Free-Vortex Aerodynamic Window Leakage Investigation.
Abstract
An experimental program was conducted to investigate the source of the leakage across a free-vortex aerodynamic window and to examine methods of reducing this leakage. Characterization of the endwall boundary layer flow via flow visualization techniques and pitot pressure measurements shows that the endwall boundary layer flow is deflected toward the free-vortex center and portions of it are ingested into the simulated laser cavity connecting duct. Passive boundary layer control by means of a base region, circumferential to the simulated laser cavity connecting duct aperture along the free-vortex inner boundary, decreased the minimum connecting duct pressure obtainable from 71 to 46 torr by reducing the amount of endwall boundary layer flow that was ingested by the connecting duct. Active boundary layer control via energization with high velocity air also reduced leakage into the connecting duct; but, because of deleterious interactions of the boundary layer flow with the nozzles used to inject the energization flow, no net improvement in the value of the ambient-to-cavity pressure ratio over the passive boundary layer control technique was obtained. Also, it was demonstrated that the free-vortex aerodynamic window can be used to exhaust purge gas flow from the simulated laser cavity connecting duct without severely compromising its performance as an aerodynamic window. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1977
- Accession Number
- ADA044422
Entities
People
- Mark D. Krosney
- Roy N. Guile
Organizations
- United Technologies Corporation