Orateur
Description
I will very briefly review the basics of the legacy of Kolmogorov
turbulence statistics. Interstellar turbulence is very far from the
simplicity of incompressible flows where Kolmogorov ideas
apply. Indeed, the interstellar medium is very dilute, extremely
compressible, multiphase, partially ionised, magnetised, and both dust
and cosmic rays travel are coupled with it. Nevertheless, we still use
the tools Kolmogorov devised to probe a variety of flows in
astrophysics. I will show how statistical laws (such as the extended
self-similarity) unexpectedly apply in isothermal
magnetohydrodynamical (MHD) simulations, and how this might be used to
detect the coherent discontinuities which quickly form in supersonic
turbulence. One of the suprising result lies in the lack of
sensitivity of the macroscopic parameters of these discontinuities to
the dissipation coefficients. This is also supported by recent work
with JB Durrive on analytical solutions of Burgers equations. I will
finally present our attempts to generate realistic (in the sense that
coherent structures are reproduced) turbulent fields at a much lower
cost than full fledge numerical simulations.