挂滴燃烧过程中微气泡的成核

利用高速显微摄像技术观测了航空煤油RP-3的微尺度挂滴燃烧过程,分析了油滴内微气泡成核的基本机理和表现形式.在凸曲率诱发的低压成核机理下,确证了3种具体成核形式:①挂丝/油滴界面成核.挂丝温度高于油滴温度,在交界面上由于温差诱导了蒸发效应形成微气泡成核.②颗粒/油滴界面成核.微油滴内的微米量级的丝状或球状杂质颗粒及胶质颗粒形成的凸曲率侧诱导低压,成为气泡的萌生的成核点.③油滴表面凹坑成核.重组分形成筏结构与油滴表面侧的线张力和表面张力同时作用,引起油滴表面内凹,凹坑的凸曲率侧气泡成核点.这些进展为深入研究微尺度燃烧奠定了基础. 

Micro bubble nucleation inside suspended droplet in combustion

High-speed microscopic camera technology was utilized to observe and research the micro-scale suspend droplet combustion process of aviation kerosene RP-3. The basic mechanism of micro bubble nucleation inside droplet and manifestation were analyzed. Under convex curvature induced nucleation mechanism at low pressure, three forms of nucleation which were confirms were including:(1) Nucleation in the interface of the suspended silk/droplet. The temperature of suspended silk was higher than the droplet temperature on interface, and temperature difference induced the evaporation effect to form the micro bubbles nucleation.(2) Nucleation in the interface of the particles/droplet. Several micrometer range filiform or globular impurity particles or colloid particles inside droplet that form convex curvature side to induce meiobar, in which burgeon bubbles nucleation points.(3) Nucleation on pits of droplet surface. Heavy components form the raft structure and the line tension and surface tension of the droplet surface side simultaneous effect cause indent of the droplet surface, which sprout bubbles nucleation points in the convex curvature side of the pit.These developments laid the foundation for further research on micro-scale combustion.