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ν is the kinematic viscosity of the fluid, ν = μ / ρ (m 2 /s); ρ is the density of the fluid (kg/m 3 ). For such systems, laminar flow occurs when the Reynolds number is below a critical value of approximately 2,040, though the transition range is typically between 1,800 and 2,100.
Viscosity is a measure of a fluid's rate-dependent resistance to a change in shape or to movement of its neighboring portions relative to one another. [1] For liquids, it corresponds to the informal concept of thickness; for example, syrup has a higher viscosity than water. [2]
Consequently, if a liquid has dynamic viscosity of n centiPoise, and its density is not too different from that of water, then its kinematic viscosity is around n centiStokes. For gas, the dynamic viscosity is usually in the range of 10 to 20 microPascal-seconds, or 0.01 to 0.02 centiPoise. The density is usually on the order of 0.5 to 5 kg/m^3.
In physics and chemistry, a non-Newtonian fluid is a fluid that does not follow Newton's law of viscosity, that is, it has variable viscosity dependent on stress. In particular, the viscosity of non-Newtonian fluids can change when subjected to force. Ketchup, for example, becomes runnier when shaken and is thus a non-Newtonian fluid.
The turbulent Schmidt number is commonly used in turbulence research and is defined as: [3] = where: is the eddy viscosity in units of (m 2 /s); is the eddy diffusivity (m 2 /s).; The turbulent Schmidt number describes the ratio between the rates of turbulent transport of momentum and the turbulent transport of mass (or any passive scalar).
kinematic viscosity: meter squared per second (m 2 /s) neutrino: xi: electromotive force: volt (V) pi: 3.14159... (irrational number) unitless rho: mass density usually simply called density kilogram per cubic meter (kg/m 3) volume charge density: coulomb per cubic meter (C/m 3) resistivity: ohm meter (Ω⋅m)
In 1877 Boussinesq proposed relating the turbulence stresses to the mean flow to close the system of equations. Here the Boussinesq hypothesis is applied to model the Reynolds stress term. Note that a new proportionality constant >, the (kinematic) turbulence eddy viscosity, has been introduced. Models of this type are known as eddy viscosity ...
A built-in density measurement based on the oscillating U-tube principle allows the determination of kinematic viscosity from the measured dynamic viscosity employing the relation =, where: ν is the kinematic viscosity (mm 2 /s), η is the dynamic viscosity (mPa·s), ρ is the density (g/cm 3).