氢氧焰入射角对石英玻璃沉积效率的影响

为提高CVD合成石英玻璃的沉积效率，对不同氢氧焰入射角的工况进行了试验和数值模拟，比较并分析了沉积效率的变化规律和二氧化硅微粒的沉积机制．结果表明：数值模拟与试验测得的沉积效率基本吻合；近沉积面的速度分布决定了二氧化硅微粒的沉积分布，二氧化硅微粒沉积的主要机制为湍流沉积，热泳沉积起协助作用；氢氧焰入射角不同，近沉积面的速度分布和沉积面的高温区域均有明显差异，入射角过大或过小，都会造成二氧化硅微粒沉积位置和沉积面高温区的重合区域减小，降低沉积效率．入射角度为22°时，沉积效率最高（71％）．

The Influence of Oxy-hydrogen Flame Incidence Angle on Deposition Efficiency in Synthetic Silica Glass Process

To improve the deposition efficiency of synthetic silica glass by chemical vapor deposition （ CVD）, the working conditions of different incidence angle of oxy-hydrogen flame were tested by experimental and numerical simulation methods. The variation law of deposition efficiency and the deposition mechanism of silica particles were analyzed. The simulation results of deposition efficiency agree with the experimental results. The deposit distribu- tion of silica particle is determined by the speed distribution near the deposition plane, and the main deposition mechanism is turbulence, supplemented by thermophoresis. There are significant differences in the speed distribu- tion near the deposition plane and the high temperature region of deposition plane with the change of incidence an- gles of oxy-hydrogen flame. If the incidence angle is too large or too small, the overlap zone between the region of particle deposition and the high-temperature region was reduced, which resulted in lower deposition efficiency. The best efficiency 71% is obtained when the incidence angle is 22°.