Measurements of reactive recirculating jet mixing in a combustor

Abstract

A ducted, subsonic, hydrogen/air turbulent jet mixing flowfield was experimentally investigated, both with and without combustion. The geometric configuration approximated a sudden expansion or dump combustor with a central air jet surrounded by a low-velocity hydrogen stream at an overall equivalence ratio of 0.12. The ratio of the duct to inner nozzle diameter was 2.5. Radial distributions of mean axial and radial velocity, axial and radial turbulent intensity, velocity cross correlation, gas composition, static temperature, and total pressure, as well as axial distributions of wall static pressure, were obtained for axial stations 0-6 duct diameters from the combustor entrance. The data indicate that mixing is slower in the chemically reactive flowfield than in the nonreactive flowfield, and that the presence of combustion has a significant effect on the size and location of the recirculation zone within the mixing duct.