Flow-Field Seeding Techniques for Large Transonic Wind Tunnels

Optical measurements including laser velocimetry (LV), particle image velocimetry (PIV), and other similar techniques are becoming a more important part of aerodynamic testing. However their implementation into large production wind tunnels is severely hindered by difficulties with flow seeding. Phase I of this program will focus on the problem of seed delivery and dispersal into a transonic stream over the small area of interest. This will limit facility contamination to minimum levels but requires a device to be installed near (or just upstream) of the test section to locate the seed distribution nozzle(s). The effect on flow quality will be evaluated as well. If this proves successful, Phase II will focus on the problem of implementing a system that can be easily installed/removed in a typical large transonic wind tunnel.