Hi,

this is a more or less general question.

1. Is it right that Euler flows can model backflows?

2. Potential flows do not contain rotation - but what does it mean? Could you give me a simple example (flowfield) with and without rotation? Does rotation have an influence on the stress terms?

Thx.

The Euler equations are applicable where the actions of viscosity can be ignored. If the backflow is pressure-driven then the use of an Euler approximation may be acceptable. If the backflow arises directly or indirectly thru the action of viscosity then an Euler solver may not be the best candidate.

Rotation as you mean it refers to vorticity. An irrotational flow is one for which the curl of the velocity is zero. The simplest example - a uniform freestream. The simplest example of a rotational flow (right off the top of my head) would be u = a*y. Since the stress terms can be recast in terms of the vorticity, I'll leave the last question for you.