Integration Of Optical Diagnostic Techniques Into The Teaching Of The Thermal And Fluid Sciences Laboratory Course

Visual presentation has always played an important role in teaching thermal and fluid related courses because "seeing is believing". However, traditional visualization techniques do not readily provide quantitative information about the flow field of interest, therefore, these techniques have primarily been used for qualitative demonstrations. In the current paper, we illustrate by example, the integration and use of two quantitative visualization/image-processing techniques into an undergraduate Thermal and Fluid sciences laboratory (TFSL) course. First, the Particle Image Velocimetry (PIV) technique is used to provide detailed whole-field velocity measurement. Sample projects include the flow-field characterization of a turbulent wake behind a circular cylinder and the droplet injection process of a Hewlett-Packard inkjet printhead. Second, the Laser Speckle Displacement (LSD) method is used to measure the density/temperature variation of selected flow fields, such as the shock-cell structure of a supersonic jet. Several sample projects involve the use of these two techniques are described in the paper. All laboratory manuals are documented in html format and made available to students before the experiments. Students are required to acquire and process PIV/speckle images and compare the processed data with other theoretical and experimental results in their laboratory reports. In our opinion, by taking advantage of the visual appeal of flow visualization techniques together with the ability to provide quantitative measurements, the integration of the advanced optical diagnostic techniques into the Thermal and Fluid Sciences Laboratory not only enhances students' understanding of the subject but also stimulate their interests in this discipline.