Numerical study on the scattering of acoustic waves by a compact vortex

Autor: Ruixuan Ma, Yimin Wang, Hu Li, Conghai Wu, Shuaibin Han, Xunnian Wang
Rok vydání: 2023
Předmět:
Zdroj: Physics of Fluids. 35:036107
ISSN: 1089-7666
1070-6631
Popis: A new family of compact vortex models is developed and taken as base vortical flows to numerically study the acoustic scattering by solving the two-dimensional Euler equations in the time domain with high-order accurate finite-difference methods and nonreflecting boundary conditions. The computations of scattered fields with very small amplitude are found to be in excellent agreement with a benchmark provided by previous studies. Simulations for the scattering from a Taylor vortex reveal that the amplitude of the scattered fields is strongly influenced by two dimensionless quantities, the vortex strength Mv based on the maximal velocity of the vortex, and the acoustic length-scale ratio [Formula: see text] defined as the acoustic wavelength relative to the vortex core size. To have a deep understanding of the roles played by these two quantities, another significant quantity used for describing quantitatively the total amount of scattering, namely, scattered sound power, is introduced. Thereupon, on the basis of a global analysis of scale effects of these two dimensionless quantities on the scattered sound power, the scattering defined in a physical coordinate system with Mv and [Formula: see text] is divided into three domains, long-wave domain, resonance domain, and geometrical-acoustics domain. For each domain, we examine the influence of Mv and [Formula: see text] in detail and derive the explicit scaling laws involved in the strength of the scattered field and these two dimensionless quantities separately. Furthermore, the computations for the scattering from a high-order compact vortex are conducted at a wide range of Mv and [Formula: see text] and compared with the results from the Taylor vortex in each domain to gain some insights into the acoustic scattering by a compact vortex.
Databáze: OpenAIRE