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30 November 2017, Volume 51 Issue 12 Previous Issue    Next Issue

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Modeling of the Reduced-Optimized Chemical Kinetic Mechanism for RP-3 Aviation Kerosene Surrogate Fuel HUANG Wenxuan,CHEN Fang,LIU Hong,HUANG Xiaobin 2017, 51 (12):  1409-1414.  doi: 10.16183/j.cnki.jsjtu.2017.12.001 Abstract ( 1057 )   Save Since traditional chemical mechanism reduction method could not take in account of both accuracy and computation amount, CROM (Combined Reduction and Optimization Method) was proposed to solve this problem. CROM was successfully executed to develop 47 species and 94 reactions for the optimized mechanism for three-component RP-3 aviation kerosene surrogate fuel. Combustion in shock tube and counterflow flame was simulated using the optimized mechanism, and the results were compared with the experimental and calculated value in the literature. The results show that the optimized mechanism can accurately predict the ignition delay time and laminar flame speed. The optimized mechanism owns less scheme and high computation efficiency, and is of great engineering application value. References | Related Articles | Metrics

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Model Updating Analysis of Structural Dynamic Problem Based on Multi-Level Weight Coefficients CHEN Luyun,YANG Nian 2017, 51 (12):  1415-1421.  doi: 10.16183/j.cnki.jsjtu.2017.12.002 Abstract ( 860 )   Save In the present article, a modified finite element model updating method for structural dynamic response was proposed. The model updating based on natural frequency and dynamic response parameter was established, respectively. The optimization formulation for dynamic model updating was deduced by consideration of frequency factor and dynamic response factor. Based on the multi-parameter factors and multi-level factors for the dynamic characteristics of the complex structure, the analytical hierarchy process approach was introduced to define of the weight coefficients. According to the dynamic model updating problem, the multi-hierarchy weight coefficient problem was presented, and the normalized model was established. Finally, a ship mounting structure was taken as an example, and its numerical analysis was carried out. The results demonstrated that the proposed method has provided a new approach to analyze the dynamic model updating problem of complex structure. References | Related Articles | Metrics

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Catalytic Capacity of Transition Metal Phthalocyanine Complexes Based on Density Functional Theory ZHOU Su,JIANG Zhen,DE LILE J R 2017, 51 (12):  1422-1427.  doi: 10.16183/j.cnki.jsjtu.2017.12.003 Abstract ( 923 )   Save The research on non-platinum (Non-Pt) materials as proton exchange membrane fuel cell (PEMFC) catalyst is one of the most important activities in the corresponding fields. Transition metal phthalocyanines (TMPcs) are thought to be potential to replace Pt. Thus, the energies of absorbing O2, OH, H2O2 and H2O on FePc, CoPc, CuPc, NiPc and TiPc surfaces are investigated. It is found that the overall performance of TMPcs as catalyst is related to oxygen adsorption energy, and the higher the value is, the better the overall performance as catalyst. Based on density functional theory (DFT), the TiPc’s adsorption energies are calculated with the following results. First, the oxygen adsorption capacity of TiPc is stronger than that of the other TMPcs. Second, the O2 adsorption energy of TiPc is higher than its OH adsorption energy. Finally, the O2 adsorption energy of TiPc is also much higher than its H2O adsorption energy. Based on the analysis of TMPcs reaction mechanism, the change of Gibbs free energy of TiPc in oxygen reduction reaction is compared with that of FePc, CoPc and Pt. The theoretical calculation shows that TiPc has no obvious energy barrier during the reaction. Based on the above results, it is estimated that the oxygen reduction capacity of TiPc can be better than that of the other TMPcs and Pt, and can be used as a catalyst for PEMFC. References | Related Articles | Metrics

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Research on the Mechanism of Moderately Thick Water-Backed Metal Plates Penetrated by High-Velocity Blunt-Nosed Projectiles CHEN Changhai1,HOU Hailiang1,ZHANG Yuanhao1,ZHU Xi1,DAI Wenxi2 2017, 51 (12):  1428-1434.  doi: 10.16183/j.cnki.jsjtu.2017.12.004 Abstract ( 966 )   Save To explore the mechanism of moderately thick water-backed metal plates penetrated by high-velocity blunt-nosed projectiles, the whole process of high-velocity blunt-nosed projectiles perpendicularly penetrating moderately thick water-backed metal plates was divided into three consecutive phases, i.e., compression and mushrooming phase, shearing and compression phase and shearing and intruding phase, according to different mechanical states and energy-dissipative mechanisms during penetrating process together with the high-velocity penetration-resistant characteristic of moderately thick water-backed metal plates. Based on the 3-phase penetration mechanism, an analytical model was established to calculate instantaneous residual velocities of the blunt-nosed projectiles perforating moderately thick water-backed metal plates. By adopting the model, the instantaneous residual velocities of cubic projectiles with 3.3g penetrating 5mm-thick water-backed steel plates were computed. Good agreements were obtained between the theoretical values and experimental results as well as corresponding numerical results. Due to the consideration for several phenomena, such as the dynamic supporting action and kinetic energy dissipation effort of the water medium behind the target, the 3-phase model can be employed to more reasonably predict the instantaneous residual velocities of the blunt-nosed projectiles perforating moderately thick water-backed metal plates, and therefore, has theoretical and engineering application value. References | Related Articles | Metrics

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The Reconstruction of Digital Holography Based on Iterative De-Noising Shrinkage-Thresholding Algorithm BAI Caijuan1,LIU Jing1,JIANG Xiaoyu2,ZHANG Guoxian1,HUANG Kaiyu1 2017, 51 (12):  1435-1442.  doi: 10.16183/j.cnki.jsjtu.2017.12.005 Abstract ( 1175 )   Save A novel algorithm, namely iterative de-noising shrinkage-thresholding (IDNST) algorithm, is presented to reconstruct the original image from digital holography in a compressed sensing framework. The proposed algorithm can reduce the computational complexity in classical digital holography process, as well as the data in transmission. The proposed algorithm adopts two new factors, i.e., the de-noising iteration factor and the shrinkage factor of regularization. Furthermore, the proposed algorithm obtains a new iterative value using the previously updated iterative values, the iteration factor and the shrinking regularization parameter. This improves the convergence speed and the reconstruction accuracy. Simulation results show that the original image can be reconstructed from the digital hologram perfectly with high probability by the IDNST algorithm. References | Related Articles | Metrics

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Maximum Entropy Method for Solving Fokker-Planck Equations Driven by Fractional Brownian Motion PENG Linga，XIE Fujib 2017, 51 (12):  1443-1447.  doi: 10.16183/j.cnki.jsjtu.2017.12.006 Abstract ( 795 )   Save In this paper, we consider the maximum entropy method for solving Fokker-Planck equations driven by fractional Brownian motion (FBM). The approximate solution of probability density function has been derived, and the numerical experiments on Ornstein-Uhlenbeck (O-U) process driven by FBM are presented to confirm our theoretical results. References | Related Articles | Metrics

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Phosphoproteomics of Pseudomonas aeruginosa SJTD-1 XING Xuejiaoa，LI Wentingb，HOU Jinglic，LIU Jianhuab 2017, 51 (12):  1448-1455.  doi: 10.16183/j.cnki.jsjtu.2017.12.007 Abstract ( 731 )   Save Instrumental Analysis Center, Shanghai Jiao Tong University, Shanghai 200240, China) Abstract： SJTD-1, a novel kind of Pseudomonas aeruginosa, is isolated from oil-contaminated soil. It has been demonstrated that this bacterium can metabolize n-alkanes (C12 to C30) in our laboratory. Pseudomonas aeruginosa SJTD-1 may have wide applications in oil pollution. In our study, phosphopeptides of Pseudomonas aeruginosa SJTD-1 were enriched by TiO2 and 13 phosphopeptides from 12 phosphoproteins were first characterized by nano-liquid chromatography-mass spectrometry (nano LC-MS). Among these identified phosphoproteins, 7 phosphoproteins were first discovered in Pseudomonas aeruginosa. We found most of these identified phosphoproteins were related to DNA replication, material transport and energy metabolism. This is the first analysis of phosphorylation proteomic in Pseudomonas aeruginosa SJTD-1, and our results provide evidence for further research on DNA replication, material or energy metabolism and membrane transport in Pseudomonas aeruginosa. References | Related Articles | Metrics

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The Brain-Computer Interface Using Functional Near-Infrared Spectroscopy JIAO Xuejun,ZHANG Zhen,JIANG Jin,WANG Chunhui,YANG Hanjun,XU Fenggang,CAO Yong,FU Jiahao 2017, 51 (12):  1456-1463.  doi: 10.16183/j.cnki.jsjtu.2017.12.008 Abstract ( 943 )   Save This paper explored the feasibility of recognizing motor imagery (MI) and motor execution (ME) in the same motion, as well as the affection of prefrontal cortex on the classification accuracy of MI and ME. We measured changes of oxygenated hemoglobin HbO2 and deoxygenated hemoglobinon (Hb) on prefrontal cortex (PFC) and motor cortex (MC) when 15 subjects performed hand extension and finger tapping tasks. Then mean, slope, quadratic coefficient and approximate entropy features were extracted from HbO2 as the input of support vector machine. With the four-class classifiers of brain-computer interface using functional near-infrared (fNIRS-BCI spectroscopy), 87.65% and 87.58% classification accuracy were realized corresponding to hand extension and finger tapping tasks. The classification accuracy increased significantly after adding PFC fNIRS signal, and greater increase emerged in finger napping than hand extension. In conclusion, it is effective for fNIRS-BCI to recognize MI and ME in the same motion, and the PFC region is sensitive in the four-class fNIRS-BCI classifiers. References | Related Articles | Metrics

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Study on Propagation Characteristics of Low Frequency Acoustic Signal in Shallow Water Environment ZHU Hanhao1，ZHENG Guangxue1，ZHANG Haigang2，ZHENG Hong1，LIN Jianmin1，TANG Yunfeng1 2017, 51 (12):  1464-1472.  doi: 10.16183/j.cnki.jsjtu.2017.12.009 Abstract ( 1215 )   Save Targeted at the issue of low-frequency acoustic propagation in typical shallow water environment, and based on specific example simulation, the research of the influence law of different ocean environment parameters on the acoustic signal propagation at low frequency is performed through taking fast field method (FFM) as the modeling approach and acoustic energy flow as the research subject. The results have been proved that the transmission loss of vertical particle velocity is larger than that of pressure and horizontal particle velocity. Ocean environment parameters, sound source parameters and geo acoustic parameters all have important effects on acoustic signal propagation at low frequency, and the sound velocity in ocean bottom exerts the most significant influence. References | Related Articles | Metrics

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Differential Game Trajectory Optimization Based on Receding Horizon Control for Multiple Constraints Tracking Systems with Additive Disturbance CHENG Ruifeng1,LIU Weidong1,GAO Li’e1,KANG Zhiqiang2 2017, 51 (12):  1473-1479.  doi: 10.16183/j.cnki.jsjtu.2017.12.010 Abstract ( 790 )   Save The problem of underwater tracking with multiple constraints in the complex ocean environment is formulated as a nonlinear differential games based on receding horizon control. The tracking relative motion model of underwater tracking is established using the agent homing detection information, on which the process constraints are developed. Using the relative motion information as state variable, the differential games model is obtained by analyzing the tracking characteristics. The nonlinear differential games tracking guidance law based impact angle constrain is derived from the underwater multiple constraints tracking systems with additive disturbance by the implementation of zero efficiency control and rolling prediction algorithm. The simulation results show that the guidance law has high time efficiency and strong robustness, which can resist the interference and adjust the constraints in real time. References | Related Articles | Metrics

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Three-Dimensional Motion Simulation and Analysis for Lateral Separation of Autonomous Underwater Vehicle Load DU Xiaoxu,CUI Hang 2017, 51 (12):  1480-1487.  doi: 10.16183/j.cnki.jsjtu.2017.12.011 Abstract ( 801 )   Save As for the safety study of lateral separation of autonomous underwater vehicle (AUV) load, a three-dimensional motion model of total system was developed. Based on the Cartesian dynamics theory of multi-body system, the three-dimensional motion model of total system considering the coupled motion between load and carrier was established using the motion equation with Lagrange multipliers. Based on the rigid body dynamic theory, the single body movement model of load and carrier after the lateral separation was deduced by the Newton-Euler method. In the process of calculation, the constraint-stabilized method was used to avoid the occurrence of the constraint violation. Lateral separation motion had been simulated under some conditions, and the results showed the effectiveness of the three-dimensional motion model developed before. References | Related Articles | Metrics

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Influence of the Cavitator Diameter on the Performance of a Supercavitating Underwater Vehicle LI Yilin，SONG Baowei 2017, 51 (12):  1488-1492.  doi: 10.16183/j.cnki.jsjtu.2017.12.012 Abstract ( 970 )   Save Based on the Reynolds Averaged Navier-Stokes (RANS) equations, two-dimensional computational fluid dynamics (CFD) simulations are performed to investigate the influence of the cavitator diameter on the hydrodynamic forces and cavitation bubble of the supercavitating underwater vehicle. Results show that the drag of the underwater vehicle increases linearly with the increase of the cavitation number until the critical value, and then grows fast and nonlinearly. The increase of the cavitator diameter leads to an increase of drag for large cavitation numbers, and it also increases the critical cavitation number. References | Related Articles | Metrics

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Vortex-Induced Motion Response of Semi-Submersible Platform in Deep Water: I. Investigation on Key Characteristics SHAN Tiebing,SHEN Zhiping 2017, 51 (12):  1493-1503.  doi: 10.16183/j.cnki.jsjtu.2017.12.013 Abstract ( 940 )   Save The characteristics of vortex-induced motion(VIM) about a semi-submersible platform in deep water are investigated systematically on the basis of the method combining numerical calculation with model test. The model test is carried out in towing tank with four horizontal mooring lines. Computational fluid dynamics (CFD) method based on viscous flow method is applied. The analytical method which is suitable for platform VIM prediction is established. Good mesh mode combined with the technology of mesh deformation and reconstruction is applied to solve non-linear fluid-structure interaction problem. Sway motion and longitudinal offset traits at different flow angles are investigated. Vortex lock-in phenomena are also studied in detail, including lock-in interval at different angles and its relative trait. The evolutionary process of VIM response versus reduced velocity is analyzed. Meanwhile, the development process of VIM response versus time series, as well as the vortex shedding traits in each step is investigated. References | Related Articles | Metrics

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Vortex-Induced Motion Response of Semi-Submersible Platform in Deep Water: II. Investigation on Hull Optimization SHEN Zhiping,SHAN Tiebing,PAN Fanghao,ZHANG Haibin,WANG Pu 2017, 51 (12):  1504-1511.  doi: 10.16183/j.cnki.jsjtu.2017.12.014 Abstract ( 995 )   Save Optimization study toward semi-submersible platform in deep water is investigated on the basis of computational fluid dynamics (CFD) numerical method. A new type of semi-submersible platform which can suppress vortex-induced motion (VIM) is presented. Model test is also carried out to testify the validity of the numerical method. The characteristics of VIM toward new and conventional platforms are studied respectively. Some key factors such as longitudinal offset, sway response, sway distribution tendency and lock-in interval are compared. The characteristics of platform motion trajectory coupled from each degree of freedom (DOF) are analyzed. Mechanism of vortex shedding suppression in new type of platform is investigated in detail. The effects of column cross section geometry and column arrangement on VIM performance of platform is studied from the uniformity, stability and amplitude of VIM response and the vortex shedding form. It indicates that this new configuration of platform where cross section geometry of each column is trapezoidal and the columns are arranged according to splayfooted type, plays a significant part in suppressing VIM, and contribute to decreasing and postponing the destructive effects toward mooring and riser system due to strong non-linear VIM. References | Related Articles | Metrics

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Numerical Simulation of the Storm Surge in Bohai Bay Based on a Coupled Ocean-Atmosphere Model LI Yong1,2，CHEN Xin3，TIAN Lizhu1,2，LI Jianfen1,2 2017, 51 (12):  1512-1519.  doi: 10.16183/j.cnki.jsjtu.2017.12.015 Abstract ( 861 )   Save The Bohai Bay coastal region is one of the worst seriously affected areas by the storm surge. In order to simulate the storm surge processes more accurately in this area, a coupled ocean-atmosphere model which combines weather research and forecasting (WRF) and regional ocean model system (ROMS) is proposed. The coupled model can be used to study the interaction between the atmosphere and the ocean under more realistic dynamic conditions. Real-time data exchange between the ocean model and the atmospheric model can be performed through an open-source coupler and a grid reconstruction program. Based on the coupled ocean-atmosphere model, a typical cold surge in Bohai Bay in mid-October 2003 is simulated and analyzed. The analysis indicates that the coupled ocean-atmosphere model could be well to simulate the variations of temperature field, wind field, tidal level and tidal current field during the cold surge affecting period. The strong cold air moves southward and the resulting northeast wind is the major force of the cold surge. It is mainly determined by the distribution characteristics of topography and coastline of the Bohai Bay. The combination of wind stress elevation caused by strong northeast wind and the astronomical tide can easily lead to a large storm surge, which brings a tremendous security risk to social economic status and public health. References | Related Articles | Metrics

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Satellite Selection with Multi-Objective Genetic Algorithm for Multi-GNSS Constellations XU Xiaojun1,2，MA Lihua1，AI Guoxiang1 2017, 51 (12):  1520-1528.  doi: 10.16183/j.cnki.jsjtu.2017.12.016 Abstract ( 1079 )   Save With the development of multi-global navigation satellite system (GNSS) constellations, more and more satellites will be available. To ensure the accuracy of positioning, we have to select optimal satellites to improve the real-time performance of the receiver. In this paper, we firstly consider that satellite selection of multi-GNSS constellation can be used as a discrete multi-objective optimization problem with constraint conditions, and a new method based on non-dominated sorting genetic algorithm (NSGA)-II is proposed. This method can comprehensively optimize the geometric dilution of precision (GDOP) and the number of selected satellites at the same time. We can obtain good positioning accuracy while reducing the amount of computation of the receiver. The simulation results show that the proposed method is effective in both static and dynamic conditions with good real-time capabilities. References | Related Articles | Metrics