Supersonic Windtunnel Digital Measurement and Imaging Laboratory

将提供设备以改进热学和流体科学的本科实验室。鉴于我国对超音速和高超音速飞行的新兴趣，可压缩流体力学的教学是至关重要的。此外，技术的快速发展为科学和工程领域提供了学生必须熟悉的新工具。超音速风洞数字测量和成像实验室以一种独特的方式满足了这两个需求。该项目的核心是一个高雷诺数的超音速风洞，排气到大气压力，能够达到2.5马赫和超过一百万的雷诺数。这是一个依靠现代、快速反应、计算机控制仪器的排污设施。由于典型的运行时间只有几秒钟，因此只有能够快速生成和存储测量值的仪器才有用。所需的主要仪器是一个多通道压力扫描仪，一台用于控制、数据采集和分析的数字计算机，以及组成独特数字成像单元的设备。最后一个单元的目的是用几种有用的光学模式之一（例如，用纹影观察激波结构，用阴影法观察单一气体湍流或多种气体混合）来拍摄流动快照。脉冲YAG激光周期性地照射流，然后图像被CCD相机捕获，数字化，并存储在控制计算机中，以便对数据进行后续图像处理。

Equipment to improve an undergraduate laboratory in the thermal and fluid sciences will be provided. In light of our nation's renewed interest is supersonic and hypersonic flight, the teaching of compressible fluid mechanics is of paramount importance. In addition, the rapid pace of technology has given the science and engineering community new tools with which the student must be familiar. The Supersonic Windtunnel Digital Measurement and Imaging Laboratory satisfies these two needs in a unique way. The heart of the project is a high Reynolds number, supersonic windtunnel, exhausting to atmospheric pressure and capable of attaining Mach 2.5 and Reynolds numbers exceeding one million. It is a blowdown facility that relies on modern, fast-response, computer-controlled instrumentation. Since the typical run time is only a few seconds, only instruments capable of quickly making and storing measurements are useful. The main instruments required are a multiple-channel pressure scanner, a digital computer for control, data acquisition, and analysis, and the equipment making up the unique digital imaging unit. The purpose of this last unit is to take snapshots of the flow in one of several useful optical modes (e.g., Schlieren to observe the shock structure, and shadowgraphy for single gas turbulence or multiple gas mixing). A pulse YAG laser illuminates the flow periodically, then the image is captured by a CCD camera, digitized, and stored in the controlling computer which allows subsequent image processing of the data.