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Energy spectrum scalar-flux

Similar relationships exist for the scalar flux energy spectrum and the scalar covariance energy spectrum. [Pg.91]

This expression applies to the case where there is no mean scalar gradient. Adding a uniform mean scalar gradient generates an additional source term on the right-hand side involving the scalar-flux energy spectrum. [Pg.97]

Figure 4.9. Sketch of CSTR representation of the SR model for 1 < Sc. Each wavenumber band is assumed to be well mixed in the sense that it can be represented by a single variable

$Figure 4.9. Sketch of CSTR representation of the SR model for 1 < Sc. Each wavenumber band is assumed to be well mixed in the sense that it can be represented by a single variable <p 2)n- Scalar energy cascades from large scales to the dissipative range where it is destroyed. Backscatter also occurs in the opposite direction, and ensures that any arbitrary initial spectrum will eventually attain a self-similar equilibrium form. In the presence of a mean scalar gradient, scalar energy is added to the system by the scalar-flux energy spectrum. The fraction of this energy that falls in a particular wavenumber band is determined by forcing the self-similar spectrum for Sc = 1 to be the same for all values of the mean-gradient source term.$

Closure of the mean scalar field equation requires a model for the scalar flux term. This term represents the scalar transport due to velocity fluctuations in the inertial subrange of the energy spectrum and is normally independent of the molecular diffusivity. The gradient diffusion model is often successfully employed (e.g., [15, 78, 2]) ... [Pg.710]

See other pages where Energy spectrum scalar-flux is mentioned: [Pg.91] [Pg.123] [Pg.135] [Pg.71] [Pg.72] [Pg.104] [Pg.93]

See also in sourсe #XX -- [ Pg.72 , Pg.78 , Pg.128 , Pg.130 , Pg.363 , Pg.366 ]

See also in sourсe #XX -- [ Pg.72 , Pg.78 , Pg.128 , Pg.130 , Pg.363 , Pg.366 ]

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Energy flux

Energy spectrum scalar

Scalar

Scalar flux