A5069193901- Hydrology and Sediment Transport Processes
- Landslides and related hazards
- Granular flow and fluidized beds
- Geological formations and processes
- Soil erosion and sediment transport
- Drilling and Well Engineering
- Hydraulic Fracturing and Reservoir Analysis
- Fatigue and fracture mechanics
- Metallurgical Processes and Thermodynamics
- Underwater Acoustics Research
- Advanced ceramic materials synthesis
- Offshore Engineering and Technologies
- Aeolian processes and effects
- Lattice Boltzmann Simulation Studies
- Geology and Paleoclimatology Research
- Geotechnical and Geomechanical Engineering
- Structural Analysis and Optimization
- Flood Risk Assessment and Management
- Coastal and Marine Dynamics
- Soil Mechanics and Vehicle Dynamics
- Pickering emulsions and particle stabilization
- Advanced Materials and Mechanics
- Hydraulic flow and structures
- Cyclone Separators and Fluid Dynamics
- Cryospheric studies and observations
Clark University
2024
Universidade Estadual de Campinas (UNICAMP)
2022
City College of New York
2016-2021
University of Pennsylvania
2014-2016
Institut de physique du globe de Paris
2012-2013
Sorbonne Paris Cité
2012-2013
Université Paris Cité
2012-2013
Abstract Fluid-sheared granular transport sculpts landscapes and undermines infrastructure, yet predicting the onset of sediment remains notoriously unreliable. For almost a century, this has been treated as discontinuous transition at which hydrodynamic forces overcome gravity-loaded grain–grain friction. Using custom laminar-shear flume to image slow dynamics deep into bed, here we find that is instead continuous from creeping flow. This occurs inside dense bed critical viscous number,...
Despite several decades of investigations, accounting for the effect wide range grain sizes composing bed rivers on bedload transport remains a challenging problem. We investigate this problem by studying experimentally influence size distribution in simple configuration bimodal sediment composed mixture 2 populations quartz grains D 1 = 0.7 ± 0.1 mm and 2.2 0.4 mm, respectively. The experiments are carried out tilted rectangular flume inside which is sheared steady spatially uniform...
Understanding the dynamics of fluid-driven sediment transport remains challenging, as it is an intermediate region between a granular material and fluid flow. Boyer \textit{et al.}\citep{Boyer2011} proposed local rheology unifying dense dry-granular viscous-suspension flows, but has been validated only for neutrally-buoyant particles in confined system. Here we generalize model to account weight particle by addition pressure $P_0$, test ability this describe idealized laboratory river. We...
Abstract. We report on a new set of measurements the morphology braided and meandering threads Kosi megafan, North Bihar, India. All develop uniform sandy sediment under similar climate. The data is composed width, depth, water discharge grain size 51 threads. Downstream slopes sinuosity are also available. Using this set, we show that share common hydraulic geometries. then use threshold theory to explain why aspect ratio almost naturally detrended, rescale according theory. As expected,...
Abstract. Bedload particles entrained by rivers tends to disperse as they move downstream. In this paper, we use the erosion-deposition model of Charru et al. (2004) describe velocity and spreading a plume tracer particles. We restrict our analysis steady-state transport above flat bed uniform sediment. The is then controlled downstream advection particle exchange with immobile bed. After transitional regime dominated initial conditions, evolution markers asymptotically towards classical...
ABSTRACT Flow-frictional resistance at the base of glaciers and ice sheets is strongly linked to subglacial water pressure. Understanding physical mechanisms that govern meltwater fluxes in channels hence critical for constraining variations flow. Previous mathematical descriptions soft-bed assume a viscous till rheology, which inconsistent with laboratory data majority field studies. Here, we use grain-scale numerical formulation coupled pore-water dynamics analyze structural stability...
The critical fluid-shear stress for the onset of sediment transport, θc, varies with history applied shear. This effect has been primarily attributed to compaction; role shear jamming is less explored. We examine response a granular bed cycles varying magnitude and direction, determine isotropic anisotropic contributions. Creep bed-load transport result in direction-dependent strain hardening θ/θc<4. Dilation-induced weakening, memory loss, occur larger stresses that fluidize bed. Our...
Laboratory experiments and particle-resolved simulations are employed to investigate the settling dynamics of a pair rigidly connected spherical particles unequal size. They yield detailed picture transient evolution terminal values aggregate's orientation angle its drift velocities as functions aspect ratio Galileo number $Ga$ , which denotes buoyancy viscous forces acting on aggregate. At low moderate velocity converge their monotonically, whereas for higher -values aggregate tends undergo...
To model soil dynamics, the particle scale deformation of sediment bed is measured as a controlled porous flow passes through it.
Abstract. We study the morphology of streams flowing on alluvial megafan Kosi River in north Bihar, India. All develop a uniform sandy sediment and under similar climate, allowing for statistically significant comparisons. Our data set includes both channels from braid isolated single-thread rivers. Using an Acoustic Doppler Current Profiler, we measure width, depth water discharge channels. Their average slope is also acquired with kinematic GPS. These morphological characteristics are...
Experiments on a submerged sediment layer creep were performed, varying the system angle and porous flow, far under avalanching stress criterion. Logarithmic decay rates of deformation are observed, with rate increasing both control parameters.
Laboratory experiments and particle-resolved simulations are employed to investigate the settling dynamics of a pair rigidly connected spherical particles unequal size. They yield detailed picture transient evolution terminal values aggregate's orientation angle its drift velocities as functions aspect ratio Galileo number $Ga$, which denotes buoyancy viscous forces acting on aggregate. At low moderate velocity converge their monotonically, whereas for higher $Ga$-values aggregate tends...
Inspired by presentations the authors during a workshop organized at Princeton Center for Theoretical Science (PCTS) in January 2022, we present perspective on some of outstanding questions related to "physics ground beneath our feet." These identified challenges are intrinsically shared with field Soft Matter but also have unique aspects when natural environment is studied.