Anchoring point of a Bunsen flame by velocity-matching method

The effect of premixed gas velocity of a Bunsen flame on its anchoring point is studied through theoretical analysis and experiments for the anchoring point is a key factor in determining flame lean blowoff characteristics. In order to predict the position of the anchoring point, the velocity-matching(VM) method is employed, by which the profile of gas velocity and flame speed of the cold flow field near the exit of a Bunsen burner are compared and the effect of cold wall quenching is introduced. The equations describing the anchoring point are figured out. The experiment on variation of the anchoring point with incoming gas velocity is conducted on a premixed methane-air laminar flame. The results show that, with the increase of in coming gas velocity, the anchoring point will move downstream and towards rather than away from the centerline of the jet, as predicted by Bernard Lewis. The prediction of the anchoring point by VM method agrees well with the experimental result within the uncertainty of less than ± 20%.