Search results for "Fluid Dynamic"
showing 10 items of 1034 documents
M8_Microfluidics_for_CNT
2018
A comparation of two sorting strategies. While the shallow channel guides the droplets more precisely to the sorting point, the confined droplets are more vulnerable to coalescence and break-up. The deep channel lowers the positioning precision, however, the droplets are more stable.
Complex singularity analysis for vortex layer flows
2021
We study the evolution of a 2D vortex layer at high Reynolds number. Vortex layer flows are characterized by intense vorticity concentrated around a curve. In addition to their intrinsic interest, vortex layers are relevant configurations because they are regularizations of vortex sheets. In this paper, we consider vortex layers whose thickness is proportional to the square-root of the viscosity. We investigate the typical roll-up process, showing that crucial phases in the initial flow evolution are the formation of stagnation points and recirculation regions. Stretching and folding characterizes the following stage of the dynamics, and we relate these events to the growth of the palinstro…
"Table 3" of "Measurement of azimuthal anisotropy of muons from charm and bottom hadrons in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detec…
2020
Summary of results for charm and bottom muon v2 as a function of multiplicity. Uncertainties are statistical and systematic, respectively.
Fluid flow simulations meet high-speed video : Computer vision comparison of droplet dynamics
2018
Hypothesis While multiphase flows, particularly droplet dynamics, are ordinary in nature as well as in industrial processes, their mathematical and computational modelling continue to pose challenging research tasks - patent approaches for tackling them are yet to be found. The lack of analytical flow field solutions for non-trivial droplet dynamics hinders validation of computer simulations and, hence, their application in research problems. High-speed videos and computer vision algorithms can provide a viable approach to validate simulations directly against experiments. Experiments Droplets of water (or glycerol-water mixtures) impacting on both hydrophobic and superhydrophobic surfaces …
Formulation predictive dissolution (fPD) testing to advance oral drug product development: an introduction to the US FDA funded ‘21st Century BA/BE’ …
2018
Over the past decade, formulation predictive dissolution (fPD) testing has gained increasing attention. Another mindset is pushed forward where scientists in our field are more confident to explore the in vivo behavior of an oral drug product by performing predictive in vitro dissolution studies. Similarly, there is an increasing interest in the application of modern computational fluid dynamics (CFD) frameworks and high-performance computing platforms to study the local processes underlying absorption within the gastrointestinal (GI) tract. In that way, CFD and computing platforms both can inform future PBPK-based in silico frameworks and determine the GI-motility-driven hydrodynamic impac…
Analytic solutions of the Navier-Stokes equations
2001
We consider the time dependent incompressible Navier-Stokes equations on an half plane. For analytic initial data, existence and uniqueness of the solution are proved using the Abstract Cauchy-Kovalevskaya Theorem in Banach spaces. The time interval of existence is proved to be independent of the viscosity.
Large-Eddy Simulation of Flow and Heat Transfer in Compact Heat Exchangers
1994
LES results are presented for different heat exchanger geometries. Subgrid terms were usually computed by the Smagorinsky model; preliminary comparative results are also given for the ‘dynamic’ subgrid model. The numerical methods used were those implemented in a commercial general-purpose code (CFDS-FLOW3D); they included a finite-volume approach, colocated body-fitted grids, central differencing for the advection terms, the SIMPLEC algorithm, and Crank-Nicolson time stepping. Predictions arc compared with experimental measurements (including local Nu distributions), and with results from a low-Reynolds number k-e model. In most cases, LES was more ‘robust’ and required little more CPU tim…
Adjoint-based inversion for porosity in shallow reservoirs using pseudo-transient solvers for non-linear hydro-mechanical processes
2020
Abstract Porous flow is of major importance in the shallow subsurface, since it directly impacts on reservoir-scale processes such as waste fluid sequestration or oil and gas exploration. Coupled and non-linear hydro-mechanical processes describe the motion of a low-viscous fluid interacting with a higher viscous porous rock matrix. This two-phase flow may trigger the initiation of solitary waves of porosity, further developing into vertical high-porosity pipes or chimneys. These preferred fluid escape features may lead to localised and fast vertical flow pathways potentially problematic in the case of for instance CO2 sequestration. Constraining the porosity and the non-linearly related pe…
Applied Mathematics versus Fluid Dynamics
2018
This paper investigates scientific, institutional, and political conflict and collaboration between two different disciplines in the first part of the 20th century: applied mathematics and fluid dynamics. It argues for the catalytic role of Richard von Mises (1883–1953) in this process and analyzes the reasons for von Mises’s considerable fame in the former and limited posthumous reputation in the latter field. I argue that von Mises’s contributions to fluid dynamics and aerodynamics suffered chiefly from two somewhat interconnected deficiencies compared to the work of his principal competitors. There was, on the one hand, von Mises’s methodological preference for applied mathematics as opp…
Evaluation of a combined activated carbon prefilter and biotrickling filter system treating variable ethanol and ethyl acetate gaseous emissions
2009
The removal of a 1:1 by weight mixture of ethanol and ethyl acetate was studied in a gas phase biotrickling filter running under conditions that simulated industrial emissions from the flexographic sector, i.e. discontinuous loading (twelve hours per day and five days per week) and oscillating concentration of the inlet stream. Three sets of experimental conditions were tested in which empty-bed residence time varied from 60 to 25s (inlet loads from 50 to 90g Cm -3 h -1 ). The biotrickling filter reached a maximum elimination capacity of 48.5g Cm -3 h -1 (removal efficiency = 68.9%) for an empty-bed residence time of 40 s. A decrease in the residence time from 40 to 25 s adversely affected …