Your opinion on a class of ODE problems

[pascal_meheut]

(01-27-2016 02:45 AM)gestrickland Wrote:  In your example equations, if you add the three together, you get d(A+B+C)/dt=0, which means A+B+C=M, M being a constant throughout the solution. I suppose this is your conservation of mass, actually embedded in the equations. If I am not missing something, you could use this equation to eliminate one of the unknowns, say A,

Isn"t more or less the same as :

(01-22-2016 08:08 PM)Namir Wrote:  At the end of each iteration of a sub-interval I re-calculate the concentration of one of the chemical, say compound A, as equal to the initial sum of concentrations (for all chemicals) minus the sum of the current concentrations of the other chemicals. This approach maintains the conservation of matter law.

but maybe less efficient?