국내 최대 기계 및 로봇 연구정보

기술보고서

기술보고서 게시판 내용
타이틀	Comparison of Numerical Techniques for Integration of Stiff Ordinary Differential Equations Arising in Combustion Chemistry
저자	Krishnan Radhakrishnan
Keyword	Chemical kinetics; Stiff ordinary differential equations; Numerical solution
URL	http://gltrs.grc.nasa.gov/reports/1984/TP-2372.pdf
보고서번호	NASA TP-2372
발행년도	1984
출처	NASA Glenn Research Center
ABSTRACT	The efficiency and accuracy of several algorithms recently developed for the efficient numerical integration of stiff ordinary differential equations are compared. The methods examined include two generalpurpose codes, EPISODE and LSODE, and three codes (CHEMEQ, CREK1D, and GCKP84) developed specifically to integrate chemical kinetic rate equations. The codes are applied to two test problems drawn from combustion kinetics. The comparisons show that BODE is the fastest code currently available for the integration of combustion kinetic rate equations. An important finding is that an interactive solutionof the algebraic energy conservation equation to compute the temperature does not result in significant errors. In addition, this method can be more efficient than evaluating the temperature by integrating its time derivative. Significant reductions in computational work are realized by updating the rate constants (k = ATN exp(-E/RT)) only when the temperature change exceeds an amount DT that is problem dependent. An approximate expression for the automatic evaluation of DT is derived and is shown to result in increased efficiency.