Velocity inertial subrange model: Difference between revisions

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<math>\Psi_{Vj}(\hat{k})=a_jC_k\varepsilon^{2/3}\hat{k}^{-5/3}</math>
<math>\Psi_{Vj}(\hat{k})=a_jC_k\varepsilon^{2/3}\hat{k}^{-5/3}</math>


[[File:InertialSubrange.png|thumb|insert caption]]
[[File:InertialSubrange.png|thumb|Sketch of velocity power density spectrum in log-log space. The vertical axis represents <math>\Psi_{Vj}(\hat{k})</math>]. The inertial subrange's -5/3 slope is highlighted.]


Here <math>\hat{k}</math> is expressed in rad/m and <math>Vj</math> represents the velocities <math>V</math>  in direction <math>j</math>.  <math>C_k</math> is the empirical Kolmogorov universal constant of C
Here <math>\hat{k}</math> is expressed in rad/m and <math>Vj</math> represents the velocities <math>V</math>  in direction <math>j</math>.  <math>C_k</math> is the empirical Kolmogorov universal constant of C

Revision as of 21:38, 11 November 2021


Short definition of Velocity inertial subrange model
The inertial subrange separates the energy-containing production range from the viscous dissipation range.

This is the common definition for Velocity inertial subrange model, but other definitions may be discussed within the wiki.



Inertial subrange for steady-flows

This theoretical model predicts the spectral shape of velocities in wavenumber space.

ΨVj(k^)=ajCkε2/3k^5/3

[[File:InertialSubrange.png|thumb|Sketch of velocity power density spectrum in log-log space. The vertical axis represents ΨVj(k^)]. The inertial subrange's -5/3 slope is highlighted.]

Here k^ is expressed in rad/m and Vj represents the velocities V in direction j. Ck is the empirical Kolmogorov universal constant of C = 1.5 [1]. Amongst the three direction, the spectra deviates by the constant aj: [2]

  • In the longitudinal direction, i.e., the direction of mean advection (j=1), a1=1855
  • In the other directions a2=a3=43a1

Inertial subrange for flows influenced by surface waves

Need to add equations and figures from Lumley & Terray[3]

Notes

  1. K. R. Sreenivasan. 1995. On the universality of the Kolmogorov constant. Phys. Fluids. doi:10.1063/1.868656
  2. S.B Pope. 2000. Turbulent flows. Cambridge Univ. Press. doi:10.1017/CBO9780511840531
  3. J. Lumley and E. Terray. 1983. Kinematics of turbulence convected by a random wave field. J. Phys. Oceanogr. doi:10.1175/1520-0485(1983)<2000:KOTCBA>2.0.CO;2