Seminar by Dr. Fabian A. Bombardelli
Date: Mon., April 25, 2016
Place: PACCAR 202
Time: 10:10 a.m.—11:00 a.m.
EXPLAINING THE INTRICACIES OF SEDIMENT TRANSPORT AT DIFFERENT SCALES WITH COMPUTATIONAL AND THEORETICAL APPROACHES
Examples of multi-phase flows are diverse: dust storms, sediment transport in rivers and estuaries, bubble plumes, and many other natural and man-made applications. To study sediment transport, the field is transitioning from old regressions of last 70 years, to mechanistic models, which combine deterministic and stochastic approaches. For reasons which are unclear, and despite the leadership of civil engineers in the field of sediment transport, the theory of two-phase flows has been developed elsewhere. These models address the interaction of carrier and disperse phases.
Still, it is not clear what to use for a given level of concentration, and for the objective of a given study. Furthermore, the action of turbulence needs to be quantified carefully depending on the problem at hand, and phenomena such as sediment entrainment need to be accounted for.
In this presentation, I describe a novel framework to analyze sediment transport, which clearly puts forward a pathway for the analysis of a host of problems. We present the application of this framework to solve the problem of sediment in suspension. For the case of transport of sediment as bed-load, we present a Lagrangian model which tracks each particle individually and addresses the Non-Fickian behavior of the particles; followed by a new computational algorithm for the Basset force. Finally, we describe theoretical and numerical approaches to deal with two-phase flows. The presentation concludes with an analysis of future work and the challenges to overcome
Examples of multi-phase flows are diverse: dust storms, sediment transport in rivers and estuaries, bubble plumes, and many other natural and man-made applications. To study sediment transport, the field is transitioning from old regressions of last 70 years, to mechanistic models, which combine deterministic and stochastic approaches. For reasons which are unclear, and despite the leadership of civil engineers in the field of sediment transport, the theory of two-phase flows has been developed elsewhere. These models address the interaction of carrier and disperse phases.
Still, it is not clear what to use for a given level of concentration, and for the objective of a given study. Furthermore, the action of turbulence needs to be quantified carefully depending on the problem at hand, and phenomena such as sediment entrainment need to be accounted for.
In this presentation, I describe a novel framework to analyze sediment transport, which clearly puts forward a pathway for the analysis of a host of problems. We present the application of this framework to solve the problem of sediment in suspension. For the case of transport of sediment as bed-load, we present a Lagrangian model which tracks each particle individually and addresses the Non-Fickian behavior of the particles; followed by a new computational algorithm for the Basset force. Finally, we describe theoretical and numerical approaches to deal with two-phase