Turbulence induced acoustics and its inverse

Many natural phenomena and technological applications in aerospace, energy, and medicine involve turbulence and acoustics. They are often weakly coupled: vortical turbulence is weakly compressible and induces sound which radiates away. Beginning with this scenario^[1] and examples of aeroacoustic predictions^[2],[3] in this regime. We examine conditions under which separating sound from turbulence becomes problematic^[4]. We discuss examples of progressively tighter coupling, such as aeroacoustic resonances, and an example of internal regulation of turbulence by acoustics^[5]. Finally, we discuss the inverted scenario where (nonlinear) acoustics induces turbulence and mixing^[4],[6]. While aiming to provide a general discussion we will also sketch many open questions.

[1] Colonius, T. and Lele, S. K. (2004) Prog. Aero. Sci., v. 40.

[2] Lele, S. K. and Nichols, J. W. (2014) Phil. Trans. R. Soc. A, v. 372.

[3] Bres, G. A. and Lele, S. K. (2019) Phil. Trans. R. Soc. A, v. 377.

[4] Lele, S. K. (2021), Ch. 9 in Adv. Approaches in Turbulence, Elsevier.

[5] Matsuno, K. and Lele, S. K. (2021) J. Fluid Mech., v. 907.

[6] Wong, M. L., Livescu, D. and Lele, S. K. (2019) Phys. Rev. Fluids, v. 4.