The mixing enhancement mechanism and unsteady evaporation characteristics of the kerosene-air in the detonation combustor

• Published in: Fuel (Guildford) 2024-09, Vol.371, p.131997, Article 131997
• Main Authors: Wang, Jiasen, Xu, Chunguang, Zhao, Jiafeng, Chen, Jie, Lin, Wei
• Format: Article
• Language: English
• Subjects: Auxiliary atomization; Evaporation; Mixing; Preheated Kerosene; Rotating detonation engine; Two-phase flow
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2024.131997

•Simulated two-phase propellant mixing and evaporation with flat plate-type auxiliary injection in RDE.•Combined IDDES method with ITCM for describing two-phase mixing and steady evaporation.•Discovered a critical pressure drop of the assist gas, leading to a peak in total pressure loss at the outlet.•Analyzed unsteady evaporation behavior of preheated kerosene in RDE from multiple perspectives. Efficient mixing of liquid fuels and supersonic airflow is crucial for the successful detonation and stable propagation of rotating detonation engines (RDEs). In supersonic airflow, gas-assisted injection technology, using methane (CH4), effectively enhances the atomization of liquid jets. This study conducted numerical simulations to analyze the mixing process of wide-range Mach supersonic airflow and transverse liquid jet under the gas-assisted scheme to characterize the flow field structure, droplet breakup, and evaporation characteristics of preheated kerosene. Furthermore, combined with the mesh adaptive refinement technology, the effects of the incoming airflow Mach number, the number of injection positions for the auxiliary gas, and the gas auxiliary pressure drop were assessed. Specifically, the turbulent flow was simulated using the Improved Delayed Detached Eddy Simulation (IDDES) method. Additionally, the Discrete Phase Model was used to explore gas–liquid interactions. The results show: 1) Dual gas assistance can significantly improve the uniformity of droplet distribution under specific conditions. 2) The presence or absence of auxiliary gas at the liquid jet inlet notably influences droplet evaporation. 3) The presence or absence of auxiliary gas at the liquid jet inlet notably influences droplet evaporation. 4) A critical point in gas injection pressure drop at inlet 1 was identified, leading to peak total pressure loss at the combustor outlet. Additionally, the total outlet pressure loss observed under the low-speed incoming airflow condition is less than 10% of that obtained for the high-speed incoming airflow condition.