This paper presents the results from a one-way coupled, Euler–Lagrangian, direct numerical simulation of bubbles injected into a turbulent boundary layer. The Reynolds number of the turbulent boundary layer varies from 420 Re 1800, and the bubble Reynolds number Reb 1. Simulation parameters were chosen to match the experiment of Sanders et al. J. Fluid Mech. 552, 353 2006 investigating bubble-i...

The mixing of transported scalars in turbulent flows is a classic topic in turbulence research. The “diffusing power” of turbulent flows was originally recognized, among others, by Taylor (1915) since the beginning of the last century. Later on, Taylor (1921, 1935) also provided the first statistical framework to predict turbulent diffusion in air streams, as well as the scalar mixing in pipe f...

G-equations are well-known front propagation models in turbulent combustion which describe the front motion law in the form of local normal velocity equal to a constant (laminar speed) plus the normal projection of fluid velocity. In level set formulation, G-equations are Hamilton–Jacobi equations with convex (L1 type) but non-coercive Hamiltonians. Viscous G-equations arise from either numeric...

Using the field theoretic renormalization group technique in the two-loop approximation, turbulent Prandtl numbers are obtained in the general A model of passive vector advected by fully developed turbulent velocity field with violation of spatial parity introduced via continuous parameter ρ ranging from ρ = 0 (no violation of spatial parity) to |ρ| = 1 (maximum violation of spatial parity). Va...

Joint velocity/scalar imaging measurements are performed in turbulent premixed natural-gas/air flames to better characterize the turbulent flux of mean reaction progress variable, ru0c0. Simultaneous two-dimensional measurements of the velocity field and the relative OH concentration are obtained by particle image velocimetry (PIV) and planar laser-induced fluorescence (PLIF) of the OH radical,...

Observations of turbulent kinetic energy (TKE) dynamics in the ocean surface boundary layer are presented here and compared with results from previous observational, numerical, and analytic studies. As in previous studies, the dissipation rate of TKE is found to be higher in the wavy ocean surface boundary layer than it would be in a flow past a rigid boundary with similar stress and buoyancy f...

We describe the diffusion and random velocities of solid particles due to stochastic forcing by turbulent gas. We include the orbital dynamics of Keplerian disks, both in-plane epicycles and vertical oscillations. We obtain a new result for the diffusion of solids. The Schmidt number (ratio of gas to particle diffusivity) is Sc ≈ 1 + (Ωtstop), in terms of the particle stopping time tstop and th...

Direct numerical simulations (DNS) and large-eddy simulations (LES) simulations of flow through a periodic channel with a constriction are performed using the dynamic Smagorinsky model at two Reynolds numbers of 2800 and 10595. The LES equations are solved using higher order compact schemes. DNS are performed for the lower Reynolds number case using a fine grid and the data are used to validate...

The degree of linear polarization has recently been found to show wide random variations over the solar disk. These variations are presumably at least partly due to fluctuations in the flux density of turbulent photospheric magnetic fields and associated variations in the degree of Hanle depolarization. In order to understand the origin of such large scale fluctuations of the turbulent magnetic...