The structure and stability of nonadiabatic flame balls

✍ Scribed by J. Buckmaster; G. Joulin; P. Ronney

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 633 KB
• Volume: 79
• Category: Article
• ISSN: 0010-2180
• DOI: 10.1016/0010-2180(90)90147-j

✦ Synopsis

Recent experiments in microgravity suggest the possibility of statiomtry spherical premixed flames (flame balls) in which the only fluxes are diffusional. We construct stationary solutions of this nature, stm-ting with simple model equations and using activation energy asymptotics. Sufflcionfly large volumetric heat losses quench the flame, and for heat losses less than the quenching value there are two possible solutions, a small flame, sad a ladle fla~. For vanishing heat loss the small solution is identical to one constructed by Zeldovich, and is known to be unstable, whereas the large solution is characterized by a flame of infinite radius. We examine the linc4ff stability of stationary solutions, and show that all small flames ate unstable to one-dimensional (radial) perturbations. Large flames are unstable to three-dimensional perturbations, bm only if they have a radius gttater than some critical value. Thus there is a band of large flames, lying between the quenching point and unstable flames, that are stable.