[mostanad]

Hi Everyone,
I have a question about immersed boundary method. As you know, IBM tries to solve Navier-Stokes equation using a Cartesian grid. So why we have something like the attached image for pressure field, even with non-zero values inside the rigid object?
Cheers,
Mohammad

[hjasak]

If you want to get rid of the internal pressure values, set the deadCell value in the boundary conditions for the immersed boundary.
The way I manipulate the matix will give you something (smooth) in dead cells, which is nice. It does not influence the solution elsewhere.

Hrv

[mostanad]

Originally Posted by hjasak

If you want to get rid of the internal pressure values, set the deadCell value in the boundary conditions for the immersed boundary.
The way I manipulate the matix will give you something (smooth) in dead cells, which is nice. It does not influence the solution elsewhere.

Hrv

Hi Hrvoje
I am quite familiar with your approach (ghost cell) in IBM. However, I am using a different algorithm which was proposed by Patankar:
A new mathematical formulation and fast algorithm for fully resolved simulation of self-propulsion
This method has been implemented in CFDEM package, and more specifically, cfdemSolverIB solver. The algorithm follows the following steps:



The main issue for me is the outer loop which is a piso/pimple algorithm. The algorithm works properly for Newtonian case as it assumes constant fluid viscosity even inside the particle.

However, when I change it to a shear-thinning power-law flow, viscosity inside the particle should be so high, and something goes wrong with algorithm and pressure around/inside the particle:





I can provide for you further information. Thank you for your time and consideration.
Mohammad

[hjasak]

I would be happy to look at this for you under a support contract. Please contact me via Wikki.


Hrv

[mostanad]

Originally Posted by hjasak

I would be happy to look at this for you under a support contract. Please contact me via Wikki.


Hrv

I send a message to you on website. I hope you can help me with this king of IBM.