Can any body name some astrophysical fluid instabilities still lacking theoretical explanation?

Dear Colleagues,

It is a fact that dust is ubiquitous almost in all the sectors of astrophysical plasma fluids. Can anyone give the quantitative values of the "dust-to-gas ratio" in varied astronomical circumstantial cases? Appropriated references are most welcome.

Kind regards,

PK Karmakar

Astrophysical fluids are gyratory and nonthermal in collective response. Is there any polytropic equation of state involving fluid rotation and nonthermal effects?

Spherical waves are ubiquitous in astrophysical environments. Can someone provide some useful references on spherical wave analysis in spherical gravito-magnetized fluids?

The existence of turbulence in astrophysical fluids has been living as a well-known unsolved problem for a couple of decades. The range transitions among three distinct scales of the micro-fluidic kinetics are still lying obscure. In this context, is there any equation of state to describe turbulent fluid media in the fabric of the modified (by turbulence) macroscopic Navier-Stokes equation?

Astrophysical fluids are nonthermal in nature. Could you please provide a list (preferably, tabular form) of various nothermal distribution laws for the constitutional particles relevant in large-scale astrophysical fluids?

Does the construction materials have any influence on accuracy of orifice flow meter? ( Working fluid: air)

In Hagen–Poiseuille equation the pressure is a function of flow rate, the dynamic viscosity of the fluid and channel geometry. I wonder in which case the effect of the shear modulus of solid has a significant role. example PDMS thickness upto 500um.