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An integration method based on a novel combined flow for aerodynamic configuration of strutjet engine

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Chinese Journal of Aeronautics 2021年第9期34卷 156-167页

作者： Longsheng XUE Chuan cheng chengpeng WANG keming cheng College of Aerospace Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Key Laboratory of Unsteady Aerodynamics and Flow Control Ministry of Industry and Information TechnologyNanjing University of Aeronautics and AstronauticsNanjing 210016China Aerospace System Engineering Shanghai Shanghai 201100China

In this paper a novel design method of aerodynamic configuration is proposed to integrate forebody,strut and inlet for strutjet engine,and a model at design point of Mach number6 is generated to investigate the aerodynamic performance by both simulations and *** basic flow field employed by proposed method is a combined flow named IBB,which is combined by Internal Conical Flow A(ICFA),truncated Busemann flow I(BI)for external section,and truncated Busemann flow II(BII)for internal *** model configuration is generated by streamline tracing method from basic flow field,in which the forebody section is traced from ICFA and BI flows,and the inlet as well as strut section is traced from BII *** simulations in Mach number 4,5,and 6 demonstrate uniform starting flow fields with relatively high total pressure recovery,which agree well with experiments in wind ***,in low Mach number cases,this inlet could start at Mach number 3 while it is unstarted at Mach number 2.7;in high Mach number cases,a uniform flow could still exist in Mach number 6.5 while a relatively strong shock wave boundary layer interaction is found in cowl area of Mach number 7 case,indicating the inlet designed by proposed method works in a relatively wide Mach number range.

关键词： Airframe-propulsion integration Busemann flow Combined flow Hypersonics Wind tunnel test

Experimental investigation of influence of strake wings on self-induced roll motion at high angles of attack

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Chinese Journal of Aeronautics 2016年第6期29卷 1591-1601页

作者： Geng Xi Shi Zhiwei cheng keming College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics

The modern high performance air vehicles are required to have extreme maneuverability,which includes the ability of controlled maneuvers at high angle of attack. However, the nonlinear and unsteady aerodynamic phenomena, such as flow separation, vortices interaction, and vortices breaking down, will occur during the flight at high angle of attack, which could induce the uncommanded motions for the air vehicles. For the high maneuverable and agile air missile, the nonlinear roll motions would occur at the high angle of attack. The present work is focused on the selfinduced nonlinear roll motion for a missile configuration and discusses the influence of the strake wings on the roll motion according to the results from free-to-roll test and PIV measurement using the models assembled with different strake wings at a = 60°. The free-to-roll results show that the model with whole strake wings(baseline), the model assembled with three strake wings(Case A)and the model assembled with two opposite strake wings(Case C) experience the spinning, while the model assembled with two adjacent strake wings(Case B), the model assembled with one strake wing(Case D) and the model with no strake wing(Case E) trim or slightly vibrate at a certain "×"rolling angle, which mean that the rolling stability can be improved by dismantling certain strake wings. The flow field results from PIV measurement show that the leeward asymmetric vortices are induced by the windward strake wings. The vortices would interact the strake wings and induce crossflow on the downstream fins to degrade the rolling stability of the model. This could be the main reason for the self-induced roll motion of the model at a = 60°.

关键词： Cruciform fins High angle of attack PIV Roll motion Strake wing

The model of hydrocarbon generation and evolution for coal and macerals in the Tuha Basin

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Chinese Science Bulletin 1998年第21期43卷 1826-1830页

作者： Changyi Zhao keming cheng China Natl Petr Corp Res Inst Petr Explorat & Dev Beijing 100083 Peoples R China

By means of Py-GC, 13C NMR and fluorescent analysis, the properties of hydrocarbon generation of macerals are determined, and the evolution model of hydrocarbon generation is established for macerals and coal of the Tuha Basin. There are two stages of oil generation for the coal of the Tuha Basin, whose R+o values are 0.40-0.80 and 0.90-1.20 respectively.

关键词： Tuha Basin hydrocarbon from coal hydrocarbon generation and evolution.

Numerical and experimental investigation into hypersonic boundary layer transition induced by roughness elements

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Chinese Journal of Aeronautics 2019年第3期32卷 559-567页

作者： Hao DONG Shicheng LIU Xi GENG Song LIU Liming YANG keming cheng Department of Aerodynamics Nanjing University of Aeronautics and Aeronautics Department of Mechanical Engineering National University of Singapore

In this work, the Direct Numerical Simulation(DNS) and Oil-Film Interferometry(OFI)technique are used to investigate the hypersonic boundary layer transition induced by single and double roughness elements at Mach number 5. For single roughness, the DNS results showed that both horseshoe vortices and hairpin vortices caused by shear layer instability can affect the boundary layer instability. The generation of the near-wall unstable structure is the key point of boundary layer transition behind the roughness element. At the downstream of the roughness element, the interaction between horseshoe vortices and hairpin vortices will spread in the spanwise *** double roughness elements, the effect of the spacing between roughness elements on the transition is studied. It is found that the case of higher spacing between roughness elements is more effective for inducing transition than the lower one. The interaction between two adjacent roughness elements can suppress the evolution of horseshoe vortices in the downstream and trigger the instability of shear layer. Thus, the transition will be suppressed accordingly.

关键词： Boundary layer transition Hypersonic Direct numerical simulation (DNS) Oil-film interferometry Roughness elements

Oblique shock train motion based on schlieren image processing

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Chinese Journal of Aeronautics 2023年第3期36卷 30-41页

作者： Longsheng XUE Chuan cheng chengpeng WANG Lantian ZHANG Kang LI keming cheng College of Aerospace Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Key Laboratory of Unsteady Aerodynamics and Flow Control Ministry of Industry and Information TechnologyNanjing University of Aeronautics and AstronauticsNanjing 210016China Beijing Institute of Tracking and Telecommunication Technology Beijing 100094China Aerospace System Engineering Shanghai Shanghai 201109China

In this paper,shock train motion in a Mach number 2.7 duct is studied experimentally,and large numbers of schlieren images are obtained by a high-speed *** image processing method based on Maximum Correlation Detection(MCD)is proposed to detect shock train motion from the schlieren images,based on which the key structures,e.g.,separation positions and separation shock angles on the top and bottom walls,can be analysed in *** oscillations of the shock train are generated by rhombus and ellipse shafts at various excitation *** to the analysis of MCD results,the distributions of the frequency components of shock train oscillation generated by the two shafts are distinctly different,in which the motion generated by the ellipse shaft is much smoother;shock train motion is mainly characterized by the oscillation of separation position while the separation shock strength is not so sensitive to downstream disturbance;there is a hysteresis loop relation between the downstream pressure and separation position.

关键词： Frequency components Hysteresis loop Maximum Correlation Detection(MCD) Schlieren image processing Shock train oscillation

Drag Reduction Effect for Hypersonic Lifting-Body Vehicle with Counterflowing Jet

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Transactions of Nanjing University of Aeronautics and Astronautics 2018年第5期35卷 789-799页

作者： Dong Hao Deng Fan Xie Feng Geng Xi cheng keming College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics General Control Department Space Transportation Technology CO.Ltd. Hypervelocity Aerodynamics Institute China Aerodynamics Research and Development Center

This study takes the novel approach of using a counterflowing jet positioned on the nose of a lifting-body vehicle to explore its drag reduction effect at a range of angles of *** studies are conducted at a freestream Mach number of 8 in standard atmospheric conditions corresponding to the altitude of 40 *** effects of jet pressure ratio and flying angles of attack on drag reduction of the model are systematically *** the reverse thrust generated from the counterflowing jet,the drag on the nose at hypersonic speeds could be reduced up to 66%.The maximum lift-to-drag ratio of the model is obtained at 6°;meanwhile,the counterflowing jet produces a drag reduction of 8.8%for the whole *** addition to the nose,the counterflowing jet influences the drag by increasing the pressure drag of the model and reducing the skin friction drag of the first cone within 8°.The results show that the potential of the counterflowing jet as a means of active flow control for drag reduction is significant in the engineering application on hypersonic lifting-body vehicles.

关键词： hypersonic lifting-body counterflowing jet drag numerical simulation

Discovery and its geological significance of the mantle- derived helium in the inclusions of the Ordovician oil-bearing reservoir rocks in the Huanghua depression,China

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Science China Earth Sciences 2004年第1期47卷 23-29页

作者： ZHANG Xnobao XU Yongchang SUN Mingliang cheng keming LIU Wenhui LIXiufen MA Liyuan State Key Laboratory of Gas Geochemistry Lanzhou Instinute of Geology.Chinese Academy of SciencesLanzhou 730000China Research Institute of Explontion and Development China National Petrole um CorpontionBeijing 100083China

The values of the helium isotopes in the inclusions of the Ordovician reservoir rocks in the Kongxi buried hill belt in the Huanghua depression were first measured and the source of helium and its geological significance were investigated in comparison with those of the helium isotopes in the conclusions in the Ordovician rocks in the Ordos basin and the Tarim basin. The input of the mantle-derived helium into the inclusions in the carbonate reservoir rocks was found from the Konggu 3 well, the Konggu 4 well, and the Konggu 7 well in the Kongxi buried hill belt. The 3He/4He and R/Ra in the conclusions in the Ordovician oil-bearing reservoir rocks in the Konggu 7 well average 2.54×10-6(3) (sample quantity, the same below) and 1.82(3), respectively. The percent of the mantle-derived helium in the inclusions of the reservoir rocks in the Konggu 7 well reaches up to an average of 23.0%(3). The age of the contribution of the mantle-derived helium to the inclusions in the Kongxi buried hill belt is in the Late Triassic or the Early Tertiary. The finding of the mantle-derived helium shows that the interaction of the deep crust with mantle and the activity of deep faults occurred, the terrestrial heat flow value was high, and mantle-derived inorganic gas pools might be formed in the Kongxi buried hill belt. The finding of the mantle-derived helium in the inclusions of oil-bearing reservoir rocks also provides a new way for researching the activity of mantle-derived matter and its associated geological problems.

关键词： oil-bearing reservoir rock mantle-derived helium geological significance Huanghua depression

SEVERAL　CONSIDERATIONS　ON　HYDROCARBON　GENERATION　MECHANISM　AND　EVOLUTION　OF　CARBONATE　ROCKS

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石油勘探与开发 1996年第5期23卷 75-80页

作者： cheng keming Wang Zhaoyun(Research Institute of Petroleum Exploration and Development, CNPC, Beijing, 100083, China)

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关键词： Marine factes Oil generation of carbonate rocks Mechanism Evaluation Oil-generatingindex Thermal evolution

Vortex dynamics over an airfoil controlled by a nanosecond pulse discharge plasma actuator at low wind speed

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Plasma Science and Technology 2019年第12期21卷 85-96页

作者： Hai DU LeiWANG Wenjie KONG Zhiwei SHI keming cheng Zheng LI School of Energy and Power Engineering Xihua UniversityChengdu 610039People's Republic of China Key Laboratory of Fluid and Power Machinery Ministry of EducationXihua UniversityChengdu 610039People's Republic of China College of Aerospace Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016People's Republic of China

The vortex dynamics of flow over an airfoil controlled by a nanosecond pulse dielectric-barrierdischarge(NS-DBD) actuator is studied at a Reynolds number of 1?×?10~5 through wind tunnel experiments and numerical simulation. The numerical method is validated through comparison of the simulated and measured results regarding the effect of the discharge of an NS-DBD actuator placed on a flat plate. The simulated results show that vorticity is mainly induced by the baroclinic torque after plasma discharge, i.e. the term(■) in the equation of vorticity evolution. Both experimental and simulated results demonstrate that after the discharge of the NS-DBD actuator a series of vortices are developed in the shear layer and pull the high-moment fluid down to the wall, enhancing the mixing of internal and external flows.

关键词： plasma actuator flow control Joule heating vortex