Intrinsic filtering errors of Lagrangian particle tracking in LES flow fields

Details Intrinsic filtering errors of Lagrangian particle tracking in LES flow fields Intrinsic filtering errors of Lagrangian particle tracking in LES flow fields

2011-08-30

arxiv.org/abs/1108.5994v1

Physics

Fluid Dynamics

39 pages, 1 table, 12 figures, submitted to Physics of Fluids

Scientific paper

Large-Eddy Simulations (LES) of two-phase turbulent flows exhibit quantitative differences in particle statistics if compared to Direct Numerical Simulations (DNS) which, in the context of the present study, is considered the exact reference case. Differences are primarily due to filtering, a fundamental intrinsic feature of LES. Filtering the fluid velocity field yields approximate computation of the forces acting on particles and, in turn, trajectories that are inaccurate when compared to those of DNS. In this paper, we focus precisely on the filtering error for which we quantify a lower bound. To this aim, we use a DNS database of inertial particle dispersion in turbulent channel flow and we perform a-priori tests in which the error purely due to filtering is singled out removing error accumulation effects, which would otherwise lead to progressive divergence between DNS and LES particle trajectories. By applying filters of different type and width at varying particle inertia, we characterize the statistical properties of the filtering error as a function of the wall distance. Results show that filtering error is stochastic and has a non-Gaussian distribution. In addition, the distribution of the filtering error depends strongly on the wall-normal coordinate being maximum in the buffer region. Our findings provide insight on the effect of subgrid-scale velocity field on the force driving the particles, and establish the requirements which a LES model must satisfy to predict correctly the velocity and the trajectory of inertial particles.

Affiliated with

Also associated with

No associations

Rating

Intrinsic filtering errors of Lagrangian particle tracking in LES flow fields does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Intrinsic filtering errors of Lagrangian particle tracking in LES flow fields, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Intrinsic filtering errors of Lagrangian particle tracking in LES flow fields will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-729087