Any method to strech the domain to infinity?
 

I am simulating a flat plane boundary layer flow.
I want to set the outflow boundary at infinity. I have tried to use the grid transformation methods of Roberts (1971), but it seems that the streching leads to instabilty in my code.

So is there any good method to strech the domain to infinity?

Thank you in advance.

If stretching causes instability in your code, there is a problem with numerical method (central difference for convection?, whats outflow BC?). So I would advice you to first analyze other possible options for your error.

OK. I see what you mean. Thank you so much.