基于发散光反射式布局的大视场显示方法研究

更大尺度风洞和试验模型以及更长射流的流场测量，对流场显示的视场尺度提出了更高要求。设计和验证两种基于发散光反射式布局的大视场显示方法，分别为反射式聚焦纹影方法和反射式阴影方法。通过改进源格栅和光源，在实验室搭建了一套反射式聚焦纹影显示装置，获得了直径约1.5 m的视场结果。视场均匀性和试验条件下的最短曝光时间表明该方法可用于大型风洞及其他场合的大视场显示。同时，为解决试验现场振动较强的测量问题，搭建了发散光反射式阴影显示装置，获得了约2.5 m长度的燃烧射流流场显示结果。最后根据发散光反射式流场显示方法的特点，开展了其在大型风洞布局的适用性评估，结果表明:该方法完全适用于大型风洞的大视场显示。

Research on large field visualizaiton based on divergent light reflective layout

Larger scale of flow-field visualization is required for larger wind tunnel, larger test model and longer jet flow. Two methods of the large field visualization were proposed which are based on divergent light reflective layout and are named as the reflective focusing schlieren method and the reflective shadow method, respectively. A reflective focusing schlieren device was built in laboratory which improves the source grid and light source. A visualization field with a diameter of about 1.5 m was obtained. The field uniformity and the minimum exposure time under test condition indicate that the reflective focusing schlieren method could be utilized for the large scale wind tunnel and other situations. Also, to realize the large field visualization for the situation with strong vibration, a diffuse reflective shadow visualization device was set up, and a visualization field with a length of about 2.5 m was obtained for a combustion jet flow. Finally, according to the characteristics of the reflective method, the applicability of the method in larger tunnel layout was evaluated, and the results show that the method is completely suitable for the large-scale wind tunnel visualization.