Experimental investigation of flame stabilization in a deflected jet

Abstract

The discrepancies in the stability limits based on the characteristic time τ_0, which were observed when burner families of different geometry were compared in Section III, have been explained by use of the residence time concept. Thus, the present experiments with burners of varying geometry have clearly shown that the residence time in the mixing zone is the proper correlation parameter for the stability limits. This parameter is not affected by the great variation the flow field encounters when the slot ratio is changed over a wide range. The experiment also has shown that the most satisfactory correlation is obtained by use of a residence time for the material in the inner part of the mixing zone. The small slot-ratio burner shows several interesting similarities with the can-type combustion chamber. The primary similarity lies in the structure of the mixing zone, because there is good reason to believe that the mixing zone in the can burner also is covered by a flow of fresh mixture for only a short distance. Hence, the successful correlation of stability limits for small slot-ratio burners, shown here, strongly suggests that the mechanism of governing importance for flame stabilization in can burners is the same as that for bluff-body flame stabilization.