Computational Assessment of Afterburning Cessation Mechanisms in Fuel Rich Rocket Exhaust Plumes

Abstract

A computational study was conducted to identify fundamental physical processes governing the cessation or shutdown of the afterburning of fuel rich rocket exhaust with the atmosphere. Several mechanisms were examined which are: 1) a relaminarization phenomenon, 2) a Damköhler number effect and 3) a classical flame extinction mechanism. Analysis of the simulation results revealed the relaminarization mechanism to be implausible while the Damköhler number effect and the flame extinction mechanisms were found to be valid. The extinction mechanism was also found to dramatically alter the emission characteristics and enhance the shutdown behavior which has important implications with respect to radiative heat transfer to the body and missile defense systems. This is a significant finding because strain rate induced extinction is a previously unrecognized phenomena occurring in rocket Approved for public release; distribution unlimited exhaust plumes during afterburning cessation.

Real‐Time Plume Velocity Measurement of Solid Propellant Rocket Motors Using TDLAS Technique

“…The standard 10‐step mechanism for H 2 /CO oxidation is used for DB and CMDB in this study. Since this reaction mechanism was firstly used in the plume simulation of Atlas by Collins [37] in 1997, this reaction mechanism is used in the studies on the after‐burning phenomenon of Calhoon [38], Candler [39], Gimelshein [40], Dong [41] and Wang [16]. It has been widely used and verified in plume simulations.…”