化学气相浸渗反应器内气体流场的数值模拟

Numerical simulation of gas flow field in chemical vapor infiltration reactor

控制化学气相浸渗(CVI)反应器内的反应气体流场是获得理想沉积物的关键技术之一,通过建立质量守恒、动量守恒、能量守恒和化学反应守恒4个微分方程及其边界条件,采用有限单元法对CVI反应器中复杂且不可观察的气体流场进行数值计算。数值计算结果表明,喷嘴形状及其与衬底相对位置对流场形貌有显著影响。采用π/6的斜口喷嘴,并使其中心轴线与通过它和圆柱形衬底交点切线的夹角为π/6时,反应器内基本消除了回流。

In order to deposit ideal matrix, it is one of the key technologies to control the flow field of reaction gases in the chemical vapor infiltration（CVI） reactor. Based on establishing four differential equations about conversations of mass, momentum, energy and chemical reaction, their boundary conditions, the complex and invisible flow field phenomena in CVI reactor chamber were investigated by numerical simulation using the finite element method. The results show that the effect of the nozzle shape and the location between the nozzle and the substrate on flow field is in evidence. The flow circumfluence in the CVI reactor is eliminated on condition that the inclination between the axes of the nozzle and the tangent of the cylinder substrate is equal to π/6, and with a bevel nozzle.