Utilization of transport of species and heat release to a DRG-method-based reduction

Abstract

We propose a new DRG-based mechanism reduction method that considers heat release rate (HRR), transport of species, and reaction rate. In the original DRG method developed by T. Lu and C. K. Law, species importance is evaluated using only the reaction rate, and PSR is used for sampling. However, combustion phenomena are also affected by the transport of species and HRR, and sampling using PSR may be inadequate to produce a skeletal mechanism that can simulate a realistic flame. Therefore, in the proposed transport and heat DRG method, a 1D premixed flame is used for sampling, and species importance is evaluated relative to reaction rate, transport flux, and HRR. The proposed method was evaluated in ethylene/air and n-butane/air 1D premixed flame, and the laminar flame speed and flame structure were obtained using skeletal mechanisms created by three DRG methods, i.e., the original, transport, and transport and heat methods. In the case of the ethylene/air premixed flame, the transport and heat DRG method produced a smaller skeletal mechanism that well-reproduced the result of the detailed mechanism. In the case of n-butane/air premixed flame, smaller skeletal mechanisms were obtained in the region of relative error on laminar flame speed of 0.1–1.0% with the transport and heat DRG method.

Keywords

• mechanism reduction
• skeletal mechanism
• heat release rate
• laminar flame speed
• transport flux