The present study describes an experimental work to investigate the effect of a nozzle exit reflector on a supersonic jet that is discharged from a convergent-divergent nozzle with a design Mach number of 2.0. An annular reflector is installed at the nozzle exit and its diameter is varied. A high-quality spark schlieren optical system is used to visualize detailed jet structures with and without the reflector. Impact pressure measurement using a pitot probe is also carried out to quantify the reflector's effect on the supersonic jet which is in the range from an over-expanded to a moderately under-expanded state. The results obtained show that for over-expanded jets, the reflector substantially increases the jet spreading rate and reduces the supersonic length of the jet, compared with moderately under-expanded jets. The reflector's effect appears more significant in imperfectly expanded jets that have strong shock cell structures, but is negligible in correctly expanded jet.
All Science Journal Classification (ASJC) codes
- Mechanical Engineering
- Physics and Astronomy(all)