Flush and Cutoff Coupling

[Bob Smith]

I have been using React (Release 8.05 build 3829) to model a continuously stirred tank reactor (CSTR) using the “flush” option and have discovered the “cutoff” option does not work as I expected. I have run a set of simulation with

 

react .05 kg/day of Br-, cutoff = .1 kg

 

and

 

time start = 0 days, end = 7 days

time start = 0 days, end = 14 days

time start = 0 days, end = 21 days

 

for these three cases the total amount of Br- reacted from the React_output.txt files is 350, 700, and 1050 g, respectively. First, all these values exceed the 0.1 kg (100 g) “cutoff” and second there is a linear coupling between “cutoff” and the length of the simulation.

 

One of the input files is attached however I find this behavior in all the simulations that I have tried.

 

Thanks

 

Bob Smith

100818_Tracer.rea

[Tom Meuzelaar]

react .05 kg/day of Br-, cutoff = .1 kg

 

Hi Bob:

 

The cutoff command does not support arguments beyond a numerical value- just constrain the variable in terms of the same units carried for the reactant.

 

I hope that helps,

 

Tom Meuzelaar

RockWare, Inc.