检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

液体火箭发动机高频燃烧不稳定问题综述

航空学报 2024年第11期45卷 106-132页

作者：汪广旭李斌谭永华高玉闪西安航天动力研究所航天液体动力全国重点实验室西安710100 中国航天科技集团航天推进技术研究院西安710100

高频燃烧不稳定现象诱发的大幅值压力振荡严重威胁液体火箭发动机可靠性,为此,国内外开展了大量深入的研究工作。为了提高对此类问题及相关研究的整体认识,系统阐述了液体火箭发动机高频燃烧不稳定问题的主要特点、关键物理机制、研究... 详细信息

高频燃烧不稳定现象诱发的大幅值压力振荡严重威胁液体火箭发动机可靠性,为此,国内外开展了大量深入的研究工作。为了提高对此类问题及相关研究的整体认识,系统阐述了液体火箭发动机高频燃烧不稳定问题的主要特点、关键物理机制、研究思路等,重点梳理了国内外在液体推进剂燃烧子过程响应机理方面的研究工作,明确指出了燃烧速率控制过程对于此类问题分析的重要意义。在此基础上,详细总结了液滴蒸发和射流掺混作为速率控制过程的高频燃烧不稳定问题数值仿真研究进展,仔细归纳了线性和非线性理论解析分析方法面临的挑战,简要介绍了基于非线性动力系统的分析方法在揭示高频燃烧不稳定非线性行为以及稳定性裕度评估方面的重要潜力。最后,针对不同工程控制措施的内在联系、应用情况等进行了分析,特别强调了燃烧释热分布控制的重要性。

关键词：液体火箭发动机高频燃烧不稳定燃烧响应速率控制过程燃烧释热分布控制

液体火箭发动机高频纵向燃烧不稳定现象的随机性

在线全文

学校读者我要写书评

暂无评论

航空学报 2024年第14期45卷 189-199页

作者：汪广旭杨宝娥谭永华高玉闪李斌西安航天动力研究所航天液体动力全国重点实验室西安710100 中国航天科技集团航天推进技术研究院西安710100

围绕自燃推进剂液体火箭发动机燃烧室高频纵向燃烧不稳定现象的随机性进行了深入探讨,分析了结构振动数据在表征燃烧室压力振荡方面的有效性,对比了理论声模态和实测振型,基于蒸发过程作为速率控制的假设,对该燃烧室的稳定性进行了分析... 详细信息

围绕自燃推进剂液体火箭发动机燃烧室高频纵向燃烧不稳定现象的随机性进行了深入探讨,分析了结构振动数据在表征燃烧室压力振荡方面的有效性,对比了理论声模态和实测振型,基于蒸发过程作为速率控制的假设,对该燃烧室的稳定性进行了分析,并提出了造成不同供应系统下稳定性差异的2种假设模型。研究表明:由结构振动传感器测得的是燃烧室结构对燃气压力振荡场的响应结果,后者存在一定的频率选择性和非线性;实测突频幅值分布与该频率下的理论声模态基本吻合,确定该燃烧室发生了高频一阶纵向燃烧不稳定现象;线性模型结果表明,该燃烧室具有一定的稳定性裕度,但不能解释系统2条件下燃烧不稳定现象随机出现这一现象;系统2条件下该燃烧室的稳定性恶化或不同工况间的稳定性波动幅值增加,造成部分工况点落入非线性不稳定性区间,成为潜在的不稳定工况。

关键词：液体火箭发动机高频纵向燃烧不稳定供应系统随机性

不同增强方向的带支柱体心立方点阵及其填充结构的压缩力学性能分析

在线全文

学校读者我要写书评

暂无评论

中国机械工程 2024年第09期35卷 1642-1652页

作者：张武昆赵剑谭永华高玉闪王珺韩子月耿小亮航天液体动力全国重点实验室西安航天动力研究所西安建筑科技大学机电工程学院西北工业大学力学与土木建筑学院

为研究不同增强方向的带支柱体心立方点阵及其填充结构的压缩力学性能，制备了硅橡胶填充点阵结构试验件。通过试验和仿真方法研究了硅橡胶填充BCC1或BCC2(加载方向分别与带支柱体心立方点阵的支柱杆方向相同或垂直)两种点阵结构的压缩... 详细信息

为研究不同增强方向的带支柱体心立方点阵及其填充结构的压缩力学性能，制备了硅橡胶填充点阵结构试验件。通过试验和仿真方法研究了硅橡胶填充BCC1或BCC2(加载方向分别与带支柱体心立方点阵的支柱杆方向相同或垂直)两种点阵结构的压缩力学性能，并采用铁摩辛柯梁理论和极限载荷法分析了两种点阵结构的等效弹性模量和压缩平台应力。结果表明：提出的理论模型能够很好地预测两种点阵结构的等效弹性模量和压缩平台应力。经过填充后两种点阵结构的压缩强度和吸能性能均会得到增强，BCC2结构的增强效果更加显著。对于BCC1点阵结构，填充提高了其内部杆件的承载力；而对于BCC2点阵结构，填充减小了其“V”形剪切带附近的杆件弯曲变形。随着点阵结构半径的增大，两种结构的吸能耦合因子均先增大后减小，而BCC1型结构的吸能耦合因子变化更明显。

关键词：力学性能点阵结构等效弹性模量填充结构

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

宽工作范围诱导轮空化不稳定及抑制

力学学报 2024年第8期56卷 2327-2337页

作者：项乐许开富陈晖谭永华李雨濛林荣浩西安航天动力研究所西安710100 航天液体动力全国重点实验室西安710100 航天推进技术研究院西安710100

涡轮泵是液体火箭发动机的心脏,在特定工况下其内部会发生空化不稳定现象,导致涡轮泵振动量级大幅增加,严重影响发动机整机工作可靠性.以决定涡轮泵抗空化能力的关键部件诱导轮为研究对象,利用空化可视化实验和数值仿真对其内部空化流... 详细信息

涡轮泵是液体火箭发动机的心脏,在特定工况下其内部会发生空化不稳定现象,导致涡轮泵振动量级大幅增加,严重影响发动机整机工作可靠性.以决定涡轮泵抗空化能力的关键部件诱导轮为研究对象,利用空化可视化实验和数值仿真对其内部空化流动特性进行深入分析,获得60%~120%设计点流量范围完整空化性能曲线,提出一种基于壳体改进的旋转空化抑制措施,并揭示抑制机理.结果表明:该型诱导轮抗空化能力随流量降低逐渐增强,空化首先发生在泄漏涡中,随空化数降低,泄漏涡空化逐渐沿吸力面向下游发展,影响相邻叶片冲角,在小流量范围诱发显著的1.2倍叶轮转频超同步旋转空化现象,直至空化延伸至叶片流道出口,导致扬程断裂;在叶尖前缘壳体设置台阶不会影响诱导轮稳态空化性能,但会改变泄漏涡空化的发展规律,使其呈现向上游摆动的趋势,削弱对相邻叶片冲角的影响,实现对全流量范围旋转空化的有效抑制.文章研究对于降低涡轮泵振动量级,进一步提升液体火箭发动机工作可靠性有一定指导意义.

关键词：涡轮泵空化不稳定数值仿真可视化实验抑制技术

在线全文

学校读者我要写书评

暂无评论

基于VOF-DPM耦合的Y型喷嘴雾化研究

化学工程 2024年第8期52卷 78-83页

作者：刘汉勇冯胜科李兵科谭永华虞育松山东华鲁恒升化工股份有限公司山东德州253024 北京航天动力研究所北京100076 航天推进技术研究院陕西西安710100 北京交通大学机械与电子控制工程学院北京100044

采用VOF-DPM(流体体积-离散相模型)耦合方法的数值模拟,研究液体黏度对Y型喷嘴内流动和喷嘴雾化性能的影响。首先对Y型喷嘴内部和外部区域进行多面体网格划分,并借助基于气液体积分数值的自适应网格加密技术有效提高气液界面识别精度。... 详细信息

采用VOF-DPM(流体体积-离散相模型)耦合方法的数值模拟,研究液体黏度对Y型喷嘴内流动和喷嘴雾化性能的影响。首先对Y型喷嘴内部和外部区域进行多面体网格划分,并借助基于气液体积分数值的自适应网格加密技术有效提高气液界面识别精度。分析喷嘴内流动与喷嘴外雾化的关联,研究液体黏度对雾化性能的影响。结果表明:重油黏度较高,流速较小,喷嘴内重油不易被气体吹散和掺混,液体雾化较难。柴油密度低于重油,易被加速,导致喷雾贯穿距离大于重油,雾化更容易,柴油的喷雾锥角与重油差距不大。重油的喷雾索特平均直径d s为137.14,略高于柴油d s约0.8%。研究对评估燃烧器燃烧性能及其适应多种燃料的改造设计具有重要的应用价值。

关键词： VOF-DPM耦合数值模拟液体黏度 Y型喷嘴雾化性能

Experimental investigation of cavitation instabilities in inducer with different tip clearances

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2021年第9期34卷 168-177页

作者： Le XIANG yonghua tan Hui CHEN Kaifu XU Science and Technology on Liquid Rocket Engine Laboratory Xi’an 710100China Academy of Aerospace Propulsion Technology Xi’an 710100China Xi'an Aerospace Propulsion Institute Xi’an 710100China

To investigate the effect of tip clearance size on cavitation characteristics in a turbopump inducer,a series of experiments have been conducted in a newly developed visualization test facility using room temperature water as working *** pressure fluctuations near the tip region were collected,and the cavity structures under various conditions were documented by a high-speed *** is found that large tip clearance distinctly reduces both the non-cavitation and cavitation *** cavitation instabilities,super-synchronous rotating cavitation,synchronous rotating cavitation and cavitation surge have been carefully identified through combination of cross-correlation analysis of pressure signals and visualization *** tip clearance displays a remarkable stabilization effect on pressure fluctuation,cavitation surge totally disappears,and the range of occurrence of synchronous rotating cavitation becomes smaller for the large tip clearance,whereas super-synchronous rotating cavitation only occurs in the large tip *** cavitation areas are smaller at large tip clearance,while the flow channels are more seriously choked when cavitation occurs heavily in comparison with those at small tip clearance,which may be responsible for the worse cavitation performance.

关键词： Cavitation instabilities Inducer Pressure fluctuation Tip clearance Visualization

Experimental investigation of thermal effect on cavitation characteristics in a liquid rocket engine turbopump inducer

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2021年第8期34卷 48-57页

作者： Chunmin WANG Le XIANG yonghua tan Hui CHEN Kaifu XU Northwestern Polytechnical University Xi'an 710072China Xi’an Aerospace Propulsion Institute Xi'an 710100China Academy of Aerospace Propulsion Technology Xi'an 710100China

The objective of this paper is to investigate the effect of water temperature on cavitation characteristics in a turbopump inducer,a series of experiments at different temperatures have been conducted in a newly developed visualization test *** is found that higher temperature shows little influence on the non-cavitation performance and breakdown characteristic in the investigated *** relationship between cavitation development and pressure fluctuation has been discussed in *** temperature displays a remarkable stabilization effect on the cavitation excited *** particular,the inception cavitation numbers of both the super-synchronous rotating cavitation and synchronous rotating cavitation are decreased at higher temperatures,and the corresponding frequencies are not affected,while the amplitudes are distinctly reduced,and the occurrence range of synchronous rotating cavitation is significantly narrowed.A generalized RayleighPlesset equation has been employed to account for the thermal effect on the bubble development,which may provide a deep insight in understanding the experimental *** effect is found to act as a remarkable dissipation mechanism to suppress the bubble growth,smooth the *** particular,the excited pressure during collapse is smaller at higher temperatures,which may lead to the stabilization effect of high temperature in this study.

关键词： Bubble dynamic Cavitation instability Inducer Thermal effect Visualization experiment

New Power for Boosting China's Aerospace Industry

在线全文

学校读者我要写书评

暂无评论

Aerospace China 2017年第1期18卷 15-20页

作者： tan yonghua Academy of Aerospace Propulsion Technology

China's new-generation launch vehicle LM-5 successfully completed its maiden launch in November *** the new technologies applied in the launch vehicle,four types of liquid rocket engines attracted extensive *** engines feature advanced concepts and technologies such as a staged combustion cycle and expander *** 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 *** 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 ***,proposals for new liquid propulsion technology development in the future in China are presented.

关键词： Launch vehicle Liquid rocket engine LOX/kerosene LOX/LH2

On tectonic movement in the South China Sea during the Cenozoic

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2009年第1期28卷 25-36页

作者： LIN Changsong CHU Fengyou GAO Jinyao tan yonghua Key Laboratory of Submarine Geosciences of State Oceanic Administration Second Institute Oceanography State Oceanic Administration Hangzhou 310012 China Second institute of Oeeanography State Oceanic Administration Hangzhou 310012 China

The tectonic movement taking place at the end of Cretaceous and the beginning of Cenozoic had opened the Cenozoic phase of polycyclic tectonic movements,then the whole crust of the South China Sea had been mainly subjected to the regional stress field of tectonic tension,which was characterized by rifting *** times of regional tectonic movement and sedimentation had been assembled into a geological development history of polycyclic ***,the tectonic movements were strongly intensified at the end of Cretacious and the beginning of Paleagene,between Late Eocene and Mid-Oligocene,during Mid-and Late *** three times of tectonic movement had built the most important regional tectonic interfaces in the South China *** movements of the South China Sea were the result and epitome of interaction of the Eurasia,Pacific and Indo-Australia plates,that is,they were introduced by polycyclic changes of directions,rates and strengths of lithospheric movements and asthenospheric flows across the Pacific and Indo-Australia plates.

关键词： South China Sea Cenozoic tectonic movement