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A unique cascade test facility has been developed for use in the Wichita State University (WSU) water table. Although small in scale, the WSU water table has the advantage of low cost and the ease with which test conditions can be varied. Water table facilities have been used in the past for cascade experiments, especially as analogies for compressible flow visualization of turbine cascades. However, the lack of a quantitative measurement technique at low speeds has precluded the use of the water table as an analogy for testing subsonic compressors and turbines. In the present experiment, the hydrogen bubble flow visualization technique is used to generate bubble time lines, and a CCD (Charge Coupled Device) video camera system captures and digitizes these time line images. A VisualBASIC® computer program is then used to determine the wake velocity profile based on the difference in bubble line positions at successive intervals of time.

The aerodynamic properties of a forward-swept wing were tested at low Reynolds numbers. The investigation was performed in a low-speed wind tunnel using a reflection plane model. Tunnel balance, model pressure taps, and flow visualization results were utilized to characterize the wing behavior over a range of Reynolds numbers from 0.25 × 106 - 0.75 × 106. In addition, the experimental data is compared to results obtained using a recently developed computer program known as WING3D. This modified Non-Planar Vortex Lattice Method program can calculate total wing lift and surface pressure distributions. The forward-swept wing has good aerodynamic qualities; in addition, the flow, on the outboard sections of the wing, remains attached beyond stall. The comparison of WING3D and experimental surface pressure distributions is good.

A basic overview of Doppler Global Velocimetry (DGV) is provided with respect to potential measurement applications. DGV, a relatively new method, is presently undergoing development and evaluation at a number of research labs. A discussion of current DGV theory, system specifications, measurement capabilities, and development activities is provided. DGV problems, challenges, and solutions unique to the method will be outlined. At this point it appears likely that DGV systems will see increased application in wind tunnels. Like other laser based measurement methods, DGV will be principally handicapped by factors related to flow seeding.

A basic one-component Doppler Global Velocimetry (DGV) system has been developed at Wichita State University. This system was evaluated on a round axisymmetric jet. The results are compared with measurements made using traditional Constant Temperature Anemometry (CTA) and Preston tube measurements at 3.2, 9.6 and 16.0 jet exit diameters downstream and along the jet centerline. The DGV results show similar trends to these measurements. Software corrections for camera misalignment, optical distortions, and laser frequency variations were necessary to assure data quality. Results indicate good agreement between the DGV and CTA measurements exist.