Print Email Facebook Twitter Contact velocities of small ellipsoids settling in turbulence Part of: 15th EuropeanTurbulence Conference 2015 (ETC15)· list the conference papers Title Contact velocities of small ellipsoids settling in turbulence Author Siewert, C. Kunnen, R.P.J. Schröder, W. Date 2015-08-27 Abstract Collisions of small and heavy non-spherical particles settling in turbulence are very important for systems such as ice clouds and proto-planetary disks where the particle spectra evolution is strongly dependent on the collision induced growth rate. Still, the influence of the particle shape on the collision probability is virtually unknown. Building on our recent investigation on the collision rate of monodisperse suspensions of ellipsoidal particles (Siewert et al., J. Fluid Mech. 758, 686-701, 2014), we show theoretically and by direct numerical simulations that the behavior of ellipsoids subject to turbulence and gravity is different from the behavior of spheres. Due to the dependence of the particle settling velocity on the particle orientation, the relative velocity at contact is influenced by turbulence. When ellipsoids differ either by mass or shape, their contact velocity is randomized by the randomized particle orientation. For particles much heavier than the fluid these orientation dependent settling velocity differences are larger than the relative velocities directly induced by the turbulent fluctuations. To reference this document use: http://resolver.tudelft.nl/uuid:ed3a58ff-a043-4902-a686-8f686fb6d7b5 Part of collection Conference proceedings Document type conference paper Rights (c) the Authors Files PDF 63.pdf 41.05 KB Close viewer /islandora/object/uuid:ed3a58ff-a043-4902-a686-8f686fb6d7b5/datastream/OBJ/view