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Taylor dispersion or Taylor diffusion is an apparent or effective diffusion of some scalar field arising on the large scale due to the presence of a strong, confined, zero-mean shear flow on the small scale. Essentially, the shear acts to smear out the concentration distribution in the direction of the flow, enhancing the rate at which it ...
It is defined as the ratio of the convection current to the dispersion current. The Bodenstein number is an element of the dispersion model of residence times and is therefore also called the dimensionless dispersion coefficient. [1] Mathematically, two idealized extreme cases exist for the Bodenstein number.
Typical values for the entrainment coefficient are of about 0.08 for vertical jets and 0.12 for vertical, buoyant plumes while for bent-over plumes, the entrainment coefficient is about 0.6. Conservation equations for mass (including entrainment), and momentum and buoyancy fluxes are sufficient for a complete description of the flow in many cases.
Dispersion can be differentiated from diffusion in that it is caused by non-ideal flow patterns [1] (i.e. deviations from plug flow) and is a macroscopic phenomenon, whereas diffusion is caused by random molecular motions (i.e. Brownian motion) and is a microscopic phenomenon.
Hydrodynamic dispersion is then embedded in the advective-dispersive-reactive equation (ADRE) assuming a Fickian closure model. Dispersion is felt at the macroscale as responsible of a spread effect of the contaminant plume around its center of mass.
Flow-induced dispersion analysis (FIDA) is an immobilization-free technology used for characterization and quantification of biomolecular interaction and protein concentration under native conditions. [1] [2] [3] In the FIDA assay, the size of a ligand (indicator) with affinity to the target analyte is measured. When the indicator interacts ...
The Morison equation contains two empirical hydrodynamic coefficients—an inertia coefficient and a drag coefficient—which are determined from experimental data. As shown by dimensional analysis and in experiments by Sarpkaya, these coefficients depend in general on the Keulegan–Carpenter number, Reynolds number and surface roughness. [4] [5]
In the table below, the dispersion relation ω 2 = [Ω(k)] 2 between angular frequency ω = 2π / T and wave number k = 2π / λ is given, as well as the phase and group speeds. [ 10 ] Frequency dispersion of gravity waves on the surface of deep water, shallow water and at intermediate depth, according to linear wave theory