What does a high diffusion coefficient mean?
diffusivity
The diffusion coefficient, also known as the diffusivity, describes how fast one material can diffuse through another material. The higher the diffusion coefficient, the faster diffusion will be.
What is diffusion coefficient formula?
Diffusion coefficient is the proportionality factor D in Fick’s law (see Diffusion) by which the mass of a substance dM diffusing in time dt through the surface dF normal to the diffusion direction is proportional to the concentration gradient grad c of this substance: dM = −D grad c dF dt.
How do you find self-diffusion coefficient?
The self-diffusion coefficient is given by g · a2 times the number of jumps per sec that the diffusing particles make. Gm is the free enthalpy for a jump, i.e. the free enthalpy barrier that must be overcome between two identical positions in the lattice.
How is the diffusion coefficient determined in a dilute solution?
One of the earliest equations for determining the diffusion coefficient in dilute solutions was the Stokes-Einstein equation, based on the model of motion of a spherical particle of diffusing substance A in a viscous liquid continuum B where r 0 is the particle (molecule) radius and η B, the liquid viscosity.
What kind of formula is Sutherland’s law based on?
This formula, often called Sutherland’s law, is based on kinetic theory of ideal gases and an idealized intermolecular-force potential. Sutherland’s law is still commonly used and most often gives fairly accurate results with an error less than a few percent over a wide range of temperatures.
Who is the author of Sutherland’s law CFD?
From CFD-Wiki. In 1893 William Sutherland, an Australian physicist, published a relationship between the dynamic viscosity, , and the absolute temperature, , of an ideal gas. This formula, often called Sutherland’s law, is based on kinetic theory of ideal gases and an idealized intermolecular-force potential.
Which is the correct definition of diffusion coefficient DAC?
chemical diffusion coefficient DA is defined as the self or tracer diffusion coefficient DAC denotes diffusion under a concentration gradient DAdenotes diffusion of tracer A (dilute) in uniform concentration In dilute solution, γA = γH = constant,