Flux Calculation

Hi all,

I am doing simulation for a problem that involves coupling between electrostatics and transport of diluted species.

In the problem I used "No Flux" condition for all species at one wall. I was able to obtain results. However, when I plot the total normal flux along that wall (with "chds.ntflux_c1" expression), the flux is NOT ZERO, not even close.

I refined the meshes near the wall but got the same problem.

Does someone know the reason and how to fix it? I am using 4.2a.

Thanks.