Hello,

I'm searching for a method to be used in a problem with no fix boundaries. An object is moving in a fluid. I'd prefer to use a fix euler orthogonal grid, if it will be possible of course.

Thank you.

Some are using the immerse boundary method for this type of problem. The method is also called " Boundary Body forces " and a good reference would be " Large eddy simulation in complex geometric configurations using boundary body forces ", by Verzicco et al., AIAA Journal, Vol. 38, No. 3, Mrach 2000.

Thank you very much for your advice, it's very intrestin'. Do you know if there is an electronic documentation on this subject in www ?

You should go to www.idealibrary.com , and try the advanced search. Choose the Journal of Computational Physics, and type " immersed boundary " in the option for the key words. You will get some papers from Peskin, Verzicco , Cortez and other guys working with the method. Professor Charles Peskin is one of the most involved researchers about this topic.

Thanks, it works !

But it's a pity that it's not a free resource... As you understand, I can't be sure that it's exactly what I need, so I'm not ready to pay for now. Maybe you know if it's possible to find some free docs about the basics of this numerical approach ?

if this boundary body forces method is used to treat moving boundary while domain calculation is still open to other methods, then I'll be very interested to read the paper.

but if this method is a boundary element type method, then it is useful for only a few problems where domain calculations can be replaced by a boundary calculation.

if in the original thread the issue is to calculate a moving body in flow field, and the body is rigid, then why not fix the body and let the fluids flow around, that is, this indeed is not a moving boundary problem.

if the body could deform, then, there are a bunch of fascinating methods to treat the moving boundary.

if you want to use fixed mesh, then it is called " boundary capturing", and the best method is " Level Set Method"

if you want to use "boundary tracking", there are: ancient Marker-Cell, Volume of fluids, meshfree and particle, Arbitrary Lagrange Euler, to name a few.

Maybe you can give a good reference for " Level Set Method" ?

Thank you for your advice, Rene.