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Effect of carbon dioxide concentration on the combustion characteristics of boron agglomerates in oxygen-containing atmospheres

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2023年第11期24卷 949-959页

作者： Lian DUAN zhixun xia Yunchao FENG Binbin CHEN Jiarui ZHANG Likun MA College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China

In ramjet combustion chambers,carbon dioxide(CO_(2))produced by the combustion of carbonaceous fuel enters the chamber together with boron *** order to investigate the effect of CO_(2)concentration present in an oxygen-containing atmosphere on the combustion characteristics and oxidation mechanisms of boron agglomerates,we used a laser ignition system,an X-ray diffractometer(XRD),and a thermogravimetric-differential scanning calorimetry(TG-DSC)combined thermal analysis ***-particle boron was tested in the laser-ignition experiments as the control *** ignition experiment results showed that with a fixed O2 concentration of 20%,when the particle temperature reaches the melting point of boron,increasing CO_(2)content causes the combustion process of boron agglomerates to transition from single-particle molten droplet combustion to porous-particle ***,XRD analysis results indicated that the condensed-phase combustion products(CCPs)of boron particles in a mixed atmosphere of O2 and CO_(2)contained B4C,which is responsible for the porous structure of the *** temperatures below 1200℃,the addition of CO_(2)has no obvious promotion effect on boron exothermic ***,in the laser-ignition experiment,when the oxygen concentration was fixed at 20%while the CO_(2)concentration increased from 0%to 80%,the maximum temperature of boron agglomerates rose from 2434 to 2573 K,the self-sustaining combustion time of single-particle boron decreased from 396 to 169 ms,and the self-sustaining combustion time of boron agglomerates decreased from 198 to 40 *** study conclusively showed that adding CO_(2)to an oxygen-containing atmosphere facilitates boron reaction and consumption pathways,which is beneficial to promoting exothermic reaction of boron agglomerates at relatively high temperatures.

关键词： Boron combustion Amorphous boron Boron-containing propellant Solid fuel ramjet

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氧化剂燃气来流下TAGN富燃料掺混燃烧特性

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固体火箭技术 2024年第3期47卷 302-309页

作者：王立民张宇张微萌刘殊远丁妍雨夏智勋胡松启国防科技大学高超声速技术实验室长沙410073 内蒙动力机械研究所呼和浩特010011 西北工业大学燃烧、热结构与内流场重点实验室西安710072 中国航天科工集团有限公司六院210所西安710065

在新型氧/燃分离式组合固体发动机中,氧化剂燃气来流工况对富燃料掺混燃烧特性具有重要影响。为揭示氧化剂来流下富燃料掺混燃烧特性,基于课题组前期建立的氧化剂/富燃料掺混燃烧反应详细机理,构建了新型氧/燃分离式组合固体发动机二维... 详细信息

在新型氧/燃分离式组合固体发动机中,氧化剂燃气来流工况对富燃料掺混燃烧特性具有重要影响。为揭示氧化剂来流下富燃料掺混燃烧特性,基于课题组前期建立的氧化剂/富燃料掺混燃烧反应详细机理,构建了新型氧/燃分离式组合固体发动机二维稳态燃烧模型。通过数值仿真分析,获得了不同来流温度和马赫数下,高氯酸铵(AP)氧化剂燃气对硝酸三氨基胍(TAGN)富燃料掺混燃烧特性的影响。结果表明,随着AP燃气来流的初温升高,沿流动方向的混合效果变强,而沿径向方向的混合效果变差,TAGN富燃料前端传热系数有所提升,燃面平均退移速率出现小幅下降;增大AP燃气来流马赫数,显著强化了AP和TAGN的掺混和传热过程,提高了TAGN燃气和AP燃气之间的反应速率,燃面平均退移速率显著增大。

关键词：氧/燃分离式组合固体发动机详细反应机理掺混燃烧混合效应

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LES of the Sandia flame series D-F using the Eulerian stochastic field method coupled with tabulated chemistry

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Chinese Journal of Aeronautics 2020年第1期33卷 116-133页

作者： Yifan DUAN zhixun xia Likun MA Zhenbing LUO Xu HUANG Xiong DENG College of Aerospace Science and Technology National University of Defense TechnologyChangsha 410073China

In this paper,the Eulerian Stochastic Field(ESF)model in the Transported Probability Density Function(TPDF)class model is combined with the Flamelet Generated Manifolds(FGM)*** method solves the joint probability density function transport equation by ESF method that considers the interaction mechanism between flame and turbulence with high *** the same time,by making use of the advantage of the FGM model,this model is able to incorporate the detailed chemical reaction mechanism(GRI 3.0)with acceptable computational *** new model has been implemented in the open source CFD suite-Open *** of the model has been carried out by simulating the Sandia flame series(three turbulent piloted methane jet flames)issued by the National Laboratory of the United *** accuracy and advancement of the ESF/FGM turbulent combustion model are verified by comparing the LES results of the new model with the rich experimental data as well as the RANS *** results demonstrate that the model has a strong ability in capturing combustion phenomena such as extinction and re-ignition in turbulent flame,which is essential in the accurate prediction of the combustion process in real combustion devices,for example,aircraft engines.

关键词： Eulerian Stochastic Field(ESF) Flamelet Generated Manifolds(FGM) Large Eddy Simulation(LES) Open FOAM Turbulent combustion

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Research progress on solid-fueled Scramjet

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Chinese Journal of Aeronautics 2022年第1期35卷 398-415页

作者： xiang ZHAO zhixun xia Likun MA Chaolong LI Chuanbo FANG Benveniste NATAN Alon GANY Department of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China Qinghe Building Ding-3 Beijing 100085China Faculty of Aerospace Engineering Technion-Israel Institute of TechnologyHaifa 32000Israel

The solid-fueled Scramjet is an interesting option for supersonic combustion *** shows significant advantages such as simple fuel supply and compactness,avoiding the complex system of tanks and pipelines that encountered in liquid-fueled *** solid-fueled Scramjet could be the simplest air-breathing engine for the hypersonic flight *** paper presents a comprehensive and systematic review of the research progress on solid-fueled Scramjet in various institutes and *** summarizes a progress overview of three types of the solid-fueled Scramjet,which covers a wealth of landmark numerical and experimental *** on this,several relevant key technologies are *** inherent scientific issues are refined,such as the mixing mechanism of multi-phase flow and supersonic airflow,ignition and combustion mechanism of the condensed phase in a supersonic airflow,and coupling mechanism of gas and solid phase in a supersonic ***,the historical development trend is clarified,and some recommendations are provided for future solid-fueled Scramjet.

关键词： Combustor performance Flame stabilization Self-ignition Solid-fueled Scramjet Supersonic combustion ramjet

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凹腔构型对超声速气-固两相富燃燃气掺混燃烧的影响

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固体火箭技术 2024年第5期47卷 620-628页

作者：马立坤杨鹏年夏智勋冯运超赵李北刘延东国防科技大学高超声速技术实验室长沙410073

凹腔作为燃烧增强装置,在超声速气-固两相富燃燃气掺混燃烧中发挥着重要作用。基于火焰稳定凹腔和斜劈装置,提出了波瓣凹腔构型,通过数值模拟深入分析了凹腔构型在超声速气流中对气-固两相富燃燃气掺混燃烧的影响。通过对流场参数、流... 详细信息

凹腔作为燃烧增强装置,在超声速气-固两相富燃燃气掺混燃烧中发挥着重要作用。基于火焰稳定凹腔和斜劈装置,提出了波瓣凹腔构型,通过数值模拟深入分析了凹腔构型在超声速气流中对气-固两相富燃燃气掺混燃烧的影响。通过对流场参数、流场云图及颗粒运动轨迹等的分析,发现富燃燃气中的气相组分和凝相颗粒在空间分布和释能过程中表现出分区运动和分区燃烧的特点。结果表明:随着燃烧过程的深入,颗粒的空间分布逐渐分散;流场参数在燃气喷口附近变化剧烈、流场下游变化缓慢;波瓣结构具备增强流场湍动能和降低流场不均匀性的能力,进而促进了各组分的掺混燃烧;采用双波瓣凹腔时展现出最优的促进效果。波瓣结构能够扩大流场中高温区域的空间分布,有效延长凝相颗粒在高温区域的停留时间,为凝相颗粒的燃烧和能量释放提供了更为有利的条件。

关键词：超声速气流气-固两相波瓣型凹腔掺混燃烧数值模拟

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Epidemiology and trend analysis on malignant mesothelioma in China

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Chinese Journal of Cancer Research 2017年第4期29卷 361-368页

作者： Jun Zhao Tingting Zuo Rongshou Zheng Siwei Zhang Hongmei Zeng Changfa xia zhixun Yang Wanqing Chen National Cancer Center/Cancer Hospital Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100021 China

Objective： Population-based cancer registration data were used to analyze the epidemiology and trend of malignant mesothelioma in China, and the result would provide basic data for its prevention and control. Methods： Malignant mesothelioma data in 2013 were retrieved from the database of National Cancer Registry. Malignant mesothelioma incidence and mortality were estimated using age-specific rate by urban/rural and gender according to the national population in 2013. Malignant mesothelioma data from 22 cancer registries were used for trend analysis during 2000-2013. Results： It is estimated that there were 2,041 new malignant mesothelioma cases and 1,659 malignant mesothelioma deaths occurred in 2013. The crude incidence rate in China were 1.50/106 （males 1.67/106, females 1.32/106）, age-standardized incidence rates by Chinese standard population （ASIRC） and by world standard population （ASIRW） were 1.03/106 and 1.02/106, respectively. The crude mortality rate in China was 1.22/106 （males 1.67/106, females 1.32/106）, age-standardized mortality rates by Chinese standard population （ASMRC） and by world standard population （ASMRW） were 0.83/106 and 0.81/106, respectively. There was an increasing trend of incidence rate for malignant mesothelioma in registration areas of China during 2000-2013 with annual percentage change （APC） of 2.5% [95% confidence interval （95% CI）： 0.6%--4.5%]. After age standardization, no significant differences were observed. No matter for crude mortality rates or age-standardized mortality rates, no significant differences were observed during 2000-2013. Conclusions： Malignant mesothelioma is the major occupational and environmental neoplasm associated with asbestos exposure. The increasing incidence trend suggests that more attention should be paid on this disease.

关键词： Malignant mesothelioma incidence mortality trend cancer registry

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Detailed modeling of aluminum particle combustion——From single particles to cloud combustion in Bunsen flames

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Chinese Journal of Aeronautics 2022年第5期35卷 319-332页

作者： Jiarui ZHANG Oliver T.STEIN Tien D.LUU Ali SHAMOONI zhixun xia Zhenbing LUO Likun MA Yunchao FENG Andreas KRONENBURG College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China Institut für Technische Verbrennung Universitat StuttgartStuttgart 70174Germany

A numerical model for aluminum cloud combustion which includes the effects of interphase heat transfer,phase change,heterogeneous surface reactions,homogeneous combustion,oxide cap growth and radiation within the Euler–Lagrange framework is *** model is validated in single particle configurations with varying particle *** combustion process of a single aluminum particle is analyzed in detail and the particle consumption rates as well as the heat release rates due to the various physical/chemical sub-models are *** combustion time of single aluminum particles predicted by the model are in very good agreement with empirical correlations for particles with diameters larger than 10μ*** prediction error for smaller particles is noticeably reduced when using a heat transfer model that is capable of capturing the transition regime between continuum mechanics and molecular *** predictive capabilities of the proposed model framework are further evaluated by simulating the aluminum/air Bunsen flames of Mc Gill University for the first *** show that the predicted temperature distribution of the flame is consistent with the experimental data and the double-front structure of the Bunsen flame is reproduced *** burning rates of aluminum in both single particle and particle cloud configurations are calculated and compared with empirical *** show that the burning rates obtained from the present model are more reasonable,while the correlations,when embedded in the Euler–Lagrange context,tend to underestimate the burning rate in the combustion stage,particularly for the considered fuel-rich flames.

关键词： Aluminum particle combustion Bunsen flame Burning time Burning rate Particle cloud

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Review of actuators for high speed active flow control

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Science China(Technological Sciences) 2012年第10期55卷 2225-2240页

作者： WANG Lin LUO ZhenBing xia zhixun LIU Bing DENG Xiong Science and Technology on Scrarnjet Laboratory National University of Defense TechnologyChangsha 410073China

Actuators are one of the key points for the development of active flow control *** methods of high speed flow control can provide enhanced propulsive efficiency and at the same time enable safe and maneuverable high speed *** development of high speed flight technology promotes the emergence of novel and robust *** review introduces the state of the art in the development of actuators that can be used in high speed active flow *** classification and different operation criteria of the actuators are *** specifications,mechanisms and applications of various popular actuator types including fluidic,mechanical,and plasma actuators are *** on the realistic need of high speed flow control and the existing results of actuators,a new actuator design method is *** last,the merits and drawbacks of the actuators are summarized and some suggestions on the development of active flow control technology are put forward.

关键词： active flow control actuators figure of merit fluidic mechanical plasma

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合成射流基微泵的控制律

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机械工程学报 2007年第11期43卷 34-39页

作者：罗振兵夏智勋国防科学技术大学航天与材料工程学院长沙410073

通过对合成射流流场数值分析,得到合成射流鞍点特征及可控特性。基于对合成射流鞍点特征及其随激励条件变化规律的分析,获得调节合成射流基微泵的控制律。通过对调节控制和未调节控制下微泵的流体力学分析,对微泵控制律进行考核验证。... 详细信息

通过对合成射流流场数值分析,得到合成射流鞍点特征及可控特性。基于对合成射流鞍点特征及其随激励条件变化规律的分析,获得调节合成射流基微泵的控制律。通过对调节控制和未调节控制下微泵的流体力学分析,对微泵控制律进行考核验证。验证结果显示:改变激励条件并相应调节分流板位置,合成射流新产生的'涡对'保持良好,微泵工作于设计状态;而分流板未控制调节下,由于分流板处于合成射流'涡对'形成和发展的关键区域,严重阻碍和破坏了合成射流'涡对'的形成和发展,合成射流对周围流体的卷吸量显著减小,微泵工作远离设计状态,泵流流量显著减小。研究结果表明:分流板控制律对微泵的控制是行之有效的,若激励器振动膜的振动幅值与激励电参数的关系已知,则可由改控制律得到微泵的电参数控制律,从而可以实现微泵的智能化控制。

关键词：微机电系统微泵合成射流鞍点控制律

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吸气式高超声速飞行器助推分离过程数值仿真

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国防科技大学学报 2019年第1期41卷 34-40页

作者：闻讯柳军夏智勋国防科技大学空天科学学院湖南长沙410073

针对吸气式高超声速冲压发动机验证性试验特殊的飞行环境和助推分离条件,以某轴对称吸气式高超声速飞行器级间分离问题为具体研究对象,采用非结构网格局部网格重构技术和非定常问题非定常六自由度问题仿真方法,对该复杂构型飞行器助推... 详细信息

针对吸气式高超声速冲压发动机验证性试验特殊的飞行环境和助推分离条件,以某轴对称吸气式高超声速飞行器级间分离问题为具体研究对象,采用非结构网格局部网格重构技术和非定常问题非定常六自由度问题仿真方法,对该复杂构型飞行器助推分离过程进行数值计算。研究得到弱干扰冷态分离状态下飞行器及助推器的运动参数和气动力参数在分离过程中的发展规律。对0.3 s内助推器的位移轨迹进行分析,判断分离方案的可行性,并给出最佳的分离工况条件。

关键词：高超声速飞行器助推分离气动特性非定常数值计算

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