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Design method of multivariable PI controller for turboprop engine based on equivalent transfer function

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Chinese Journal of Aeronautics 2024年第9期37卷 237-260页

作者： Shancheng LI yong wang Haibo zhang Jiangsu Province Key Laboratory of Aerospace Power System College of Energy and Power EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China

Traditional centralized Proportional Integral(PI)controller design methods based on Equivalent Transfer Functions(ETFs)have poor decoupling effect in turboprop *** this paper,a centralized PI design method based on dynamic imaginary matrix and equivalent transfer function is ***,a method for solving equivalent transfer functions based on the dynamic imaginary matrix is proposed,which adopts dynamic imaginary matrix to describe the dynamic characteristics of the system,and obtains the equivalent transfer function based on the dynamic imaginary matrix ***,for the equivalent transfer function,a central-ized PI control gain is designed using the Taylor expansion ***,this paper further proves that the centralized PI design method proposed in this paper has integral ***-ering the impact of altitude and Mach number on turboprop engines,a linear feedforward control method based on the transfer function matrix is further proposed based on the centralized PI con-troller,and the stability of the entire comprehensive control method is ***,to ensure the safe and effective operation of the turboprop engine,a temperature and torque limiting protection controller is designed for the turboprop *** results show that the centralized PI con-troller design method and linear feedforward control method proposed can effectively improve the control quality of turboprop engine control systems.

关键词： Multivariable control sys-tems Equivalent transfer function Disturbance compensation control Control parameter design Turboprop engine control

Influence of pressure disturbance wave on dynamic response characteristics of liquid film seal for multiphase pump

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Petroleum Science 2024年第3期21卷 2048-2065页

作者： Qing-ping Li Jin-Ya zhang Jia-Xiang zhang yong-Xue zhang CNOOC Research Institute Company Limited Beijing100028China State Key Laboratory of Natural Gas Hydrate Beijing100028China College of Mechanical and Transportation Engineering China University of PetroleumBeijing2249China

Slug flow or high GVF(Gas Volume Fraction)conditions can cause pressure disturbance waves and alternating loads at the boundary of mechanical seals for multiphase pumps,endangering the safety of multiphase pump *** mechanical seal model is simplified by using periodic boundary conditions and numerical calculations are carried out based on the Zwart-Gerber-Belamri cavitation ***(User Define Function)programs such as structural dynamics equations,alternating load equations,and pressure disturbance equations are embedded in numerical calculations,and the dynamic response characteristics of mechanical seal are studied using layered dynamic mesh *** results show that when the pressure disturbance occurs at the inlet,as the amplitude and period of the disturbance increase,the film thickness gradually *** the fundamental reason for the hysteresis of the film thickness change is that the pressure in the high-pressure area cannot be restored in a timely *** maximum value of leakage and the minimum value of axial velocity are independent of the disturbance period and determined by the disturbance *** mutual interference between enhanced waves does not have a significant impact on the film thickness,while the front wave in the attenuated wave has a promoting effect on the subsequent film thickness changes,and the fluctuation of the liquid film cavitation rate and axial velocity under the attenuated wave condition deviates from the initial *** with pressure disturbance conditions,alternating load conditions have a more significant impact on film thickness and *** actual operation,it is necessary to avoid alternating load conditions in multiphase pump mechanical seals.

关键词： Multiphase pump Liquid film seal Pressure disturbance wave Dynamic response characteristics

复式钢管混凝土墩柱轴压性能及承载力提高分析

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Effect of Heat Treatment on Structure and Magnetic Performance of Ni-Fe-P Alloy Obtained by Electroless Plating

工程力学 2025年第1期42卷 209-222页

作者：张玉芬郝圣旺李栋磊方永坚燕山大学建筑工程与力学学院秦皇岛066099 河北工业大学土木与交通学院天津300401 河北省土木工程绿色建造与智能运维重点实验室秦皇岛066099

为提升矩形钢管混凝土独柱墩的工作性能，在其截面内套异心双圆钢管形成新型复式钢管混凝土墩柱。该文进行了7个墩柱轴压荷载试验，通过对比空钢管柱、矩形墩柱和夹层墩柱分析了新型墩柱的破坏形态、钢管应变发展及承载力和延性差异，... 详细信息

为提升矩形钢管混凝土独柱墩的工作性能，在其截面内套异心双圆钢管形成新型复式钢管混凝土墩柱。该文进行了7个墩柱轴压荷载试验，通过对比空钢管柱、矩形墩柱和夹层墩柱分析了新型墩柱的破坏形态、钢管应变发展及承载力和延性差异，最后利用钢管和混凝土的组合效应原理进行组合墩柱轴压承载力提高分析。研究得出新型复式钢管混凝土墩柱轴压破坏形态为鼓曲破坏，其极限承载力较夹层墩柱提高20%，较矩形墩柱提高22%，延性提高效果更为明显;新型墩柱内、外钢管应变发展充分，说明钢管较好地发挥了竖向承载和横向约束混凝土的能力;根据钢板的正则化宽厚比和屈曲后强度计算得出，内、外钢管在混凝土的支撑下承载力提高15%，混凝土在钢管的约束下承载力提高49%;根据约束组合效应得出，新型墩柱整体承载力提高31%;采用等效套箍系数计算的新型墩柱承载力与试验值绝对误差在4%以内，说明新型复式钢管混凝土墩柱符合钢管混凝土统一理论。研究结果表明，新型复式钢管混凝土墩柱在约束混凝土效应方面明显提高，构件的承载力较高、延性较好，具有较强的工程应用前景。

关键词：新型复式钢管混凝土墩柱轴压性能破坏形态承载力套箍系数

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Chemical Research in Chinese Universities 2005年第6期21卷 718-722页

作者： wang Sen-lin zhang yong College of Materials Science and Engineering ChinaCollege of Information Science and Engineering Huaqiao University Quanzhou 362021 P. R.China

The electroless deposition of Ni68-Fe10.5-P21.5 alloy has been investigated. The crystallization behavior of the deposit was comparatively studied by using differential scanning calorimetry and X-ray diffractometry. The deposit transforms into a square Ni3P phase at 380. 0 ℃, then changes into a cubic FeNi3 phase at 490. 0 ℃. The microhardness, the size of the formed grains and the magnetic performance of the deposit increase with the increase of the heat treatment temperature below 500 ℃, then they decrease after this temperature. The effect of heat treatment time at 500 ℃ on the surface micromorphology, the structure and the magnetic performance of the deposit were also studied. The resuits show that with the increase of heat treatment time, the extent of crystallization of the deposit increases and the size of the formed grains becomes uniform. The results also show that the magnetic performance of the deposit under heat treatment for 40 min is maximal and then decreases with the increase of heat treatment time. The property change of the deposit is related to the crystal structure and the size of the formed grains of the deposit.

关键词： Electroless plating Ni-Fe-P alloy Heat treatment Magnetic performance

Mass production of magnetocaloric LaFeMnSiB alloys with hydrogenation

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Journal of Iron and Steel Research International 2017年第4期24卷 462-468页

作者： Tao zhang Cheng-yong wang Lugee Li yong zhang Cui-lan Liu Guangdong University of Technology Guangzhou 510006GuangdongChina Dongguan Eontech Co. Ltd.Dongguan 523662GuangdongChina State Key Laboratory of Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China Baotou Research Institute of Rare Earth Baotou 014030Inner MongoliaChina

LaFe_（11.39）Mn_（0.35）Si_（1.26）B_（0.1）Hxalloys were prepared by *** were annealed at 1343Kfor30-90 hto form the NaZn13 ***-rich andα-Fe secondary phases were also *** hydrogenation at 553 Kand 0.15 MPa of H_2 pressure for 5hwas employed to improve the Curie temperature of the alloys to 279 *** maximum magnetic entropy change,relative cooling power,and adiabatic temperature change of LaFe_（11.39）Mn_（0.35）Si_（1.26）B_（0.1）H_x annealed at 1343 Kfor 90hafter hydrogen absorption are 6.38J/（kg·K）（magnetic changesμ0ΔH =1.65T）,100.1J/kg（μ0ΔH =1.65T）,and 2.2 K（μ0ΔH =1.48T）,*** the maximum magnetic entropy change of the LaFe_（11.39）Mn_（0.35）Si_（1.26）B_（0.1）H_x alloys is lower than those of similar alloys with high purity raw materials,the relative cooling power is nearly the *** effect of impurities of the raw materials used was also *** is assumed that the impurity of 0.2wt.% Al is responsible for the reduced entropy change of the resulted *** LaFe_（11.39）Mn_（0.35）Si_（1.26）B_（0.1）H_x alloys prepared by this method could be a low cost alternative material for room temperature magnetic cooling applications.

关键词： Magnetocaloric effect Annealing Hydrogenation Adiabatic temperature change Relative cooling power Maximum magnetic entropy change

The Edge Sensor of Segmented Mirror Based on Fringes of Equal Thickness

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Research in Astronomy and Astrophysics 2023年第6期23卷 238-251页

作者： Xi zhang Heng Zuo yong zhang Ye-ping Li Nanjing Institute of Astronomical Optics and Technology National Astronomical ObservatoriesChinese Academy of SciencesNanjing 210042China Key Laboratory of Astronomical Optics and Technology Nanjing Institute of Astronomical Optics and TechnologyChinese Academy of SciencesNanjing 210042China University of Chinese Academy of Sciences Beijing 100049China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China

Co-phase and co-focus detection is one of the key technologies for large-aperture segmented mirror *** this paper,a new edge sensor based on fringes of equal thickness is developed,which can detect each segment's relative piston,tilt,and tip errors from the *** on the co-focus demand for many ground-based seeing limited segmented mirror telescopes,an edge sensor prototype based on such a principle is built and applied in the indoor segmented mirror experiment system in the *** to the co-focus requirement of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope,many simulations and experiments are carried out for cofocus error detection of the segmented mirror *** results show that the co-focus accuracy is better than 002 rms,which can meet the co-focus requirements of most large or extremely large segmented mirror astronomical telescopes.

关键词： instrumentation:interferometers astronomical instrumentation methods and techniques techniques:interferometric

A model for automatic identification of human pulse signals

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第10期9卷 1382-1389页

作者： Hui-yan wang Pei-yong zhang College of Computer Science and Information Engineering Zhejiang Gongshang University Hangzhou 310018 China Institute of VLSI Design Zhejiang University Hangzhou 310027 China

This paper presents a quantitative method for automatic identification of human pulse signals. The idea is to start with the extraction of characteristic parameters and then to construct the recognition model based on Bayesian networks. To identify depth, frequency and rhythm, several parameters are proposed. To distinguish the strength and shape, which cannot be represented by one or several parameters and are hard to recognize, the main time-domain feature parameters are computed based on the feature points of the pulse signal. Then the extracted parameters are taken as the input and five models for automatic pulse signal identification are constructed based on Bayesian networks. Experimental results demonstrate that the method is feasible and effective in recognizing depth, frequency, rhythm, strength and shape of pulse signals, which can be expected to facilitate the modernization of pulse diagnosis.

关键词： Pulse signal identification Feature extraction Bayesian network Quantitative diagnosis Wavelet transform

Sand source and formation mechanism of riverine sand dunes: a case study in Xiangshui River, China

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Journal of Arid Land 2019年第4期11卷 525-536页

作者： wang yong YAN ping HAN Guang WU Wei zhang Run Faculty of Geographical Science Beijing Normal UniversityBeijing100875China State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal UniversityBeijing100875China College of Resources and Environment Hunan Normal UniversityChangsha410081China Key Laboratory of Tibetan Environment Changes and Land Surface Processes Institute of Tibetan Plateau ResearchChineseAcademy of SciencesBeijing100101China

Riverine sand dunes develop as a result of fluvial-aeolian interactions. The primarily barchan dune chains along the Xiangshui River(a branch of the Xar Moron River in the western part of the Horqin Sandy Land of China) form a typical riverine dune field. We collected a series of samples from the riverine sand dunes parallel to the direction of the prevailing wind and investigated the sand sources and formation mechanisms of these dunes by determining the grain size, heavy mineral content and optically stimulated luminescence(OSL) of the samples. The sand of the near-river dunes was coarser than the sand of the dunes distant from the river, indicating that coarse sand of the valley mainly deposited on near-river dunes. The heavy mineral analysis suggested that wind-sand activity levels were intense on the upwind dunes, but relatively weak on the downwind dunes. This indicated that the sand sources for the near-river dunes were more abundant than those of the distant dunes. Our OSL analysis of samples suggested that the deposition rates on dunes near the river were greater than the deposition rates on dunes distant from the river. The development of dunes along the river indicated that the river played an important role in dune formation and development. In addition, airflow fluctuation and the formation of the waveform dunes had a type of feedback relationship. Grain size, heavy mineral and OSL analyses are widely used methods in wind-sand research. Sand dune grain size characteristics reflect the effects of airflow on the transport and separation of sand materials, as well as the physical characteristics of the sand sources. Heavy mineral characteristics are often used to investigate the relationships between sediments and sand sources. OSL indicates dune age, revealing formation of dunes. Therefore, it is useful to explore dune sand sources, as well as the mechanisms underlying dune formation, by determining grain size, heavy mineral content and OSL. This study in

关键词： riverine dune grain size heavy mineral optically stimulated luminescence(OSL) Horqin Sandy Land

In Situ Laser Coating of Calcium Phosphate on TC4 Surface for Enhancing Bioactivity

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Journal of Iron and Steel Research International 2007年第3期14卷 73-78页

作者： DENG Chi wang yong zhang Ya-ping GAO Jia-cheng Department of Physics Leshan Teachers College Leshan 614004 Sichuan China School of Materials Science and Engineering Chongqing University Chongqing 400044 China

Titanium alloy has been a successful implant material owing to its excellent ratio of strength to weight, toughness, and bio-inert oxide surface. Significant progress has been made in improving the bioactivity of titanium alloy by coating its oxide surface with calcium phosphates. In the present study, in situ coating was reported on Ti6Al4V（TC4） surface with calcium phosphate （Ca-P） bioceramics synthesized and synchronously cladded by laser beam. This coating was grown by first preplacing directly the raw powders, which contain 80% of CaHPO4 · 2H2O, 20% of CaCO3, and dram of rare earth （RE）, on the TC4 surfaces, and then exposing the surfaces to the laser beam with a power density of 12. 73-15.27 MW · m^-2 and a scanning velocity of 10.5 m/s. The resultant coating was characterized using scanning electron microscopy （SEM）, X-ray diffraction （XRD）, thermogravimetric analysis and Different-thermal Scanning （TG-DSC）, and Energy Dispersive X-ray Detection （EDX）. The results show that these laser ceramics include hydroxyapatite （HA）, tricalcium phosphate （TCP）, Ca2 P2 O7, and other Ca-P phases, and the interface between the coating and the TC4 substrate has tighter fixation, in which the chemical bonding is approved. These laser hybrid coatings are useful in enhancing the bioactivity of titanium alloy surfaces.

关键词： titanium alloy surface calcium phosphate ceramics laser cladding bioactivity