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Aerodynamic measurement of a large aircraft model in hypersonic flow 被引量:2
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作者 孟宝清 韩桂来 +1 位作者 张德良 姜宗林 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第11期310-315,共6页
Accurate aerodynamic measurements in the hypersonic flow of large aircraft models in tunnels have practical significance, but pose a significant challenge. Novel aerodynamic force measurement methods have been propose... Accurate aerodynamic measurements in the hypersonic flow of large aircraft models in tunnels have practical significance, but pose a significant challenge. Novel aerodynamic force measurement methods have been proposed,but lack theoretical support. The forms of the force signals techniques for signal processing and calculation of aerodynamics are especially problematic. A theoretical study is conducted to investigate the dynamic properties based on models of the draw-rod system and slender rods. The results indicate that the inertia item can be neglected in the rod governing equation;further, the solutions show that the signals of each rod are a combination of aerodynamic signals(with a constant value) and sine signals, which can be verified by experimental shock tunnel results. Signal processing and aerodynamics calculation techniques are also found to be achievable via the flat part of the signals. 展开更多
关键词 hypersonic aerodynamic measurement theoretical study vibration
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Shock relations in gases of heterogeneous thermodynamic properties
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作者 HU ZongMin ZHOU Kai +2 位作者 PENG Jun LI JinPing JIANG ZongLin 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2017年第7期1050-1057,共8页
Shock relations usually found in literatures are derived theoretically under the assumption of homogeneous thermodynamic properties, i.e., constant ratio of specific heats, γ. However, high temperature effects post a... Shock relations usually found in literatures are derived theoretically under the assumption of homogeneous thermodynamic properties, i.e., constant ratio of specific heats, γ. However, high temperature effects post a strong shock wave may result in thermodynamic heterogeneities and failure to the original shock relations. In this paper, the shock relations are extended to take account of high-temperature effects. Comparison indicates that the present approach is more feasible than other analytical approaches to reflect the influence of γ heterogeneity on the post-shock parameters. 展开更多
关键词 shock wave imperfect gas heterogeneous theoretical solution
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Spectral measurements of hypervelocity flow in an expansion tunnel 被引量:2
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作者 C.K.Yuan K.Zhou +2 位作者 Y.F.Liu Z.M.Hu Z.L.Jiang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2019年第1期24-31,I0002,共9页
Atmospheric reentry vehicles and planetary probes fly through the atmosphere at hypervelocity speed. At such speed, there is a significant proportion of heat load to the vehicle surface due to radiative heating. Accur... Atmospheric reentry vehicles and planetary probes fly through the atmosphere at hypervelocity speed. At such speed, there is a significant proportion of heat load to the vehicle surface due to radiative heating. Accurate prediction needs a good knowledge of the radiation spectrum properties. In this paper, a high-speed camera and spectrograph coupled to an intensified charge-coupled device have bee n impleme nted to inv estigate the rad i at io n flow over a semi-cylinder model. The experiments were carried out in the JF16 expansi on timnel with secondary shock velocity of 7.9 km·s^-1. Results show that the emissio n spectrum comprises several atomic lines and molecular band systems. We give detailed data of the radiation spectrum, shock shape, shock detached distance and radiation intensity varying with space and wavelength. This valuable experimental dataset will be helpful to validate computational fluid dynamics codes and radiation models, which equates to increased prediction accuracy of radiation heating. Also, some suggestions for spectral measurement in hypervelocity flow field were list in the end. 展开更多
关键词 SPECTRAL measurement HYPERVELOCITY FLOW RADIATION EXPANSION TUNNEL
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Electrodeposition of a dendrite-free 3D Al anode for improving cycling of an aluminum-graphite battery 被引量:4
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作者 Junfeng Li Kwan San Hui +8 位作者 Shunping Ji Chenyang Zha Chengzong Yuan Shuxing Wu Feng Bin Xi Fan Fuming Chen Zongping Shao Kwun Nam Hui 《Carbon Energy》 SCIE CAS 2022年第2期155-169,共15页
Aluminum-metal batteries show great potential as next-generation energy storage due to their abundant resources and intrinsic safety.However,the crucial limitations of metallic Al anodes,such as dendrite and corrosion... Aluminum-metal batteries show great potential as next-generation energy storage due to their abundant resources and intrinsic safety.However,the crucial limitations of metallic Al anodes,such as dendrite and corrosion problems in conventional aluminum-metal batteries,remain challenging and elusive.Here,we report a novel electrodeposition strategy to prepare an optimized 3D Al anode on carbon cloth with an uniform deposition morphology,low local current density,and mitigatory volume change.The symmetrical cells with the 3D Al anode show superior stable cycling(>450 h)and low-voltage hysteresis(~170 mV)at 0.5 mA cm^(−2).High reversibility(~99.7%)is achieved for the Al plating/stripping.The graphite||Al‐4/CC full batteries show a long lifespan of 800 cycles with 54 mAh g^(−1) capacity at a high current density of 1000 mA g^(−1),benefiting from the high capacitive-controlled distribution.This study proposes a novel strategy to design 3D Al anodes for metallic-Al-based batteries by eliminating the problems of planar Al anodes and realizing the potential applications of aluminum-graphite batteries. 展开更多
关键词 3D Al anode ionic liquid metallic plating/stripping stability
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Experiment investigation on visualization and operating characteristics of closed loop plate oscillating heat pipe with parallel channels 被引量:1
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作者 SHI Wei-xiu PAN Li-sheng 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第9期2410-2418,共9页
Using ethanol or acetone as the working fluid, visualization of oscillations in steady state was observed visually by high-speed cameras, and temperature oscillating and heat transfer characteristics of closed-loop pl... Using ethanol or acetone as the working fluid, visualization of oscillations in steady state was observed visually by high-speed cameras, and temperature oscillating and heat transfer characteristics of closed-loop plate oscillating heat pipe with parallel channels(POHP-PC) were experimentally investigated by varying liquid filled ratios(50%, 70%, 85%), section scales(1 mm×1 mm and 1 mm×1.5 mm), inclination angles, working fluids and heating inputs. It was found that during operating there was mixed flow consisting of plug flow and annular flow in channels of oscillating heat pipe at steady-state. There was an equilibrium position for working fluid of condenser during oscillating, and periodic oscillations occurred up and down in the vicinity of equilibrium position. With heat input increasing, equilibrium position rose slowly as a result of vapor pressure of evaporation.Evaporation temperature oscillating amplitude possessed a trend of small-large-small and frequency trend was of small-large during steady-state. It may be generally concluded that temperature, whether evaporator or condenser, fluctuated sharply or rose continuously when oscillating heat pipe coming to dry burning state. Simultaneously, it was found that temperature difference of cooling water possibly dropped with heat input rising during dry burning state. Thermal resistance of No. 2 with acetone was lower than that of No. 1 during experiments, but No. 2 achieving heat transfer limit was earlier than No. 1. However, with ethanol, thermal resistance of No. 1 and No. 2 were similar with the heating input less than 110-120 W and filling ratios of 50% and 70%. And with filling ratio of 85%, heating transfer performance of No. 2 was better compared to No. 1 during all the experiments. 展开更多
关键词 closed loop with parallel channels plate oscillating heat pipe VISUALIZATION temperature oscillating heat transfer performance filling ratio section scale
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Performance analysis of a zeotropic mixture(R290/CO_2) for trans-critical power cycle 被引量:3
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作者 潘利生 魏小林 史维秀 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第3期572-577,共6页
Low critical temperature limits the application of CO_2 trans-critical power cycle.The binary mixture of R290/CO_2has higher critical temperature.Using mixture fluid may solve the problem that subcritical CO_2 is hard... Low critical temperature limits the application of CO_2 trans-critical power cycle.The binary mixture of R290/CO_2has higher critical temperature.Using mixture fluid may solve the problem that subcritical CO_2 is hardly condensed by conventional cooling water.In this article,theoretical analysis is executed to study the performance of the zeotropic mixture for trans-critical power cycle using low-grade liquid heat source with temperature of200℃.The results indicated that the problem that CO_2 can't be condensed in power cycle by conventional cooling water can be solved by mixing R290 to CO_2.Variation trend of outlet temperature of thermal oil in supercritical heater with heating pressure is determined by the composition of the mixture fluid.Gliding temperature causes the maximum outlet temperature of cooling water with the increase of mass fraction of R290.There are the maximum values for cycle thermal efficiency and net power output with the increase of supercritical heating pressure. 展开更多
关键词 CO2 R290 Zeotropic mixture Low-grade heat energy Trans-critical power cycle
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Self-sustained catalytic combustion of CO enhanced by micro fluidized bed: stability operation, fluidization state and CFD simulation 被引量:2
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作者 Zirui Zhang Chenhang Zhang +6 位作者 Huan Liu Feng Bin Xiaolin Wei Running Kang Shaohua Wu Wenming Yang Hongpeng Xu 《Frontiers of Environmental Science & Engineering》 SCIE EI CSCD 2023年第9期147-156,共10页
A micro fluidized bed reactor was used to study the self-sustaining catalytic combustion of carbon monoxide(CO).The Cu_(1−x)Ce_(x)O_(y) catalyst,as well as the pure CuO and CeO_(2),are used to investigate the contribu... A micro fluidized bed reactor was used to study the self-sustaining catalytic combustion of carbon monoxide(CO).The Cu_(1−x)Ce_(x)O_(y) catalyst,as well as the pure CuO and CeO_(2),are used to investigate the contributing mechanism of different active sites including dispersed CuO and Cu–Ce solid solutions.The ignition temperature(Ti)of CO over these catalysts at a flow rate of 2000 mL/min followed the order:74℃(Cu_(0.5)Ce_(0.5)O_(y))<75℃(Cu_(0.25)Ce_(0.75)O_(y))<84℃(Cu_(0.75)Ce_(0.25)O_(y))<105℃(CuO)<500℃(CeO_(2)).Furthermore,the lean combustion limits(equivalence ratioϕ)over these catalysts under the flow rates of 750–3000 mL/min(through fixed,bubbling,and fluidized bed)were also measured,which are Cu_(0.5)Ce_(0.5)O_(y)<Cu_(0.25)Ce_(0.75)Oy<Cu_(0.75)Ce_(0.25)O_(y)<CuO<CeO_(2).The fluidized bed was simulated using the Eulerian two-fluid model(TFM)coupled with a diffusion/kinetic-limited reaction model to evaluate the influence of operation conditions on the self-sustained combustion of CO.The predicted maximum temperature agreed with the experimental measurements,demonstrating the validity of the kinetic model and simulation parameters.The results of catalytic combustion with increasing CO concentrations suggest that the catalytic combustion reaction could co-exist with the flamed combustion.When a high concentration of CO is used,a blue-purple flame caused by CO combustion appears in the upper part of the fluidized bed,indicating that the range of CO-containing exhaust gas purification could be expanded to a larger range using the fluidized-bed catalytic combustion technique. 展开更多
关键词 Self-sustained catalytic combustion Carbon monoxide Cu_(1-x)Ce_(x)O_(y) Fluidized bed Computational fluid dynamics
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Flow and Leakage Characteristics in Sealing Chamber of a Variable Geometry Hypersonic Inlet
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作者 XIA Feng SUN Bo +3 位作者 YU Jianyi YUE Lianjie GAO Yu DAI Chunliang 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2022年第6期663-671,共9页
When the variable geometry hypersonic inlet is sealed with ceramic wafers,the cavity flows inside the sealing chamber can be affected by the boundary layer near the side wall.To study the influence of the boundary lay... When the variable geometry hypersonic inlet is sealed with ceramic wafers,the cavity flows inside the sealing chamber can be affected by the boundary layer near the side wall.To study the influence of the boundary layer thickness near the side wall on the flow and leakage characteristics in sealing chamber,the numerical calculation of the cavity flow in the sealing chamber under different inflow boundary layer thicknesses is carried out.The results show that three-dimensional cavity flow structures are close to being asymmetric,and the entrance pressure of the leakage path can also be affected by asymmetry;with the increase of the thickness of the boundary layer,the pressure at the cavity floor and the seal entrance decreases.Finally,the existing leakage prediction model is modified according to the distribution rule of the cavity floor and the flow properties in the leakage path. 展开更多
关键词 variable geometry inlet ceramic wafer seal vortex structure leakage rate asymmetry three-dimensional cavity flow
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Regulation Law of Turbine and Generator in Organic Rankine Cycle Power Generation Experimental System
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作者 潘利生 王怀信 史维秀 《Transactions of Tianjin University》 EI CAS 2014年第4期237-242,共6页
In the performance experiment of organic Rankine cycle power generation experimental system, the loadresistance-regulation method is one of the most important regulation methods. However, the regulation law has not be... In the performance experiment of organic Rankine cycle power generation experimental system, the loadresistance-regulation method is one of the most important regulation methods. However, the regulation law has not been clear enough to guide the experiment, which is unfavorable to the experimental research on organic Rankine cycle. In this paper the regulation law of turbine and generator by the load-resistance-regulation method is studied theoretically and experimentally. The results show that when the thermal cycle parameters keep constant, the turbine speed increases with the increase of load resistance and there is a maximum value of transmission-generator efficiency with the variation of the turbine speed; when the turbine speed and generator speed keep constant, the transmissiongenerator efficiency decreases and gradually tends to zero with the increase of load resistance. 展开更多
关键词 organic Rankine cycle (ORC) regulation law load-resistance-regulation method
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多重激波/激波干扰导致的进气道唇口处极端气动载荷的研究
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作者 林明月 杨帆 +1 位作者 胡宗民 韩桂来 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2024年第4期113-124,共12页
对于以吸气式推进为动力的高超声速飞行器来说,多重激波/激波干扰将在进气道唇口诱导极端气动载荷,对飞行器热防护系统的设计提出更高的要求.本研究对由两道入射斜激波与弓形激波干扰产生的多重激波干扰流场下的壁面气动载荷进行了详细... 对于以吸气式推进为动力的高超声速飞行器来说,多重激波/激波干扰将在进气道唇口诱导极端气动载荷,对飞行器热防护系统的设计提出更高的要求.本研究对由两道入射斜激波与弓形激波干扰产生的多重激波干扰流场下的壁面气动载荷进行了详细的理论和数值研究.伴随射流流场和双射流流场是多重激波干扰流场的两种主要模式,分别对应两道入射斜激波诱导的超声速射流由滑移线或亚声速区分隔的情况.理论分析结果表明,在相同边界条件下,双射流流场诱导的壁面峰值压力近乎伴随射流流场的两倍.为了验证理论分析结果,开展了无黏瞬态数值计算.数值计算结果验证了理论分析给出的不同干扰模式下壁面峰值压力之间的大小关系.对比理论分析和数值计算结果发现,理论预测的壁面峰值压力略低于数值计算的值.同时,本文数值验证了由两个IV型超声速射流组成的双射流流场的存在. 展开更多
关键词 激波干扰 气动载荷 进气道唇口 热防护系统 峰值压力 吸气式 超声速射流 射流流场
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Heat Recuperation for the Self-Condensing CO_(2)Transcritical Power Cycle
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作者 PAN Lisheng SHI Weixiu +2 位作者 SUN Yin SUN Yiwei WEI Xiaolin 《Journal of Thermal Science》 SCIE EI CAS CSCD 2024年第5期1630-1641,共12页
The supercritical CO_(2)Brayton cycle has potential to be used in electricity generation occasions with its advantages of high efficiency and compact structure.Focusing on a so-called self-condensing CO_(2)transcritic... The supercritical CO_(2)Brayton cycle has potential to be used in electricity generation occasions with its advantages of high efficiency and compact structure.Focusing on a so-called self-condensing CO_(2)transcritical power cycle,a model was established and four different layouts of heat recuperation process were analyzed,a without-recuperation cycle,a post-recuperation cycle,a pre-recuperation cycle and a re-recuperation cycle.The results showed that the internal normal cycle's share of the whole cycle increases with increasing the cooling pressure and decreasing the final cooled temperature.Heat load in the supercritical heater decreases with increasing the cooling pressure.From perspective of performance,the re-recuperation cycle and the pre-recuperation cycle have similar thermal efficiency which is much higher than other two layouts.Both thermal efficiency and net power output have a maximum value with the cooling pressure,except in the condition with the final cooled temperature of 31℃.Considering both the complexity and the economy,the pre-recuperation cycle is more applicable than the other options.Under 35℃of the final cooled temperature,the thermal efficiency of the pre-recuperation cycle reaches the peak 0.34 with the cooling pressure of 8.4 MPa and the maximum net power output is 2355.24 kW at 8.2 MPa of the cooling pressure. 展开更多
关键词 CO_(2)transcritical power cycle heat recuperation process self-condensing
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Experimental Investigation on the Performance of[APMIm][NTf_(2)]for Capturing CO_(2)from Flue Gas of the Cement Kiln Tail 被引量:1
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作者 PAN Lisheng SHI Weixiu +1 位作者 LI Bing WEI Xiaolin 《Journal of Thermal Science》 SCIE EI CAS CSCD 2021年第5期1780-1788,共9页
Facing the global warming trend,humanity has been paying more and more attention to the Carbon Capture,Utilization and Storage.Large amounts of CO_(2)is emitted with burning fossil fuel as well as by some special indu... Facing the global warming trend,humanity has been paying more and more attention to the Carbon Capture,Utilization and Storage.Large amounts of CO_(2)is emitted with burning fossil fuel as well as by some special industrial processes like the decomposition of calcium carbonate in a cement plant.The cement industry contributes about 7%of the total worldwide CO_(2)emissions and the CO_(2)concentration of flue gas of the cement kiln tail even exceeds 30%.Ionic liquid is considered to be an effective and potential material to capture CO_(2).In order to investigate the performance of ionic liquids for capturing CO_(2)from flue gas of the cement kiln tail,an experiment system was established and an ionic liquid,[APMIm][NTf_(2)](1-aminopropyl-3-imidazolium bis(trifluoromethylsulfonyl)imine),was tested using pure CO_(2)and simulated gas.The results showed that both physical and chemical absorption play roles while physical absorption dominates in the absorption process.Both the absorption capacity and rate decrease with raising the operating temperature.In the experiment with pure CO_(2),the absorption capacity is 0.296molCO_(2)⋅molIL−1 at 30℃ and 0.067molCO_(2)⋅molIL−1 at 70℃.Meanwhile,the ionic liquid can be regenerated for recycling without obvious changes of the absorption capacity.When the ionic liquid is used for flue gas of the cement kiln tail rather than pure CO_(2),a sharp decrease of the absorption capacity and rate was observed obviously.The absorption capacity at 30℃ dropped even to 0.038molCO_(2)⋅mol_(IL)^(−1),12.8%of that for pure CO_(2).Additionally,a natural desorption of CO_(2)from the ionic liquid was observed and affected the experimental results of the absorption capacity and the absorption-desorption rate to some extent. 展开更多
关键词 ionic liquid CO_(2)absorption Carbon Capture Utilization and Storage(CCUS) flue gas of the cement kiln tail
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Transitional wave configurations between Type Ⅲ and Type Ⅳ oblique-shock/bow-shock interactions 被引量:2
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作者 Jun PENG Shuai LI +3 位作者 Fan YANG Mingyue LIN Guilai HAN Zongmin HU 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2023年第3期96-106,共11页
The interactions of oblique/bow shock waves are the key flow phenomena restricting the design and aerothermodynamic performance of high-speed vehicles.Type Ⅲ and Type Ⅳ Shock/Shock Interactions(SSIs)have been extens... The interactions of oblique/bow shock waves are the key flow phenomena restricting the design and aerothermodynamic performance of high-speed vehicles.Type Ⅲ and Type Ⅳ Shock/Shock Interactions(SSIs)have been extensively investigated,as such interactions can induce abnormal aerodynamic heating problems in hypersonic flows of vehicles.The transition process between these two distinct types of shock/shock interactions remains unclear.In the present study,a subclass of shock/shock interaction configuration is revealed and defined as Type Ⅲa.Type Ⅲa interaction can induce much more severe aerodynamic heating than a Type Ⅳ interaction which was ever reported to be the most serious in literature.The intense aerodynamic heating observed in this configuration highlights a new design point for the thermal protection system of hypersonic vehicles.A secondary Mach interaction between shock waves in the supersonic flow path of a Type Ⅲ configuration is demonstrated to be the primary mechanism for such a subclass of shock/shock interaction configuration. 展开更多
关键词 Shock interactions Transitional configuration Aerodynamic heating Shear layer Mach interaction
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Role of oxygen species and active phase of CuCeZrO_(x) prepared with bacterial cellulose for toluene catalytic oxidation
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作者 Chenhang Zhang Chenchen Zhao +3 位作者 Running Kang Qinglan Hao Baojuan Dou Feng Bin 《Carbon Resources Conversion》 EI 2023年第4期255-261,共7页
The present study investigates the active phases and the role of oxygen species in the toluene oxidation process over CuCeZrO_(x) catalysts prepared with bacterial cellulose(BC),and compares them with nitric acid pick... The present study investigates the active phases and the role of oxygen species in the toluene oxidation process over CuCeZrO_(x) catalysts prepared with bacterial cellulose(BC),and compares them with nitric acid pickling CuCeZrO_(x)-BC(H)and CeZrO_(x)-BC catalysts.The investigation is carried out using in-situ DRIFT,O_(2)-TPD,H_(2)-TPR,XRD,and TEM techniques.Our findings suggest that dispersed CuO species on the catalyst surface,Cu-Ce-Zr-O,and Ce-Zr-O solid solutions are active for toluene oxidation over CuCeZrO_(x)-BC,with corresponding activities decreasing successively.The in-situ DRIFT results demonstrate that gaseous oxygen facilitates the chemisorption of toluene on active oxygen species,forming benzoyl oxide species and partially oxidizing the absorbed intermediates to benzyl alcohol at room temperature.Furthermore,lattice oxygen is experimentally found to be involved in the deep oxidation of toluene,and the lattice oxygen present in dispersed CuO species dominates the toluene oxidation process over CuCeZrO_(x)-BC. 展开更多
关键词 Cu-Ce-Zr catalyst Oxygen species Active phase In-situ DRIFT Catalytic oxidation
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Advances in critical technologies for hypersonic and high-enthalpy wind tunnel 被引量:10
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作者 Zonglin JIANG Zongmin HU +1 位作者 Yunpeng WANG Guilai HAN 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2020年第12期3027-3038,共12页
Hypersonic and high-enthalpy wind tunnels and their measurement techniques are the cornerstone of the hypersonic flight era that is a dream for human beings to fly faster,higher and further.The great progress has been... Hypersonic and high-enthalpy wind tunnels and their measurement techniques are the cornerstone of the hypersonic flight era that is a dream for human beings to fly faster,higher and further.The great progress has been achieved during the recent years and their critical technologies are still in an urgent need for further development.There are at least four kinds of hypersonic and high-enthalpy wind tunnels that are widely applied over the world and can be classified according to their operation modes.These wind tunnels are named as air-directly-heated hypersonic wind tunnel,light-gas-heated shock tunnel,free-piston-driven shock tunnel and detonation-driven shock tunnel,respectively.The critical technologies for developing the wind tunnels are introduced in this paper,and their merits and weakness are discussed based on wind tunnel performance evaluation.Measurement techniques especially developed for high-enthalpy flows are a part of the hypersonic wind tunnel technology because the flow is a chemically reacting gas motion and its diagnosis needs specially designed instruments.Three kinds of the measurement techniques considered to be of primary importance are introduced here,including the heat flux sensor,the aerodynamic balance,and optical diagnosis techniques.The techniques are developed usually for conventional wind tunnels,but further improved for hypersonic and high-enthalpy tunnels.The hypersonic ground test facilities have provided us with most of valuable experimental data on high-enthalpy flows and will play a more important role in hypersonic research area in the future.Therefore,several prospects for developing hypersonic and high-enthalpy wind tunnels are presented from our point of view. 展开更多
关键词 High-enthalpy flow Hypersonic wind tunnel Aerospace vehicle Aerodynamic balance Heat flux sensor Optical measurement technique
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Influence of Filling Ratio and Working Fluid Thermal Properties on Starting up and Heat Transferring Performance of Closed Loop Plate Oscillating Heat Pipe with Parallel Channels 被引量:6
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作者 SHI Weixiu PAN Lisheng 《Journal of Thermal Science》 SCIE EI CAS CSCD 2017年第1期73-81,共9页
Using ethanol or acetone as the working fluid, the performance of starting up and heat transfer of closed-loop plate oscillating heat pipe with parallel channels(POHP-PC) were experimentally investigated by varying fi... Using ethanol or acetone as the working fluid, the performance of starting up and heat transfer of closed-loop plate oscillating heat pipe with parallel channels(POHP-PC) were experimentally investigated by varying filling ratio, inclination, working fluids and heating power. The performance of the tested pulsating heat pipe was mainly evaluated by thermal resistance and wall temperature. Heating copper block and cold water bath were adopted in the experimental investigations. It was found that oscillating heat pipe with filling ratio of 50% started up earlier than that with 70% when heating input was 159.4 W, however, it has similar starting up performance with filling ratio of 50% as compared to 70% on the condition of heat input of 205.4 W. And heat pipe with filling ratio of 10% could not start up but directly transit to dry burning. A reasonable filling ratio range of 35%-70% was needed in order to achieve better performance, and there are different optimal filling ratios with different heating inputs- the more heating input, the higher optimal filling ratio, and vice versa. However, the dry burning appeared easily with low filling ratio, especially at very low filling ratio, such as 10%. And higher filling ratio, such as 70%, resulted in higher heat transfer( dry burning) limit. With filling ratio of 70% and inclination of 75°, oscillating heat pipe with acetone started up with heating input of just 24 W, but for ethanol, it needed to be achieved 68 W, Furthermore, the start time with acetone was similar as compared to that with ethanol. For steady operating state, the heating input with acetone was about 80 W, but it transited to dry burning state when heating input was greater than 160 W. However, for ethanol, the heating input was in vicinity of 160 W. Furthermore, thermal resistance with acetone was lower than that with ethanol at the same heating input of 120 W. 展开更多
关键词 closed loop with parallel channels PLATE pulsating HEAT pipe FILLING ratio working fluid thermalproperties start up HEAT transfer PERFORMANCE
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Development of the detonation-driven expansion tube for orbital speed experiments 被引量:9
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作者 JIANG Zong Lin WU Bo +2 位作者 GAO Yun Liang ZHAO Wei HU Zong Min 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2015年第4期695-700,共6页
The hypersonic flow at orbital speeds is a fundamental issue for the ground tests of aerospace crafts.The detonation-driven high-enthalpy expansion tube(JF16 expansion tube)was developed to investigate re-entry physic... The hypersonic flow at orbital speeds is a fundamental issue for the ground tests of aerospace crafts.The detonation-driven high-enthalpy expansion tube(JF16 expansion tube)was developed to investigate re-entry physics.A forward detonation cavity(FDC)driver was applied in the JF16 expansion tube to create stable driving flows.The sound speed ratio of the detonated to test gas was examined to minimize the magnitude of test flow perturbations.The acceleration section length,incident shock decay and diaphragms thickness were investigated in detail to obtain optimal operation parameters.Flow visualization was also carried out with schlieren system to demonstrate the test flow stability and the effective test duration.Experimental data showed that the test flow with a velocity of 8.3 km/s and a total enthalpy up to 40 MJ/kg can be generated successfully and the test duration lasts for more than 50μs. 展开更多
关键词 detonation driver shock-expansion tube high-enthalpy flow test flow
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Numerical investigation on flow nonuniformity-induced hysteresis in scramjet isolator 被引量:4
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作者 Tinglong HUANG Lianjie YUE +3 位作者 Shenghu MA Qifan ZHANG Peng ZHANG Xinyu CHANG 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2020年第12期3176-3188,共13页
Numerical simulation and theoretical analysis were conducted to study the hysteresis inside scramjet isolator during the reciprocating process of back pressure variation.It is revealed that only a regular reflection i... Numerical simulation and theoretical analysis were conducted to study the hysteresis inside scramjet isolator during the reciprocating process of back pressure variation.It is revealed that only a regular reflection is theoretically possible for two leading shocks when the inflow Mach number is greater than 2.0,and no hysteresis can occur in the transition between shock reflection types.Nevertheless,wall suction,gas injection,and background waves cause non-uniformity of the incoming flow and would make hysteresis possible.Besides the classical hysteresis in the transition between shock reflection,new kinds of hysteresis were found in both the deflection angle of separated boundary layer and the location of the shock train.Moreover,the occurrence of hysteresis in the deflection angle of the separated boundary layer is accompanied with the shock reflection hysteresis.In the case with background waves or gas injection,hysteresis in the starting position of leading shock was observed too.As back pressure decreases,the leading shock does not follow the same path as that as the back pressure increases,and it is anchored at the location where the background shock or the injection interacts with the leading shock.It is inferred that,if two strong adverse pressure gradient regions move towards and interact with each other,hysteresis will take place when they start to separate. 展开更多
关键词 Adverse pressure gradient Back pressure Hysteresis effects Non-uniform flow Shock train
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Optimization of the MUSCL scheme by dispersion and dissipation 被引量:3
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作者 LENG Yan LI XinLiang +1 位作者 FU DeXun MA YanWen 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2012年第5期844-853,共10页
A second-order optimized monotonicity-preserving MUSCL scheme(OMUSCL2) is developed based on the dispersion and dissipation optimization and monotonicity-preserving technique.The new scheme(OMUSCL2) is simple in expre... A second-order optimized monotonicity-preserving MUSCL scheme(OMUSCL2) is developed based on the dispersion and dissipation optimization and monotonicity-preserving technique.The new scheme(OMUSCL2) is simple in expression and is easy for use in CFD codes.Compared with the original second-order or third-order MUSCL scheme,the new scheme shows nearly the same CPU cost and higher resolution to shockwaves and small-scale waves.This new scheme has been tested through a set of one-dimensional and two-dimensional tests,including the Shu-Osher problem,the Sod problem,the Lax problem,the two-dimensional double Mach reflection and the RAE2822 transonic airfoil test.All numerical tests show that,compared with the original MUSCL schemes,the new scheme causes fewer dispersion and dissipation errors and produces higher resolution. 展开更多
关键词 MUSCL scheme monotonicity-preserving RESOLUTION dissipation/dispersion error OPTIMIZATION
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Investigation on the Pinch Point Position in Heat Exchangers 被引量:2
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作者 PAN Lisheng SHI Weixiu 《Journal of Thermal Science》 SCIE EI CAS CSCD 2016年第3期258-265,共8页
The pinch point is important for analyzing heat transfer in thermodynamic cycles. With the aim to reveal the importance of determining the accurate pinch point, the research on the pinch point position is carried out ... The pinch point is important for analyzing heat transfer in thermodynamic cycles. With the aim to reveal the importance of determining the accurate pinch point, the research on the pinch point position is carried out by theoretical method. The results show that the pinch point position depends on the parameters of the heat transfer fluids and the major fluid properties. In most cases, the pinch point locates at the bubble point for the evaporator and the dew point for the condenser. However, the pinch point shills to the supercooled liquid state in the near critical conditions for the evaporator. Similarly, it shifts to the superheated vapor state with the condensing temperature approaching the critical temperature for the condenser. It even can shift to the working fluid entrance of the evaporator or the supereritical heater when the heat source fluid temperature is very high compared with the absorb- ing heat temperature. A wrong position for the pinch point may generate serious mistake. In brief, the pinch point should be founded by the itcrativc method in all conditions rather than taking for granted. 展开更多
关键词 pinch point position heat exchanger heat transfer phase transition supercritical condition
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