Effects of Jet Reynolds Number on the Performance of Axisymmetric and Nonaxisymmetric Gas Burner Flames

An investigation of the effects of burner exit Reynolds number on the relative effects of burner geometry (circular and elliptic with an aspect ratio 2:4) in a propane jet flame is presented. Circular and elliptic burners of the equivalent area of a circular burner of diameter 5.2 mm were studied. Air entrainment into the nonreacting jets, emission indices of NO, NO2, and CO, visible flame length, flame temperature profiles, radiative fraction of heat release, and soot concentration were measured. Results show that an increase in Re decreases the benefits of higher air entrainment into the flame due to elliptic burner geometry. Similarly, the effects of changes in NO and CO emission indices level off at higher burner Re. The measurements of visible flame length, radiative fraction of heat release, temperature profiles, and soot concentrations corroborate the observed emission index results.