闭合循环运行是实现高功率重复频率HF激光器小型化、实用化的重要技术途径。为了实现闭合循环电激励重复频率HF激光器激光能量的稳定性输出，研究闭合循环HF激光器的流场特性，建立了激光器管道的数学仿真模型，利用流体分析计算软件ANSYS，分析了激光器内增益区气体介质流场分布。根据流场分布均匀性要求，提出了增益区的注入段和传输段的不同的结构假设，对不同结构条件下流场进行了模拟计算及分析。最终设计了均匀性更佳的通流管道，并实验测量了激光器内增益区气体介质的流速分布，实验结果与理论仿真一致。

Closed circulation is an important way to achieve miniaturization and practicability of high-power pulsed HF lasers. To obtain stable output energy of closed circulation pulsed HF laser, the characteristics of the closed circulation HF laser is studied, and the numerical model of the laser duct is established. Based on the ANSYS application software , the flow rate distribution of the gas medium inside the gain region is analyzed. To acquire better distribution uniformity, different structures of the injection section and transmit section are developed, and corresponding flow fields are simulated and analyzed. A circulation duct with improved distribution uniformity is designed, and the flow rate distribution of the gain region is measured. The results of the experiment and the simulation are consistent.