Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.
Negative concentration values in Transport of Diluted Species Study
Posted Oct 5, 2014, 3:36 a.m. EDT Fluid & Heat, Computational Fluid Dynamics (CFD), Microfluidics 2 Replies
Please login with a confirmed email address before reporting spam
Hello all,
I am analyzing a fluid flow and concentration gradient in microfluidic device. Device has a main horizontal channel and 256 vertical side channels to on both sides (up and down). I have two fluid inflows one from a top and other from bottom. Top fluid flow carries a chemical species to the device. Model runs fines but when I plot the concentration of the bottom side channels it shows me some negative values. The lowest concentration of a species can take 0 physically.
Please help me to identify the error that causes this problem. Could it be something with the mesh or solver configuration (relative/absolute error etc.)?
I am analyzing a fluid flow and concentration gradient in microfluidic device. Device has a main horizontal channel and 256 vertical side channels to on both sides (up and down). I have two fluid inflows one from a top and other from bottom. Top fluid flow carries a chemical species to the device. Model runs fines but when I plot the concentration of the bottom side channels it shows me some negative values. The lowest concentration of a species can take 0 physically.
Please help me to identify the error that causes this problem. Could it be something with the mesh or solver configuration (relative/absolute error etc.)?
2 Replies Last Post Oct 6, 2014, 11:45 p.m. EDT
Please login with a confirmed email address before reporting spam
Posted:
1 decade ago
How many mesh elements you have in the cross section of the main channel?
Please login with a confirmed email address before reporting spam
Posted:
1 decade ago
Lasse,
After question I refined the mesh near these negative values. Actually it resolved the issue. I could not go for extremely fine mesh grid since my computing power is limited. So I just refined the mesh in the problematic area.
Thank you very much for the clue.
Shehan
After question I refined the mesh near these negative values. Actually it resolved the issue. I could not go for extremely fine mesh grid since my computing power is limited. So I just refined the mesh in the problematic area.
Thank you very much for the clue.
Shehan