Mass flow rate characteristics of sub-/supercritical multiphase kerosene fuel nozzle

To precisely design multiphase fuel nozzles, so that they can be applied to the aero-engines with the technology of cooling the turbine cooling air, the fuel mass flow rate of sub-/supercritical kerosene in an axisymmetric model nozzle was studied. By adjusting the fuel temperature under multiple sets of fixed injection pressure, the mass flow rate change of sub-/supercritical fuel was obtained. According to the phase conditions of kerosene, the flow rate curves were divided into three phase regimes, i.e., liquid, gas-liquid, and supercritical, and the mechanisms in the process of flow rate changing with kerosene injection status under different phase conditions were discussed. The flow rate prediction methods in the liquid and the supercritical regime, as well as the fitting correlation of the discharge coefficient in the gas-liquid regime, were proposed. Results showed that, as injection temperature increased from normal temperature to 750 K, the flow rates slowly decreased in the liquid regime, sharply declined in the gas-liquid regime, and then gradually declined in the supercritical regime beyond the inflection point temperature. The maximum error between the calculated and experimental results was 3.8%, and the square of the correlation coefficient of the fitting correlation was 0.947 8, which can serve multiphase nozzle design. Meanwhile, the acquired mass flow rate data can provide the boundary conditions for the research of injection structures downstream the nozzles, supporting advanced aeroengine design and development. © 2022 BUAA Press. All rights reserved.