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An artificial neural network approach for aerodynamic performance retention in airframe noise reduction design of a 3D swept wing model

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Chinese Journal of Aeronautics 2016年第5期29卷 1213-1225页

作者： tao jun Sun Gang School of Information Science and Technology Fudan University Shanghai 200433 China Department of Aeronautics & Astronautics Fudan University Shanghai 200433 China

With the progress of high-bypass turbofan and the innovation of silencing nacelle in engine noise reduction, airframe noise has now become another important sound source besides the engine noise. Thus, reducing airframe noise makes a great contribution to the overall noise reduction of a civil aircraft. However, reducing airframe noise often leads to aerodynamic performance loss in the meantime. In this case, an approach based on artificial neural network is introduced. An established database serves as a basis and the training sample of a back propagation （BP） artificial neural network, which uses confidence coefficient reasoning method for optimization later on. Then the most satisfactory configuration is selected for validating computations through the trained BP network. On the basis of the artificial neural network approach, an optimization pro- cess of slat cove filler （SCF） for high lift devices （HLD） on the Trap Wing is presented. Aerody- namic performance of both the baseline and optimized configurations is investigated through unsteady detached eddy simulations （DES）, and a hybrid method, which combines unsteady DES method with acoustic analogy theory, is employed to validate the noise reduction effect. The numerical results indicate not merely a significant airframe noise reduction effect but also excellent aerodynamic performance retention simultaneously.

关键词： Aerodynamic performanceretention Airframe noise Artificial neural network Noise reduction Slat cove filler

Simulation of 3D Flow in Turbine Blade Rows including the Effects of Coolant Ejection

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Journal of Thermal Science 2008年第2期17卷 111-115页

作者： Jian-jun LIU Bai-tao AN Yun-tao ZENG Institute of Engineering Thermophysics Chinese Academy of SciencesP. O. Box 2706 Beijing 100080 CHINA

This paper describes the numerical simulation of three-dimensional viscous flows in fir-cooled turbine blade rows with the effects of coolant ejection. A TVD Navier-Stokes flow solver incorporated with Baldwin-Lomax turbulence model and multi-grid convergence acceleration algorithm are used for the simulation. The influences of coolant ejection on the main flow are accounted by volumetric coolant source terms. Numerical results for a four-stage turbine are presented and discussed.

关键词： Numerical Simulation Air-Cooled Turbine Blade Row Coolant Ejection

Test research on sticking mechanism during hot rolling of SUS 430 ferritic stainless steel

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International Journal of Minerals,Metallurgy and Materials 2010年第5期17卷 573-578页

作者： jun-xian Liu Yong-jun Zhang Jing-tao Han School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

The sticking phenomenon during hot rolling of SUS 430 ferritic stainless steel was investigated by means of a two-disc type high-temperature wear tester. The test results indicate that sticking particles on the surfaces of high chromium steel （HiCr） and high-speed steel （HSS） rolls undergo nucleation, growth, and saturation stages. Grooves on the roll surface generated by grinding provide nucleation sites for sticking particles. The number of sticking particles on the HiCr roll surface is greater than that on the HSS roll surface. The average surface roughnesses （Ra） of HiCr and HSS rolls change from 0.502 and 0.493 μm at the initial stage to 0.837 and 0.530 μm at the saturation stage, respectively. The test further proves that the sticking behavior is strongly dependent on roll materials, and the HSS roll is more benefi- cial to prevent particles sticking compared with the HiCr roll under the same hot-rolling conditions.

关键词： ferritic steel stainless steel hot rolling sticking rolls

Superfluid λ transition in charged AdS black holes

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Science China(Physics,Mechanics & Astronomy) 2023年第12期66卷 29-36页

作者： Ning-Chen Bai Lei Li jun tao Center for Theoretical Physics College of PhysicsSichuan UniversityChengdu 610065China School of Physics and Electronic Engineering Sichuan University of Science and EngineeringYibin 643000China

We observe a superfluid λ transition in the P-V criticality of charged Ad S black holes,within a holographic extended thermodynamics that considers the variation of Newton’s constant *** calculate the critical exponents and find that they coincide with those of a superfluid transition in liquid4He and the Bose-Einstein condensation of hard-sphere Bose ***,the independence of entropy and thermodynamic volume in the holographic framework allows us to construct a well-defined Ruppeiner *** associated scalar curvature suggests that the black holes show similar microscopic interactions with the hard-sphere Bose gas,where the superfluid(condensed)phase is dominated by repulsive interactions,while the normal(gas)phase is dominated by attractive *** findings might provide us with new insights into the quantum aspect of charged Ad S black holes.

关键词： black hole thermodynamics holography superfluid phase transition Ruppeiner geometry

Effect of water injection on hydrogen generation during severe accident in PWR

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Nuclear Science and Techniques 2009年第5期20卷 312-316页

作者： tao jun CAO Xuewu School of Mechanical and Power Engineering Shanghai Jiao Tong University Shanghai 200240 China

Effect of water injection on hydrogen generation during severe accident in a 1000 MWe pressurized water reactor was studied. The analyses were carried out with different water injection rates at different core damage stages. The core can be quenched and accident progression can be terminated by water injection at the time before cohesive core debris is formed at lower core region. Hydrogen generation rate decreases with water injection into the core at the peak core temperature of 1700 K, because the core is quenched and reflooded quickly. The water injection at the peak core temperature of 1900 K, the hydrogen generation rate increases at low injection rates of the water, as the core is quenched slowly and the core remains in uncovered condition at high temperatures for a longer time than the situation of high injection rate. At peak core temperature of 2100–2300 K, the Hydrogen generation rate increases by water injection because of the steam serving to the high temperature steam-starved core. Hydrogen generation rate increases significantly after water injection into the core at peak core temperature of 2500 K because of the steam serving to the relocating Zr-U-O mixture. Almost no hydrogen generation can be seen in base case after formation of the molten pool at the lower core region. However, hydrogen is generated if water is injected into the molten pool, because steam serves to the crust supporting the molten pool. Reactor coolant system (RCS) depressurization by opening power operated relief valves has important effect on hydrogen generation. Special attention should be paid to hydrogen generation enhancement caused by RCS depressurization.

关键词： PWR 核技术研究发展 RCS

Thermodynamics and microstructures of Euler–Heisenberg black hole in a cavity

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Communications in Theoretical Physics 2023年第9期75卷 91-103页

作者： Qin Yu Qi Xu jun tao Center for Theoretical Physics College of PhysicsSichuan UniversityChengdu610065China

Euler–Heisenberg black holes with quantum electrodynamics(QED) correction are embraced by a cavity in this paper, which serves as a boundary of the black hole spacetime and contributes to the equilibrium of the system. We explore the thermodynamic properties of the black hole, including the phase transitions and phase structures. The small/large black hole phase transition occurs for a negative QED parameter, while the reentrant phase transition can be observed for a small positive QED parameter. Then the thermodynamic geometry is investigated to diagnose microscopic interactions of black hole thermodynamic systems. For the reentrant phase transition, the small black holes are dominated by repulsion for the first-order coexistence curve, while the interaction between the small black hole molecules could be attractive or repulsive for the small/large black hole phase transition.

关键词： black hole thermodynamics phase transition microstructure

Federated Learning with Blockchain for Privacy-Preserving Data Sharing in Internet of Vehicles

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China Communications 2023年第3期20卷 69-85页

作者： Wenxian Jiang Mengjuan Chen jun tao School of Cyber Science and Engineering Southeast UniversityNanjing 211189China College of Computer Science and Technology Huaqiao UniversityXiamen 361021China Key Lab of CNII MOESoutheast UniversityNanjing 211189China Purple Mountain Laboratories:Networking Communications and Security Nanjing 211111China

Data sharing technology in Internet of Vehicles(Io V)has attracted great research interest with the goal of realizing intelligent transportation and traffic ***,the main concerns have been raised about the security and privacy of vehicle *** mobility and real-time characteristics of vehicle data make data sharing more difficult in Io *** emergence of blockchain and federated learning brings new *** this paper,a data-sharing model that combines blockchain and federated learning is proposed to solve the security and privacy problems of data sharing in Io ***,we use federated learning to share data instead of exposing actual data and propose an adaptive differential privacy scheme to further balance the privacy and availability of ***,we integrate the verification scheme into the consensus process,so that the consensus computation can filter out low-quality *** data shows that our data-sharing model can better balance the relationship between data availability and privacy,and also has enhanced security.

关键词： blockchain federated learning privacy data sharing Internet of Vehicles

Quantum gravity effects on spectroscopy of Kerr-Newman black hole in gravity's rainbow

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Communications in Theoretical Physics 2022年第2期74卷 90-98页

作者： Cheng-Zhou Liu Jin-jun tao Department of Physics Shaoxing UniversityShaoxing 312000China

The effects of quantum gravity on spectroscopy for the charged rotating gravity’s rainbow are investigated in this *** utilizing an action invariant obtained from particles tunneling through the event horizon,the entropy and area spectrum for the modified Kerr-Newman black hole are *** equally spaced entropy spectrum characteristic of Bekenstein’s original derivation is ***,the entropy spectrum is independent of the energy of the test particles,although the gravity’s rainbow itself is the energy *** that,the quantum gravity effects of gravity’s rainbow has no influence on the entropy *** the other hand,due to the spacetime quantum effects,the obtained area spectrum is different from the original Bekenstein *** is not equidistant and is dependent on the horizon *** that,by analyzing the area spectrum from a specific rainbow function,a minimum area with a Planck scale is derived for the event *** this point,the area quantum is zero and the black hole radiation ***,the black hole remnant for the gravity’s rainbow is obtained from the area *** addition,the entropy for the modified Kerr-Newman black hole is calculated and the quantum correction to the area law is obtained and discussed.

关键词： black hole spectroscopy gravity’s rainbow quantum effects

Paleoenvironment reconstruction of the Middle Ordovician thick carbonate from western Ordos Basin, China

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Petroleum Science 2023年第1期20卷 48-59页

作者： Jia-Qi Yang jun-tao Zhang Zhi-Liang He tao Zhang School of Energy Resources China University of GeosciencesBeijing100083China SINOPEC Exploration and Production Research Institute Beijing100083China China Petrochemical Corporation Ltd. Beijing100728China

Reconstructing paleoenvironments has long been considered a vital component for understanding the development and evolution of carbonate *** Middle Ordovician Period is considered the archetypical greenhouse interval,and also a critical period in biological *** Middle Darriwilian isotope carbon excursion has been observed in many areas of the world and may be related to the biological explosions caused by decreases in the *** thick carbonate rocks in the fifth member of the Middle Ordovician Majiagou Formation in the Dingbei area of the Ordos Basin were chosen as an example,based on the concentration of major,trace and rare earth elements as well as C,O and Sr isotopic analyses,the paleoenvironment was *** its impact on natural gas exploration was *** results show that the seawater paleotemperature was 29℃,suboxicanoxic paleoredox conditions were observed,and the seawater paleosalinity was high.A large number of plankton in the biological explosion caused a rapid increase in the total organic carbon in carbonate rocks,which provided natural gas as supplemental source *** by early meteoric water,the dissolution of gypsum laid the foundation for high-quality reservoirs,and the residual gypsum also further preserved natural *** study provides new data for the paleoenvironment and a theoretical basis for further natural gas exploration.

关键词： Middle darriwilian isotope carbon excursion Paleoenvironment Natural gas exploration Middle ordovician Ordos basin