Particle Diffusion in Stably Stratified Flows
2010 (English)In: PROGRESS IN TURBULENCE III / [ed] Peinke, J.; Oberlack, M.; Talamelli, A., 2010, Vol. 131, 163-166 p.Conference paper (Refereed)
Numerical simulations are used to study the vertical dispersion of fluid particles in homogeneous turbulent flows with a stable stratification. The results of direct numerical simulations are in good agreement with the relation for the long time fluid particle dispersion, = 2 epsilon(P)t / N-2, derived by , though with a small dependence on the buoyancy Reynolds number. Here, is the mean square vertical particle displacement, epsilon p is the dissipation of potential energy, t is time and N is the Brunt-Vaisala frequency. A simulation with hyperviscosicity is performed to verify the relation = (1 + pi C-PL)2 epsilon(P)t / N-2 for shorter times, also derived by . The agreement is reasonable and we find that C-PL similar to 3. The onset of a plateau in is observed in the simulations at t similar to E-P / epsilon(P) which scales as 4E(P) / N-2, where E-P is the potential energy.
Place, publisher, year, edition, pages
2010. Vol. 131, 163-166 p.
, Springer Proceedings in Physics, ISSN 0930-8989 ; 131
VERTICAL DIFFUSION, TURBULENCE
IdentifiersURN: urn:nbn:se:kth:diva-27127ISI: 000283758200039ISBN: 978-3-642-02224-1OAI: oai:DiVA.org:kth-27127DiVA: diva2:375145
Proceedings of the iTi Conference in Turbulence 2008, Bertinoro, ITALY, OCT 12-15, 2008
QC 201012072010-12-072010-12-062010-12-07Bibliographically approved