I want to model forces acting on single chared collide in nanochannel with charged walls.

electrical potential diffrence set along the nanochannel and cause electroosmosis flow in channel.

main forces acting on particle are:

drag force and electrostatic force.

now I am trying to calculate these forces in Comsol to obtain velocity of particle,I am using an article to adapt my data but my data does not seems to be true.

I am struggling with it for months...