Streamwise Vorticity Effects in a Curved Diffuser with Slot Jet Flow Control (Preprint)
Abstract
A slot jet is used to increase the diffusion level of a curved, diffusing wind tunnel passage. The passage entrance coincides with the tunnel throat, which has respective Mach and Reynolds numbers of 0.7 and 187000 (based on throat height) and jet Reynolds numbers ranging from 10000 to 22000. Each of four presented configurations uses linear slot jet flow control at the same relative location. Three configurations include co- or counter-rotating vortex generator (VG) fins of varying heights upstream of the slot jet, while the other configuration has no VGs. The configurations are tested for varying flow control input and evaluated primarily on the basis of passage exit total pressure surveys. At baseline conditions (minimum slot jet flow), the shorter VG designs were found to provide some diffusion enhancement and loss reduction compared to the non-VG configuration, whereas the tall counter-rotating VGs exhibit an increase in loss. With the addition of slot jet flow, all configurations showed an initial decline followed by a net increase in performance of similar magnitude, with choked slot jet flows tending to lead to flow instabilities. Upon further increases in slot jet flow, all configurations eventually achieved a stable flow pattern. A noteworthy change in the flow pattern, with substantially improved uniformity, is documented near 6% flow control input and will be the subject of more detailed investigation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2006
- Accession Number
- ADA473587
Entities
People
- David Car
- Jordi Estevadeordal
- S. T. Bailie
Organizations
- Air Force Research Laboratory