Experimental Investigation on the Combustion and Emission Characteristics of Near-/Supercritical Kerosene in Aero-Engine Combustion Chambers

To support the development of future high-performance aero-engine technology, the combustion and emission characteristics of near-/supercritical kerosene are investigated in this study using a single-cup combustor rig. Stable combustion under near-/supercritical fuel injection conditions have been achieved in the combustor. The effects of operating parameters on combustion performance and emission characteristics have been systematically investigated, including fuel-to-air ratio, kerosene injection temperature, and inlet air temperature. The experimental results show that: (1) In the investigated fuel-to-air ratio (FAR) range, the best overall combustion and emission performance of supercritical kerosene is observed at FAR = 0.046. Specifically, the outlet temperature distribution factor (OTDF), emission index of carbon monoxide (CO) (EICO), emission index of unburned hydrocarbons (UHC) (EIUHC), and emission index of NO_x (EI_NOx) decreases by 14.65%, 60.0%, 29.49%, and 33.76%, respectively, while the combustion efficiency increases by 0.59%. (2) With increasing kerosene injection temperature, compared with the ambient-temperature conditions, the OTDF, EICO, and EIUHC of supercritical kerosene decrease by 34.06%, 79.16%, and 54.30%, respectively, while the EINOx and combustion efficiency increase by 59.02% and 1.76%, respectively. (3) With increasing combustor inlet temperature (T3), the OTDF, EICO, and EIUHC progressively decrease in the near-/supercritical regions, whereas T4avg, combustion efficiency, and EINOx gradually increase.