Extension of the ILDM method to the domain of slow chemistry

This work focuses on the construction of reduced kinetic models and the use of these models for the simulation of combustion processes governed by strongly coupled thermo-chemical and convection/diffusion sub-processes. The ILDM method is used to reduce the system dynamics in the composition space to lower dimensional manifolds. This manifold approximates an invariant system manifold of slow motions. A modification of the ILDM approach based on a special system representation is suggested, which allows to use an ILDM of low dimension even in cases where the standard formulation would require a high dimension. In this way difficulties of generating relatively high dimensional ILDMs are overcome. The approach allows a more accurate description of coupled thermo-chemical and transport sub-processes. When the processes are split a method of extension of the ILDM manifold to cover all the domain of interest in the full state space is suggested. It is based on the assumption of slow chemistry inside the low-temperature zone of the flame. To verify the approach 1D stationary free flat laminar flames are investigated. It is shown that the approximation allows a representation of the full system dynamics governed by detailed chemical kinetics and molecular transport.