Patchy Wet Granular Matter

• Applicant: Privatdozent Dr. Kai Huang
• Subject Area: Statistical Physics, Nonlinear Dynamics, Complex Systems, Soft and Fluid Matter, Biological Physics
• Term: from 2015 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 290337193

• Final Report Year: 2021

Final Report Abstract

Understanding the dynamics of wet granular matter (e.g. wet sand on the beach) from a physical perspective is a topic of building fundamentals for a wide range of applications with substantial impact on our society: From the prediction of natural disasters (e.g. landslide, debris flow) to the enhancement of energy efficiency in industries (e.g. granulation process). At the ‘microscopic’ scale, our investigation on ‘patchy’ particle-particle interactions as well as energy injection into different DoF through mechanical agitations shed light on the development of more sophisticated models for large scale simulations of wet granular materials, which are abundant in nature and are typically composed of irregular shaped particles. At the ‘macroscopic’ scale, our investigations on the critical behavior (e.g. orderdisorder transition) in agitated wet granular matter – a nonequilibrium model system – revealed that the existing knowledge for systems in thermodynamic equilibrium can be extended to understand granular dynamics, provided that the particles are effectively mobilized. We identified a ‘rotator-crystal’ phase, which builds another bridge to existing equilibrium systems. The techniques developed in the project shall shed light on a broader audience: For instance chemists working in drop-on-demand applications are currently using the inkjet printing technique, the set-voronoi technique can be potentially useful for pedestrian follow analysis, radar technique can be used in human-machine interactions and autonomous driving. We believe that further investigations in those directions can potentially build more interdisciplinary research in the future.

Publications

• Clustering and melting in a wet granular monolayer. EPJ Web Conf. 140, 08003 (2017)
  Ramming, P. & Huang, K.
  
• Density-wave fronts on the brink of wet granular condensation. Scientific Reports 7, 3613 (2017)
  Zippelius, A., Huang, K.
  
• Dynamics of wet granular hexagons. Phys. Rev. E 95, 030901 (2017)
  Baur, M. & Huang, K.
  
• Preface: Focus on imaging methods in granular physics. Review of Scientific Instruments 88, 051701 (2017)
  Amon, A. et al.
  
• The role of initial speed in projectile impacts into light granular media. Scientific Reports 10, 1–12 (2020)
  Huang, K., Hernández-Delfin, D., Rech, F. , Dichtl, V. & Hidalgo, R. C.
  
• Dynamics of wetting explored with inkjet printing. EPJ Web Conf. 140, 09035 (2017)
  Völkel, S. & Huang, K.
  
• Radar for tracer particles. Review of Scientific Instruments 88, 051801 (2017)
  Ott, F., Herminghaus, S. & Huang, K.
  
• Internal and surface waves in vibrofluidized granular materials: Role of cohesion. Phys. Rev. E, 97, 052905 (2018)
  Huang, K.
  
• Coupling between rotational and translational motions of a vibrated polygonal disk. New J. Phys. 22, 123018 (2020)
  Völkel, S. & Huang, K.
  
• Set-Voronoi Tessellation for Particulate Systems in Two Dimensions. in Traffic and Granular Flow 2019 (Springer, 2020)
  Völkel S., Huang K.