Numerical studies of transient opposed-flow flames using adaptive time integration

Numerical simulations of unsteady opposed-flow flames are performed using a n adaptive time integration method designed for differential-algebraic syst ems. The compressibility effect is considered in deriving the system of equ ations, such that the numerical difficulties associated with a high-index s ystem are alleviated. The numerical method is implemented for systems with detailed chemical mechanisms and transport properties by utilizing the Chem kin software. Two test simulations are performeds hydrogen/air diffusion fl ames with an oscillatory strain rate and transient ignition of methane agai nst heated air. Both results show that the rapid transient behavior is succ essfully captured by the numerical method.