Experimental Investigation of Combustion and Propulsion for Shock-Induced Combustion Ramjets

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Authors
  1. Higgins, A.
Corporate Authors
Defence R&D Canada - Suffield, Ralston ALTA (CAN);Reactive Energetics, Montreal QC (CAN)
Abstract
An investigation of the shock-induced-combustion ramjet propulsive cycle was carried out in the 38-mmbore ram accelerator facility at the University of Washington. Titanium-alloy shcramjet projectiles were launched into reactive propellants at Mach numbers greater than 5.5 to determine if the combustion process could be shock initiated and stabilized, what levels of thrust can be generated, the reactivity of the projectile material in hypersonic flow, and to evaluate the efficacy of investigating the operating characteristics of hypersonic propulsive cycles using gun-launched projectiles. Experiments with four different projectile configurations were carried out in methane- and ethane-based propellants with and without carbon dioxide diluent. Positive acceleration was observed in CH4/O2 /CO2 and C2H6/O2 propellants in the Mach range of 5.5 - 7 (1.7 - 2.1 km/s) for distances of up to 6 meters. In the majority of cases, the acceleration process was terminated by either unstart, cruise at constant velocity (i.e., thrust equal drag), or wave fall off. Sustained accelerations greater than 9000 g and average specific thrust 150 N*s/kg were achieved in these experiments. The hypersonic projectile drag coefficient (based on projected frontal area of the projectile) in the Mach range of 5 – 6 was determined to be CD = 0.09 from experiments in which the propellant did not ignite (wave fall-off). Details of the experime
Keywords
Ram accelerator;Shcramjet;Titanium projectiles;Hypersonic;Hypersonic projectiles;Hypersonic propulsion;Thrust;Shock initiation
Report Number
DRDC-SUFFIELD-CR-2007-249 — Contractor Report
Date of publication
01 Dec 2006
Number of Pages
54
DSTKIM No
CA030613
CANDIS No
529230
Format(s):
CD ROM

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