Influence of Strain Rate on the Structure of Counterflow Laminar Nonpremixed Wet Carbon Monoxide Flames

Abstract

[Abstract] The structure of laminar wet carbon monoxide-fueled diffusion flames at various strain rates namely; 260, 520, 780 and 1040 s -1 were studied experimentally and computationally using an opposed-jet configuration. The measured on-axis temperature distributions were found to be in reasonably good agreement with the predictions and the computed flame thickness becomes thinner with increasing the strain rate K, with its thickness varying inversely with K . Computational results demonstrate that the heat release rate profiles are characterized by two peaks; the main and secondary peaks. The location for the secondary peak for the present fuel appeared to be consistent with the location of the corresponding maximum H-radical location. Computational results further showed that, as the strain rate increased the peak values of the reaction rates for the most important reaction steps namely; CO+OH→ CO2+H, H+O2→O+OH and H+O2+M→HO2+M get larger, verifying the results obtained for the temperature, the major and minor species and indicating the importance of the role played by those reactions on the oxidation process of the wet carbon monoxide diffusion flames. The present results provide the basis for the turbulent combustion models using the laminar flamelet approach which may give a more realistic description of turbulence-chemistry interactions.