Wang & Rutland (2005): Temp & \(\phi\) effects on ignition of n-heptane spray
Title
Effects of temperature and equivalence ratio on the ignition of \(n\)-heptane fuel spray in turbulent flow
Authors
- Wang, and C. J. Rutland
Summary
DNS was performed to study the autoignition process of \(n\)-heptane fuel spray in the isotropic turbulent field. Finally, a correlation was derived relating ignition delay times to temperature and equivalence ratio.
- Euler-Lagrangian approach
- \(n\)-heptane with 44 species and 112 reactions
- Different initial temperature and equivalence ratio.
- Effect of initial temperature
- Temperature decrerases at first due to evaporation.
- There is an additional slight temperature decrease due to direct decomposition and atomic hydrogen abstraction of \(n\)-heptane.
- After evaporation, there is an another period of very slight temperature increase due to cool flame chemistry, including the production of CO: This period is an ignition delay between initial fuel decomposition and very rapid heat global temperature rise.
- Effect of equivalence ratio
Adopted \(\phi\): 0.5, 1.0 and 1.5 with same initial temperature of 1300 K.
- The effect of increasing the global equivalence ratio is to add more spray particles, increasing the evaporative colling so that the ignition delay is increased.