军用战机机上人员吸入气CO2浓度的仿真研究

人体吸入过高浓度的CO_2气体会产生不良反应。航空供氧防护领域往往重点关注供氧装备的氧气浓度,忽视了CO_2浓度。特别是机上人员处于高度紧张或运动状态下,呼出CO_2气量增加,将直接影响面罩内的CO_2浓度。为保证面罩内CO_2浓度符合航空标准的要求和确保机上人员的用氧安全,通过仿真和实验验证的方法,研究了机上人员处于安静状态和运动状态下,面罩内CO_2浓度的动态变化情况。数学模型表明,吸气相面罩内CO_2浓度取决于飞行高度、呼吸流率和吸入气体积等参数。动态仿真和实验验证表明,安静状态下呼吸,机上人员的面罩CO_2浓度接近或超过军标规定。可见,供氧装备应增加机上人员安静呼吸状态下的供氧量,可稀释面罩内存留CO_2气体,降低其浓度,确保供氧防护安全。

Simulation Study of CO2 during inspiration of Crew on Military Aircraft

Mixed gas with high concentration CO2 that was inspired would produce adverse reactions to human body. In the domain of oxygen supplement protection, O2 concentration of gas in mask was more focused, however, CO2 concentration was ignored. Crew on board would expire more CO2 gas under the state of tension or exercise that it would affect the CO2 concentration of gas in the mask. Mathematical model shows the CO2 concentration of gas in the mask during inhalation phase is determined by flying height, flow rate of breathe and the volume of inspired gas and so on. The results of dynamic simulation and experimental verification show CO2 concentration of mask gas approaches or exceeds the regulation of military standard when crew breathe under resting state. It is concluded that oxygen supplement equipment should increase the rate of flow when crew breathe under resting state. This measurement could dilute CO2 in the mask, and then reduce its concentration. Thereby, it could guarantee the safety to oxygen supplement protection for crew.