FARGO in shearingbox

[jaehanbae]

Hello,

While I was testing the FARGO module with a shearing box setup I found discrepancy between simulations with vs. without FARGO. I'm attaching two movie files showing density and velocity fields in (top row) X-Z plane (Y=-0.5) and (bottom row) X-Y plane (Z=0). I didn't include a colorbar but the two movies used the same range, from 1.0e-5 to 1.0e-5. For these movies I used the default test/HD/ShearingBox setup (using smaller CFL and longer integration), but I found suspicious outcomes in other shearing box simulations when I turn on the FARGO module. I don't seem to be able to upload idefix.ini file, so I'm copying/pasting them below.

Thank you,
Jaehan

https://github.com/user-attachments/assets/823c0f45-c6c3-4d97-8a06-529fcfc4b1bc
https://github.com/user-attachments/assets/c893ff86-d26c-421e-add6-0c9bc32b050c

idefix.ini without FARGO
`[Grid]
X1-grid 1 -0.5 32 u 0.5
X2-grid 1 -0.5 32 u 0.5
X3-grid 1 -0.5 32 u 0.5

[TimeIntegrator]
CFL 0.3
tstop 20.0
first_dt 1.e-4
nstages 2

[Hydro]
solver hllc
rotation 1.0
shearingBox -1.5

[Gravity]
bodyForce userdef

[Boundary]
X1-beg shearingbox
X1-end shearingbox
X2-beg periodic
X2-end periodic
X3-beg periodic
X3-end periodic

[Output]
vtk 0.1
dmp 2.0
analysis 0.1`

idefix.ini with FARGO
`[Grid]
X1-grid 1 -0.5 32 u 0.5
X2-grid 1 -0.5 32 u 0.5
X3-grid 1 -0.5 32 u 0.5

[TimeIntegrator]
CFL 0.3
tstop 20.0
first_dt 1.e-4
nstages 2

[Hydro]
solver hllc
rotation 1.0
shearingBox -1.5

[Gravity]
bodyForce userdef

[Fargo]
velocity shearingbox

[Boundary]
X1-beg shearingbox
X1-end shearingbox
X2-beg periodic
X2-end periodic
X3-beg periodic
X3-end periodic

[Output]
vtk 0.1
dmp 2.0
analysis 0.1`

[glesur]

Hi @jaehanbae , thanks for reporting this. It seems to be related to one of the source term for the energy equation when Fargo is enabled (the problem doesn't show up with an isothermal EOS).

I'm still investigating the root of the problem, I'll report when I have a better understanding of what's happening.

[jaehanbae]

Thanks @glesur! That makes sense, cause my other shearing box simulations showing suspicious behavior also used an adiabatic EOS. Looking forward to hearing more updates.

[glesur]

I've just pushed a branch fixFargoSBEnergy that is supposed to fix this issue. Let me know if this works.

[jaehanbae]

I can confirm that it works now. Thank you!

[glesur]

solved and merged in #346