Three dimensional numerical simulations of liquid-fueled Rotating Detonation Engines

Rotating Detonation Engines (RDEs) powered by liquid fuels have gained significant interest in recent years due to their compact design, safety and high efficiency. However, the complex multiphase effects and associated heterogeneity can result in less efficient detonative combustion. In this work, we focus on comparing the properties of RDEs operating on liquid n-Dodecane fuel with those using purely gaseous fuel. Detailed 3D numerical simulations were performed using the FLASH¹ code using a two-way coupled Euler-Lagrange framework, accounting for droplet deformation, breakup, and evaporation². A 3D unrolled configuration of an RDE was used with uniform injection of premixed 20 μm n-Dodecane liquid fuel droplets and pure oxygen. Due to the presence of unburnt fuel droplets and parasitic combustion, the liquid fuel RDE exhibited lower thrust, a weaker detonation wave, and a lower detonation wave velocity compared to the pure gas phase fuel case. These preliminary results suggest fuel droplet breakup effects significantly impact the performance of RDEs. Understanding these multiphase effects are critical to the design of liquid-fueled RDEs.

¹B. Fryxell et al., Astrophys. J., Suppl. Ser. 131, 273 (2000).

²B. J. Musick et al., Combust. Flame, Suppl. 257, 113035 (2023).