I am actually working with 2D poiseuille flow where theres is an cylindric obstacle that moves because of flow force to the right, according to the Newton’s movement laws. The fact is that it seems that it works fairly good, but however the results are far from being realistic. One clear indicator that makes me feel doubtful is the particle density. this one decreases as the particle moves to the right along the channel (because of the drag). It seems that there is an decrease of the density inside the particle when this moves, specially with the recent updated liquid to solid nodes that come from the right.
Should I force all the solid not-boundary nodes have to be density = 1 somehow? Do you have any explanation for this phenomenon?
I am quite puzzled there. In addition, how do I treat the moving obstacle? Do I need another relaxation time or other stuff to be considered?
I am using the improved curved boundary treatment presented by wei li fang and Zhang (2000) and so, a no-slip bounceback. 2DQ9, SRT.
If you need more data , please ask for it.