Dynamics of ignition of stoichiometric hydrogen-air mixtures by moving heated particles
Studying thermal ignition mechanisms is a key step for evaluating many ignition hazards. In the present work, two-dimensional simulations with detailed chemistry are used to study the reaction pathways of the transient flow and ignition of a stoichiometric hydrogen/air mixture by moving hot spheres. For temperatures above the ignition threshold, ignition takes place after a short time between the front stagnation point and separation location depending upon the sphere's surface temperature. Closer to the threshold, the volume of gas adjacent to the separation region ignites homogeneously after a longer time. These results demonstrate the importance of boundary layer development and flow separation in the ignition process.
© 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. Received 2 April 2016, Revised 20 May 2016, Accepted 23 May 2016, Available online 28 June 2016. This work was carried out in the Explosion Dynamics Laboratory of the California Institute of Technology. J. Melguizo-Gavilanes was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) Postdoctoral Fellowship Program. R. Mével, S. Coronel and J.E. Shepherd by The Boeing Company through a Strategic Research and Development Relationship Agreement CT-BA-GTA-1. This work used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation grant number ACI-1053575.
Accepted Version - JMG-sphereIJHE_revised.pdf