No-slip or slip wall？

[love-zly]

In your relevant paper, I found that the model used ideal gas. I have a problem that ideal gas has no viscosity, should slip boundary conditions be used on the wall? However, in the tutorials, the no-slip wall was used. I will appreciate it if anyone can answer my confusion.

[mizufeu]

"ideal gas has no viscosity" does not hold.

[love-zly]

"ideal gas has no viscosity" does not hold.

My understanding is that only the state equation of ideal gases was used, but it did not mean that viscosity was not considered.