title: Acceleration of passive tracers in compressible turbulent flow.
abstract: In compressible turbulence at high Reynolds and Mach numbers, shocklets emerge as a new type of flow structure in addition to intense vortices as in incompressible turbulence. Using numerical simulation of compressible homogeneous isotropic turbulence, we conduct a Lagrangian study to explore the effects of shocklets on the dynamics of passive tracers. We show that shocklets cause very strong intermittency and short correlation time of tracer acceleration. The probability density function of acceleration magnitude exhibits a -2.5 power-law scaling in the high compression region. Through a heuristic model, we demonstrate that this scaling is directly related to the statistical behavior of strong negative velocity divergence, i.e., the local compression. Tracers experience intense acceleration near shocklets, and most of them are decelerated, usually with large curvatures in their trajectories.
authors: State Key Laboratory for Turbulence and Complex Systems, Center for Applied Physics and Technology, College of Engineering, Peking University, Beijing, 100871, China.
authors: Yantao
authors: Y
authors: Yang
authors: Jianchun
authors: J
authors: Wang
authors: Yipeng
authors: Y
authors: Shi
authors: Zuoli
authors: Z
authors: Xiao
authors: X T
authors: XT
authors: He
authors: Shiyi
authors: S
authors: Chen