微重力火災燃燒與傳統火災模型挑戰與應用

現代火災工程多以浮力對流主導為基本假設，然在微重力或低浮力條件下，燃燒機制將產生本質差異。本文回顧相關研究指出，當自然對流顯著削弱時，火焰傳熱由對流主導轉為擴散與輻射主導；在燃燒三要素交互作用下，燃燒產物滯留將改變局部溫度與濃度分布，進而影響火焰蔓延與熄滅條件。國際Saffire等大尺度實驗亦顯示，材料可燃性極限與臨界氧濃度於低浮力環境下與地面條件存在顯著差異。此現象不僅限於太空場域，在通風受限或高氣密密閉系統中亦可能出現類似機制。因此，有必要重新檢視低浮力條件下之燃燒模型與安全設計原則，以提升密閉或低壓環境之火災風險評估能力。

Modern fire engineering is largely developed on the fundamental assumption that buoyancy-driven convection governs flame behavior, heat transfer, and smoke movement. However, under microgravity or low-buoyancy conditions, combustion mechanisms exhibit essential differences. This review highlights that when natural convection is significantly weakened, flame heat transfer shifts from convection-dominated to diffusion- and radiation-dominated regimes. Within the interaction of the fire triangle, the accumulation of combustion products alters local temperature and concentration fields, thereby influencing flame spread and extinction characteristics. Largescale experiments such as NASA’s Saffire series further demonstrate that material flammability limits and critical oxygen concentrations under low-buoyancy environments differ from those observed under normal gravity. Such phenomena are not limited to space applications; similar mechanisms may arise in ventilation-restricted or highly airtight enclosed systems. Therefore, it is necessary to re-examine combustion models and safety design principles under low-buoyancy conditions to improve fire risk assessment and thermal safety strategies for enclosed or lowpressure environments.