【作者】 李春野；

【导师】 唐豪；

【作者基本信息】 南京航空航天大学 ， 热能工程， 2009， 硕士

【摘要】 小型PDE在给定容积下释放能量,客观上希望单位容积燃料的能量更大,因此液体燃料小型PDE的研究具有重要的意义。要成功起爆首先要解决燃油、空气的喷射与混合问题。采用数值模拟和试验的方法,系统地研究了煤油/空气的掺混特性,进行了小管径PDE可爆混气关键技术的研究。取得了大量的科研成果,为深入研究以液态煤油为燃料,以空气为氧化剂的小型PDE的工作性能提供了依据。研究了不同进气温度和燃油温度对煤油/空气混合物混合特性的影响,在进气温度为373k时,能够很好的雾化和蒸发,能够保证形成均匀的可燃混气,保证了点火器的稳定点火,为产生稳定传播的爆震波提供了条件。设计了多种结构的气动阀,分析了不同结构气动阀的工作机理,采用数值模拟和试验的方法进行气动阀研究,数值模拟研究结果验证了气动阀模型的合理性,研究结果表明:在低速进气条件下,采用旋流为主的气动阀PDE有利于形成可燃混气。在较高速进气条件下,采用以直流为主并且部分旋流气动阀PDE有利于提高煤油的雾化质量,利于形成均匀的可燃混气。设计建立了多种PDE计算模型,采用控制方程和k ?εRealizable湍流模型,采用颗粒轨迹模型,对燃油喷射系统性能进行了数值模拟通过求解三维N-S方程和k ?ε湍流模型来分析混合室中煤油、空气的混合流动特性。数值模拟了不同进口压力,不同进气温度、不同煤油温度、煤油的喷射流量等对煤油/空气混合物混合特性的影响,研究结果为实验成功的产生爆震波提供了理论依据。在气动阀后增加预混段,预混段对通过气动阀初步雾化的煤油,起到了进一步强化雾化掺混的作用,把该结构应用到实验中,实验成功的产生了爆震波。本文研究了不同结构的气动阀、不同结构的PDE头部结构、以及不同的工况对PDE内煤油/空气掺混特性的影响。通过在气动阀后增加预混段等方法成功的取得了可爆混气,为实验的成功奠定了基础。气动阀不仅可以充当推力臂,还可以对燃油起到很好的雾化作用。头部结构对初步雾化的燃油,起到了二次雾化的作用。不同的进口速度、不同的温度以及不同的进口压力、以及煤油不同的喷射压力等都对煤油/空气的掺混特性起到了至关重要的影响。更多还原

【Abstract】 Energy releases from the constant volume in small scale PDE, which expects much more energy in units volume,so it has great significance for researching on liquid fuel of small scale PDE. The fuel-air injection and mixing is one of the most important issues on detonation. Researching on the mixing character of kerosene/air ,and the key technology about explosive mixed gas of small scale PDE by numerical simulation and experiment. Achieved a great deal of scientific results,which provided evidence for researching on the performance of micro-PDE using liquid kerosene as fuel and air as oxidant.Researching on the effect of mixing character about the different temperature of air and kerosene,oil will be well evaporated and atomizated ,and kerosene/air will become uniform mixed combustible gas when the temperature is at 373k,which will ensure the stablility ignition and stablility spread of the detonation wave. Different aero-valves were designed and their mechanisms were analyzed.Through numerical and experimental methods, numerical simulation results show the rationality of aero-valves model, the results show that: The quality of kerosene atomization of PDE with swirlaero-valve is quite high, and the quality of kerosene atomization of PDE with straight flow aero-valve and partial swirl is best when quite high filling tube speed. Designed and established several PDE model,analyzing mixing character of kerosene/air using Realizable turbulence equation model and particle trajectory model to solve three-dimensional N-S and turbulence model of the fuel injection system performance.Numerical simulation of the different import pressure、different import temperature、different kerosene’s temperature and the flow of kerosene impact of kerosene/air mixed characreristics.The results provide theoretical basis for experiment.Adding the pre-mixed part which play a great role in mixing kerosene/air.Using the structure of the experiment,the experiment get detonation successfully.Researching on different aero-valve model,different structure of PDE head,as well as the different condition on the impact of kerosene/air mixed character of PDE.Through adding the pre-mixed part after the aero-valve,we get the explosive mixed gas,which provide the basis of successful experiment.The aero-valve can not only act as a thrust arm, but also played a very good role in the atomization of fuel. The structure of head has played a secondary role in the atomization. The different import speed, different temperatures and different import pressures, as well as the different jet pressures of kerosene, which all played a great role in kerosene/air mixed characteristic.更多还原