Experimental study on combustion characteristics of Chinese RP-3 kerosene

In order to illustrate the combustion characteristics of RP-3 kerosene which is widely used in Chinese aero-engines, the combustion characteristics of RP-3 kerosene were experimentally investigated in a constant volume combustion chamber. The experiments were performed at four different pressures of 0.1 MPa, 0.3 MPa, 0.5 MPa and 0.7 MPa, and three different temperatures of 390 K,420 K and 450 K, and over the equivalence ratio range of 0.6–1.6. Furthermore, the laminar combustion speeds of a surrogate fuel for RP-3 kerosene were simulated under certain conditions. The results show that increasing the initial temperature or decreasing the initial pressure causes an increase in the laminar combustion speed of RP-3 kerosene. With the equivalence ratio increasing from 0.6 to 1.6, the laminar combustion speed increases initially and then decreases gradually.The highest laminar combustion speed is measured under fuel rich condition(the equivalence ratio is 1.2). At the same time, the Markstein length shows the same changing trend as the laminar combustion speed with modification of the initial pressure. Increasing the initial pressure will increase the instability of the flame front, which is established by decreased Markstein length. However, different from the effects of the initial temperature and equivalence ratio on the laminar combustion speed,increasing the equivalence ratio will lead to a decrease in the Markstein length and the stability of the flame front, and the effect of the initial temperature on the Markstein length is unclear. Furthermore, the simulated laminar combustion speeds of the surrogate fuel agree with the corresponding experimental datas of RP-3 kerosene within 10% deviation under certain conditions.     

连续爆轰发动机的研究进展

连续爆轰发动机是一种基于爆轰波将推进剂的化学能转化成热能的新概念发动机,近年来受到世界各主要国家的高度关注。现已成功获得多种燃料长时间稳定的连续爆轰,较深入地认识了连续爆轰流场结构,初步测得推力和比冲,验证了连续爆轰发动机的性能优势并在火箭模态、冲压模态以及涡轮模态下都实现了稳定连续爆轰。对连续爆轰发动机的工作原理,以及近年来世界各主要国家在连续爆轰发动机的基础研究和应用研究方面取得的代表性成果进行了综述,并给出尚待解决的问题,为其进一步工程化应用提供参考。     

低温推进剂深度过冷加注技术研究及对运载火箭性能影响分析

介绍了运载火箭深度过冷加注技术国内外研究现状,分析了深度过冷加注对火箭性能影响。经分析显示,深度过冷加注在降低增压系统规模、减小贮箱容积需求、降低贮箱壁厚、提高发动机预冷适应性、提高推进剂整体品质及发射适应性、缩短加注发射流程等方面均有明显作用。提出了实现深度过冷加注的关键技术及主要技术方案设计。     

RP-3航空煤油与其模型燃料雾化特性的对比试验

为了获得RP-3航空煤油与其模型燃料的雾化特性,在燃油喷嘴雾化激光测试平台上对相对喷射压力分别为200、400、600、800 kPa时,RP-3航空煤油及由14%正癸烷/10%正十二烷/30%异十六烷/36%甲基环己烷/10%甲苯（摩尔分数）组成的模型燃料的雾化特性（雾化锥角、雾化粒度、油滴速度）进行了试验测试,并完成了两者的对比分析。结果表明:随着相对喷射压力的升高,RP-3航空煤油与其模型燃料的雾化锥角与油滴速度逐渐增大,索太尔平均直径（SMD）逐渐减小;随着离喷嘴出口轴向距离的增加,RP-3航空煤油与其模型燃料的SMD值与油滴速度逐渐减小;在各相对喷射压力下,模型燃料的雾化锥角与油滴速度要略高于RP-3航空煤油,SMD值则要略低;但是,两者之间差异较小,说明该模型燃料的雾化特性与RP-3航空煤油有较高的相似性。      

Frictional resistance of supercritical pressure RP-3 flowing in a vertically downward tube at constant heat fluxes

Based on the demands of compact heat exchangers and micro cooling channels applied for aviation thermal protection, the flow resistance characteristics of aviation kerosene RP-3 were experimentally studied in a vertically downward circular miniature tube with an inner diameter of 1.86 mm at supercritical pressures and constant heat fluxes. A long and short tube method was used to accurately calculate the frictional pressure drop, and experimental conditions are supercritical pressures of 4 MPa, mass flow rates of 2–4 g/s (i.e., mass fluxes of 736–1472 kg/(m²?s)), heat fluxes of 100–500 kW/m², and inlet temperatures of 373–673 K. Results show that the sharp variations of thermophysical properties, especially density, have significant influences on frictional resistances. Generally, the frictional pressure drop and the friction factor increase with increasing inlet temperatures, and this trend speeds up in the relatively high-temperature region. However, the friction factor has a sudden decline when the fuel outlet temperature exceeds the pseudo-critical temperature. The frictional pressure drop and the friction factor basically remain unchanged with increasing heat flux when the inlet temperature is relatively low, but increase quickly when the inlet temperature is relatively high. Besides, a larger mass flux yields a higher pressure drop but does not necessarily yield a higher friction factor. Finally, an empirical friction factor correlation is proposed and shows better predictive performance than those of previous models.     

液氧/煤油发动机试车主要参数测量方法研究

针对液氧/煤油发动机地面试车中测量参数类型多,各参数测量原理不同,采集装置各异、校准方法复杂,测量过程出现转速数据波动,低温温度测量精度低,低温压力零位漂移,负推力修正及低频脉动压力参数测量等诸多技术问题进行了深入研究,提出了解决途径、验证方法等。     

脉冲纹影技术及其在超声速燃烧室流场显示中的应用

超声速燃烧室内部流场具有流速快、温度高、背景光辐射强等特点,其流场显示较为困难.为此设计了一套脉冲纹影系统,该系统通过缩短曝光时间来冻结流场;另一方面,利用脉冲火花光源在短曝光时间内脉冲放电能量远高于燃烧室背景辐射能量的特点,有效消除了燃烧室背景辐射的影响.利用该系统对马赫数3.0的超临界煤油燃烧流场结构进行研究,得到了超临界煤油燃烧过程的清晰流场结构图像及其演化过程.     

固体发动机复合材料壳体的电子束固化

叙述了电子束固化技术在固体火箭发动机复合材料壳体工艺中的应用，讨论了该技术的优点和局限性，介绍了在航空航天其它领域内的推广情况。     

碳氢燃料超燃研究与应用

通过分析与试验表明 ,技术风险小、性能可靠、近期能够实现的、以煤油为燃料的弹用冲压发动机是一种适宜于飞行Ma =6左右的高超声速导弹的推进装置。采用尾喷管几何喉道可调的方法 ,有利于提高煤油冲压发动机亚燃工况的性能 ,满足飞行器对低马赫数 (Ma=2 5左右 )接力与加速状态推力特性的要求。以煤油与氢为燃料的双燃料冲压发动机具有广阔的应用前景     

火箭发动机橡胶件贮存寿命的蒙特卡罗仿真

应用蒙特卡罗（ Ｍ－ Ｃ） 随机抽样方法，对固体导弹的火箭发动机橡胶构件的老化特性进行了仿真计算，通过对其残余变形积累和贮存寿命的可靠性评估，作出了相应的关系曲线图。从计算结果和关系曲线可以看出，所得出的结论是符合实际情况的，表明文中方法的正确性和可行性。