gpusph no-slip boundary condition

Hello everyone! Is the no-slip boundary setting already built in the GPUSPH code? Now I am using GPUSPH to simulate the Poiseuille flow. But I have not found a proper setting to achieve the no-slip effect on the wall boundaries. If there is no this type boundary condition setting, how to add this setting? Thanks and regards!

Mar 20 '15 07:03 Fei2015

Hi Fei,

yes no-slip boundaries are the default. The problem is that some types of boundary conditions do not allow for proper imposition of the wall shear stresses and thus will give you wrong results. I'm developing and using the semi-analytical boundary conditions and I can guarantee that they will give you correct results. I'm not sure about any of the other ones though.

Best, Arno

Mar 20 '15 13:03 Azrael3000

Hi Arno,

Thank you for your reply! Actually I tried to add the semi-analytical boundary by add the additional line : m_simparams.boundarytype= SA_BOUNDARY; in the file Poiseuille flow case file DynBoundsExample.cc , but the result was the same with the result of the default boundary condition LJ_BOUNDARY. So I am want to know how to implement the semi-analytical boundary condition properly?

Thanks and regards!

Mar 20 '15 15:03 Fei2015

You need a specific set of particles at the boundary with SA_BOUNDARY. We have a few generic wrappers that will let you do this, but to be honest I've never looked into them. Instead I always create my geometry using Crixus. If you want to start with a Poiseuille flow it is already there. Have a look at InputProblem.* for that. In the header file you will find that you can select different cases and one of them is called SmallChannelFlow, which is what you are looking for. We are already working on documentation, so things should get better in a few months :) Until then feel free to ask questions.

Mar 21 '15 00:03 Azrael3000