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Hydromechanical model for hydraulic fractures using XFEM

Bo HE

《结构与土木工程前沿（英文）》 2019年 第13卷 第1期   页码 240-249 doi: 10.1007/s11709-018-0490-6

摘要： In this study, a hydromechanical model for fluid flow in fractured porous media is presented. We assume viscous fluids and the coupling equations are derived from the mass and momentum balance equations for saturated porous media. The fluid flow through discrete cracks will be modelled by the extended finite element method and an implicit time integration scheme. We also present a consistent linearization of the underlying non-linear discrete equations. They are solved by the Newton-Raphson iteration procedure in combination with a line search. Furthermore, the model is extended to includes crack propagation. Finally, examples are presented to demonstrate the versatility and efficiency of this two-scale hydromechanical model. The results suggest that the presence of the fracture in a deforming, porous media has great impact on the fluid flow and deformation patterns.

关键词： multi-phase medium     porous     fracture     multi-scale method    

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Review of fluid and control technology of hydraulic wind turbines

Maolin CAI, Yixuan WANG, Zongxia JIAO, Yan SHI

《机械工程前沿（英文）》 2017年 第12卷 第3期   页码 312-320 doi: 10.1007/s11465-017-0433-2

摘要：

This study examines the development of the fluid and control technology of hydraulic wind turbines. The current state of hydraulic wind turbines as a new technology is described, and its basic fluid model and typical control method are expounded by comparing various study results. Finally, the advantages of hydraulic wind turbines are enumerated. Hydraulic wind turbines are expected to become the main development direction of wind turbines.

关键词： wind turbine     hydraulic system     fluid model     control technology    

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Modelling the thresholds of nitrogen/phosphorus concentration and hydraulic retention time for bloom

《环境科学与工程前沿（英文）》 2022年 第16卷 第10期 doi: 10.1007/s11783-022-1564-1

摘要：

● A new model for bloom control in open land scape water was constructed.

关键词： Reclaimed water landscape     Algal bloom     Nitrogen and phosphorus     Hydraulic retention time     Threshold     Control model    

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Model-based nonlinear control of hydraulic servo systems: Challenges, developments and perspectives

Jianyong YAO

《机械工程前沿（英文）》 2018年 第13卷 第2期   页码 179-210 doi: 10.1007/s11465-018-0464-3

摘要：

Hydraulic servo system plays a significant role in industries, and usually acts as a core point in control and power transmission. Although linear theory-based control methods have been well established, advanced controller design methods for hydraulic servo system to achieve high performance is still an unending pursuit along with the development of modern industry. Essential nonlinearity is a unique feature and makes model-based nonlinear control more attractive, due to benefit from prior knowledge of the servo valve controlled hydraulic system. In this paper, a discussion for challenges in model-based nonlinear control, latest developments and brief perspectives of hydraulic servo systems are presented: Modelling uncertainty in hydraulic system is a major challenge, which includes parametric uncertainty and time-varying disturbance; some specific requirements also arise ad hoc difficulties such as nonlinear friction during low velocity tracking, severe disturbance, periodic disturbance, etc.; to handle various challenges, nonlinear solutions including parameter adaptation, nonlinear robust control, state and disturbance observation, backstepping design and so on, are proposed and integrated, theoretical analysis and lots of applications reveal their powerful capability to solve pertinent problems; and at the end, some perspectives and associated research topics (measurement noise, constraints, inner valve dynamics, input nonlinearity, etc.) in nonlinear hydraulic servo control are briefly explored and discussed.

关键词： hydraulic servo system     adaptive control     robust control     nonlinear friction     disturbance compensation     repetitive control     noise alleviation     constraint control    

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Thermal and hydraulic characteristics of a large-scaled parabolic trough solar field (PTSF) under cloud

Linrui MA, Zhifeng WANG, Ershu XU, Li XU

《能源前沿（英文）》 2020年 第14卷 第2期   页码 283-297 doi: 10.1007/s11708-019-0649-4

摘要： To better understand the characteristics of a large-scaled parabolic trough solar field (PTSF) under cloud passages, a novel method which combines a closed-loop thermal hydraulic model (CLTHM) and cloud vector (CV) is developed. Besides, the CLTHM is established and validated based on a pilot plant. Moreover, some key parameters which are used to characterize a typical PTSF and CV are presented for further simulation. Furthermore, two sets of results simulated by the CLTHM are compared and discussed. One set deals with cloud passages by the CV, while the other by the traditionally distributed weather stations (DWSs). Because of considering the solar irradiance distribution in a more detailed and realistically way, compared with the distributed weather station (DWS) simulation, all essential parameters, such as the total flowrate, flow distribution, outlet temperature, thermal and exergetic efficiency, and exergetic destruction tend to be more precise and smoother in the CV simulation. For example, for the runner outlet temperature, which is the most crucial parameter for a running PTSF, the maximum relative error reaches −15% in the comparison. In addition, the mechanism of thermal and hydraulic unbalance caused by cloud passages are explained based on the simulation.

关键词： parabolic trough solar field (PTSF)     thermal hydraulic model     cloud passages     transients    

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Cohesive zone model-based analyses of localized leakage of segmentally lined tunnels

《结构与土木工程前沿（英文）》 2023年 第17卷 第4期   页码 503-521 doi: 10.1007/s11709-023-0927-4

摘要： This paper presents a novel approach for simulating the localized leakage behavior of segmentally lined tunnels based on a cohesive zone model. The proposed approach not only simulates localized leakage at the lining segment, but also captures the hydromechanically coupled seepage behavior at the segmental joints. It is first verified via a tunnel drainage experiment, which reveals its merits over the existing local hydraulic conductivity method. Subsequently, a parametric study is conducted to investigate the effects of the aperture size, stratum permeability, and spatial distribution of drainage holes on the leakage behavior, stratum seepage field, and leakage-induced mechanical response of the tunnel lining. The proposed approach yields more accurate results than the classical local hydraulic conductivity method. Moreover, it is both computationally efficient and stable. Localized leakage leads to reduced local ground pressure, which further induces outward deformation near the leakage point and slight inward deformation at its diametrically opposite side. A localized stress arch spanning across the leakage point is observed, which manifests as the rotation of the principal stresses in the adjacent area. The seepage field depends on both the number and location of the leakage zones. Pseudostatic seepage zones, in which the seepage rate is significantly lower than that of the adjacent area, appear when multiple seepage zones are considered. Finally, the importance of employing the hydromechanical coupled mechanism at the segment joints is highlighted by cases of shallowly buried tunnels subjected to surface loading and pressure tunnels while considering internal water pressure.

关键词： segmentally lined tunnel     localized leakage     cohesive element     hydraulic behavior     numerical modeling    

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液压挖掘机工作装置的动力特性修改研究

杨为,冯培恩,秦大同

《中国工程科学》 2005年 第7卷 第9期   页码 30-33

摘要：

为提高液压挖掘机工作装置动态性能的优化效率，在对该结构进行试验模态研究的基础上，用双模态空间动力修改方法进行了动力特性修改研究，研究结果表明：质量修改对该结构的1阶、2阶固有频率和阻尼比有显著影响，对其他阶结构动态特性的影响很小；刚度修改对该结构1阶至5阶的固有频率和阻尼比均有明显影响，高阶的固有频率和阻尼比对刚度的变化敏感。所得到的结论揭示了模态参数调整对液压挖掘机工作装置动力特性的影响规律，为提高机械产品的总体质量奠定了基础。

关键词： 双模态空间动力修改法     模态     液压挖掘机     工作装置    

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Hydraulic model for multi-sources reclaimed water pipe network based on EPANET and its applications in

JIA Haifeng, WEI Wei, XIN Kunlun

《环境科学与工程前沿（英文）》 2008年 第2卷 第1期   页码 57-62 doi: 10.1007/s11783-008-0013-0

摘要： Water shortage is one of the major water related problems for many cities in the world. The planning for utilization of reclaimed water has been or would be drafted in these cities. For using the reclaimed water soundly, Beijing planned to build a large scale reclaimed water pipe networks with multi-sources. In order to support the plan, the integrated hydraulic model of planning pipe network was developed based on EPANET supported by geographic information system (GIS). The complicated pipe network was divided into four weak conjunction subzones according to the distribution of reclaimed water plants and the elevation. It could provide a better solution for the problem of overhigh pressure in several regions of the network. Through the scenarios analysis in different subzones, some of the initial diameter of pipes in the network was adjusted. At last the pipe network planning scheme of reclaimed water was proposed. The proposed planning scheme could reach the balances between reclaimed water requirements and reclaimed water supplies, and provided a scientific basis for the reclaimed water utilization in Beijing. Now the scheme had been adopted by Beijing municipal government.

关键词： diameter     Beijing municipal     reclaimed     planning     elevation    

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液力传动箱上箱体强度分析与优化

刘传峰,田爱琴

《中国工程科学》 2008年 第10卷 第5期   页码 70-74

摘要：

计算机模拟模型分析法是机械设计开发的革命，运用有限元分析法可有效地规避设计风险和失误。对液力传动箱上箱体进行三维建模,提出了力学分析模型，将两个方案进行了有限元分析对比，指导设计方案的改进，提出最终解决方案，解决了设计难题。

关键词： 液力传动箱     力学模型     有限元分析     应力图     静强度     疲劳强度    

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Multiobjective trajectory optimization of intelligent electro-hydraulic shovel

《机械工程前沿（英文）》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0706-2

摘要： Multiobjective trajectory planning is still face challenges due to certain practical requirements and multiple contradicting objectives optimized simultaneously. In this paper, a multiobjective trajectory optimization approach that sets energy consumption, execution time, and excavation volume as the objective functions is presented for the electro-hydraulic shovel (EHS). The proposed cubic polynomial S-curve is employed to plan the crowd and hoist speed of EHS. Then, a novel hybrid constrained multiobjective evolutionary algorithm based on decomposition is proposed to deal with this constrained multiobjective optimization problem. The normalization of objectives is introduced to minimize the unfavorable effect of orders of magnitude. A novel hybrid constraint handling approach based on -constraint and the adaptive penalty function method is utilized to discover infeasible solution information and improve population diversity. Finally, the entropy weight technique for order preference by similarity to an ideal solution method is used to select the most satisfied solution from the Pareto optimal set. The performance of the proposed strategy is validated and analyzed by a series of simulation and experimental studies. Results show that the proposed approach can provide the high-quality Pareto optimal solutions and outperforms other trajectory optimization schemes investigated in this article.

关键词： trajectory planning     electro-hydraulic shovel     cubic polynomial S-curve     multiobjective optimization     entropy weight technique    

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Effects of slip length and hydraulic diameter on hydraulic entrance length of microchannels with superhydrophobic

Wenchi GONG, Jun SHEN, Wei DAI, Zeng DENG, Xueqiang DONG, Maoqiong GONG

《能源前沿（英文）》 2020年 第14卷 第1期   页码 127-138 doi: 10.1007/s11708-020-0661-8

摘要： This paper investigated effects of slip length and hydraulic diameter on the hydraulic entrance length of laminar flow in superhydrophobic microchannels. Numerical investigations were performed for square microchannels with Re ranging between 0.1 and 1000. It is found that superhydrophobic microchannels have a longer hydraulic entrance length than that of conventional ones by nearly 26.62% at a low Re. The dimensionless hydraulic entrance length slightly increases with the increasing slip length at approximately Re<10, and does not vary with the hydraulic diameter. A new correlation to predict the entrance length in square microchannels with different slip lengths was developed, which has a satisfying predictive performance with a mean absolute relative deviation of 5.69%. The results not only ascertain the flow characteristics of superhydrophobic microchannels, but also suggest that super hydrophobic microchannels have more significant advantages for heat transfer enhancement at a low Re.

关键词： laminar flow     hydraulic entrance length     super hydrophobic surface     slip length     hydraulic diameter    

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Simulation analysis of pressure regulation of hydraulic thrust system on a shield tunneling machine

Zhibin LIU, Haibo XIE, Huayong YANG

《机械工程前沿（英文）》 2011年 第6卷 第3期   页码 377-382 doi: 10.1007/s11465-011-0226-y

摘要：

Hydraulic thrust system is an important system in a shield tunneling machine. Pressure regulation of thrust cylinders is the most important function for thrust system during tunnel excavation. In this paper, a hydraulic thrust system is explained, and a corresponding simulation model is carried out in order to study the system characteristics. Pressure regulation of a certain group’s cylinders has little influence on regulation of the other groups’ cylinders. The influence will not affect the process much during tunnel excavation. Pump displacement may have a greater effect on pressure regulation and oil supply flow rate should be adaptive to the system’s demand. A exacting situation is simulated to explain how pressure regulation works during tunnel excavation.

关键词： tunnel     hydraulic thrust system     pressure regulation     simulation    

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A novel high-temperature and high-pressure hydraulic pump based on mononeuron control

Linhui ZHAO, Xin FANG

《机械工程前沿（英文）》 2009年 第4卷 第2期   页码 219-223 doi: 10.1007/s11465-009-0024-y

摘要： Based on structures and characteristics of traditional hydraulic pumps, this paper proposes a novel high-temperature and high-pressure hydraulic pump (HHHP) that can work under 150°C and 28 MPa to overcome problems of traditional high-temperature plunger pumps. The HHHP is designed with the structure of mechanical division and double cylinder parallel. The control signals of two cylinders are two separate triangle waveforms with 90° phase difference. Because the output waveforms of two cylinders have the same characteristics as the control signals, the HHHP can obtain a stable output after two separate waveforms are superposed. A mononeuron self-adaptive PID control algorithm is also improved by modifying parameters and . Two improved controllers are used to control the two cylinders, respectively, making two displacements of plungers match each other. Therefore, reduced fluctuations and stable pressure output is obtained. Besides simulation, tests on the built prototype test system are carried out to verify the performance of HHHP. Results show that the improved control approach can limit fluctuations to a lower level and the HHHP system attains good outputs under different signal periods and different pressures.

关键词： mononeuron PID control     hydraulic pump     pressure fluctuation    

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Distributed monitoring and diagnosis system for hydraulic system of construction machinery

Xiaohu CHEN, Wenfeng WU, Hangong WANG, Yongtao ZHOU,

《机械工程前沿（英文）》 2010年 第5卷 第1期   页码 106-110 doi: 10.1007/s11465-009-0089-7

摘要： This paper mainly presents a distributed monitoring and diagnosis system for the hydraulic system of construction machinery based on the controller area net (CAN) field bus. The hardware of the distributed condition monitoring and fault diagnosis system is designed. Its structure including the sensors, distributed data acquisition units, central signal processing unit, and CAN field bus is introduced. The software is also programmed. The general software design and its realization are studied in detail. The experiments and applications indicate that the distributed condition monitoring and fault diagnosis system can effectively realize its function of real-time online condition monitoring and fault diagnosis for the hydraulic system of construction machinery.

关键词： construction machinery     hydraulic system     distributed condition monitoring     controller area net (CAN) field bus     fault diagnosis    

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Passive convergence-permeable reactive barrier (PC-PRB): An effective configuration to enhance hydraulic

《环境科学与工程前沿（英文）》 2022年 第16卷 第12期 doi: 10.1007/s11783-022-1591-y

摘要：

● A novel PRB configuration based on passive convergent flow effect was proposed.

关键词： Passive convergence-permeable reactive barrier (PC-PRB)     Permeable reactive barrier configuration     Numerical simulation     Hydraulic performance evaluation     Sensitivity analysis    

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标题 作者 时间 类型 操作

Hydromechanical model for hydraulic fractures using XFEM

Bo HE

期刊论文

Review of fluid and control technology of hydraulic wind turbines

Maolin CAI, Yixuan WANG, Zongxia JIAO, Yan SHI

期刊论文

Modelling the thresholds of nitrogen/phosphorus concentration and hydraulic retention time for bloom

期刊论文

Model-based nonlinear control of hydraulic servo systems: Challenges, developments and perspectives

Jianyong YAO

期刊论文

Thermal and hydraulic characteristics of a large-scaled parabolic trough solar field (PTSF) under cloud

Linrui MA, Zhifeng WANG, Ershu XU, Li XU

期刊论文

Cohesive zone model-based analyses of localized leakage of segmentally lined tunnels

期刊论文

液压挖掘机工作装置的动力特性修改研究

杨为,冯培恩,秦大同

期刊论文

Hydraulic model for multi-sources reclaimed water pipe network based on EPANET and its applications in

JIA Haifeng, WEI Wei, XIN Kunlun

期刊论文

液力传动箱上箱体强度分析与优化

刘传峰,田爱琴

期刊论文

Multiobjective trajectory optimization of intelligent electro-hydraulic shovel

期刊论文

Effects of slip length and hydraulic diameter on hydraulic entrance length of microchannels with superhydrophobic

Wenchi GONG, Jun SHEN, Wei DAI, Zeng DENG, Xueqiang DONG, Maoqiong GONG

期刊论文

Simulation analysis of pressure regulation of hydraulic thrust system on a shield tunneling machine

Zhibin LIU, Haibo XIE, Huayong YANG

期刊论文

A novel high-temperature and high-pressure hydraulic pump based on mononeuron control

Linhui ZHAO, Xin FANG

期刊论文

Distributed monitoring and diagnosis system for hydraulic system of construction machinery

Xiaohu CHEN, Wenfeng WU, Hangong WANG, Yongtao ZHOU,

期刊论文

Passive convergence-permeable reactive barrier (PC-PRB): An effective configuration to enhance hydraulic

期刊论文