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Response of a hypersonic blunt cone boundary layer to slow acoustic waves with assessment of various routes of receptivity

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Applied Mathematics and Mechanics(English Edition) 2018年第11期39卷 1643-1660页

作者： bingbing wan Jisheng LUO Caihong SU Laboratory for High-Speed Aerodynamics School of Mechanical Engineering Tianjin University

The hypersonic boundary-layer receptivity to slow acoustic waves is investigated for the Mach 6 flow over a 5-degree half-angle blunt cone with the nose radius of 5.08 mm. The plane acoustic wave interacts with the bow shock, and generates all types of disturbances behind the shock, which may take various routes to generate the boundarylayer unstable mode. In this paper, two routes of receptivity are investigated in *** is through the disturbance in the entropy layer. The other is through the slow acoustic wave transmitted downstream the bow shock, which can excite the boundary-layer mode due to the synchronization mechanism. The results show that, for a low frequency slow acoustic wave, the latter route plays a leading role. The entropy-layer instability wave is able to excite the first mode near the neutral point, but its receptivity efficiency is much lower.

关键词： receptivity entropy layer blunt cone hypersonic boundary layer

基于全局稳定性理论的eN方法对高超声速有迎角锥背风流向涡转捩分析

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空气动力学学报 2024年第1期42卷 33-44,I0001页

作者：陈曦涂国华万兵兵袁先旭陈坚强陈久芬空天飞行空气动力科学与技术全国重点实验室绵阳621000 中国空气动力研究与发展中心超高速空气动力研究所绵阳621000

有迎角圆锥表面存在周向压力梯度,压力梯度驱使流体从迎风面的高压区向背风面的低压区流动,导致背风中心线附近出现大尺度流向涡结构,从而进一步失稳触发转捩。本文利用全局稳定性理论与e^(N)方法,研究3个不同工况下高超声速有迎角圆锥... 详细信息

有迎角圆锥表面存在周向压力梯度,压力梯度驱使流体从迎风面的高压区向背风面的低压区流动,导致背风中心线附近出现大尺度流向涡结构,从而进一步失稳触发转捩。本文利用全局稳定性理论与e^(N)方法,研究3个不同工况下高超声速有迎角圆锥的流向涡转捩问题。研究发现,Mack模态在上游流向涡较弱时为主导模态,但当流场出现周向卷曲、流向涡逐渐增强时逐渐减弱,此时流向涡失稳模态出现,并逐渐成为主导不稳定性。基于全局稳定性得到不稳定模态的N值。结合风洞实验测量结果可判断,在迎角2°时转捩N值不到3,而在迎角4°、转捩完成时的N值可达6左右。

关键词：边界层转捩流向涡全局不稳定性分析风洞实验 N值

An improved yeast two-hybrid approach for detection of interacting proteins

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Frontiers in Biology 2006年第2期1卷 120-126页

作者： wan bingbing Shi Yan Huo Keke State Key Laboratory of Genetic Engineering Institute of GeneticsSchool of Life SciencesFudan UniversityShanghai 200433China

Yeast two-hybrid approach is popularly used nowadays as an important technical method in the field of studying protein-protein *** yeast two-hybrid system is obviously advantageous in searching interacting proteins and setting up the network of proteins interaction,not all of proteins can use routine yeast two-hybrid method to search interacting *** important proteins,such as some nucleoprotein transcriptional factor,carry out the regular method and construct the bait-BD vector to screen the library containing AD ***,it usually results in failures because it contains the activate domain and can self-activate the reporter *** this study,we changed the research strategy,fused the bait gene(FOXA3)with the AD vector to screen the library containing BD vector,so that we constructed a two-hybrid library containing BD vector and can bypass the interference of *** we used this two-hybrid library to screen FOXA3,a hepatocyte nuclear factor,and found out an interacting protein:complement component C3.

关键词： yeast two-hybrid system protein-protein interaction human liver cDNA library FOXA3

Effects of trace ytterbium addition on microstructure,mechanical and thermal properties of hypoeutectic Al-5Ni alloy

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Journal of Rare Earths 2022年第8期40卷 1305-1315页

作者： Kang wang Shaodong Hu Yanglin Zhong Shuoxun Jin Zirong Zhou Zhiyu wang Jiongcai Chen bingbing wan Wenfang Li School of Materials Science and Engineering Dongguan University of TechnologyDongguan 523808China Institute of Science and Technology Innovation Dongguan University of TechnologyDongguan 523808China

Over the past decade,the cast aluminum alloys with excellent mechanical and conductivity properties have emerged as potential materials for thermal ***,the traditional Al-Si based alloys are difficult to make significant breakthrough in conductivity *** hypoeutectic Al-5Ni alloy also possesses sound castability and is expected to be applied in thermal management *** this study,the effects of ytterbium(Yb element) at 0-0.5 wt% on the microstructures as well as the electrical/thermal conductivity and mechanical properties of the Al-5Ni alloy were systematically *** experimental results indicate that the addition of Yb at a relatively low amount not only reduces the secondary dendrite arm spacing of the α-Al grains,but also modifies the morphology and distribution of eutectic boundary ***,it is found that the dosage of Yb at 0.3 wt% in the Al-5Ni alloy can simultaneously improve the yield strength,ultimate tensile strength and electrical/thermal *** strengthening and toughening of the Al-5Ni alloy are mainly attributed to the decrease of secondary dendrite arm spacing and the improvement of eutectic *** transmission electron microscopy/selected area electron diffraction(TEM/SAED) analysis indicates that the ytterbium in Al-5Ni alloy will form Al_(3)Yb phase,which mainly agglomerates in the Al_(3)Ni phase *** phase is helpful to decrease the solubility of impurity elements(e.g.,Fe and Si) in the α-Al matrix,which is beneficial to electrical/thermal *** value of this study lays foundation for manufacturing Al-Ni alloys with high thermal conductivity and acceptable mechanical properties.

关键词： Aluminum alloys Ytterbrium Trace dosage Mechanical properties Thermal conductivity Rare earths

Progress in flight tests of hypersonic boundary layer transition

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Acta Mechanica Sinica 2021年第11期37卷 1589-1609,I0001页

作者： Guohua Tu Jianqiang Chen Xianxu Yuan Qingtao Yang Maochang Duan Qiang Yang Yi Duan Xi Chen bingbing wan Xinghao Xiang State Key Laboratory of Aerodynamics China Aerodynamics Research&Development CenterMianyang621000China Hypervelocity Aerodynamics Institute China Aerodynamics Research and Development CenterMianyang621000China Science and Technology on Space Physics Laboratory China Academy of Launch Vehicle TechnologyBeijing100076China

Boundary layer transition(BLT)can cause a sharp rise in heat flux and skin friction,which can seriously affect the flight performance and safety of hypersonic flight ***,the mechanism,prediction and control of transition have become important issues that must be dealt with for the development of advanced flight vehicles,and it is also a research hotspot of particular interest to major aerospace *** to other transition research approaches,model flight tests can better present the transition problems under real flight conditions,thus have been carried out extensively over the past 30 *** United States,Germany,France,Australia,and other countries have carried out transition research based on flight tests,such as the Pegasus wing-glove crossflow transition and the Hypersonic Boundary Layer Transition(HyBOLT)transition control flight test of the United States,the joint research project of the Hypersonic International Flight Research and Experimentation-1(HIFiRE-1)circular cone and the HIFiRE-5 elliptic cone transition flight tests between the United States and Australia,the flight test of compression surface transition of the scramjet forebody(LEA)in France and so *** these flight tests suffered various setbacks,they still obtained valuable transition ***,the United States is carrying out the concave-surface transition flight tests of Hypersonic Boundary Layer Transition(BOLT)and *** its first model flight test mission for verification purpose launched successfully in 2015,several hypersonic BLT flight tests have been conducted by China Aerodynamics Research and Development Center(CARDC).The flight tests have measured valid transition data under flight conditions,obtained the transition front and its dynamical variation on blunt cones at various angles of attack and a lifting body Hypersonic Transition Research Vehicle(HyTRV).The crossflow traveling waves in high-altitude flight were measured for the first t

关键词： Hypersonic flow Boundary layer transition Flight test MF-1 HyTRV

More tree growth reduction due to consecutive drought and its legacy effect for a semiarid larch plantation in Northwest China

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Journal of Forestry Research 2024年第2期35卷 188-196页

作者： Yanfang wan Pengtao Yu Yanhui wang Jiamei Li Yushi Bai Yipeng Yu bingbing Liu Xiaocha Wei Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration Ecology and Nature Conservation InstituteChinese Academy of ForestryBeijing 100091People’s Republic of China

Extreme climate has increasingly led to negative impacts on forest ecosystems globally,especially in semiarid areas where forest ecosystems are more ***,it is poorly understood how tree growth is affected by different drought *** 2006–2009,the larch plantations in the semiarid areas of Northwest China were negatively affected by four consecutive dry years,which was a very rare phenomenon that may occur frequently under future climate *** this study,we analyzed the effect of these consecutive dry years on tree growth based on the data of the tree rings in the dominant layer of the forest canopy on a larch *** found that the tree-ring width index(RWI)in dry years was lower than that in normal years,and it experienced a rapidly decreasing trend from 2006 to 2009(slope=-0.139 year^(-1),r=-0.94)due to water supply deficits in those dry *** induced legacy effects of tree growth reduction,and consecutive dry years corresponded with greater growth reductions and legacy *** reductions and legacy effects were significantly stronger in the third and fourth consecutive dry years than that of single dry year(p<0.05),which might have been due to the cumulative stress caused by consecutive dry *** results showed that larch trees experienced greater tree growth reduction due to consecutive dry years and their legacy effect,and the trees had lower recovery rates after consecutive dry *** results highlight that consecutive dry years pose a new threat to plantations under climate warming,and thus,the effect of climate extremes on tree growth should be considered in growth models in semiarid areas.

关键词： Tree rings Drought effects Legacy effects Growth-climate relationships Larix principis-rupprechtii

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超声速绕钝板熵层不稳定性的研究

空气动力学学报 2018年第2期36卷 247-253页

作者：万兵兵罗纪生天津大学力学系天津300072

为了研究熵层的不稳定性,首先选择马赫数为4.5、前缘为圆头的0°钝板模型,利用直接数值模拟得到基本流场,然后在此基础上进行线性稳定性分析,同时通过经验方法确定熵层和边界层区域。研究发现,对于某一流向站位的基本流剖面,存在两个广... 详细信息

为了研究熵层的不稳定性,首先选择马赫数为4.5、前缘为圆头的0°钝板模型,利用直接数值模拟得到基本流场,然后在此基础上进行线性稳定性分析,同时通过经验方法确定熵层和边界层区域。研究发现,对于某一流向站位的基本流剖面,存在两个广义拐点,分别位于边界层和熵层。针对熵层的广义拐点,进行稳定性分析研究了熵层中不稳定模态特性,得出该模态的不稳定区域集中在前缘附近,且扰动增长率很小。通过直接数值模拟熵层扰动的演化,发现在前缘附近扰动幅值也是缓慢上升,之后缓慢下降。另外,距离前缘较远处的数值模拟得到的扰动幅值与LST结果比较,二者吻合得很好,说明熵层在下游具有很好的平行性。

关键词：钝板直接数值模拟熵层线性稳定

高超声速尖锥边界层压力脉动和热流脉动特性试验

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航空学报 2022年第2期43卷 235-243页

作者：李强万兵兵杨凯朱涛中国空气动力研究与发展中心计算空气动力研究所绵阳621000 中国空气动力研究与发展中心超高速空气动力研究所绵阳621000

高频脉动热流是激波风洞研究高超声速边界层转捩的重要测试量,利用尖锥模型在中国空气动力研究与发展中心Ф2 m激波风洞(FD-14A)内开展来流马赫数10、单位雷诺数分别为1.2×10^(7)/m、4.7×10^(6)/m、2.4×10^(6)/m流场条件下的风洞试... 详细信息

高频脉动热流是激波风洞研究高超声速边界层转捩的重要测试量,利用尖锥模型在中国空气动力研究与发展中心Ф2 m激波风洞(FD-14A)内开展来流马赫数10、单位雷诺数分别为1.2×10^(7)/m、4.7×10^(6)/m、2.4×10^(6)/m流场条件下的风洞试验。获得了不同工况和流态条件下尖锥模型边界层热流脉动和压力脉动频谱特性,通过与高频脉动压力频谱结果和线性稳定性理论计算结果对比,证明了自研的原子层热电堆热流传感器(ALTP)的频谱响应能力,可用于高超声速边界层转捩研究工作。试验发现热流脉动具有压力脉动不一样的频谱特征,湍流条件下压力脉动的各频率能量分布比较均匀,而热流脉动随频率增大能量衰减比较明显;相比于压力脉动,热流脉动信号更不容易受到干扰,本次试验在马赫数10、单位雷诺数2.4×10^(6)/m流场条件下,测量的热流脉动第二模态波峰值频谱相对于压力脉动更早凸显出来。

关键词：高超声速边界层转捩激波风洞高频脉动压力高频脉动热流线性稳定性

高超声速流动稳定性及转捩工程应用若干研究进展

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空气动力学学报 2020年第2期38卷 368-378页

作者：黄章峰万兵兵段茂昌天津大学力学系天津300072 中国空气动力研究与发展中心空气动力学国家重点实验室绵阳621000

流动稳定性及转捩是高超声速流动研究的热点和难点,近年来在理论基础研究方面取得了很大进展,但在工程应用方面还存在明显的不足。本文回顾了近年来高超声速流动稳定性及转捩在工程应用研究的若干进展,介绍了流动稳定性在复杂外形流、... 详细信息

流动稳定性及转捩是高超声速流动研究的热点和难点,近年来在理论基础研究方面取得了很大进展,但在工程应用方面还存在明显的不足。本文回顾了近年来高超声速流动稳定性及转捩在工程应用研究的若干进展,介绍了流动稳定性在复杂外形流、非平行流、局部突变流、强三维流方面的工程化拓展研究,总结了转捩预测e^N方法在感受性、积分方法、转捩判据、软件开发方面的工程化研究进展;结合风洞试验、弹道靶试验、飞行试验,对零迎角锥、椭圆锥、小迎角锥和大迎角锥的典型案例进行了应用;展望了高超声速流动稳定性和转捩在工程应用的未来。

关键词：流动稳定性转捩工程应用 e^N方法高超声速流动