TY - GEN
T1 - Numerical investigation of the combined effects of gravity and turbulence on the motion of small and heavy particles
AU - Siewert, C.
AU - Kunnen, R.
AU - Meinke, M.
AU - Schröder, W.
PY - 2014
Y1 - 2014
N2 - Numerical studies [1, 2] show that the influence of gravity and turbulence on the motion of small and heavy particles is not a simple superposition. However, in [3] it is shown that these studies may be artificially influenced by the turbulence forcing scheme. In the present study, a new numerical setup to investigate the combined effects of gravity and turbulence on the motion of small and heavy particles is presented, where the turbulence is only forced at the inflow and is advected through the domain by a mean flow velocity. Within a transition region the turbulence develops to a physical state which shares similarities with grid-generated turbulence in wind tunnels. In this flow, trajectories of about 43 million small and heavy particles are advanced in time. It is found that for a specific particle inertia the particles fall faster in a turbulent flow compared with their fall velocity in quiescent flow. Additionally, specific regions within the turbulent vortices cannot be reached by the particles as a result of the particle vortex interaction. Therewith, the particles tend to cluster outside the vortices. These results are in agreement with the theory of Dávilla and Hunt [4].
AB - Numerical studies [1, 2] show that the influence of gravity and turbulence on the motion of small and heavy particles is not a simple superposition. However, in [3] it is shown that these studies may be artificially influenced by the turbulence forcing scheme. In the present study, a new numerical setup to investigate the combined effects of gravity and turbulence on the motion of small and heavy particles is presented, where the turbulence is only forced at the inflow and is advected through the domain by a mean flow velocity. Within a transition region the turbulence develops to a physical state which shares similarities with grid-generated turbulence in wind tunnels. In this flow, trajectories of about 43 million small and heavy particles are advanced in time. It is found that for a specific particle inertia the particles fall faster in a turbulent flow compared with their fall velocity in quiescent flow. Additionally, specific regions within the turbulent vortices cannot be reached by the particles as a result of the particle vortex interaction. Therewith, the particles tend to cluster outside the vortices. These results are in agreement with the theory of Dávilla and Hunt [4].
UR - https://www.scopus.com/pages/publications/84919895915
U2 - 10.1007/978-3-319-03158-3_10
DO - 10.1007/978-3-319-03158-3_10
M3 - Conference contribution
AN - SCOPUS:84919895915
SN - 978-3-319-03157-6
T3 - Notes on Numerical Fluid Mechanics and Multidisciplinary Design
SP - 93
EP - 101
BT - New Results in Numerical and Experimental Fluid Mechanics IX : Contributions to the 18th STAB/DGLR Symposium, Stuttgart, Germany, 2012
A2 - Dillmann, A.
A2 - Heller, G.
A2 - Krämer, E.
A2 - Kreplin, H.-P.
A2 - Nitsche, W.
A2 - Rist, U.
PB - Springer
CY - Cham
T2 - 18th DGLR/STAB Symposium, November 3-7, 2012, Stuttgart, Germany
Y2 - 6 November 2012 through 7 November 2012
ER -