Regensburg 2010 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 6: Poster Session I

DY 6.25: Poster

Monday, March 22, 2010, 16:00–18:00, Poster B2

Numerical calculation of the filter efficiency of fibrous aerosol filters — Egbert Zienicke and •Hartmut Grille — Institut für Physik, TU Ilmenau, 98684 Ilmenau, Gemany

An important environmental task is the suppression of soot emission from Diesel engines in traffic. New EU and US norms do not only set limits for the total mass of soot per km, but also prescribe the maximally allowed number of particles. The challenge for the construction of Diesel particle filters is the maximization of the filter effectivity and the minimization of the pressure drop.

The computation of the effectivity of a fibrous filter is based on the single fiber efficiency, which is obtained by numerical integration of the particle trajectories in the Kuwabara cell around a single fiber. The soot particle paths are influenced by (i) Stokes friction in the flow of the exhaust gas, (ii) Brownian motion and (iii) the particle inertia. The single fiber efficiency depends on the flow velocity, particle size, fiber diameter, the filter porosity, and the exhaust gas temperature. For the goal of designing more efficient filters a large part of this parameter space has to be treated with sufficient statistics. As each trajectory can be computed independently, this task is an ideal candidate for parallelization. This has been realized with Nvidia graphic cards in the CUDA frame work. We compare our numerically received single fiber efficiencies with experimental data and analytical approximations.