Lagrangian velocity and acceleration correlations of large inertial particles in a closed turbulent flow

Abstract

We investigate the response of large inertial particle to turbulent fluctuations in a inhomogeneous and anisotropic flow. We conduct a Lagrangian study using particles both heavier and lighter than the surrounding fluid, and whose diameters are comparable to the flow integral scale. Both velocity and acceleration correlation functions are analyzed to compute the Lagrangian integral time and the acceleration time scale of such particles. The knowledge of how size and density affect these time scales is crucial in understanding partical dynamics and may permit stochastic process modelization using two-time models (for instance Saw-ford's). As particles are tracked over long times in the quasi totality of a closed flow, the mean flow influences their behaviour and also biases the velocity time statistics, in particular the velocity correlation functions. By using a method that allows for the computation of turbulent velocity trajectories, we can obtain unbiased Lagrangian integral time. This is particularly useful in accessing the scale separation for such particles and to comparing it to the case of fluid particles in a similar configuration.

References in corpus (2)

• Turbulent transport of material particles: An experimental study of finite size effects
• On the properties of steady states in turbulent axisymmetric flows

Cited by in corpus (4)

• Simultaneous temperature and velocity Lagrangian measurements in turbulent thermal convection
• Velocity and acceleration statistics in particle-laden turbulent swirling flows
• Design, construction and validation of an instrumented particle for the lagrangian characterization of flows. Application to gravity wave turbulence
• Finite-sized rigid spheres in turbulent Taylor-Couette flow