Construction of one-step H2/O2 reaction mechanism for predicting ignition and its application in simulation of supersonic combustion

This study developed a method to establish a one-step global reaction mechanism for predicting the ignition delay time. The activation energy database applied in 850-1800K temperature, 0.1-100 atm pressure and a wider excess air coefficient within the range of flammable limit was constructed and the one-step reaction mechanism was then obtained for a specified chemical reaction state through a look-up or Lagrange interpolation technology. The present one-step global mechanism is able to predict the accurate ignition delay time compared with the detailed mechanism, and is superior to the other available reduced mechanisms. Coupled to a high-order in-house Computational Fluid Dynamics (CFD) code, the current reaction mechanism is successfully applied to numerical simulations of supersonic chemically reacting mixing layers under different flow conditions. The numerical predictions of supersonic combustion process, ignition position as well as averaged flow fields, using the present mechanism are comparable to the results using the detailed mechanism. Therefore, this simplified reaction mechanism is suitable for fast simulation-based designs in industrial.