Program

09.30Coffee and registration
10.10Opening
10.15Hans Kuipers

 

Recent advances in the multi-scale simulation of mass, momentum and heat transfer in dense gas-particle flows

 

Dense gas-particle flows involving momentum, mass and heat transfer are frequently encountered in industrial processes involving granulation, coating and polymerization. In these flows both (effective) fluid-particle and (dissipative) particle-particle interactions need to be accounted for because (the competition between) these phenomena to a large extent govern the prevailing flow phenomena, i.e. the formation and evolution of heterogeneous structures. These structures have significant impact on the quality of the gas-solid contact and as a direct consequence thereof strongly affect the performance of the process. Additional complexities arise due to enhanced dissipation due to wet particle-particle collisions which prevail in processes such as spray drying, coating and granulation.

 

Due to the inherent complexity of these multiphase flows a multi-scale modeling approach is adopted in which both fluid-particle and particle-particle interactions can be properly accounted. The idea is essentially that fundamental models, taking into account the relevant details of fluid-particle interaction (DNS) and particle-particle interaction (DEM), are used to develop closure laws to feed continuum models (TFM) which can be used to compute the flow structures on a much larger (industrial) scale. In this presentation recent advances in the area of multi-scale simulation of dense gas-particle flows will be highlighted with emphasis on coupled mass, momentum and heat transfer. In addition, areas which need substantial further attention will be discussed.

 

11.15Stefan LudingFluid-Solid interactions for atoms and particles.

The interactions of fluids and solids has many aspects and involves a multitude of mechanisms and phenomena at multiple scales. The focus of this presentation is on two of those:
1) the transition from a solid to a fluid (e.g. relevant for the release of avalanches and landslides) as well as the transition from a fluid to a solid-like behavior (related to jamming and shear-thickening in various materials like suspensions or soft and granular matter.
2) the interaction of the fluid with the solid boundaries, which leads to short-ranged ordering, 
layering or cristallization, e.g. a wall-induced microstructure that renders the fluid behaving
much differently from a bulk-fluid due to the existence of this fabric/structure on the atomistic or particle scale.
12.00Coffee Break
12.30Jacco Snoeijer

Solid Capillarity

 

The forces of surface tension are known to determine the shape of droplets and liquid menisci. In principle, elastic solid interfaces also exhibit a surface tension but its effect is usually not considered. In this lecture we will show how solid mechanics can be influenced, or even governed, by “solid capillarity”. Examples range from shape instabilities of very soft gels to the adhesion of nanoparticles. It will be discussed to what extent one can unify problems of liquid-wetting and solid-adhesion.

13.15Lunch
14.45Wolfgang Wall

Recent extensions and advances in computational fluid-structure interaction

 

Fluid-Structure Interaction (FSI) problems, as well as many other coupled multi-field problems, have received much attention in recent years and continue to attract more interest. The main reason is that they are of great relevance to many fields of engineering (civil, mechanical, aerospace, bio, etc.) and applied sciences. Similarly, the development and application of corresponding numerical simulation methodologies have received wide attention over the past decades. Thanks to many advances in computational sciences and computing hardware, the numerical modeling and solution of a difficult subset of such problems that was thought to be unfeasible even five years ago, is either feasible today or will become feasible within the nearby future.
In this talk we will sketch a couple of extensions and advances that we have been able to realize for our computational approaches for FSI in recent times. And in some sense all the topics could be subsumed under the guiding principle of superior use of enrichment. For this purpose we will briefly sketch a fixed grid approach for FSI that we have developed over the last years and that is based on enriching the underlying function space. We will show how to use a similar principle to embed different fluid meshes into each other in a consistent way that also allows for a single solve of the field on these two meshes. This approach allows to develop a hybrid ALE-fixed grid approach for FSI that allows highest quality near the fluid-structure interface within a fixed grid scenario. A different way of using an enrichment enabled us to develop a novel and very promising approach for efficiently tackling turbulent flows - both in the context of finite elements and discontinuous Galerkin techniques.
If time allows we will finish with a brief look into multi-order coupling and a different formulation for FSI and it's very useful application for relevant clinical problems and/or briefly address efficient monolithic schemes for such setups that we recently even could extend to general n-field coupled problems.

 

15.45Harald van Brummelen

Modeling and simulation of multi-fluid-solid interaction

 

Multi-fluids are fluids that consist of multiple constituents, e.g. of multiple phases of the same fluid (liquid or gas) or of multiple distinct species (e.g. water and air). The interaction of such composite fluids with elastic solids leads to multitudinous intricate physical phenomena. In this presentation, we consider a computational model for multi-fluid--solid interaction based on a diffuse-interface model for the fluid. We consider various aspects related to fluid-solid surface tension and contact-line motion, and their

representation in the diffuse-interface fluid model. In addition, we will discuss specific aspects of the numerical solution procedure. We close with indicating challenges and open questions.

16.30Closure
16.50Drinks
17.30End