fluctuating pressure contours calculated by Seo and Mittal[63] (left) and the present method (right). The contour level ranges from −0.005ρ f c 2 (blue) to 0.005ρ f c 2 (red).An immersed boundary method for fluid-structure-acoustics interactions involving large deformations and complex geometries Deformation of a red blood cell induced by acoustic waves: instantaneous fluctuating pressure contour with A * = 0.4 at tc/D = 0.4 (a), 0.6 (b) and 0.8 (c).…”

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An immersed boundary method for fluid–structure–acoustics interactions involving large deformations and complex geometries

Wang

Tian

Lai

2020

Journal of Fluids and Structures

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This paper presents an immersed boundary (IB) method for fluid-structure-acoustics interactions involving large deformations and complex geometries. In this method, the fluid dynamics is solved by a finite difference method where the temporal, viscous and convective terms are respectively discretized by the third-order Runge-Kutta scheme, the fourth-order central difference scheme and a fifth-order W/TENO (Weighted/Targeted Essentially Non-oscillation) scheme. Without loss of generality, a nonlinear flexible plate is considered here, and is solved by a finite element method based on the absolute nodal coordinate formulation. The no-slip boundary condition at the fluid-structure interface is achieved by using a diffusion-interface penalty IB method. With the above proposed method, the aeroacoustics field generated by the moving boundaries and the associated flows are inherently solved. In order to validate and verify the current method, several benchmark cases are conducted: acoustic waves scattered from a stationary cylinder in a quiescent flow, sound generation by a stationary and a rotating cylinder in a uniform flow, sound generation by an insect in hovering flight, deformation of a red blood cell induced by acoustic waves and acoustic waves scattered by a stationary sphere. The comparison of the sound scattered by a cylinder shows that the present IB-WENO scheme, a simple approach, has an excellent performance which is even better than the implicit IB-lattice Boltzmann method. For the sound scattered by a sphere, the IB-TENO scheme has a lower dissipation compared with the IB-WENO scheme. Applications of this technique to model fluid-structure-acoustics interactions of flapping foils mimicking an insect wing section during forward flight and flapping foil energy harvester are also presented, considering the effects of foil shape and flexibility. The difference of the force and sound generations of the foils are compared. For wing during forward flight, the results show that flexible wing generates larger thrust with higher acoustic pressure. In terms of the energy harvester, the current results show that the geometrical shape has no significant effects on the force and sound generation, and the flexibility of the plate tends to deteriorate the power extraction efficiency. The flexible plate also induces larger fluctuating pressure at the frequency of 2f (f is the flapping frequency) and weaker sound at the frequencies of f and 3f . The successful validations and applications show that the IB method handled by delta function, whose accuracy is generally lower than that of the internal flow solver, is accurate for predicting the arXiv:1905.00182v1 [physics.flu-dyn] 1 May 2019An immersed boundary method for fluid-structure-acoustics interactions involving large deformations and complex geometries A PREPRINT dilatation and acoustics, and thus is an attractive alternative for modelling fluid-structure-acoustics interactions involving large deformations and complex geometries.Keywords Immersed boundary method · lar...

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Section: Sound Generation By An Insect In Hovering Flightsupporting

confidence: 85%

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confidence: 99%