Estimation of Enthalpy Effects in Direct-Connect Dual-Mode Combustor

Abstract

To estimate the enthalpy effects of test gas in a direct-connect dual-mode combustor, an experimental study was conducted. Wall pressures were compared under two cases with different types of air heater (combustion heater and electric heater) at various H₂ fuel equivalence ratios. Considering flame holding, dual-mode transition and wall pressure value, matching total enthalpy was found to be more effective than matching total temperature in terms of mitigating vitiation effects in the case of a combustion heater. On the other hand, for vitiation flow, matching total temperature is more effective than matching total enthalpy for ignition to duplicate that of clean air flow. Therefore, flow total condition (total temperature or total enthalpy) should be selected according to experimental candidates.