建立自由旋涡气动窗口全流场仿真模型，对大密封压比气动窗口的全流场展开数值研究，得到自由旋涡气动窗口的流场结构，发现大密封压比气动窗口形成的自由旋涡射流在光束输出通道内无明显的波系结构.根据模拟结果对自由旋涡气动窗口的性能进行优化，对自由旋涡喷管上壁面型线进行二次粘性修正.优化自由旋涡射流场后，激光器输出光束通道内压力分布稳定上升；增加扩压器外端壁吹气1.19 MPa、内端壁吹气1.68 MPa时，自由旋涡射流总能提高，气动窗口密封压力从37.5 torr降低至6 torr.该研究结果对自由旋涡气动窗口技术的发展具有参考意义.

The model of the free vortex aerodynamic window with high pressure-ratio was established, and the whole flow field of the aerodynamic window was simulated. The result shows that there is no obvious wave through the export channel of the laser; with the contour of the free-vortex nozzle optimized, the shock wave behind the output of the free vortex nozzle disappeared, and the free-vortex jet flow field get better; with the boundary flow of the diffuser optimized, the total energy of the jet is heightened. The sealing pressure of the aerodynamic window is reduced from 37.5torr to 6torr. The results do effort to the free-vortex aerodynamic window′s research and development.