Miniature Supersonic Burner for the Study of Combustion at Extreme Conditions. II: External Flow

Abstract

A miniature supersonic burner has been designed with the purpose of studying extreme flow-chemistry interaction. The system combines a first-stage, lean premixed methane/air burner that creates a vitiated flow at pressure and a second-stage burner where additional fuel (methane) is added to the flow before exiting the system through a converging nozzle. In this part, a one-dimensional (1D) detailed chemistry calculation of the reacting flow at the exit of the jet is conducted. The mixture of gases is allowed to expand isentropically to the conditions expected at the exit of the supersonic jet. The viscous and conducting flow field through a shock wave is calculated using the GRI3. kinetic scheme. The structure of the standing detonation downstream of the Mach stem is examined for different initial concentrations of hydrogen atoms. Results point to the extreme suppression of chemistry through the supersonic flow field and the creation of low Damköhler numbers in the exit of the miniature burner.