Study of precursors to blowout of stagnation stabilised flames

Lean blow out was studied in two different jet impingement burners, viz., Axisymmetric and 2-D slot burner They respectively have single and multiple stagnation points. In the axisymmetric burner, there were no precursors prior to blowout. Precursors were observed in 2-D slot burner. The flame lost part of the stagnation line stabilisation from either or both ends of the line and regained it during the precursor event. This suggested that the precursor events will require that there be multiple stabilisation points adjacent to each other. Increasing the gap between the stagnation body and the jet lip weakened the precursor events.