mixing length

mixing length

[′mik·siŋ ‚leŋkth]
(physics)
A mean length of travel, characteristic of a particular motion, over which an eddy maintains its identity; it is analogous to the mean free path of a molecule; physically, the idea implies that mixing occurs by discontinuous steps, that fluctuations which arise as eddies with different characteristics wander about, and that the mixing is done almost entirely by the small eddies.
References in periodicals archive ?
According to the Boussinesq eddy viscosity assumption (Boussinesq, 1877), the logarithmic law for velocity profile was solved by using the mixing length method (Prandtl, 1925; Khan et al.
Logarithm law (Prandtl, 1925), derived by the mixing length method, is the most popular equation used to express the mean velocity in a cross section of turbulent shear flow.
To gain some understanding of the phenomena taking place in the mixing zone in T-junctions, numerical investigations have been carried out to determine the thermal mixing length.
The initial turbulence intensity was set at 5% of the mean flow, and the integral length scale was estimated with the mixing length model of Prandtl.
The Cobras could well be without their cleverest fast bowler - in terms of mixing length, line and pace - Charl Langveldt, after he injured himself diving in the field against Bangalore.
It has been recently shown that TKE eddy-diffusivity approaches with simple mixing length formulations can realistically represent the top-entrainment in dry convective boundary layers (Teixeira and Cheinet 2004; Teixeira et al.
Because the available reactor volume is slightly different when different elements are used (Table 2), the downstream volumes were defined in terms of the corresponding additional mixing length [lambda], the length of the section downstream of the probe that is part of the apparent volume over which the mean residence time is measured.
More versatile than Farrel's original continuous mixer, the unit features extra mixing length and residence time and what the supplier terms a vastly expanded processing window.
Because glass fiber breakage should, of course, be kept to a minimum, the mixing length for glass fiber compounding is generally 50% shorter and less intensive than for kaolin.
Of course, this conclusion is very well known empirically in fluid mechanics, where it serves as the basis for Prandtl's mixing length hypothesis in free turbulent flows and for the entrainment hypothesis used in the integral analysis of jets and plumes.
The vertical diffusion is parameterised using a prognostic equation for the turbulent kinetic energy (TKE) and a diagnosed mixing length, according to Estournel and Guedalia (1987) for stable conditions and to Bougeault and Lacarriere (1989) for unstable stratification.