Research On Fuel Adaptability Of Aviation Piston Engine

As an important part of the modern navigation industry,the status of Unmanned Aerial Vehicles(UAV)is increasing in the field of aviation technology.As the premise and foundation of the UAV system’s development,the power plant directly determines the development level and the forward speed of UAV system.The small two-stroke piston gasoline engines have become the preferred choice for UAV because of its advantages of small size,light weight,high power to weight ratio weight and low fuel consumption.Aircraft engines require very high safety due to their special use.Gasoline fuel can’t meet the needs of high safety owing to its volatile characteristics.As the most widely used fuel in aviation field,Aviation kerosene is the ideal fuel for replacing gasoline because it has Stable chemical properties and it is easy to transport.Therefore,this paper takes a two-stroke direct injection gasoline engine as the research object,aims to change the research object to the Aviation kerosene engine,carry out a fuel suitability study.In this paper,the working principle,machine performance and control strategy of the engine are studied by bench test.The results of the study show that the maximum power of the engine is 93.1kW/7800 rpm,and the characteristics of the speed characteristics under heavy load are obviously "three phases";The electric control system of the engine takes the engine operating status of speed,load,cooling temperature and exhaust temperature as the inputs,and takes fuel injection,ignition,exhaust valve control as the outputs.And the control system includes fuel injection pulse width MAP table,fuel injection advance angle MAP table,ignition advance angle MAP table and exhaust valve MAP table.According to the structural parameters and test data,the simulation model of the research object was established by GT-Power software.The combustion,machine performance and control parameters after changing the fuel to aviation kerosene are researched.The optimal performance and control parameters are predicted based on the simulation model.The results indicate: After changing the fuel,the combustion center has delayed and the total heat release has reduced under the cruise conditions.The dynamic and economy of the engine under aeronautical conditions has decreased slightly;Through optimizing the control parameters,the economic performance of aviation kerosene engine slightly higher than the original machine,and its dynamic performance is similar to the original machine.The simulation results are verified by calibration test,the results show that the phenomenon that combustion center has delay and the total heat release has reduced in test is more serious than the phenomenon in simulation.Furthermore,the ignition delay period is longer in test;The power which is optimized by calibration test increased by 2.35 kW,but it is slightly lower than the power of original engine.Fuel consumption rate is dropped significantly by optimization.In conclusion,this paper studies the adaptability of a two-stroke GDI engine to aviation kerosene by simulation and experiment.Dynamic and economic performance can reach the level close to the original gasoline through optimizing the control parameters.This paper proves that the problem of engine performance declined caused by replacing the fuel to aviation kerosene can be improved by optimizing control parameters.