free-flight wind tunnel

例句：

1. 1.The free-flight wind tunnel is used to test the performance of aircraft engines.
   自由飞行风洞用于测试飞机发动机的性能。
2. 2. The research team used the free-flight wind tunnel to study the aerodynamics of the new design.
   研究团队使用自由飞行风洞研究了新设计的气动特性。
3. 3. The free-flight wind tunnel is an essential tool for testing the stability and control of aircraft in flight.
   自由飞行风洞是测试飞行器飞行稳定性和控制的重要工具。