共查询到20条相似文献,搜索用时 31 毫秒
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A mathematical model for the non-equilibrium combustion of droplets in rocket engines is developed. This model allows to determine the divergence of combustion rate for the equilibrium and non-equilibrium model. Criterion for droplet combustion deviation from equilibrium is introduced. It grows decreasing droplet radius, accommodation coefficient, temperature and decreases on decreasing diffusion coefficient. Also divergence from equilibrium increases on reduction of droplet radius.Droplet burning time essentially increases under non-equilibrium conditions. Comparison of theoretical and experimental data shows that to have adequate solution for small droplets it is necessary to use the non-equilibrium model. 相似文献
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液体火箭发动机燃烧不稳定性试验研究简述 总被引:4,自引:1,他引:3
简要回顾了液体火箭发动机燃烧不稳定性研究的进展,主要论述了燃烧不稳定性模拟试验的原理及作用。指出燃烧不稳定性研究与液体火箭发动机研制是相互依存,相互促进的;燃烧不稳定性研究需要重视基础理论研究,重视模拟实验技术的开发及应用。 相似文献
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《中国航天(英文版)》2021,(2)
Throttling of large-thrust liquid rocket engines, which can improve mission adaptability of a carrier rocket, reduce risk and facilitate rocket recovery, is a key technology for current and future space development. This paper summarizes the state of the art and trends of throttling technology for large-thrust liquid rocket engines at home and abroad. According to the working principles of propulsion for rocket engines, throttling the propellant flow rate is a major way of adjusting thrust, and regulation devices along with adjustable injectors are primary measures of throttling propellant flow rates. This paper clarifies the working principles of typical regulation devices and adjustable injectors, introduces the regulation schemes of typical large-thrust engines such as YF-100, RD-170, and SSME, and summarizes the main characteristics of current throttleable large-thrust engines. Finally, critical technologies and development trends of throttling are discussed, including combustion stability and reliable cooling of thrust chambers at low thrust levels, turbopump stability, and stable regulation and precise control in a wide range of operating conditions. 相似文献
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动态燃烧稳定性评定是液体火箭发动机燃烧稳定性鉴定考核的重要途径之一。通过调研国内外液体火箭发动机动态稳定性评定研究的相关资料,并结合CPIA655关于稳定性评定的准则,详细阐述了动态燃烧稳定性评定的研究内容,重点分析了不同扰动方法和动态压力测量的特点,并指出了动态燃烧稳定性评定的基本准则和关键技术。 相似文献
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《中国航天(英文版)》2017,(1)
China's new-generation launch vehicle LM-5 successfully completed its maiden launch in November 2016.Among the new technologies applied in the launch vehicle,four types of liquid rocket engines attracted extensive attention.These engines feature advanced concepts and technologies such as a staged combustion cycle and expander cycle.The engines are the results of hard effort of more than ten years,which is also an epitome of the development history of China's aerospace industry.This paper gives a brief introduction to the technological schemes,main parameters,development process and application of the four types of engines that powered the new-generation launch vehicle.Finally,proposals for new liquid propulsion technology development in the future in China are presented. 相似文献
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在我国的载人登月技术方案中,为实现软着陆,登月舱需要一种大推力、高性能、多次起动,能够大范围变推力的泵压式发动机.通过研究国外登月用下降级发动机技术发展现状和趋势,基于我国氢氧发动机和低温推进剂空间贮存水平,进行了深度变推发动机的系统方案研究;通过分析比对燃气发生器循环和膨胀循环系统优缺点,确定发动机系统方案为涡轮串联闭式膨胀循环;采用空间可长时间贮存的液氧/甲烷推进剂组合,可满足任务周期要求;根据推力深度调节时对各组合件性能要求,确定喷注器燃烧稳定技术和燃烧室身部传热技术是深度变推发动机研制的核心关键技术. 相似文献
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为研究烃类推进剂航天动力技术在中国的后续发展和未来应用方向,对比分析煤油、甲烷和丙烷等典型烃类推进剂的物理化学性质和应用特性,简要介绍烃类推进剂航天动力在一次性运载火箭、可重复使用运载器、高性能上面级推进、无毒空间推进和吸气式推进领域的发展动态及应用状况。当前国内外航天动力系统的发展和应用情况表明,以液氧煤油发动机和液氧甲烷发动机为代表的烃类推进剂航天动力将引领未来高性能低成本航天推进系统的发展趋势,依照中国液氧/烃火箭发动机的研制进展和技术水平,以其为核心的新型动力体系在中国未来的天地往返、载人登月和深空探测等多任务适应性方面具有良好应用前景。 相似文献
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小推力推进系统起动过程的分析 总被引:4,自引:0,他引:4
本文对小推力推进系统各部件建立了数学模型,并对此系统进行了数值计算。计算结果表明,在燃烧时滞较大时,该系统响应较慢,发动机参数的超调量较大,达到稳态所需的时间较长;轨控发动机与姿控发动机共用同一个供应系统时,姿控发动机受燃烧时滞的影响更大。减小燃烧时滞有利于提高发动机在起动过程的响应能力和稳定性。在起动阶段,高室压推进系统比低室压推进系统响应快,高室压轨控发动机的参数能较快地稳定下来,但其超调量较大;高室压姿控发动机虽然响应快,但其超调量大,达到稳态所需的时间长于低室压姿控发动机。本文所得结论为提高小推力推进系统在起动过程的响应能力提供了参考。 相似文献
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液体火箭发动机健康监控技术是改进和提高运载火箭、航天器可靠性与安全性的核心技术之一,对其进行研究具有重要的学术价值和工程应用价值。液体火箭发动机健康监控技术的研究主要包括液体火箭发动机故障检测与诊断理论方法、液体火箭发动机健康监控系统两方面。该文介绍了基于模型驱动的方法、基于数据驱动的方法和基于人工智能的方法,阐明了液体火箭发动机故障检测与诊断理论方法的研究现状,通过对美国液体火箭发动机典型健康监控系统的介绍,阐明了液体火箭发动机健康监控系统研究的若干进展及现状,并对液体火箭推进系统健康监控技术的演变趋势作了简要评述。 相似文献
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The transient behaviour of the liquid propellant rocket engine is accompanied by non-stationary heat processes in the combustion chamber, the cooling jacket, and the injector. Based on the analysis of the phenomena, which take place in the liquid propellant rocket engine after cut-off command, the major stages of the curve of the rocket thrust drop were defined. A mathematical model of heat processes is suggested, which includes the calculation of transient heat transfer in the chamber, and the detection of boiling-up of the liquid fuel components in the cooling jacket and in the injector. The determination of the law of the rocket thrust drop and a calculation of the after-effect impulse (AEI) are presented. The calculated transient heat flux the combustion chamber and the transient wall temperatures were compared with experimental data, which were received during starting, and with the impulsive behaviour of the liquid propellant rocket engine. 相似文献
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《中国航天(英文版)》2020,(2)
Liquid propellant rocket engines for a launch vehicle are an essential aerospace technology, representing the advanced level of hi-tech in a country. In recent years, China's aerospace industry has made remarkable achievements, and liquid rocket engine technology has also been effectively developed. In this article, the development processes of China's liquid rocket engines are discussed. Then, the performance features of China's new generation liquid rocket engines as well as the flight tests of the new-generation launch vehicles are introduced. Finally, the development direction and the most recent progress of the next generation large-thrust liquid rocket engine is presented. 相似文献