What cannot I use palabos with gas dynamics??

Lattice Boltzmann Method LBM: Algorithms
#1

Hi, community.

I want to use a example. I am seeing some examples, and I would like to work cavity2D with gas. I have been to read isoThermalDynamics’ file where says … it cuts out the modes at higher Knudsen numbers and therefore can not be used in the regime of rarefied gases … …

My question is, Cannot I to use the regime of rarefied gases at all cases with Palabos library ?.

Thanks your time and your response

#2

Hi mfduqued ;
Have you figured out how to use Palabos with gas? I need to model gas dynamic as well. Any suggestion would help me ?
Thank you

#3

Hello,
it is not because of Palabos but rather because of the models. As such it is certainly possible to implement models for rarefied gazes in Palabos (which is a completely generic library). You could be the first!

1 Like
#4

Hi Michelle,

only to clarify a bit: with gas dynamics, people usually mean “compressible flows”, whereas rarefied gas dynamics refers to high-Knudsen number flows (i.e. when the molecular mean free path is higher than the characteristic scale length).

Despite this, we use quasi-incompressible lattice Boltzmann to simulate a gas at low Ma numbers. Quasi-incompressible LBM can be used as well to simulate thermal flows under the Boussinesq hypothesis.

To simulate compressible flows (high Ma, high Re) you need a high order scheme for LBM. Regarding the rarefied gas dynamics (high Ma/Re ratio), generally, the standard method is the DSMC. I guess it is possible to use LBM to simulate hi-Kdnunsen flows, but you need to have the right (collision) models to handle it (see for instance https://iopscience.iop.org/article/10.1209/epl/i2004-10393-0/pdf). This at best of my knowledge. Now, as Orestis said, it would be nice if somebody implements high Knudsen models into palabos.

Cheers,

mars