The dumbbell model is a coupled hydrodynamic-kinetic model for polymeric fluids in which the configurations of the dumbbells are described by stochastic differential equations. We prove well-posedness of this model by deriving directly a priori estimates on the stochastic model. Our results can be used to analyze stochastic simulation methods such as the ones that are based on Brownian configur...

We present a simulation technique for the direct simulation of the motion of spherical particles suspended in fluids at low Reynods numbers. We use this method to simulate bidisperse suspensions at varying size ratios of the suspended spheres and compare to analytic results of Batchelor for the low concentration regime. We find that the pair correlation functions indicate that three body hydrod...

CASC2D is a physically-based, distributed model that simulates the response of a watershed to precipitation. Basic processes in the model include: precipitation, interception, infiltration, surface runoff and channel flow, and erosion and deposition of upland soil and channel bed sediment. Model performance is demonstrated by applications to numerous sites such as Goodwin Creek, MS. This waters...

The transfer of Cryptosporidium oocysts from the surface water to the sediment beds of streams and rivers influences their migration in surface waters. We used controlled laboratory flume experiments to investigate the deposition of suspended Cryptosporidium parvum oocysts in streambeds. The experimental results demonstrate that hydrodynamic interactions between an overlying flow and a sediment...

Sandy or permeable sediment deposits cover the majority of the shallow ocean seafloor, and yet the associated bacterial communities remain poorly described. The objective of this study was to expand the characterization of bacterial community diversity in permeable sediment impacted by advective pore water exchange and to assess effects of spatial, temporal, hydrodynamic, and geochemical gradie...

We present the validation and application of a numerical model for the simulation of wave-induced sediment transport. Our approach is a oneway coupling of an inviscid flow model (i.e., a Numerical Wave Tank based on potential flow theory; NWT) to a Navier-Stokes solver, to simulate near bottom wave-induced turbulent boundary layer flows. Only two-dimensional incident wave fields have been consi...

in this paper, a batch hydrogenation reactor performance was modeled using a hydrodynamic and reaction sub-models. the reaction expressions were obtained from the information reported in literature. experimental studies were conducted in order to generate the experimental data needed to validate the model. the comparison between the experimental data and model predictions seems quite satisfacto...