Polydisperse effects in jet spray flames

Abstract

A laminar jet polydisperse spray diffusion flame is analysed mathematically for the first time using an extension of classical similarity solutions for gaseous jet flames. The analysis enables a comparison to be drawn between conditions for flame stability or flame blow-out for purely gaseous flames and for spray flames. It is found that, in contrast to the Schmidt number criteria relevant to gas flames, droplet size and initial spray polydispersity play a critical role in determining potential flame scenarios. Some qualitative agreement for lift-off height is found when comparing predictions of the theory and sparse independent experimental evidence from the literature.

Keywords:

• spray diffusion flames
• polydisperse sprays
• jet flames
• flame lift-off
• SMD

Acknowledgements

JBG acknowledges the partial support of the Lady Davis Chair in Aerospace Engineering and a grant from the Israel Ministry of Science.

Disclosure statement

No potential conflict of interest was reported by the authors.