Hello. I am Ali, a PhD student in condensed matter physics. I am looking to investigate active particles using lattice Boltzmann method. For this purpose, I have installed both Espresso 4.2.2 and Espresso Python. I have used Walberla to simulate Poiseuille flow. In order to apply the torque from Poiseuille flow to the raspberry particles, I have used virtual sites according to your instructions in "Rigid arrangements of particles". But the problem is that Walbrella works only in Espresso Python and does not work in Espresso 4.2.2 and virtual sites work in Espresso 4.2.2 but does not work in Espresso Python. In other words, the torque is not applied to the active particles from the Poiseuille flow (my code is available in the attachment).
First question: Why is torque not applied to my particles?
Second question:
Have I done the simulation of active particles in a Poiseuille flow correctly? if not Where did I do wrong?
Third question:
Is it possible to have walberla in Espresso 4.2.2?
Question 4: Is it necessary to use walberla to create a Poiseuille flow? or is there any simpler method?
active particles in poiseuille flow.py