火灾烟雾颗粒凝并分形特性研究

Study on fractal coagulation characteristics of fire smoke particles

火灾烟雾颗粒因布朗运动由初期的主粒子凝并形成大颗粒的凝团结构,其外形呈现出分形特征,根据分形理论对火灾烟雾颗粒凝团结构进行分析研究,采用场发射扫描电镜对多种材料的烟雾颗粒图像进行测试,通过对烟雾凝团图像进行处理,获得了火灾探测中常见的多种材料的分形维数和分形系数,给出了烟雾颗粒的主粒子粒径,并对其影响因素进行了对比分析,为火灾烟雾探测中颗粒凝并分形特性研究提供有益的探索.

Primary particles produced in the early fire period evolve into bigger aggregates due to Brown coagulation, which take on fractal properties. In this article, smoke particle images were obtained by a field emission scanning electron microscope （SEM）, and the fractal characteristics of the particles were analyzed based on the power law of fractal theory. By using digital image processing technique, more fractal parameters such as the fractal dimension, fractal prefactor, primary particles＇ size and radius of gyration were obtained. The results can provide a fundamental basis for fire smoke detection research.