中文摘要：

为了解决单光程纹影系统在高马赫数、低静压流场显示中灵敏度低的问题,研制了国内首套最大口径为Φ900 mm的双光程纹影系统。与单光程纹影系统相比,双光程纹影系统具有更高的灵敏度,能提供更多的流场细节,能拓宽纹影技术的应用范围。通过用LED四色光源代替常规的彩色刀口、增加补偿透镜、优化照相物镜和精细调节LED四色光源,较好地消除了试验流场重影。通过增加入射光阑,有效减弱了试验流场中出现的光源光斑。对单光程纹影流场图与双光程纹影流场图进行了比较。在马赫数Ma=10、试验总压为2.0MPa、试验总温为1100K、攻角为0°~15°试验条件下,通过双光程纹影系统,获得了大钝头模型清晰的试验流场图像。最后分析了双光程纹影技术的优缺点及改进方向。

英文摘要：

In order to solve low sensitivity of flow visualization using a single-pass schlieren system under the conditions of higher Mach number, low static pressure, the double-pass schlieren system with Ф900 mm caliber of light beam of spherical mirror in China, was developed. Compared with a singlepass one, higher sensitivity was obtained, and more flow detail can be provided and the range of application of the schlieren technique can be expanded through a double-pass schlieren system. The out- of-focus flow image was eliminated by replacing colorful knife edge with the LED light source of the four-color-light, by adding the compensating lens, optimizing object lens and adjusting finely the LED light source. The flow image on the common aviation vehicle （CAV） model obtained using double-pass schlieren system was compared with that obtained using single-pass schlieren one. The incident diaphragm was added before the object lens so that a light spot was removed. The vivid flow image on the big blunt model was obtained under experimental condition of Mach number 10, total pressure 2.0 MPa, total temperature 1 100 K, angle of attack from 0° to 15°. The advantage and disadvantage of a doublepass schlieren system was analyzed.