Multiphase Science and Technology A Quarterly

ISSN for PRINT: 0276-1459

For Online Access

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2004, Volume16

Issue 4

111 pages

DOI: 10.1615/MultScienTechn.v16.i4

Issue price - $140.00

Maurizio Picciotto
Centro Interdipartimentale di Fluidodinamics e Idraulica, Dipartimento di Energetica e Macchine, Universita degli Studi di Udine, Via delle Scienze 208, 33100 Udine, Italy

Cristian Marchioli
Centro Interdipartimentale di Fluidodinamics e Idraulica, Dipartimento di Energetica e Macchine, Universita degli Studi di Udine, Via delle Scienze 208, 33100 Udine, Italy

Alfredo Soldati
Centro Interdipartimentale di Fluidodinamics e Idraulica, Dipartimento di Energetica e Macchine, Universita degli Studi di Udine, Via delle Scienze 208, 33100 Udine, Italy

The problem of particle preferential distribution in turbulent boundary layer is addressed. Several observations confirm that, in this type of flow, particles have a non-uniform distribution in the wall normal direction and it has also been observed that, when in the viscous sub-layer, particle distribution is not uniform in the wall parallel plane so that particles appear segregated along streamwise streaks with strong time persistency. Starting from our previous works [1, 2], in which we examined the mechanisms for particle transfer toward and away from the wall, we aim at characterizing the regions of particle preferential distribution. Particle motion in the wall region is deminated by instantaneous Reynolds stresses — i.e. strong downwash of outer fluid toward the wall, sweeps, and strong upwash of fluid away from the wall, ejections — which are generated by the coherent vortical structures populating the wall region.
Specifically, in this work we correlate particle preferential position with the distribution of the coherent structures in the wall region. Results confirm that particles tend to avoid the strongly coherent vortifcal structures and tend to concentrate in regions neighbouring the wall which are characterized by low shear stress values where the flow is generally directed away from the wall.

DOI: 10.1615/MultScienTechn.v16.i4.10 Download article, 281-293 pages

Article price - $45.00

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