Lv Hui, Gu Yin, Zhou Rui, Pei Pei, Cai Zhiyong
School of Safety Science, Tsinghua University, Beijing 100084, China.
Institute of Public Safety Research, Department of Engineering Physics, Tsinghua University, Beijing, 100084, China.
Heliyon. 2024 Sep 24;10(22):e38341. doi: 10.1016/j.heliyon.2024.e38341. eCollection 2024 Nov 30.
Although firefighting aircrafts are effective for fighting forest fires, they are affected by a variety of risks related to forest fires during flight operations such as thermal radiation, temperature rise, decrease in air density, and changes in updraft aerodynamics. Quantifying these influences poses a significant challenge. Our research reveals that safety standards predominantly hinge on technical indicators like flight height, speed, and angle of attack, which makes it possible to quantify the above effects. A general method framework for analysing firefighting flight safety criteria was constructed in this study. Using relevant physical models, such as heat radiation, temperature, air density, and updraft in a forest fire environment, safety criteria with an analytical form were established. The corresponding safety constraints of each criterion were calculated quantitatively, and the most stringent constraint was determined based on multiple factors to obtain a comprehensive safety constraint boundary composed of the critical height, stall speed, and critical angle of attack. Finally, the effectiveness of the method is validated through a simulation case. The research results show that the constrained boundary calculation method proposed in this study can provide a scientific foundation for developing technical specifications for forest aviation safety and aviation fire task plan.
尽管消防飞机在扑救森林火灾方面很有效,但在飞行作业期间,它们会受到与森林火灾相关的各种风险影响,如热辐射、温度升高、空气密度降低以及上升气流空气动力学变化。量化这些影响是一项重大挑战。我们的研究表明,安全标准主要取决于飞行高度、速度和攻角等技术指标,这使得量化上述影响成为可能。本研究构建了一个分析消防飞行安全标准的通用方法框架。利用森林火灾环境中的热辐射、温度、空气密度和上升气流等相关物理模型,建立了具有解析形式的安全标准。对每个标准的相应安全约束进行了定量计算,并基于多个因素确定了最严格的约束,以获得由临界高度、失速速度和临界攻角组成的综合安全约束边界。最后,通过一个模拟案例验证了该方法的有效性。研究结果表明,本研究提出的约束边界计算方法可为制定森林航空安全技术规范和航空灭火任务计划提供科学依据。