Archive

25 July 2023, Volume 40 Issue 4 Previous Issue    Next Issue
---
        

For Selected:

Download Citations EndNote Ris BibTeX

Toggle Thumbnails

Select

Numerical Simulation of DLR-F11 High-lift Configuration Yongyan GUO, Zhichun ZENG, Lei HE, Qianwei HE, Xueqin YAN, Zhong ZHAO 2023, 40(4): 401-415.  DOI: 10.19596/j.cnki.1001-246x.8612 Abstract ( )   HTML ( )   PDF (29391KB) ( )   In order to evaluate the simulation capability of the National Numerical Wind-tunnel CFD software PHengLEI for subsonic flows over the complex high lift configuration, the 2nd AIAA High-Lift Prediction Workshop DLR-F11 configuration is selected and simulated. The grid convergence analysis, the Reynolds number effects and the influence of the slat track as well as the flap track faring are presented. The comparison with the experimental data and reference values indicates that the results have good credibility and validity in the linear segment before stall, and the results near angle of stall agree well with reference values. With the additional components of the slat track and the flap track fairing, separated flow features on the wing can be correctly captured.

Select

Phase Field Crystal Method Study on Inhibitory Mechanism of the Growth of Kirkendall Voids During Deformation Process at the Interface of Metal Micro Interconnect Structures Wenjing MA, Jin WANG, Hui GUO, Meini LYU, Hongze ZHANG, Dongde LI 2023, 40(4): 416-424.  DOI: 10.19596/j.cnki.1001-246x.8618 Abstract ( )   HTML ( )   PDF (21865KB) ( )   In this paper, the phase field crystal method is employed to simulate and study the inhibition effect of the growth of Kirkendall voids at the interface of metal micro interconnection structures during the deformation process. The effect of bidirectional constant rate of strain on the microstructure evolution and growth kinetics of Kirkendall voids with different orientation differences at the symmetric interface of metal micro interconnects is mainly studied. The research results show that the interface of the metal micro interconnect structure has a tendency of amorphization under the action of bidirectional constant rate of strain, and the atomic mismatch and defect density of the interface increase, thereby inhibiting the growth of Kirkendall voids. The bidirectional constant rate of strain does not change the nucleation mode of Kirkendall voids in the case of symmetric interface orientation, and the nucleation modes of Kirkendall voids are all grain boundary nucleation after the system nucleation point is saturated. The Kirkendall voids are uniformly distributed at the small-angle symmetrical and large-angle symmetrical interfaces of the metal micro interconnect structure. The average size and area of Kirkendall voids increase with evolution time. The average size, area and growth index of Kirkendall voids gradually decrease with the increase of the misorientation of the small-angle symmetric interface. The average size and area of Kirkendall voids gradually decrease with the increase of the misorientation of the large-angle symmetric interface, while the growth index increases. The bidirectional constant rate of strain can effectively reduce the growth size and area of Kirkendall voids, inhibit the growth of Kirkendall voids, and improve the reliability of metal micro interconnect structures.

Select

Molecular Dynamics Simulation of Deformation Behavior of NiAl Nanowire Under Bending Zhaozhao WEI, Kai LIU, Huijun LI 2023, 40(4): 425-435.  DOI: 10.19596/j.cnki.1001-246x.8594 Abstract ( )   HTML ( )   PDF (8099KB) ( )   To date most studies of metallic nanowire are mainly focused on the atomistic mechanisms in tensile or compressive deformation, while little attention has been paid to the bending deformation behavior of nanowire. A full understanding of the bending properties of nanowire, however, can help improve the reliability and service life of nanodevices, particularly for the flexible and stretchable systems. In this work, we investigate the bending behavior of a NiAl nanowire on different loading conditions using molecular dynamics simulations. The NiAl nanowire under bending loads was shown to undergo elastic and plastic deformation. The bending modulus during elastic deformation was determined to be around 48.9 GPa, showing good agreement with the reported calculations. The plastic deformation, independent of temperature, strain rate and size, was produced by stress-induced martensitic transformation from B2 to L10 phases, leading to good bending ductility even under low temperature and high strain rate. Moreover, the NiAl nanowire exhibits superelasticity under bending with total recovery of deformation, which is driven by the reverse transformation from the L10 to B2 phases.

Select

Evolutions of Asymmetric Multiple-X Lines Reconnection with Influences of Guiding Field Lingjie LI 2023, 40(4): 436-442.  DOI: 10.19596/j.cnki.1001-246x.8627 Abstract ( )   HTML ( )   PDF (8947KB) ( )   Influences of guiding field on asymmetry multiple-X lines reconnection are investigated using two-dimensional compressible resistive MHD models. It is found that the external guiding field By0 can promote multiple-X lines reconnection occur during the asymmetry reconnection processes for the case of multiple-X lines reconnection occur without the guidance field. Multiple-X lines reconnection occurs faster as By0 becomes larger. For the case that there is no multiple-X lines reconnection appeared without a guiding field, the secondary magnetic island will be induced when including a certain guiding field. Further study found that multiple-X lines reconnection could not be induced when the guiding field becomes large enough. Both cases show that the guiding field can promote or induce the occurrence of the multiple-X lines reconnection, and there is a threshold value. When By0 exceeded the threshold value, the promoting or inducing effect becomes weak. The results here can be useful for understanding some observed data, even for the multiple-X lines reconnection observations.

 

Select

Effect of Magnetization Pinning on Spin Wave Modes in Spin Wave Conduit of Yttrium Iron Garnet Shizhu QIAO, Xiaobo WANG, Guoquan YANG 2023, 40(4): 443-452.  DOI: 10.19596/j.cnki.1001-246x.8608 Abstract ( )   HTML ( )   PDF (12669KB) ( )   The effect of magnetization pinning at corners on spin wave dynamics in a spin wave conduit of yttrium iron garnet is investigated by using micromagnetic simulation. The simulation results reveal that two-magnon scattering brought on by this magnetization pinning scatters spin waves in various directions, resulting in a more dispersed spin wave pattern in k space. The evolution patterns of spin waves suggest that spin waves modes resonate at different applied magnetic fields, and magnetization pinning-induced magnon scattering brings the resonance fields of spin wave modes closer together. In addition, this magnon scattering modifies the intensity of spin wave modes at resonance, by more than 40 percent, for example, though altering their relaxation rate. By lengthening spin wave conduits the effects of this magnetization pinning could be limited, which may improve the performance of spin wave conduits.

Select

Spectral Characteristics and Dissociation Characteristics of Monofluorodichloroethane Molecule in External Electric Field Qifan LIU, Haokui YAN, Abulimiti BUMALIYA, Mei XIANG, Huan AN, Jingyan ZHENG 2023, 40(4): 453-460.  DOI: 10.19596/j.cnki.1001-246x.8591 Abstract ( )   HTML ( )   PDF (5761KB) ( )   Using density functional theory at B3LYP/6-311+G(d, p) level, the spectral characteristics and dissociation characteristics of (-0.05~0.05 a.u.) monofluorodichloroethane molecules under different applied electric fields are studied. It includes the ground state structure, total energy, dipole moment, highest occupied orbital energy level, lowest vacant orbital energy level, energy gap, infrared spectrum, Raman spectrum, UV-visible absorption spectrum and potential energy curve of between C and Cl bond under electric field. In the y-axis direction, with the increase of negative electric field, the distance between C atom and Cl nucleus increases, the highest occupied orbital energy level decreases, the total energy of the system, the lowest unoccupied orbital energy level and the energy gap increase first and then decrease, and the dipole moment decreases first and then increases. The applied electric field can affect the absorption intensity and absorption peak frequency of the infrared spectrum, Raman spectrum and UV-visible light absorption spectrum of monofluorodichloroethane. The infrared spectrum, Raman spectrum and UV-visible light absorption spectrum appear red shift or blue shift with the change of electric field. The barrier between C and Cl atoms gradually decreases with the increase of negative electric field and reaches -0.05 a.u. When C atom breaks with one of the Cl atoms, when a C—Cl bond in the molecule breaks, the applied strength is -0.04 a.u. When the electric field of, another C—Cl bond is broken, and the molecule is gradually dissociated under the electric field. The research results improve the theoretical data of the influence of external electric field on mono-fluorodichloroethane molecules.

Select

Discrete Alfvén Eigenmodes in High Performance Scenarios with ITBs on EAST Wanpo ZHU, Shuanghui HU, Xuefeng OUYANG, Sijie OUYANG, Yuandan LAN 2023, 40(4): 461-472.  DOI: 10.19596/j.cnki.1001-246x.8636 Abstract ( )   HTML ( )   PDF (10224KB) ( )   In this paper, the instability of the discrete Alfvén eigenmodes (αTAEs, where α denotes a parameter of plasma pressure gradient) are simulated in the high performance plasma with internal transport barriers (ITBs) on the EAST. The simulation results show that there is an abundance of αTAEs on EAST, and it mainly locates in the core region within the ITB foot, where the temperature or the density gradient varies abruptly. Because the ITBs observed in the EAST are relatively localized and close to the core, the distribution of αTAEs in the radial radius is narrow.In the high performance scenario with localized magnetic shear reversal, the ITB region is closer to the plasma edge, the αTAEs locate in a larger radial region. However, in the ITB region, due to the strong negative magnetic shear, the αTAEs are only found near the ITB foot; the αTAEs frequency decreases as the pressure gradient decreases closer to the ITB foot. In addition, the αTAEs in the scenarios with localized magnetic shear reversal on the DIII-D and China Fusion Engineering Test Reactor (CFETR) are also compared, and it is similar to that on EAST, where the αTAEs do not exist in the strong magnetic shear region. The simulations on CFETR show that there are higher frequencies αTAEs in the core region and more abundant αTAEs are excited into unstable modes by energy particles.

Select

Transmission Line Computation Model for Metal-Insulator-Metal Plasmonic Waveguide Connected with Stub-shaped Resonator Jianfei GUAN, Tao CHEN 2023, 40(4): 473-481.  DOI: 10.19596/j.cnki.1001-246x.8629 Abstract ( )   HTML ( )   PDF (6555KB) ( )   Based on the well-known analogy of propagation modes between metal-insulator-metal (MIM) waveguides and microwave transmission lines, an improved transmission line model (ITLM) have been proposed to describe reflection coefficients of a MIM waveguide stub. The Fresnel formula have been employed to predict the phase shift resulting from the reflection of surface plasmon polaritons (SPP) from the stub's end, which allows the ITLM to describe the influence of the stub-shaped resonators arranged in the side-coupled configuration on the transmission spectrum of main waveguide more precisely. In this paper, the improved transmission line models of MIM waveguide side coupled to single stub and double-side symmetric stubs have been proposed, and the predicted transmission spectrum by the ITLM is well agreed with simulation results of the finite element method. Specifically, transmission minimum predicted by ITLM is more close to that calculated by numerical methods than the classical transmission line model. Moreover, it is verified that ITLM possess much higher efficiency in calculating the transmission spectrum of the MIM waveguide connected with stub-shaped resonators than the finite element method employed in this work.

Select

Effects of Secondary Electron Emission Coefficient on the Plasma Wall Potential with Super-extensive Electrons Xiaoyun ZHAO, Bingkai ZHANG, Shigang LI, Yijia TANG 2023, 40(4): 482-489.  DOI: 10.19596/j.cnki.1001-246x.8611 Abstract ( )   HTML ( )   PDF (1059KB) ( )   A one-dimensional model is used to study the effects of secondary electron emission coefficient on plasma wall potential with Maxwell distribution of primary electrons and partially super-extensive electrons. By numerical simulation, the results show that when the secondary electron emission coefficient of the wall is small, the wall potential decreases with the increase of the concentration ratio, the temperature ratio and super-extensive parameter of the super-extensive electrons to the primary electrons. The wall potential increases with the increase of the concentration ratio, the temperature ratio and super-extensive parameter of the super-extensive electrons to the primary electrons.

Select

Firing Activity of Memristive Izhikevich Neural Network Under Electromagnetic Field Coupling Limei LU, Duqu WEI 2023, 40(4): 490-499.  DOI: 10.19596/j.cnki.1001-246x.8582 Abstract ( )   HTML ( )   PDF (22929KB) ( )   The electrophysiological environment inside and outside the neuron will generate an electric field due to the transmission and concentration of ions, which will then excite the magnetic field, and the formed electromagnetic field will work together to regulate the electrical activity of the neuron. Therefore, considering the influence of electromagnetic field, this paper introduces electric field variables and magnetic flux variables into the traditional neuron model and uses electrical synaptic coupling to construct neuron network, then studies the collective dynamic behavior of memristive Izhikevich neural network under electromagnetic field coupling. Through numerical simulation, it is found that the increase of the electrical synaptic coupling value will change the firing pattern of neurons, and make the neural network achieve synchronization. Increasing the coupling value of magnetic field can increase the firing activity of neurons, and have a beneficial effect on the network synchronization, while increasing the electric field can inhibit the electrical activity of neurons. In addition, when electrical synaptic and magnetic field coupling work together, the smaller value of the magnetic field coupling, the more effective the electrical synaptic coupling can promote network synchronization. The electric field is more effective in suppressing electrical activity given the strength of the electrical synaptic coupling. The findings are expected to provide new perspectives for understanding signal encoding and transmission in the nervous system.

Select

A Chessboard Model for Simultaneous Optimization of Mass Exchange Networks Zhikang YI, Guomin CUI, Zhiqiang ZHOU, Yuan XIAO, Siheng XIONG, Xiubao MA 2023, 40(4): 500-510.  DOI: 10.19596/j.cnki.1001-246x.8566 Abstract ( )   HTML ( )   PDF (4163KB) ( )   A chessboard model of mass exchange networks (CBM-MEN) is proposed. The CBM-MEN has characteristics of compact structure, simple expression, and flexible stream arrangement. A phase of eliminating mass exchanger is added to a random walk algorithm with compulsive evolution. The algorithm is combined with the chessboard model. During optimization process, the mass exchange load is used as an optimization variable. Finally, the simultaneous optimization method is applied to two cases, recovery of copper from liquid effluents of an etching plant and dephenolization of aqueous wastes. The total annual cost of optimized structures is decreased by 5.8‰ and 1.6‰, respectively. It shows that the method has good search domain and search capability.

Select

Research on Salt Dome Identification Algorithm Based on Image Segmentation Li LOU, Fengxia ZHANG, Boxun HAN 2023, 40(4): 511-518.  DOI: 10.19596/j.cnki.1001-246x.8588 Abstract ( )   HTML ( )   PDF (4877KB) ( )   Salt dome identification is of great significance for oil and gas exploration. Many important resources are located near the salt dome, but manual identification is time-consuming, labor-intensive and subjective. To solve this problem, this paper proposes a salt dome identification method based on image segmentation to realize automatic and high-precision identification of salt dome. The method is based on the original U-Net network for migration learning. The SENet loaded with the pre training model is used as the backbone network of the encoder. The salt dome features in the seismic image are enhanced, the important features in the image are highlighted, and the unimportant features are suppressed. In addition, according to the characteristics of salt dome segmentation task, Lovasz Softmax loss function is introduced for standardization experiment to improve the segmentation effect of salt dome boundary. The experimental results on the data set provided by the TGS salt dome identification challenge show that the method has finally achieved 97.5% Accuracy and 87.26% IoU on the test set. Compared with UNet and USKNet, the IoU has increased by 12.59 percentage points and 1.6 percentage points, respectively, reflecting the effectiveness and universality of this method.

Select

Chaos Prediction of Motor System Based on NG-RC Wenxin CAO, Duqu WEI 2023, 40(4): 519-526.  DOI: 10.19596/j.cnki.1001-246x.8615 Abstract ( )   HTML ( )   PDF (6317KB) ( )   In this paper, chaos prediction of motor system is realized based on the next generation reservoir computing, and unknown variable data can be predicted based on existing data. Compared with the traditional reservoir computing, the next generation reservoir computing uses direct connection of data itself and requires smaller training data sets. And the next generation reservoir computing avoids the complex parameter optimization calculation of traditional reserve pool network through high-dimensional conversion, which greatly improves the computing speed. This research result provides a new research idea for chaotic prediction of motor systems.