The group RHINOS at the Leichtweiß-Institute for Hydraulic Engineering at the Technical University of Braunschweig carries out particle-resolved simulations of dense particle laden suspensions at the transition between the viscous and inertial regimes. The transition between these two regimes, however, has not been investigated in a systematic manner yet, and, hence, remains only poorly understood. This may be problematic for the predictive modeling of situations that are more relevant for engineering practices and natural flows involving sediment transport. In addition, the constitutive laws to describe particle-laden suspension flow processes have so far mostly been based on studies of dense suspensions of neutrally buoyant particles in either highly viscous shearing flows or at much larger flow rates where inertial effects play the dominant role. The current project aims at bridging the gap about the rheology of dense suspensions in the transition between the viscous and inertial regimes. The campaign would yield highly-resolved data of laminar pressure-driven shearing flows across an idealized sediment bed for a wide range of Stokes numbers as the ratio of competing inertial and viscous effects. These data will be used to improve existing two-phase modeling approaches that have become popular for macroscopic sediment transport models.
C. Rettinger, S. Eibl, U. Rüde, B. Vowinckel (2022). Rheology of mobile sediment beds in laminar shear flow: Effects of creep and polydispersity. Journal of Fluid Mechanics, 932, A1 (PDF verfügbar).
B. Vowinckel, E. Biegert, E. Meiburg, P. Aussillous, É. Guazzelli. Rheology of mobile sediment beds sheared by viscous, pressure-driven flows. Journal of Fluid Mechanics, 921, A20, 2021 (PDF verfügbar).
C. Rettinger, S. Eibl, U. Rüde, S. Konidena, B. Vowinckel (2022). Comparative Study of the Rheological Behavior of Sheared Bi- and Polydisperse Sediment Beds via Fully Resolved Simulations. (IAHR, 2022).