Two and Three-Dimensional Simulation of Sound Generated by Flow Around a Circular Cylinder

Abstract

The objective of this paper is to calculate the far-field sound generated from low mach number flow around a two-dimensional and three-dimensional circular cylinder in the subcritical regime using the Lighthill acoustic analogy. For the two-dimensional case, the timedependent incompressible flow is predicted using unsteady Reynolds-averaged Navier-Stokes models. For the three-dimensional case, the flow was obtained by solving the filtered Navier-Stokes equations of the Large Eddy Simulation model. As a benchmark, a flow-field with a Reynolds number of 90,000 is employed. The obtained numerical results such as Strouhal number, fluctuating lift and mean drag are compared with experiments. The computed unsteady pressure fluctuations on the cylinder wall are used as a sound source for the acoustic solver. Comparison between the two-dimensional numerical results and the experiment shows that computed acoustic field overpredict the noise amplitude; however, good agreement is obtained if an appropriate correlation length is taken into account. The sound measurements obtained by Revell et al. were carried out with a much longer span cylinder length when compared to the span used for the three-dimensional LES simulations. Therefore, the far-field sound is estimated by two correction methods proposed, respectively, by Kato et al. and Seo & Moon. The aerodynamic and acoustic results obtained by the threedimensional approach agree favorably well with the corresponding experimental data.

The Interaction of Porous Material Coating With the Near Wake of Bluff Body

“…Similar to the results in Ref. [26], the inability of the two-dimensional method used to model three-dimensional turbulence is part of the reason. Also, it is stated [27,28] that the measured fluctuating forces are considerably affected by many factors, such as aspect ratio, blockage, turbulence intensity, tube end boundaries, etc.…”

Large-eddy simulation of circular cylinder flow at subcritical Reynolds number: Turbulent wake and sound radiation

“…Overall, it is comparably good with the one from the up-wind scheme but B-spline [10] Upwind [20] Fig. 7 Ensemble averaged streamwise velocities at y = 0. The solid line is the computation result from Kravchenko et al [21] using the B-spline method.…”

“…Meanwhile, Boudet et al [5] and Seo et al [6] used LES to calculate the sound generated by a cylinder at the Reynolds number 4.6 × 10 4 . Moreover, Orselli et al [7] investigated a similar case at the Reynolds number 9.0 × 10 4 , and Li et al [8] studied the mixing layer noise.…”

The effect of a moving ground on the flow and aerodynamic noise behaviour of a simplified high-speed train bogie

“…However, the error introduced is relatively small for the current cases at a low Mach number. For example, Orselli et al [16] investigated the case of flow passing over a circular cylinder at a Mach number of 0.2 based on the acoustic analogy method. Using the incompressible flow field solutions as the noise source data, they found that the noise predicted using an off-body permeable surface was slightly higher than that calculated on the cylinder wall surfaces.…”