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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    

Design approach for single piston hydraulic free piston diesel engines

Wei WU, Shihua YUAN, Jibin HU, Chongbo JING,

《机械工程前沿(英文)》 2009年 第4卷 第4期   页码 371-378 doi: 10.1007/s11465-009-0069-y

摘要: The operating characteristics of a single piston hydraulic free piston diesel engine differ significantly from conventional diesel engines and this provides a theoretical basis for controlling and optimizing the design of the engine. The design of the proposed engine intended as a power supply for a hydraulic propulsion vehicle is presented. An engine performance forecast model was generated in AMESim. The performance of the prototype engine is predicted and the predictive results are verified with experiments. The particular features of the engine are discussed. The dynamic characteristics of the prototype engine are analyzed and the results indicate the rationality and feasibility of the engine design parameters. The features of the controllable working frequency and the intermittence output flows are provided. The flow capacity characteristics of the hydraulic valves on the prototype engine are offered. The methods for starting and the operation after misfire are presented.

关键词: free piston engine (FPE)     diesel engine     hydraulic equipment     simulation     experiment    

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    

Stable expression and control parameters in the numerical simulation of unsaturated flow

Zhiyuan ZHANG; Xu LI; Yongkang WU; Xiaokang LI

《结构与土木工程前沿(英文)》 2022年 第16卷 第12期   页码 1501-1514 doi: 10.1007/s11709-022-0893-2

摘要: The Richards’ equation describes the flow phenomenon in unsaturated porous media and is essential to hydrology and environmental science. This study evaluated the numerical stability of two different forms of the Richards’ equation. Sensitivity analyses were performed to investigate the control parameters of the equation. The results show that the h-form Richards’ equation has better applicability for calculating variable saturation flows than the θ-form Richards’ equation. For the h-form Richards’ equation, the hydraulic conductivity of the soil in the low-suction range and the specific moisture capacity in the high-suction range primarily influenced the solution. In addition, sensitivity analyses indicated that the saturated hydraulic conductivity, initial condition, and air-entry pressure have a higher sensitivity to the simulation results than the saturated water content, rainfall intensity, and decline rate of hydraulic conductivity. Moreover, their correctness needs to be guaranteed first in numerical simulations. The research findings can provide a helpful reference for improving the reliability of numerical simulations of unsaturated flows.

关键词: Richards’ equation     sensitivity analysis     unsaturated soil     hydraulic diffusivity     seepage simulation    

CFD Simulation of thermal hydraulic characteristics in a typical upper plenum of RPV

Mingjun WANG, Lianfa WANG, Yingjie WANG, Wenxi TIAN, Jian DENG, Guanghui SU, Suizheng QIU

《能源前沿(英文)》 2021年 第15卷 第4期   页码 930-945 doi: 10.1007/s11708-021-0728-1

摘要: A comparative computational fluid dynamics (CFD) study was conducted on the three different types of pressurized water reactor (PWR) upper plenum, named TYPE 1 (support columns (SCs) and control rod guide tubes (CRGTs) with two large windows), TYPE 2 (SCs and CRGTs without windows), and TYPE 3 (two parallel perforated barrel shells and CRGTs). First, three types of upper plenum geometry information were collected, simplified, and adopted into the BORA facility, which is a 1/5 scale system of the four-loop PWR reactor. Then, the geometry, including the upper half core, upper plenum region, and hot legs, was built using the platform. After that, an unsteady calculation to simulate the reactor balance operation at hot full power scenario was performed. Finally, the differences of flowrate distribution at the core outlet and temperature distribution and transverse velocity inside the hot legs with different upper plenum internals were compared. The results suggest that TYPE 1 upper plenum internals cause the largest flowrate difference at the core outlet while TYPE 3 leads to the most even distributed flowrate. The distribution and evolution pattern of the tangential velocity inside hot legs is highly dependent on the upper plenum internals. Two counter-rotating swirls exist inside the TYPE 1 hot leg and only one swirl revolving around the hog leg axis exist inside the TYPE 2 hot leg. For TYPE 3, two swirls like that of TYPE 1 rotating around the hot leg axis significantly increase the temperature homogenization speed. This research provides meaningful guidelines for the future optimization and design of advanced PWR upper plenum internal structures.

关键词: pressurized water reactor (PWR)     upper plenum     internal structures     temperature distribution     computational fluid dynamics (CFD)    

环境友好型全水压冲击凿岩机动力学建模与数值仿真

岳文辉,刘德顺,伍先明,朱萍玉,李夕兵

《中国工程科学》 2007年 第9卷 第8期   页码 57-61

摘要:

介绍了以普通水作为传动、支撑推进、排屑和润滑介质的环境友好型全水压凿岩机;建立了以弹性杆、弹簧为基本单元的冲击凿岩机 波动力学模型;对YST–25全水压凿岩机进行了动态数值仿真与分析。研究结果表明:活塞最大压应力为102 MPa,最大拉应力为28 MPa,满足 了强度设计要求;钎杆中的应力比活塞的大;尽量减小活塞的截面积变化有利于延长活塞寿命;为了保证凿岩速度和能量传递效率,YST–25凿 岩机宜于在中硬到硬岩中钻进。这为环境友好型全水压冲击凿岩机的改进设计和效能评估提供了依据。

关键词: 冲击     波动力学     仿真     水压凿岩机    

导弹特种装备与训练模拟系统研制

黄先祥,谢建,高钦和

《中国工程科学》 2001年 第3卷 第2期   页码 65-70

摘要:

导弹特种装备与模拟训练系统综合运用多学科先进技术,建立了数十个数学、物理和网络模型,研制出上百台仪器设备,实现了导弹全武器系统与发射全过程的模拟。简要介绍了系统的组成、功用和简要技术方案。对大型高可靠液压系统设计、自动调平与起竖的实现、导弹高精度定位、大型复杂电器系统电磁兼容设计等主要技术问题做了详细论述。

关键词: 导弹     训练模拟     液压系统     细分控制     电磁兼容    

A novel methodology for forecasting gas supply reliability of natural gas pipeline systems

Feng CHEN, Changchun WU

《能源前沿(英文)》 2020年 第14卷 第2期   页码 213-223 doi: 10.1007/s11708-020-0672-5

摘要: In this paper, a novel systematic and integrated methodology to assess gas supply reliability is proposed based on the Monte Carlo method, statistical analysis, mathematical-probabilistic analysis, and hydraulic simulation. The method proposed has two stages. In the first stage, typical scenarios are determined. In the second stage, hydraulic simulation is conducted to calculate the flow rate in each typical scenario. The result of the gas pipeline system calculated is the average gas supply reliability in each typical scenario. To verify the feasibility, the method proposed is applied for a real natural gas pipelines network system. The comparison of the results calculated and the actual gas supply reliability based on the filed data in the evaluation period suggests the assessment results of the method proposed agree well with the filed data. Besides, the effect of different components on gas supply reliability is investigated, and the most critical component is identified. For example, the 48th unit is the most critical component for the SH terminal station, while the 119th typical scenario results in the most severe consequence which causes the loss of 175.61×10 m gas when the 119th scenario happens. This paper provides a set of scientific and reasonable gas supply reliability indexes which can evaluate the gas supply reliability from two dimensions of quantity and time.

关键词: natural gas pipeline system     gas supply reliability     evaluation index     Monte Carlo method     hydraulic simulation    

Resistance of large caisson in floating transport considering the influence of air

Junjie ZHENG, Zongzhe LI, Dongan ZHAO, Qiang MA, Rongjun ZHANG,

《结构与土木工程前沿(英文)》 2010年 第4卷 第3期   页码 331-338 doi: 10.1007/s11709-010-0085-3

摘要: This paper deals with the floating resistance of super large caisson by numerical simulation, and the influence of air resistance on the caisson, which is often ignored by previous researchers, is considered. The floating caisson of Taizhou Highway Bridge’s middle tower pier is investigated, and the software package FLUENT is used to simulate the floating process of large-scale rounded rectangular steel caisson. This simulation adopts the volume of fluid (VOF) model with water-air two-phase flow, which can take both the hydraulic resistance and air resistance into account. Subsequently, the analyses on hydraulic resistance and air resistance under different working conditions, such as different flow velocities and different draughts of water are performed, and the results are compared with those calculated by related empirical formula. The comparison shows that the air resistance takes up notable portion in the total resistance on the floating caisson, and the effect of air resistance on the safety of caisson should be paid sufficient attention to rather than be ignored.

关键词: large-scale caisson     numerical simulation     hydraulic resistance     air resistance    

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    

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    

溪洛渡施工总布置三维动态可视化图形仿真研究

钟登华,朱慧蓉,郑家祥

《中国工程科学》 2003年 第5卷 第11期   页码 65-70

摘要:

溪洛渡水电站是在金沙江拟建的最大水电站,为直观准确地描述其施工总布置设计所涉及的各施工环节之间复杂的动态空间关系,将施工总布置系统分为若干子系统,对整个设计施工过程进行动态可视化图形仿真研究。设计3维动态图形仿真数据流向,将溪洛渡施工总布置动态图形仿真数据分为空间数据和属性数据,以GIS为平台组织数据结构,构造施工总布置3维动态可视化数字模型;在3维动态可视化数字基础上实现施工总布置3维动态可视化图形仿真演示和动态图形仿真数据可视化查询,给施工总布置设计与决策提供一个科学、直观的可视化分析途径。

关键词: 溪洛渡工程     施工总布置     图形仿真     地理信息系统     数字水利    

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    

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    

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    

标题 作者 时间 类型 操作

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

Zhibin LIU, Haibo XIE, Huayong YANG

期刊论文

Design approach for single piston hydraulic free piston diesel engines

Wei WU, Shihua YUAN, Jibin HU, Chongbo JING,

期刊论文

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

期刊论文

Stable expression and control parameters in the numerical simulation of unsaturated flow

Zhiyuan ZHANG; Xu LI; Yongkang WU; Xiaokang LI

期刊论文

CFD Simulation of thermal hydraulic characteristics in a typical upper plenum of RPV

Mingjun WANG, Lianfa WANG, Yingjie WANG, Wenxi TIAN, Jian DENG, Guanghui SU, Suizheng QIU

期刊论文

环境友好型全水压冲击凿岩机动力学建模与数值仿真

岳文辉,刘德顺,伍先明,朱萍玉,李夕兵

期刊论文

导弹特种装备与训练模拟系统研制

黄先祥,谢建,高钦和

期刊论文

A novel methodology for forecasting gas supply reliability of natural gas pipeline systems

Feng CHEN, Changchun WU

期刊论文

Resistance of large caisson in floating transport considering the influence of air

Junjie ZHENG, Zongzhe LI, Dongan ZHAO, Qiang MA, Rongjun ZHANG,

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

溪洛渡施工总布置三维动态可视化图形仿真研究

钟登华,朱慧蓉,郑家祥

期刊论文

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

期刊论文

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