DYNAMIC STUDY OF COUPLED HEAVY HYDROCARBON PYROLYSIS AND COMBUSTION

摘要

Hypersonic flight at over Mach 5 can be achieved with supersonic combustion ramjets. The regenerative cooling presents the advantage of using the fuel as a coolant, which results in its pyrolysis. Both cooling channel and combustion chamber are studied numerically by coupling the transient phenomena with detailed pyrolysis and combustion chemistry (360 species and 2777 reactions). A Mach 6 flight configuration has been chosen to study the impact of fuel mass flow rate on the combustion for equivalence ratio varying from 0.01 to 1. The time characteristics of the phenomena have been determined. A higher flow rate provides higher hot gas temperatures and faster stabilization time and auto-ignition delay. This affects positively the flame anchoring. Several analytical laws are proposed for later development of a control strategy. A hysteresis has been found due to the heat transfer dynamics.