Accession Number : ADA189714

Title :   An Experimental Investigation of Rocket Ramjet Nozzle Assembly Base Pressures.

Descriptive Note : Master's thesis,

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH

Personal Author(s) : Wesling, Timothy R

PDF Url : ADA189714

Report Date : Dec 1987

Pagination or Media Count : 153

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.

Descriptors :   *BASE PRESSURE, *NOZZLE CLUSTERS, *ROCKET NOZZLES, *RAMJET ENGINE NOZZLES, ASSEMBLY, CLUSTERING, COVERINGS, EXHAUST GASES, EXITS, EXPANSION, FLIGHT, GEOMETRY, MACH NUMBER, PLENUM CHAMBERS, PRESSURE, PRESSURE GRADIENTS, RAMJET ENGINES, RANGE(DISTANCE), RATIOS, RECIRCULATION, ROCKET RAMJETS, THESES, THRUST, DUCTED ROCKETS, EXHAUST PLUMES, INTERACTIONS, TWO DIMENSIONAL FLOW, METHOD OF CHARACTERISTICS, NOZZLE AREA RATIO

Subject Categories : Rocket Engines
      Jet and Gas Turbine Engines

Distribution Statement : APPROVED FOR PUBLIC RELEASE