[alsawy]

I'm simulating a rotating axial fan using sliding mesh. the domain has only one cell zone (which is a moving mesh).
for pressure inlet & outlet bounds, the transient formulation should it be Second order or BOUNDED second order?
I've read here that bounded second order provides the same Accuracy for the second order with more stability.
but in my case (moving mesh, compressible flow) will the bounded second order work fine?

[LuckyTran]

You should pretty much always use bounded second order. That's because regular second order is unbounded and produces non-physical oscillations (i.e. you can completely overshoot and undershoot). If your solution is stable enough then bounded/un-bounded would have produced similar results anyway.

Unless you have a specific need (i.e. you are benchmarking or validating against a specific objective), then always use bounded second order.