TY - JOUR
T1 - A general lumping analysis of a reaction system coupled with diffusion
AU - Li, Genyuan
AU - Rabitz, Herschel
N1 - Funding Information:
Acknowledgements-The authors acknowledge support from the Office of Naval Research and the Air Force Office of Scientific Research.
PY - 1991
Y1 - 1991
N2 - A general lumping analysis of a reaction system coupled with diffusion is presented. This analysis can be applied to any reaction system with n species for both steady-state and transient conditions. Here we consider lumping by means of an n̂ × n constant matrix M with rank n̂ (n̂ ≤ n). When the diffusivity is independent of position and concentration, represented by the vectors r and y, respectively, it is found that under steady-state conditions, a reaction system having a species concentration vector y(r) coupled with diffusion is exactly lumpable if and only if there exist nontrivial fixed JT[y(r)]D-1-invariant subspaces M [here JT[y(r)] is the transpose of the Jacobian matrix for the chemical reaction rate vector f[y(r)] and D-1 is the inverse of the constant effective diffusivity matrix], no matter what value y(r) takes; under transient conditions, there exist simultaneously D- and JT[y(r, t)]-invariant subspaces M. When D is a function of position or concentrations, M is simultaneously invariant to JT(y) and D(r), D[y(r)] or D[y(r, t)]. The approach used to determine the constrained approximate lumping schemes for a nondiffusion system can also be used in a reaction-diffusion system, except that the constant basis matrices Ak's of JT(y) are replaced by Bk = AkD-1 under steady-state conditions, or the extra matrix D is added under transient conditions. For n onconstant D, the basis constant matrices Di's of D(r), D[y(r)] or D[y(r, t)] are added.
AB - A general lumping analysis of a reaction system coupled with diffusion is presented. This analysis can be applied to any reaction system with n species for both steady-state and transient conditions. Here we consider lumping by means of an n̂ × n constant matrix M with rank n̂ (n̂ ≤ n). When the diffusivity is independent of position and concentration, represented by the vectors r and y, respectively, it is found that under steady-state conditions, a reaction system having a species concentration vector y(r) coupled with diffusion is exactly lumpable if and only if there exist nontrivial fixed JT[y(r)]D-1-invariant subspaces M [here JT[y(r)] is the transpose of the Jacobian matrix for the chemical reaction rate vector f[y(r)] and D-1 is the inverse of the constant effective diffusivity matrix], no matter what value y(r) takes; under transient conditions, there exist simultaneously D- and JT[y(r, t)]-invariant subspaces M. When D is a function of position or concentrations, M is simultaneously invariant to JT(y) and D(r), D[y(r)] or D[y(r, t)]. The approach used to determine the constrained approximate lumping schemes for a nondiffusion system can also be used in a reaction-diffusion system, except that the constant basis matrices Ak's of JT(y) are replaced by Bk = AkD-1 under steady-state conditions, or the extra matrix D is added under transient conditions. For n onconstant D, the basis constant matrices Di's of D(r), D[y(r)] or D[y(r, t)] are added.
UR - http://www.scopus.com/inward/record.url?scp=0011384724&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0011384724&partnerID=8YFLogxK
U2 - 10.1016/0009-2509(91)80163-S
DO - 10.1016/0009-2509(91)80163-S
M3 - Article
AN - SCOPUS:0011384724
SN - 0009-2509
VL - 46
SP - 2041
EP - 2053
JO - Chemical Engineering Science
JF - Chemical Engineering Science
IS - 8
ER -