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Inviscid Flow
Posted May 24, 2011, 12:27 p.m. EDT Fluid & Heat, Computational Fluid Dynamics (CFD) Version 4.3b 3 Replies
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I want to model a 2d inviscid flow in comsol v4.1, but when I set Dynamic viscosity=0 , I have some convergence problem.
It can be solved by using full Navier-Stokes Equations, but when I set the dynamic viscosity to zero, it does not converge.
should I use lower value instead of Zero?
what is the classic way of modeling the inviscid flow in COMSOL?
best
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Inviscid fluid is often (but not always) associated with irrotational flow theory.
If this applies to you, this is pretty straightforward in COMSOL :
since the flow is irrotational, you can write
u = grad (phi) (u derives from a potential phi).
together with mass conservation div (u) = 0
implies
laplacian (phi) = 0 (Laplace equation in COMSOL).
You only need to derive phi wrt space to get the velocity component.
Do not forget to think about the boundary conditions : a condition on u or v writes into a Neumann boundary condition for phi where you imposes n.grad (phi) = for instance d(phi)/dx = u along a vertical boundary.
Good luck,
Eric Favre