[aditya92in]

Question answered, thanks

[FMDenaro]

Originally Posted by aditya92in

Hi all,

I am doing a masters thesis project on the Immersed Boundary Method. I plan to use the Volume of Solid IBM. To do this, my first test case is to achieve vortex shedding for a cylinder. I am coding a 2D-test case. I use the Fractional Step method, with AB-2 for momentum and diffusion, while, Central Differencing for spatial gradients. I use the Pressure Projection class of Fractional Step Methods, taken from Chorin. My professor had advised me against, using this. He had told me, to use the Pressure Correction, method as opposed to pressure projection, because, we push the velocity to make it divergence free in Pressure Correction, while we remove the divergent part of the velocity field in Pressure Projection, to make it divergence free. I don't understand this reason, very clearly. My understanding is that both do the same thing. Could somebody explain this ?

Thank you
Aditya

The NS system for incompressible flow requires that you get a final solution satisfying the constraint div v =0, no matter of the method you use. The differences between the two methods you cited are more in the nature of the numerical formulation. In particula, in the projection methods the velocity is projected onto the subspace of divergent-free functions so I do not understand the statement "while we remove the divergent part of the velocity field "