An experimental program was conducted to study the burning of laminar gas jet diffusion flames in a zero-gravity environment. The tests were conducted in the Lewis Research Center 2.2-Second Zero-Gravity Facility. The photographic results indicated that a sudden decrease in gravity level from 1 to 0 effected an immediate reduction in the length of the flame. Continued time in zero gravity resulted in the flame expanding away from the burner until extinguishment appeared to occur. Nondimensionalization of the governing flow equation yielded the parameters used to correlate the buoyancy effects.

An experimental program was conducted to study the burning of laminar gas jet diffusion flames in a zero-gravity environment. The tests were conducted in the Lewis Research Center 2.2-Second Zero-Gravity Facility. The photographic results indicated that a sudden decrease in gravity level from 1 to 0 effected an immediate reduction in the length of the flame. Continued time in zero gravity resulted in the flame expanding away from the burner until extinguishment appeared to occur. Nondimensionalization of the governing flow equation yielded the parameters used to correlate the buoyancy effects.

An experimental program was conducted to study the burning of laminar gas jet diffusion flames in a zero-gravity environment. The tests were conducted in the Lewis Research Center's 2.2- Second-Zero-Gravity Facility and were a part of a continuing effort investigating the effects of gravity on basic combustion processes. The photographic results indicate that steady state gas jet diffusion flames existed in zero gravity but they were geometrically quite different than their normal-gravity counterparts. Methane-air flames were found to be approximately 50 percent longer and wider in zero gravity than in normal gravity.

The objective of this effort was to gain a better understanding of the fundamental phenomena involved in laminar gas jet diffusion flames in the absence of buoyancy by studying the transient phenomena of ignition and flame development, (quasi-) steady-state flame characteristics, soot effects, radiation, and, if any, extinction phenomena. This involved measurements of flame size and development, as well as temperature and radiation. Additionally, flame behavior, color, and luminosity were observed and recorded. The tests quantified the effects of Reynolds number, nozzle size, fuel reactivity and type, oxygen concentration, and pressure on flame characteristics. Analytical and numerical modeling efforts were also performed. Methane and propane flames were studied in the 2.2 Second Drop Tower and the 5.18-Second Zero-Gravity Facility of NASA LeRC. In addition, a preliminary series of tests were conducted in the KC-135 research aircraft. Both micro-gravity and normal-gravity flames were studied in this program. The results have provided unique and new information on the behavior and characteristics of gas jet diffusion flames in micro-gravity environments. Bahadori, M. Yousef and Edelman, Raymond B. Unspecified Center NASA-CR-191109, E-7720, NAS 1.26:191109 NAS3-22822; RTOP 694-03-0A...