Noncircular jets in combustion systems

Combustion dynamics of burners with corners were studied using Planar Laser Induced Fluorescence (PLIF) imaging. The effect of sharp corners on the air flow dynamics, shown earlier in cold flow tests, was also found in the reacting flow of a flame. The sharp corners interrupted the coherent structures generated in an axisymmetric shear flow. The combustion at the flat sections of the flame occurred in periodic, coherent large scale structures but was continuous and homogeneous in the vertices sections. The azimuthal structure of the noncircular flame changed in a pattern similar to that found in nonreacting flows. Combined regions of small- and large-scale mixing in the same flow, a unique feature of burners having sharp corners, is beneficial for combustion applications.