A Computational performance study on cheaper fuels for Micro Jet Engine as Jet A1 replacement without performance penalties
2022-26-1155
05/26/2022
- Event
- Content
- Micro Jet Engines are used in UAVs, MAVs, and missiles increasingly. Even though they have a lower thermal efficiency, they have a higher thrust to weight ratio and endurance than electric motors. This lower thermal efficiency incurs expensive fuels and higher fuel consumption. The purpose is to test the performance of a designed Micro jet Engine with cheaper ethanol, kerosene, and automotive diesel. As diesel has a higher energy density and heating value than Jet A1, it outperforms jet a1. The ordinary refined kerosene is also tested. At a nominal air fuel ratio of 60, i.e., 1.5 g/s for this designed 0.086 kg/s engine air flow rate, all three fuels perform approximately the same in steady state simulations, as per steady state simulations : kerosene provides 2240 K, jet a1 provides 2311 K, the ethyl alcohol provides 2350 K and kerosene burns at 2274 K. These steady state simulation results is better for performance comparison between the fuels while for real time combustion exit temperature, transient simulation is used. As per transient simulation, the kerosene seems to burn gentler than other fuels which seems to be healthy for the combustor, the kerosene mixes with the air readily having a lower density, but burning at an average temperature of 1300 K; while the ethanol mixes readily with the air at a reaction temperature of 1590 K. The jet A1 having the highest density refuses to mix but mixes only after 0.9 milliseconds, while the above mixes completely at 0.5 milliseconds, which reduces the thermal efficiency of jet A1 combustion. Jet A1 burns at a highest recorded temperature of 2400 K, can be deemed as unhealthy for the engine and healthy for the process. But with engine dependent combustion criteria, the flow rates for each fuel changes and various factors such as soot, emissions needs to be accounted for. This study presents the engine performance results of the above fuels at the same mass flow rate and the feasibility of its usage on a Micro Jet Engine for unaltered performance.
- Citation
- A, A., and Renald, C., "A Computational performance study on cheaper fuels for Micro Jet Engine as Jet A1 replacement without performance penalties," SAE Technical Paper 2022-26-1155, 2022, .