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High-fidelity simulation of blade vortex interaction of helicopter rotor based upon TENO scheme

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Chinese Journal of Aeronautics 2023年第10期36卷 275-292页

作者： Wei BIAN Guoqing zhao Xi CHEN bo WANG Qijun zhao National Key Laboratory of Rotorcraft Aeromechanics College of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China

Numerical simulation methods for unsteady vortex field of helicopter rotor with high resolution and low dissipation TENO8-AA primitive variables reconstruction schemes are established based on moving-embedded grid and Navier-Stokes ***,the Targeted Essentially Non-Oscillatory(TENO)scheme are developed by employing ENO-like candidate stencil selection strategy,and the candidate stencil is adopted with optimal weight in smooth region while it is discarded completely in discontinuous region,which reduces the dissipation and dispersion errors and approaches better spectral ***,the aerodynamic characteristics of Helishape-7A model rotor in Blade Vortex Interaction(BVI)state and the flowfield of Lynx rotor in hover are simulated,which validates that the blade tip vortex trajectory with larger wake age and more details of vortex can be captured by TENO8-AA scheme with only a quarter of grid points and half time comparing to WENO-JS ***,the simulation accuracy of thrust coefficient is improved by up to 36%.Finally,the analyses for BVI and aeroacoustic characteristics of Operational Loads Survey(OLS)rotor are conducted,and the different forms of interaction mechanism are explored,such as oblique and parallel *** results indicate that TENO scheme not only ensures the resolution of simulation in discontinuous region,but also minimizes the numerical dissipation in smooth region dominated by blade tip ***,the acoustic pressure peak prediction error of rotor in BVI state is significantly reduced to 5.6%and 0.8%at two microphone locations,respectively.

关键词： Aeroacoustics Blade tip vortex Blade vortex interaction Helicopter rotor TENO scheme

Direct constructions and proofs for CCA secure(LR)IBE with dual system encryption

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Science China(Information Sciences) 2017年第11期60卷 306-308页

作者： Yi zhao bo YANG School of Computer Science Shaanxi Normal University State Key Laboratory of Information Security Institute of Information EngineeringChinese Academy of Sciences

Dear editor,In the past decade,the development of identitybased cryptography has been highly *** to its superiority in the task of key distribution as well as its expressive ability,many related techniques have been made industrial *** and boyen[1]developed the first secure construction(BB1)in the standard model under a weakened adaptive notion called selective-ID *** then,ongoing research has contributed to enhancing the performance of IBE schemes in the standard model.

关键词： IBE CCA Direct constructions and proofs for CCA secure

Influence factors on natural frequencies of composite materials

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Frontiers of Mechanical Engineering 2020年第4期15卷 571-584页

作者： bo WANG Feng zhao Zixu zhao Kunpeng XU School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819China Key Laboratory of Vibration and Control of Aero-Propulsion Systems(Ministry of Education) Northeastern UniversityShenyang 110819China

Compared with traditional materials, composite materials have lower specific gravity, larger specific strength, larger specific modulus, and better designability structure and structural performance. However, the variability of structural properties hinders the control and prediction of the performance of composite materials. In this work, the Rayleigh–Ritz and orthogonal polynomial methods were used to derive the dynamic equations of composite materials and obtain the natural frequency expressions on the basis of the constitutive model of laminated composite materials. The correctness of the analytical model was verified by modal hammering and frequency sweep tests. On the basis of the established theoretical model, the influencing factors, including layers, thickness, and fiber angles, on the natural frequencies of laminated composites were analyzed. Furthermore, the coupling effects of layers, fiber angle, and lay-up sequence on the natural frequencies of composites were studied. Research results indicated that the proposed method could accurately and effectively analyze the influence of single and multiple factors on the natural frequencies of composite materials. Hence, this work provides a theoretical basis for preparing composite materials with different natural frequencies and meeting the requirements of different working conditions.

关键词： composite material hammering and frequency sweep test structural parameter natural frequency

SIV:A Structural Integrity Verification Approach of Cloud Components with Enhanced Privacy

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Tsinghua Science and Technology 2019年第5期24卷 557-574页

作者： bo zhao Peiru Fan Pengyuan zhao Mingtao Ni Jinhui Liu School of Cyber Scienee and Engineering. Wuhan University Wuhan 430072 China. School of Computer Science Shaanxi Normal University Xi'an 710062 China

Private data leakage is a threat to current integrity verification schemes of cloud components. To address this issue, this work proposes a privacy-enhancing Structural Integrity Verification (SIV) approach. It is made up of three processes: proof organization, proof transformation, and integrity judgement. By introducing a Merkle tree technique, the integrity of a constituent part of a cloud component on a node is represented by a root value. The value is then masked to cipher texts in proof transformation. With the masked proofs, a structural feature is extracted and validated in an integrity judgement by a third-party verification provider. The integrity of the cloud component is visually displayed in the output result matrix. If there are abnormities, the corrupted constituent parts can be located. Integrity is verified through the encrypted masked proofs. All raw proofs containing sensitive information stay on their original nodes, thus minimizing the attack surface of the proof data, and eliminating the risk of leaking private data at the source. Although some computations are added, the experimental results show that the time overhead is within acceptable bounds.

关键词： integrity verification cloud components structural feature privacy

Dielectronic Recombination for the Self-Consistent-Field Average Ions

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Chinese Physics Letters 1996年第9期13卷 664-667页

作者： zhao Li-bo LI Shi-chang Institute of Applied Physics and Computational Mathematics Beijing 100088

A self-consistent-field theoretical method has been developed to treat the dielectronic recombination(DR)of average ions with *** on the method,the rate coefficients for DR into a special state can be *** an example,t... 详细信息

关键词： population method presented

Recent progress in solution assembly of 2D materials for wearable energy storage applications

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Journal of Energy Chemistry 2021年第11期30卷 27-42,I0002页

作者： Dong Zhou Liang zhao bo Li Department of Mechanical Engineering Villanova UniversityVillanovaPA 19085USA Hybrid Nano-Architectures and Advanced Manufacturing Laboratory Villanova UniversityVillanovaPA 19085USA

Wearable energy storage devices are desirable to boost the rapid development of flexible and stretchable electronics. Two-dimensional (2D) materials, e.g., graphene, transition metal dichalcogenides and oxides, and MXenes, have attracted intensive attention for flexible energy storage applications because of their ultrathin 2D structures, high surface-to-volume ratio, and unique physical/chemical properties. To achieve commercialization of 2D material-based wearable energy storage devices (2DM-WESDs), scalable and cost-efficient manufacturing is a critical challenge. Among existing manufacturing technologies, solution-based assembly strategies show strong potential to achieve low-cost and scalable production. A timely review of the recent progress in solution-based assembly strategies and the resultant 2DM-WESDs will be meaningful to guide the future development of 2DM-WESDs. In this review, first, a brief introduction of exfoliation and solution preparation of 2D material species from bulk materials is discussed. Then, the solution-based assembly strategies are summarized, and the advantages and disadvantages of each method are compared. After that, two major categories of 2DM-WESDs, supercapacitor and battery, are discussed, emphasizing their state-of-the-art energy storage performances and flexibilities. Finally, insights and perspectives on current challenges and future opportunities regarding the solution assembly of 2DM-WESDs are discussed.

关键词： 2D materials Solution assembly Wearable Energy storage

Imaging of the Space-time Structure of a Vortex Generator in Supersonic Flow

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Chinese Journal of Aeronautics 2012年第1期25卷 57-63页

作者： WANG Dengpan XIA Zhixun zhao Yuxin WANG bo zhao Yanhui Science and Technology on Scramjet Laboratory National University of Defense TechnologyChangsha 410073China

The fine space-time structure of a vortex generator （VG） in supersonic flow is studied with the nanoparticle-based planar laser scattering （NPLS） method in a quiet supersonic wind tunnel. The fine coherent structure at the symmetrical plane of the flow field around the VG is imaged with NPLS. The spatial structure and temporal evolution characteristics of the vortical structure are analyzed, which demonstrate periodic evolution and similar geometry, and the characteristics of rapid movement and slow change. Because the NPLS system yields the flow images at high temporal and spatial resolutions, from these images the position of a large scale structure can be extracted precisely. The position and velocity of the large scale structures can be evaluated with edge detection and correlation algorithms. The shocklet structures induced by vortices are imaged, from which the generation and development of shocklets are discussed in this paper.

关键词： vortex generator nanoparticle-based planar laser scattering vortical structure evolution characteristic shocklet

Calculation of Hugoniot properties for shocked nitromethane based on the improved Tsien's EOS

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Acta Mechanica Sinica 2010年第3期26卷 365-370页

作者： bo zhao Ji-Ping Cui Jing Fan Key Laboratory of High Temperature Gas Dynamics Institute of Mechanics Chinese Academy of SciencesBeijing 100190 China

We have calculated the Hugoniot properties of shocked nitromethane based on the improved Tsien＇s equa- tion of state （EOS） that optimized by ＂exact＂ numerical molecular dynamic data at high temperatures and pressures. Comparison of the calculated results of the improved Tsien＇s EOS with the existed experimental data and the direct simu- lations show that the behavior of the improved Tsien＇s EOS is very good in many aspects. Because of its simple analytical form, the improved Tsien＇s EOS can be prospectively used to study the condensed explosive detonation coupling with chemical reaction.

关键词： Equation of state High pressures andtemperatures Shocked nitromethane Hugoniot properties

Theoretical analysis of the coupling between Feshbach states and hyperfine excited states in the creation of 23Na40K molecule

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Chinese Physics B 2020年第2期29卷 218-223页

作者： Ya-Xiong Liu bo zhao Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics University of Science and Technology of ChinaHefei 230026China Shanghai Branch CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum PhysicsUniversity of Science and Technology of ChinaShanghai 201315China

We present an intensive study of the coupling between different Feshbach states and the hyperfine levels of the excited states in the adiabatic creation of 23Na40K ground-state *** use coupled-channel method to calculate the wave function of the Feshbach molecules,and give the short-range wave function of triplet *** energies of the hyperfine excited states and the coupling strength between the Feshbach states and the hyperfine excited states are *** results can be used to prepare a specific hyperfine level of the rovibrational ground state to study the ultracold collisions involving molecules.

关键词： Feshbach resonance stimulated Raman adiabatic passage ultracold molecule