Passive Control Technique to Reduce Afterburning in Rocket Engines

Client

U.S. Navy

Project Objectives

• Design and develop a passive control technique using vortex entrainment methods to reduce afterburning in the exhaust of rocket engines
• Afterburning in missile exhausts produces a large infrared signature that aids detection by the enemy.  Current afterburning control techniques utilize chemical additives which limit missile performance.  A passive technique is desired.

Summary of Project and Results (Non-Confidential)

• Used vortex entrainment between the fuel rich exhaust and cold surrounding air to passively control afterburning
• The strategy was to cool the fuel rich exhaust with surrounding air in large vortices before the vortices dissipated and combustion would occur via fine molecular mixing
• Designed compressible flow vortex generators to produce a wide range of vortex scales
• Tested the vortex generators on rocket exhausts
• Measured vortex formation and propagation using laser sheet visualization
• Measured the reduction in afterburning using an infrared camera and optical averaging

Typical Afterburning Exhaust from the Rocket Engine