A robust explicit time integration method for stiff chemical reaction equations is proposed and applied to zero-dimensional ignition and one-dimensional combustion flow problems. The proposed method based on a multi-time scale method significantly improves the robustness of the original method by introducing two new strategies: automatic adjustment of time step size for each characteristic group using a quasi-steady-state assumption and automatic reset of base time step size using two appropriate criteria. The results for several zero-dimensional ignition problems demonstrate the robustness and accuracy of the proposed method compared to existing explicit and implicit integration methods. The present study also provides a computational cost estimation of various terms in the governing equations using a one-dimensional combustion problem (knocking simulation), where the Navier– Stokes equations are coupled with the chemical reaction equations. As well as the zero-dimensional problems, the robustness and capability of the proposed method are demonstrated. While the proposed method alleviates the occupancy of chemical reaction part in the total computational cost compared to an implicit time integration method, it is found that the transport properties calculations relatively increase with considerable amounts, suggesting efficient modeling of transport properties calculations for multi-dimensional combustion problems.
|Number of pages
|International Journal of Energetic Materials and Chemical Propulsion
|Published - 2015
- Computational fluid dynamics
- Detailed chemical kinetic mechanisms
- Explicit time integration
- Stiff combustion chemistry