S. Pirker1, S. Radl2, S. Schneiderbauer1
1Johannes Kepler University/AT, 2Princeton University/US
This mini-symposium focuses on the kinetic theory based mathematical modelling of medium to dense gas-particle. Based on the fundamental assumption of ‘molecular chaos’ at grain level, the behaviour of the multitude of particles can be described either within an Eulerian or within a Lagrangian frame of reference. While the first case results in the field of classical kinetic theory based Eulerian particle methods, the latter case is captured by statistical Lagrangian methods, where inter-particle collisions are implemented by probability based ‘virtual’ collision partners.
Although the fundaments for either modelling concept have been laid several decades ago, still several challenges prevail: On the one hand, in the Eulerian approach the question of how to account for poly-dispersity is still stimulating a lot of modelling activities (e.g. Direct Quadrature Method of Moments (DQMoM), hybrid Eulerian-Lagrangian models). Also the question of how to account for particle clusters on the sub-grid scale (e.g. Energy Minimization Multi-Scale (EMMS) approach, sub-grid filtering, additional cluster phase) concerns many research groups. Finally, the interaction between particle clouds and fluid turbulence still needs to be focused (e.g. particle influence on sub-grid viscosity in Large Eddy Simulations LES). On the other hand, the feasibility of picturing dense gas-particle flows by statistical Lagrangian methods is of great concern. Accounting for particle clouds rather than for individual particles has been proposed as a possible remedy. Further modelling activities on the Lagrangian side include probability based models for particle agglomeration and re-fragmentation. This list of actual modelling challenges could be easily extended.
Typical application fields of these models comprise pneumatic conveying (e.g. particle rope formation behind bends), particle separation in medium to highly laden cyclones or any kind of particle processing in fluidized beds, risers or similar equipment.
This mini-symposium will provide a platform for discussion on these or related topics. Potential participants are encouraged to present their theoretical research as well as applications and/or experimental validations.