I have read the different length scales of turbulence and the dominant processes in these scales from attached papers. I do not understand them clearly. From paragraph 5 on page 2159 of Varney (2011), I read that the range in which viscosity is dissipating energy is known as viscous subrange. But, from paragraph 3 on page 2603 of Rapp (2004), I read that in viscous subrange, the tracer variance is effectively destroyed by molecular diffusion.
Links for Varney (2011) and Rapp (2004), respectively are:
Article The electron density dependence of polar mesosphere summer echoes
https://doi.org/10.5194/acp-4-2601-2004
Could anyone briefly explain the following length scales and the process responsible for dissipation of energy and the destruction of the variance in tracer (like neutral air density fluctuations).
i. Inertial subrange
ii. Viscous subrange
iii. Diffusive subrange
iv. Convective subrange
v. inertial-convective subrange
vi. viscous-convective subrange
vii. viscous-diffusive subrange
Thanks
Have you read the book "Turbulent Flows" by Pope? It is instructive for your goal.
I suggest also to distinguish first the case of homogeneous isotropic turbulence from the case of confined turbulence.
@ Filippo Maria Denaro
I have started reading the book, "Turbulent Flows" by Pope , but was difficult to differentiate the different scales. That's why i ask the question to get some clue from experts in the field of turbulence.
THANKS
Start first to analyse the case of homogeneous turbulence and consider the general energy spectra. You can see the range of the peak in the spectra, associated to the integral lenght scale (the large characteristic lenght scale of the problem). Then, the energy cascade appears having a constant slope in the inertial range. Finally, you see a decaying in the energy starting at the level of the Taylor lenght scale that is the largest lenght scale at which energy dissipation due to molecular diffusion acts. The final lenght scale is the Kolmogorov one, the smallest where dissipation act. Consider that you can read each wavenumber along the spectra as different lenght scale since k=pi/l.
Once you have studied this characteristic lenght scales, you can work on the wall-turbulence where the viscous sublayer, transition and log layer appear depending on the distance from the wall.
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