Turbulent gaseous combustion part I: Local species concentration measurements

Abstract

Experimental measurements were made of fuel mixture fraction profiles and species concentration profiles (O 2, N 2, CH 4, CO, CO 2, H 2O, and tracer Ar) in turbulent natural gas diffusion flames. Twenty-eight tests were performed in an axisymmetric combustor with coaxial feed of fuel and air. The test variables included type and arrangement of sample probe, combustor wall temperature, and air feed temperature. Gas samples were obtained with both water-quench and water-cooled probes. Direct water-quench probes were more effective in quenching reactions inside the sampling probe than water-cooled probes; however, some of the CO 2 in the gas samples was dissolved in the quench water. A 350 K change in the wall temperature had a negligible effect on gas mixing rates, but did alter the local gas species distributions somewhat. More complete combustion was achieved with elevated air feed temperatures, but more complete mixing was obtained at lower air temperatures. The results provide a data base for evaluating predictive computer models.