Acceleration statistics of tracer and light particles in compressible homogeneous isotropic turbulence. (25th March 2022)

• Record Type: Journal Article
• Authors: Wang, Xiangjun; Wan, Minping; Biferale, Luca
• Is Part Of: Journal of fluid mechanics. Volume 935(2022)
• Publication Date: 2022-03-25
• Subjects: particle/fluid flow -- compressible turbulence -- turbulence theory; Fluid mechanics -- Periodicals; 532.005
• DOI: 10.1017/jfm.2022.35
• Languages: English
• ISSNs: 0022-1120

Abstract

Abstract: Abstract : The accelerations of tracer and light particles (bubbles) in compressible homogeneous isotropic turbulence are investigated by using data from direct numerical simulations up to turbulent Mach number $M_t =1$ . For tracer particles, the flatness factor of acceleration components, $F_a$, increases gradually for $M_t \in [0.3, 1]$ . On the contrary, $F_a$ for bubbles develops a maximum around $M_t \sim 0.6$ . The probability density function of longitudinal acceleration of tracers is increasingly skewed towards the negative value as $M_t$ increases. By contrast, for light particles, the skewness factor of longitudinal acceleration, $S_a$, first becomes more negative with the increase of $M_t$, and then goes back to $0$ when $M_t$ is larger than $0.6$ . Similarly, differences among tracers and bubbles appear also in the zero-crossing time of acceleration correlation. It is argued that all these phenomena are intimately linked to the flow structures in the compression regions close to shocklets.