Extinction, discharge, and thrust characteristics of methanol fueled meso-scale thrust chamber

A meso-scale heat recirculating thrust chamber has been developed for use with methanol, by utilizing steam/oxygen as an oxidizer. The steam/oxygen mixture serves as a surrogate for hydrogen peroxide. The extinction regimes, discharge characteristics, and both steady state and pulsing thrust characteristics are presented. Differences between the extinction behavior of the thrust chamber both without and with the nozzle were explored and a non-dimensional extinction criterion established to predict low Re extinction. The discharge characteristics: coefficient of discharge and characteristic velocity efficiency were determined and correlated to throat Reynolds number. Thrust measurements taken with the indirect method show reasonable agreement with the isentropic solution for the experimental stagnation conditions, suggesting high nozzle efficiency despite low chamber pressures and high gas temperatures. The behavior of the thrust chamber in pulsed configuration was tested with methanol/oxygen and methanol/water/oxygen mixtures. High speed cinematography was used to study the evolution of the flame during the pulse.

► A swiss-roll meso-scale thruster is developed for methanol bi-propellant propulsion.
► Extinction behavior is studied and a non-dimensional parameter used to predict extinction.
► Discharge through low Re nozzles is studied for both cold and reacting flows.
► A thrust stand is developed to indirectly measure mN thrust with high precision.
► The performance characteristics are studied in both steady state and pulsed modes.