Abstract:

Research on the effect of air flow with diffusion flame characteristics of laminar jets under microgravity can provide theoretical support for fire detection in aerospace research. A short-term (3.6 s) microgravity experiment was conducted in the Drop tower facility of the National Microgravity Laboratory of China to obtain the characteristics of methane flames under different coflowing air speeds. Preliminary drop tower experimental results showed that characteristics of laminar jet diffusion flames could be affected by low air flow velocities in microgravity environment. The phenomenon of flame oscillation couldn't be observed in microgravity with coflow velocities of 0~0.5 m/s, the luminous flame length and diameter decreased with coflow velocity increasing, but the luminous flame diameter didn't change significantly compared to luminous flame length; the radiative heat loss fraction for the methane-fueled flames in microgravity decreased with coflow velocity increasing, and the radiative heat loss fraction was much larger for flames in microgravity than in normal gravity.

Key words: