Mastorakos, Markides, Pedersen-Mjaanes, Marchione
A novel autoignition flow reactor has been built at Cambridge and has provided new insights into the structure of autoignition zones in flowing non-uniform turbulent mixtures. Typical photographs of autoignition are shown below for acetylene. The flow comes from the left and the fuel is injected centrally. From images like these, the statistics of the location of the autoignition spots can be quantified and these are then related to the characteristics of the background turbulence. You can also see a movie (13Mb) of the evolution of typical autoignition spots of acetylene taken with a fast intensified camera at 7kHz. (Internal reflections make the spots in the movie appear as symmetric pairs.)
Figure 1. Colour photographs (exposure time: 1/125s) of acetylene autoignition. Uair = 10m/s, Tair = 820K.