[stevie]

Hello all,

What parameter should we consider while choosing computational domain size? For example in many papers they mention that inlet is located at 10c upstream of the leading edge, where c is a chord length of an airfoil. What made them choose exactly 10c and not something else?

Thanks.

[fluid23]

It really depends on your model. In many cases just use 10 x legnth in the streamwise direction. This done so that the boundary conditions do not have unintended consequences on your solution. You could get away with more, and proabably less. 10c is just a nice easy round number to use.

I would probably go a little further downstream though to fully capture your wake.

[canopus]

As already stated

so that the boundary conditions do not have unintended consequences on your solution

The domain size also determines if the boundary conditions hold correct.

For e.g. if you want to apply a zero gradient boundary condition it should be far away from recirculation zones.