群发性火灾，是离散分布的可燃性材料同时燃烧而形成的火灾场景，此类火灾的发展过程中，易发生多火源耦合燃烧现象，引起火灾强度的剧烈变化，形成城市或森林区域大火，造成重大火灾损失。因此，针对群发性火灾的发展与突变问题，以散布火源为研究对象，开展火阵列自由燃烧模拟实验。对于既定的火源，获取不同燃料种类和离散分布特征（火源数目和火源间距）条件下燃烧域内各火源燃烧速率、温度场、辐射热流和火焰高度等燃烧特性表征量，并以此分析各特征量随燃烧时间的变化趋势和在燃烧空间上的分布特征，揭示燃烧区域辐射热流、火焰形态、燃烧速率间耦合作用机制，并基于池火燃烧模型构建多火源燃烧总热辐射经验模型，开展数值模拟并结合实验和辐射模型探讨多火源燃烧时空演化过程关键影响因素，从而提出火焰融合现象和热辐射导致燃烧蔓延的临界条件。本项目对于深入理解多点火源耦合燃烧动力学演化规律有重要意义，可为群发性火灾的预防与控制提供科学指导。

Group fires, generated by the burning of discrete combustible materials, can easily develop into urban or wildland mass fires in practice,with great growth of burning intensity. Multiple fires burning is the fundamental process involved in group fires, in which the fires generally have significant influence on each other due to two major fire interaction effects -the air entrainment restriction and radiation heat feedback enhancement. Due to the fire interaction effects, multiple fires burning may lead to extreme fire behaviors such as fire merging and fire whirl, and especially, the data and theory for single fires cannot be directly extra polated to multiple fires. For specific fire source conditions, the interaction effects among fires mainly depend on the fuel distribution conditions such as fire spacing and number of fire points. Therefore, the experiments of multiple discrete fires are designed to study the development and mutation of free burning group fires. For specific fire source conditions, the combustion characteristics, such as burning rate of each fire point, temperature, radiation flux and flame height, will be measured under different fuel types and distribution conditions such as fire spacing and number of fire points. Fire merging phenomenon also will be observed from the video. Based on these experimental data, the time variation and spatial distribution of multiple fires burning behavior can be analyzed. Radiation heat feedback enhances the flame length and burning rate of each fire point and also is affected by the flame state and burning intensity. The dynamic coupling mechanism can be discussed according to the analysis of multiple fires burning behavior and a experimental model to calculate the total radiation heat of burning area will be developed founded on combustion models of single pool fire. Further, based on the experiments and thermal radiation model, numerical simulation is intended to explore the key factors controlling the developing process of multiple fires burning, and some new criteria will be developed to identify the conditions for fire merging and identifying the conditions for fire spreading from burning multiple fire points to nearby discrete fire sources due to thermal radiation. This project is very significant to understand the combustion dynamics of multiple fires in depth, and can provide scientific support for the preventing and controlling of group fires.