Hasil untuk "Hydraulic engineering"

I. Chang, Minhyo Lee, A. Tran et al.

Abstract Various applications of biopolymer-based soil treatment (BPST) in geotechnical engineering have been implemented in recent years, including dust control, soil strengthening and erosion control. Despite BPST methods can ensure the effectiveness of engineering while meeting environmental protection requirements, BPST technology requires further validation in terms of site applicability, durability, and economic feasibility. This study aims to provide a state-of-the-art review and future prospective of BPST. Current biopolymer types, engineered and assessed in laboratory scales, are described along with site implementation attempts. The effect of biopolymers on soil behavior is reviewed with regard to geotechnical engineering application and practice, including soil consistency limits, strength parameters, hydraulic conductivity, soil-water characteristics, and erosion control. The economic feasibility and sustainability of BPST application in ground improvement and earth stabilization practices is discussed. This review postulates biopolymers to be a promising new, environmentally friendly ground improvement material for geotechnical and construction engineering practice.

Lijian Ouyang, Dongqiu Li, Shihao Cui et al.

Vertical slot fishways are a crucial measure to mitigate the blockage of fish migration caused by hydraulic engineering infrastructures, but their passage efficiency is often hindered by the complex interactions between fish behavior and hydrodynamic conditions. This study combines computational fluid dynamics (CFD) simulations with behavioral laboratory experiments to identify the hydrodynamic characteristics and swimming strategies of three types of fishways—Central Orifice Vertical Slot (COVS), Standard Vertical Slot (SVS), and L-shaped Vertical Slot (LVS)—using the endangered species <i>Schizothorax prenanti</i> from the upper Yangtze River as the study subject. The results revealed that (1) a symmetric and stable flow field was formed in the COVS structure, yet the passage ratio was the lowest (50%); in the SVS structure, high turbulent kinetic energy (peak of 0.03 m²/s²) was generated, leading to a significant increase in the fish’s tail-beat angle and amplitude (<i>p</i> < 0.01), with the passage time extending to 10.2 s. (2) The LVS structure induced a controlled vortex formation and created a reflux zone with low turbulent kinetic energy, facilitating a “wait-and-surge” strategy, which resulted in the highest passage ratio (70%) and the shortest passage time (6.1 s). (3) Correlation analysis revealed that flow velocity was significantly positively correlated with absolute swimming speed (<i>r</i> = 0.80), turbulent kinetic energy, and tail-beat parameters (<i>r</i> > 0.68). The LVS structure achieved the highest passage ratio and shortest transit time for <i>Schizothorax prenanti</i>, demonstrating its superior functionality for upstream migration. This design balances hydrodynamic complexity with low-turbulence refuge zones, providing a practical solution for eco-friendly fishways.

Zhi-Bing Li, Wei-Jiang Chen, Hao Wang et al.

To address the mitigation of excessive short-circuit currents in power grids and the arcing-resistant technology for large oil-filled equipment, this paper proposes a 550 kV fast SF6 circuit breaker solution, the equipment development and engineering implementation were systematically executed to validate the technology. A new electromagnetic repulsion trip device is used to replace the traditional electromagnet, achieving rapid conversion of the control valve oil circuit and reducing the mechanism activation time from the conventional <inline-formula> <tex-math notation="LaTeX">$10\sim 14$ </tex-math></inline-formula> ms to within 4 ms; by enhancing the operating power of the hydraulic disc spring mechanism, the output force is increased, and the buffer design is optimized, reducing the opening time from <inline-formula> <tex-math notation="LaTeX">$19\sim 25$ </tex-math></inline-formula> ms to within 8 ms; the design of SF6 arc-extinguishing chamber is improved and optimized from the aspects of contact gap, arc-blowing pressure, and electric field distribution, reducing the short arcing time from <inline-formula> <tex-math notation="LaTeX">$12\sim 14$ </tex-math></inline-formula> ms to within 8 ms. The successful development of the 550 kV fast SF6 circuit breaker achieves a breaking current of 63 kA, a breaking time of no more than 25 ms (approximately half that of conventional circuit breakers). The developed fast circuit breaker has been successfully applied in the Shunjiang sub-station 500kV short-circuit current flexible suppression demonstration project, and further enhances reliability with pilot applications for arcing-resistant of converter transformers at the Dongping and Bangguo converter stations of the Jinshang-Hubei and Longdong-Shandong &#x00B1;800 kV ultra-high voltage direct current transmission projects, respectively, with good application prospects.

Xin Lin, Xun Li, Yan Zhou et al.

Non-equilibrium solidification during NiTi alloys manufacturing via Laser Beam Powder Bed Fusion (PBF-LB), induces dendritic morphologies and heterogeneous precipitate distribution. However, the underlying mechanisms governing dislocation interactions remain poorly understood. An improved phase-field model coupled with melt pool temperature field is proposed to simulate the impact of dendritic growth behavior on precipitate distribution under spatiotemporal variations of temperature gradient (G) and solidification rate (R). Additionally, this study proposes a volume-conserved deformation scheme that couples the phase-field crystal (PFC) method with a thermal-stress dynamics model to simulate the influence of precipitates on dislocation motion. The results reveal that reduced volumetric energy density enhances cooling rates, decreasing primary dendrite arm spacing (PDAS), mitigating elemental segregation, and refining Ti2Ni precipitates with homogeneous grain boundary dispersion. Uniformly dispersed precipitates shorten dislocation recovery time and increase pinning probability at phase interfaces, resulting in effectively hindering dislocation glide while promoting multiplication and entanglement. This leads to high-density disordered dislocation networks, contrasting with well-defined dislocation cells formed under high energy density.

Janusz Michał Filipczyk, Karol Krystian Plesiński , Kacper Cedro

Aim of the study: The paper presents the results and experiences related to the use of BIM technology in hydraulic and land reclamation projects. The authors rely on their extensive experience gained from various projects in the field. The article aims to demonstrate modern BIM technology’s potential and possibilities in designing hydraulic and land reclamation structures. Material and methods: The research focuses on areas such as hydrotechnics, land reclamation, embankments, ditches, as well as the use of specific tools and software such as HEC-RAS, Autocad Civil 3D, MacroStacion Inroads, OpenRoads Designer, and Allplan. Combined with CFD (Computational Fluid Dynamics) modelling, BIM technology is crucial in analyzing and designing engineering structures. Results and conclusions: The article discusses the benefits of using BIM technology, such as improved collaboration and data exchange between different disciplines involved in the project, more efficient hydraulic analysis, precise and consistent models, and the ability to visualize projects for better understanding and communication with stakeholders.

Caroline Kozak, Cristovão Vicente Scapulatempo Fernandes

As contribuições de poluição por vias difusas associadas aos diferentes tipos de uso e ocupação da terra exercem grande influência na degradação da qualidade da água de rios. Para isso, com base em uma abordagem quali-quantitativa, pretende-se estimar o quanto de carga poluidora é inserida em um corpo hídrico durante um evento de chuva, analisando os tradicionais parâmetros de qualidade da água (NT, PT, COD, DQO, turbidez e SS) e se avaliar as potenciais implicações sobre os instrumentos de Gestão de Recursos Hídricos.  A pesquisa teve como estudo de caso uma bacia experimental, com características diversas de uso da terra. Para a compilação dos dados, foi utilizada a amostragem automática para coleta de amostras em dois pontos do Rio Barigui, estudo de caso em destaque. Como resultado, o ponto com maior influência urbana apresentou maiores contribuições de poluição do que o ponto com maior influência de área vegetada. Em termos de SS, estima-se um aporte anual de 116 ton/ha inserido no ecossistema aquático em um evento de chuva que ocorreu após 30 dias sem chuva. Neste contexto demonstra-se a necessidade de se reavaliar os normativos legais que regem os instrumentos de gestão de recursos hídricos para consideração dos efeitos de poluição difusa.

A. Barbati, J. Desroches, A. Robisson et al.

H. Yoshida, Tatsuya Yoshimoto, Daiki Umino et al.

We propose an autonomous operation system for hydraulic excavators that fully automatizes the sequence of excavation and loading in indoor environments at actual shield-tunneling construction sites. This system possesses all the components and functions necessary for excavation and loading. It also consists of an architecture composed of a networked control system. This architecture enables the system to mitigate the physical limitations of sensors and computers such as installation locations and computing power. We also devised practical engineering solutions that make our system highly accurate and efficient for actual construction sites, such as prediction control concerning hydraulic and mechanical delays and an external actuator that requires no special modifications to construction machinery.

Shima Atashgahi, A. Tabarsa, A. Shahryari et al.

Yu Zhao, P. He, Yongfa Zhang et al.

A. Bomers, R. Schielen, R. Schielen et al.

Grid shape (curvilinear/structured versus triangular/unstructured) and grid size affect model output. In this study structured, unstructured and hybrid grids with a high and low resolution were compared. As a case study, we use the Waal River (with main channel and floodplains). We studied simulated water levels using the six grids, considering equal main channel friction, which enabled to study the isolated effects of grid shape and size. The spread in simulated water levels was found to be rather large with a maximum deviation of 78 cm. Therefore, calibration was performed such that simulated water levels resembled measured water levels by adjusting the main channel friction. This enabled us to draw conclusions on the choice of optimal usage of the grids in engineering studies. Bathymetry accuracy and numerical friction, both as a result of grid resolution, and numerical viscosity as a result of grid shape play a vital role. The analysis shows that unstructured grids are affected most by the calibration which is reflected in the wide spreading of calibrated friction values. From the six grids studied, the hybrid grid with curvilinear grid cells in the main channel and triangular grid cells in the floodplain is recommended for hydraulic modelling since computation time is low, while model output shows sufficient accuracy.

Mingyang Wu, Dongming Zhang, Wen Wang et al.

Abstract Hydraulic fracturing is an important technology widely applied in engineering practice for the exploitation of unconventional oil and gas resources. Further research on its mechanism has the potential to advance the development of unconventional reservoir exploitation. In this study, previously acquired experimental data, including surface fracture image and fluid pressure curve, were used for modelling and comparison. Employing digital core reconstruction and the combined finite-discrete element method, A process of modelling crack geological model was proposed based on the rock surface sketch after fracturing. Two-dimensional models were established according to the surface fracture morphology of specimens. The feasibility of these numerical models was simultaneously verified by fluid pressure curves and the surface fracture morphology obtained in physical experiments. The evolution of fracture morphology during hydraulic fracturing was analysed. Simulation results indicate that: (1) the simulation method of this study is more suitable for simulation of coal hydraulic fracturing than for shale hydraulic fracturing; (2) the rapid rise of fluid pressure might be accompanied with the initiation and development of micro-fractures, leading to the occurrence of larger fractures; (3) the hydraulic fracturing process on the experimental scale could induce significantly larger maximum total area and wider fractures in coal specimens than in shale specimens. This indicates that coal hydraulic fracturing forms more complex fractures than in shale; (4) when the rock elastic modulus increases, the maximum fracture width and fracture total area decreases, and fracture length is extended. (5) The initiation and propagation pressures are positively related to the elastic modulus in the fluid pressure evolution. The crack geological model proposed in this study provides direct guidance for crack reconstruction in simulations. Moreover, the research results may provide a guidance for studies on the evolution of hydraulic fracture under the influence of rock heterogeneity.

Lingling Zhao, Fei Xu, Jun Xia et al.

Potential evapotranspiration (PET) is a comprehensive factor that characterises climate change, and considering the numerous methods to calculate PET, it is difficult to objectively select a method according to the requirements. In this study, the applicability of 12 commonly used PET estimation methods in China was studied. Based on temperature and humidity, China is divided into 11 temperature zones (TZ) and 5 arid and humid regions (AHRs). The study used the FAO Penman–Monteith (P-M) method as the standard, and the applicability of the 12 methods was analysed using four factors: correlation, annual mean values, seasonal distribution, and parameter characteristics. The results show that the radiation-based methods have the best monthly correlation with the P-M method, the temperature-based methods are second best, and mass-transfer-based methods perform the worst. Among these, the P-T method is the best, and the Hamon method is the worst. The Kharrufa and Abtew methods have the better applicability in higher TZs, whereas the Harg method has the least applicability. The seasonal distribution of radiation-based methods (excluding the Jensen method) in the different AHRs and different TZs is better than that of temperature-based and mass-transfer-based methods. According to the evaluation results of all factors, the Rohwer, P-T, and Mark methods are recommended when the data conditions are not conducive for the P-M method. HIGHLIGHTS There are many methods to calculate PET, while it is difficult to choose objectively according to the needs.; The applicability of 12 commonly used PET estimation methods in China was studied from four aspects.; Variation range of the national annual value estimated is 288.72–1355.1 mm.; The P-M method and energy-based methods have the highest monthly correlation.; The Rohwer, P-T, and Mark methods are recommended.;

Dongtao Ji, Weigang Lu, Linguang Lu et al.

In engineering, the highest operating head of the pumping station is usually controlled to be slightly lower than the lowest saddle bottom head of the axial-flow pump. However, in the practical operation, it is found that the highest operating head of the pumping station is obviously lower than the saddle bottom head of the pump device, which leads to the reduction of the operating range of the pumping station. To investigate the difference of lowest saddle bottom head between axial flow pump and axial flow pump device and apply it correctly, the energy performance tests of the TJ04-ZL-06 hydraulic model and its corresponding pump device were carried out to obtain the external curves, and numerical simulation was carried out to analyze and compare the internal flow field and pressure distribution. The results show that when the flow rate decreases, the first saddle-shaped region of the axial-flow pump and the saddle-shaped region of the pump device are caused by the decrease of the lift coefficient due to the increase of the attack angle between flow and blade. When the flow rate is less than 0.32Qd, the influence range of backflow in the inlet pipe is large, which leads to the high-pressure zone near the wall of the inlet pressure measurement section during the pump performance test, and hence the second saddle-shaped region of the axial-flow pump is essentially a measurement illusion. It is suggested that the inlet pressure measurement section should be set at least 4Dp away from the inlet flange of the impeller when testing the performance of the axial-flow pump under the condition of small flow rate, and the first saddle bottom head of the axial-flow pump or the saddle bottom head of the corresponding pump device can be considered as the control value of the highest head of the pumping station.

Yanyan Gao, H. Qian, Xinyan Li et al.

Riccardo Scarfone, S. Wheeler, M. Lloret-Cabot

AbstractAccurate modeling and prediction of the variation of the hydraulic conductivity of unsaturated soils at a very low degree of saturation has important implications in various engineering pro...

L. Zeng, Heng Wang, Z. Hong

Abstract The hydraulic conductivity of naturally sedimented and reconstituted clays is often interpreted using the settlement–time curves measured from consolidation tests. Understanding the accuracy of the interpreted hydraulic conductivity is essential in geological and geotechnical engineering. To the best knowledge of the authors, such a work has been little reported up to now. This study aims at investigating the errors of the interpreted hydraulic conductivity via the comparison between the interpreted values and the measurements. The ratios of the interpreted values of hydraulic conductivity over the measurements are examined based on the data from the consolidation–hydraulic conductivity tests performed in this study in conjunction with those published by our research team. The investigated clays cover wide geological origins and depositional states. The geological origins and depositional states are linked with the errors of the interpreted hydraulic conductivity for understanding the roles of these factors in the uncertainty of the interpreted hydraulic conductivity. The causes responsible for the discrepancy in hydraulic conductivity between the interpretations and the measurements are identified. The probability distribution of the errors of the interpreted hydraulic conductivity is also investigated.

Yujie Shen, Yanling Liu, Long Chen et al.

Abstract As the mechanical dual of a capacitor via the force-current analogy, an inerter has been successfully applied in various fields such as automotive engineering, civil engineering and aerospace engineering. The introduction of an inerter not only allows the use of network synthesis analogy to design mechanical layouts but also opens the door to adopt electrical element impedances to simulate the corresponding mechanical elements. This paper combines both of these ideas and presents a new form of a mechatronic inerter, namely the hydraulic electric inerter (HEI), which consists of a hydraulic piston inerter and a linear motor. On the basis of the HEI device, a bicubic impedance function is considered in the optimal design of a vehicle suspension system employing both mechanical elements and electrical elements. In addition, a methodology for reducing the order of the bicubic impedance function is proposed, and the network is finally realized by utilizing inerter, spring and damper elements. Then, by comparison with a passive suspension, the advantages of the new vehicle ISD (inerter-spring-damper) suspension, called the vehicle HE-ISD (hydraulic electric-inerter spring damper) suspension, are demonstrated by numerical simulations. Finally, a HEI device is designed, and bench tests of the vehicle HE-ISD suspension are carried out. Experimental results indicate that, the vehicle HE-ISD suspension is superior to the passive suspension system, the RMS (root-mean-square) value of the suspension working space is improved by 19.97%, and the RMS value of the dynamic tire load is improved by 10.21%.

Zhenghe Liu, Xiaokai Ren, Xiao Lin et al.

E. Strmčnik, F. Majdič, M. Kalin

Abstract The low-speed, high-torque, orbital hydraulic motor is a component that often uses mineral oil to convert hydraulic energy into the rotational motion of a shaft. The main purpose of our research was to investigate the possibility of using water, which is a much less environmentally damaging working fluid than oil. The limitations of water lubrication were overcome with an appropriate surface-engineering approach. The surface coated with diamond-like carbon (DLC) significantly reduced both the friction and the wear. The lowest coefficients of friction in this study, taking into account all the tested parameters, were obtained when the stainless-steel/DLC (SS/DLC) contact was tested in water. The friction of the SS/DLC in water was even lower than the friction of the SS/DLC or SS/SS contact in oil. Furthermore, the wear coefficient of the SS/DLC in water was comparable to the wear coefficient of the SS/SS in oil. The surface hardness, surface roughness and applied force were also varied, but they did not play such an important role as employing the DLC coating. The SS/DLC contact can thus be considered as a very promising solution for an orbital hydraulic motor from the tribological and environmental points of view.