An Experimental Investigation of Rocket Ramjet Nozzle Assembly Base Pressures.
Abstract
This study investigated base pressures of clustered rocket-ramjet nozzles under shrouded and unshrouded conditions. Twelve combinations of expansion ratios and shrouds for rocket-ramjet nozzle clusters in cold flow were investigated. Pressure measurements were made along the base of the rocket-ramjet cluster under simulated altitude conditions ranging up to 70,000 feet and flight Mach numbers to just over 3.0. Comparisons were made of the effects on nozzle base pressures of altitude, ramjet plenum pressure, nozzle geometry and shrouding. A potential increase in base pressure thrust of certain nozzle geometries is shown to be possible. As the ramjet nozzle exit distance from there centerline of the nozzle assembly increases for unshrouded cases, base pressure thrust also increases. This appears to be due to recirculation of exhaust gases. These appear to be variations in performance caused by changes in the distance of the shroud from the nozzle assembly centerline. Also, there is a pressure gradient between nozzles in the base region which is affected by configuration and which has an important effect on evaluating base pressures.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1987
- Accession Number
- ADA189714
Entities
People
- Timothy R. Wesling
Organizations
- Air Force Institute of Technology