Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.
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.
Concentrated Chemical Species
Posted May 23, 2013, 6:55 p.m. EDT Fluid & Heat, Chemical Reaction Engineering Version 4.3a, Version 4.3b 1 Reply
Please login with a confirmed email address before reporting spam
Hello All,
I am in trouble defining the constraint for the dependent variables (mass fractions) in Concentrated Chemical Species physics.
I have the mass fraction of Species A to E and one inert (total 6 chemical species): wA, wB, wC, wD, wE and wI (inert). There are two reactions:
A + B < = > C + D .......(1)
C + B < = > D + E .......(2)
Now, the reaction (2) is in equilibrium with reaction (1) and I have the rate law for the reaction (1), so from equilibrium I can calculate the concentration of E in reaction (2). In Comsol I don't need to define wE (mass fraction of E), as I can calculate its concentration from the equilibrium but it is only possible when I satisfy the condition wA+wB+wC+wD+wE+wI = 1. So somehow I need to let Comsol know that there is another chemical component E which is in equilibrium with the remaining, and constraint is sum of all species mass fractions = 1.
let me know how to deal with such situation in Comsol.
Thanks all
Mayur
I am in trouble defining the constraint for the dependent variables (mass fractions) in Concentrated Chemical Species physics.
I have the mass fraction of Species A to E and one inert (total 6 chemical species): wA, wB, wC, wD, wE and wI (inert). There are two reactions:
A + B < = > C + D .......(1)
C + B < = > D + E .......(2)
Now, the reaction (2) is in equilibrium with reaction (1) and I have the rate law for the reaction (1), so from equilibrium I can calculate the concentration of E in reaction (2). In Comsol I don't need to define wE (mass fraction of E), as I can calculate its concentration from the equilibrium but it is only possible when I satisfy the condition wA+wB+wC+wD+wE+wI = 1. So somehow I need to let Comsol know that there is another chemical component E which is in equilibrium with the remaining, and constraint is sum of all species mass fractions = 1.
let me know how to deal with such situation in Comsol.
Thanks all
Mayur
1 Reply Last Post May 24, 2013, 11:38 a.m. EDT
Please login with a confirmed email address before reporting spam
Posted:
1 decade ago
Hello All,
I am in trouble defining the constraint for the dependent variables (mass fractions) in Concentrated Chemical Species physics.
I have the mass fraction of Species A to E and one inert (total 6 chemical species): wA, wB, wC, wD, wE and wI (inert). There are two reactions:
A + B < = > C + D .......(1)
C + B < = > D + E .......(2)
Now, the reaction (2) is in equilibrium with reaction (1) and I have the rate law for the reaction (1), so from equilibrium I can calculate the concentration of E in reaction (2). In Comsol I don't need to define wE (mass fraction of E), as I can calculate its concentration from the equilibrium but it is only possible when I satisfy the condition wA+wB+wC+wD+wE+wI = 1. So somehow I need to let Comsol know that there is another chemical component E which is in equilibrium with the remaining, and constraint is sum of all species mass fractions = 1.
let me know how to deal with such situation in Comsol.
Thanks all
Mayur
I am in trouble defining the constraint for the dependent variables (mass fractions) in Concentrated Chemical Species physics.
I have the mass fraction of Species A to E and one inert (total 6 chemical species): wA, wB, wC, wD, wE and wI (inert). There are two reactions:
A + B < = > C + D .......(1)
C + B < = > D + E .......(2)
Now, the reaction (2) is in equilibrium with reaction (1) and I have the rate law for the reaction (1), so from equilibrium I can calculate the concentration of E in reaction (2). In Comsol I don't need to define wE (mass fraction of E), as I can calculate its concentration from the equilibrium but it is only possible when I satisfy the condition wA+wB+wC+wD+wE+wI = 1. So somehow I need to let Comsol know that there is another chemical component E which is in equilibrium with the remaining, and constraint is sum of all species mass fractions = 1.
let me know how to deal with such situation in Comsol.
Thanks all
Mayur