复杂通道内激光传输的气体热效应

 借助现有的流体力学分析软件，运用用户自定义函数的方式，建立了一套完整的光场流场耦合相互作用仿真模型。针对一种特殊的激光内传输通道，对光场流场耦合相互作用的气体热效应问题进行了仿真计算。仿真结果表明:通道内气体速度分布是非常不均匀的，但在无激光加热时，气体密度基本保持均匀分布；将激光加热效应引入到流场以后，气体密度分布会发生明显变化；激光加热引起的气体非均匀密度分布使得激光通过传输通道后，产生双鱼眼型结构的光场相位分布。

Thermal blooming in complicated pipe flow

Based on the computational fluid dynamics (CFD) software, an emluator for the optics and fluency coupling effects is established by means of the user defined function (UDF). Thermal blooming effects in a special tube with axial pipe flow are modeled. The simulated results indicate that the velocity distribution of the pipe flow is very asymmetric. However, the fluid density distribution is almost not changed without laser beam heating. As laser beam couples with the fluency, the fluid density distribution varies greatly. The heterogeneous fluid density distribution induces the optical path distinction of the double pearl eye form. This phenomenon is also observed in the previous experiments.