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