摘要
理论上和实际上,载人航天器都有发生火灾的可能,载人航天器的火灾安全问题是微重力燃烧研究的重要内容.氧气浓度和气流速度对给定固体材料的可燃性具有显著影响,在固体表而的逆向和同向传播火焰中,都存在由氧气浓度和气流速度决定的可燃极限,即气流速度较高时的吹熄和气流速度较低时的冷熄.极限氧气浓度和极限气流速度两个极限参数,是衡量材料可燃性的关键指标.在微重力条件下,当低速气流存在时,固体材料发生有焰燃烧和闷烧的可能性都大大增强.因此,剔除材料中的潜在燃料是航天器防火的主要措施.但是,在航天器使用的材料中,仅有很少一部分是阻燃的,为了保证火灾安全,还必须采取火灾检测和灭火措施.当前美国和俄罗斯采取的火灾安全方案,既有相似性,也有各自的特点.在载人航天器的火灾安全问题中,尚有很多问题和方案有待研究或检验.考虑到我国的实际情况,作者认为,通过实验对照和数值模拟的方法,开展材料在微重力条件下的燃烧特性的常重力模拟,对于我国载人航天器的火灾安全具有现实意义.
Theoretically and practically, fire is possible to break out aboard a manned spacecraft. Therefore, the fire safety for manned spacecraft is an important part of microgravity combustion research. The oxygen concentration and gas velocity have a significant effect on the flammability of solid materials. For both counter-flow and concurrent-flow flame spreading over solid materials, the flammability has a limit determined by oxygen concentration and gas velocity, i.e., it is a blow-off extinction at high gas velocity, but a quenching extinction at low gas velocity. The limit oxygen concentration and the limit gas velocity are critical index to evaluate the flammability of materials. Under microgravity, the possibility of occurring both flaming combustion and smoldering is increased in a low speed flow. Consequently, eliminating the potential fuel in materials used in spacecraft is the main measure for fire prevention. However, materials used for a spacecraft that can resist combustion are very few. To ensure fire safety, the fire detection and the fire fighting method are necessary. There are similarities and differences between the fire safety projects in America and Russia. At present, there are still many problems to be resolved for the fire safety for manned spacecraft. Considering the actual condition of our country, the present author thinks that the simulation under the normal condition of the microgravity combustion characteristics of materials using both experimental and numerical methods is practical and important for fire safety of our country's manned spacecraft.
出处
《力学进展》
EI
CSCD
北大核心
2005年第1期100-115,共16页
Advances in Mechanics
基金
中国科学院知识创新工程重要方向(KJCX2-SW-L05)资助项目
