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Moving boundary problem in the pitting corrosion of multigrain
Posted Feb 22, 2017, 11:57 p.m. EST Chemical Reaction Engineering Version 5.2 2 Replies
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Hello, everyone
I'm facing a problem about the pitting corrosion of multigrain structure. I want to get dynamics results of the pitting corosion rate. I know that we can get the velocity of the electrode boundary movement using v=i*M/(n*F*rho), when it comes to the multigrains problem, can we get the different moving velocity among different grains? In the experiement, there are many grains along the front of the pit, the first grain will be corroded away, and then it comes to the boundary of the next grain, so another chemical reaction will have with a new overpotential condition. Can we simulate this corrosion process? When I tried this with multigrain (multi domain) model, the movement of the electrode boundary was limited within one grain (one domian), is this the limitation of the software, or is there any way to solve this problem? Thank you.
Best
Xin
I'm facing a problem about the pitting corrosion of multigrain structure. I want to get dynamics results of the pitting corosion rate. I know that we can get the velocity of the electrode boundary movement using v=i*M/(n*F*rho), when it comes to the multigrains problem, can we get the different moving velocity among different grains? In the experiement, there are many grains along the front of the pit, the first grain will be corroded away, and then it comes to the boundary of the next grain, so another chemical reaction will have with a new overpotential condition. Can we simulate this corrosion process? When I tried this with multigrain (multi domain) model, the movement of the electrode boundary was limited within one grain (one domian), is this the limitation of the software, or is there any way to solve this problem? Thank you.
Best
Xin
2 Replies Last Post Feb 25, 2017, 8:03 a.m. EST
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Posted:
8 years ago
Hello Mr Wu,
I am a beginner to COMSOL,
I am trying to solve a simple electrochemistry problem with "corrosion primary current distribution interface". However, I am getting convergence error as below. Kindly help me out if possible. Thank you.
Undefined variable.
- Variable: comp1.siec.nnondefr
- Geometry: geom1
- Boundary: 4
Failed to evaluate Jacobian of expression.
- Expression: comp1.siec.nnondefr
Failed to evaluate Jacobian of operator.
- Operator: mean
- Geometry: geom1
- Point: 8
Failed to evaluate Jacobian of variable.
- Variable: comp1.siec.nnondefr
- Geometry: geom1
- Point: 8
Failed to evaluate Jacobian of expression.
- Expression: (comp1.des1.Hmbs*comp1.des1.nnondefz)*dvol_geometry
Failed to evaluate Jacobian of expression.
- Expression: (comp1.des1.Hmbs*(comp1.des1.nnondefr*test(vmbsr)+comp1.des1.nnondefz*test(vmbsz)))*(dvol_geometry)
I am a beginner to COMSOL,
I am trying to solve a simple electrochemistry problem with "corrosion primary current distribution interface". However, I am getting convergence error as below. Kindly help me out if possible. Thank you.
Undefined variable.
- Variable: comp1.siec.nnondefr
- Geometry: geom1
- Boundary: 4
Failed to evaluate Jacobian of expression.
- Expression: comp1.siec.nnondefr
Failed to evaluate Jacobian of operator.
- Operator: mean
- Geometry: geom1
- Point: 8
Failed to evaluate Jacobian of variable.
- Variable: comp1.siec.nnondefr
- Geometry: geom1
- Point: 8
Failed to evaluate Jacobian of expression.
- Expression: (comp1.des1.Hmbs*comp1.des1.nnondefz)*dvol_geometry
Failed to evaluate Jacobian of expression.
- Expression: (comp1.des1.Hmbs*(comp1.des1.nnondefr*test(vmbsr)+comp1.des1.nnondefz*test(vmbsz)))*(dvol_geometry)
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Posted:
8 years ago
Hello, everyone
I'm facing a problem about the pitting corrosion of multigrain structure. I want to get dynamics results of the pitting corosion rate. I know that we can get the velocity of the electrode boundary movement using v=i*M/(n*F*rho), when it comes to the multigrains problem, can we get the different moving velocity among different grains? In the experiement, there are many grains along the front of the pit, the first grain will be corroded away, and then it comes to the boundary of the next grain, so another chemical reaction will have with a new overpotential condition. Can we simulate this corrosion process? When I tried this with multigrain (multi domain) model, the movement of the electrode boundary was limited within one grain (one domian), is this the limitation of the software, or is there any way to solve this problem? Thank you.
Best
Xin
I'm not sure that I understand your problem properly but it may be worthwhile for you to check out the 'deformed geometry' interface. Support recently helped me resolve a problem that I was having where I needed to pass a slightly deformed geometry to another study where it was subjected to different physics. The "moving mesh ALE" interface may be more appropriate for you as well. If you upload your model, I could take a look at it and see if I can get a better grasp of what you're trying to accomplish.