Optical Study of the Flow in a Mach 6 Nozzle.
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OHIO SCHOOL OF ENGINEERING
Pagination or Media Count:
A qualitative experimental study was performed to visualize the flow in a Pratt and Whitney contoured minimum length gas dynamic laser nozzle. The study was done on a blowdown wind tunnel and the test section was designed to model a single channel of flow in the gas dynamic laser. The nozzle has an area ratio of 66 and accelerates the flow to a Mach number of 6 allowing for boundary layer effects. Dry air or nitrogen at 80F total temperature was used as the flowing media. Total pressure was varied from 90 to 180 psig. The flow was visualized using schlieren optical techniques. Neither separation nor disturbances caused by wakes or shock waves was observed in the divergent section of the nozzle. It was determined that the nozzle performed as designed. Using schlieren photographs, it was determined that the nozzle accelerated the flow to Mach 6. The nozzle did follow ideal gas flow characteristics even though it had a throat height of 0.0058 in. Nozzle throat shocks observed in previous studies and thought to be induced by a non-uniform boundary layer growth in the throat region were not observed in this study.
- Lasers and Masers
- Fluid Mechanics