飞机货舱烟气运动数值模拟研究

Numerical Study of Smoke Movement in Aircraft Cargo Compartment

基于Star-ccm+建立了某飞机货舱烟气运动的数值计算模型,获取舱内温度及遮光率等关键参数,分析不同烟雾发生器产烟质量分数和位置下的烟气运动规律,为飞机货舱烟雾探测系统的适航审定发展提供理论指导。结果表明:当产烟质量分数的数量级不变时,温度和烟雾探测响应时间无显著变化,遮光率增长速率随产烟质量分数的增大而增大。当烟雾发生器位于货舱壁面时,烟雾发生器径向温度先减小后增大,温度场呈明显的环状,且相同径向距离处的壁面温度明显高于其他位置。相较于烟雾发生器位于货舱中央,靠近顶棚区域的遮光率增长速率增大,低于顶棚区域的遮光率增长速率减小。烟雾在离开发生表面时和到达顶棚前,除垂直扩散外还存在水平扩散,且水平扩散更强烈。

Star-ccm+was used to establish a numerical computation model of smoke movement in an aircraft cargo compartment.The key parameters,such as cabin temperature and shading rate,were obtained to analyze the smoke movement patterns under different smoke generator mass fractions and positions which provide theoretical guidance for the development of airworthiness certification of aircraft cargo hold compartment smoke detection systems.The results show that the temperature and smoke detection response time do not change significantly when the smoke mass fraction is constant,but the growth rate of shading rate increases with the increase of smoke mass fraction.When the smoke generator is located at the cargo compartment wall,the smoke generator radial temperature decreases and then increases,and the temperature field shows an obvious ring shape.The wall temperature at the same radial distance is significantly higher than other locations.The shading rate growth rate increases in the area near the roof and decreases in the area below the roof compared to when the smoke generator is in the center of the cargo compartment.The smoke diffuses horizontally in addition to vertically as it leaves the generating surface and before it reaches the roof,and the horizontal diffusion is more intense.