Is it possible to simulate a debris extended to 1pc in TDE?

[Shigaharuki3012]

I was trying to get the velocity of debris after TDE in a large distance in a simulation.But when I try to simulate TDE and let the debris evolve freely,calculation stopped at a distance of several $\times R_{\mbox{sun}}$ instead of larger distance,for our purpose,e.g,1pc. And errors were:

WARNING! cons2prim: Internal energy < 0 on particle 5049: u = -4.811E+03
 FATAL ERROR! eos: utherm < 0 : u = -4.811E+03

Settings of star were:

polytrope
eos=adiabatic
M_*=4.25M_sun
R_*=11R_sun

Settings of TDE were:

Mbh=4e+06M_sun
beta=1.1
e=1
Rini=1000Rsun
incline =       24.060    ! inclination (in x-z plane)

[danieljprice]

this could be:

• timestep too big
• something else has gone wrong in your simulation (suggest to have a look with splash)
• or a "known issue" as detailed in Liptai & Price (2019) it is not fully guaranteed that viscous dissipation is always positive definite in the full GR case

suggest to try using a smaller C_cour to see if that fixes the issue

[Shigaharuki3012]

Thank you for your reply! I will have a try as you've mentioned above!