An implicit-explicit hybrid solver for a system of stiff kinetic equations

Journal Article · Thu Dec 01 04:00:00 EST 1994 · Journal of Computational Physics

DOI:https://doi.org/10.1006/jcph.1994.1213· OSTI ID:105490

Sun, Pu; Chock, D P; Winkler, S L ^[1]

---

1. Ford Motor Co., Dearborn, MI (United States)

A new stiff ordinary differential equation solver has been devised that separates the unknown variables into a fast group and a slow group. The fast variables are solved using the implicit backward-differentiation formulas but with a Jacobian of much smaller dimension than that of the original stiff system. The slow variables are solved using a simple explicit Adams-Bashforth scheme. The method, applied to a stiff atmospheric chemical system, yields an accuracy in the solution comparable to that of the commonly-used LSODE method at a relative tolerance level of 10{sup {minus}3} and an absolute tolerance level of 10{sup {minus}7} ppm, with one-third the execution time of LSODE. The method can be further fine-tuned to optimize its accuracy and execution time. As it is, the method should be an excellent candidate for the chemistry solver in air quality, combustion, and reactive flow models.

• OSTI ID: 105490
• Journal Information: Journal of Computational Physics, Journal Name: Journal of Computational Physics Journal Issue: 2 Vol. 115; ISSN 0021-9991; ISSN JCTPAH
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
99 GENERAL AND MISCELLANEOUS
ATMOSPHERIC CHEMISTRY
CHEMICAL REACTION KINETICS
DIFFERENTIAL EQUATIONS
KINETIC EQUATIONS
NUMERICAL SOLUTION