Hasil untuk "Hydraulic engineering"

H. Sinan Bank, Daniel R. Herber

Modern engineering design platforms excel at discipline-specific tasks such as CAD, CAM, and CAE, but often lack native systems engineering frameworks. This creates a disconnect where system-level requirements and architectures are managed separately from detailed component design, hindering holistic development and increasing integration risks. To address this, we present the conceptual framework for the GenAI Workbench, a Model-Based Systems Engineering (MBSE) environment that integrates systems engineering principles into the designer's workflow. Built on an open-source PLM platform, it establishes a unified digital thread by linking semantic data from documents, physical B-rep geometry, and relational system graphs. The workbench facilitates an AI-assisted workflow where a designer can ingest source documents, from which the system automatically extracts requirements and uses vision-language models to generate an initial system architecture, such as a Design Structure Matrix (DSM). This paper presents the conceptual architecture, proposed methodology, and anticipated impact of this work-in-progress framework, which aims to foster a more integrated, data-driven, and informed engineering design methodology.

Bianca Trinkenreich, Fabio Calefato, Geir Hanssen et al.

The adoption of Large Language Models (LLMs) is not only transforming software engineering (SE) practice but is also poised to fundamentally disrupt how research is conducted in the field. While perspectives on this transformation range from viewing LLMs as mere productivity tools to considering them revolutionary forces, we argue that the SE research community must proactively engage with and shape the integration of LLMs into research practices, emphasizing human agency in this transformation. As LLMs rapidly become integral to SE research - both as tools that support investigations and as subjects of study - a human-centric perspective is essential. Ensuring human oversight and interpretability is necessary for upholding scientific rigor, fostering ethical responsibility, and driving advancements in the field. Drawing from discussions at the 2nd Copenhagen Symposium on Human-Centered AI in SE, this position paper employs McLuhan's Tetrad of Media Laws to analyze the impact of LLMs on SE research. Through this theoretical lens, we examine how LLMs enhance research capabilities through accelerated ideation and automated processes, make some traditional research practices obsolete, retrieve valuable aspects of historical research approaches, and risk reversal effects when taken to extremes. Our analysis reveals opportunities for innovation and potential pitfalls that require careful consideration. We conclude with a call to action for the SE research community to proactively harness the benefits of LLMs while developing frameworks and guidelines to mitigate their risks, to ensure continued rigor and impact of research in an AI-augmented future.

Md Saeed Siddik, Hao Li, Cor-Paul Bezemer

Context: Jupyter Notebook has emerged as a versatile tool that transforms how researchers, developers, and data scientists conduct and communicate their work. As the adoption of Jupyter notebooks continues to rise, so does the interest from the software engineering research community in improving the software engineering practices for Jupyter notebooks. Objective: The purpose of this study is to analyze trends, gaps, and methodologies used in software engineering research on Jupyter notebooks. Method: We selected 146 relevant publications from the DBLP Computer Science Bibliography up to the end of 2024, following established systematic literature review guidelines. We explored publication trends, categorized them based on software engineering topics, and reported findings based on those topics. Results: The most popular venues for publishing software engineering research on Jupyter notebooks are related to human-computer interaction instead of traditional software engineering venues. Researchers have addressed a wide range of software engineering topics on notebooks, such as code reuse, readability, and execution environment. Although reusability is one of the research topics for Jupyter notebooks, only 64 of the 146 studies can be reused based on their provided URLs. Additionally, most replication packages are not hosted on permanent repositories for long-term availability and adherence to open science principles. Conclusion: Solutions specific to notebooks for software engineering issues, including testing, refactoring, and documentation, are underexplored. Future research opportunities exist in automatic testing frameworks, refactoring clones between notebooks, and generating group documentation for coherent code cells.

Morgan M. Fong, Hilary Egan, Marc Day et al.

Background: Harnessing advanced computing for scientific discovery and technological innovation demands scientists and engineers well-versed in both domain science and computational science and engineering (CSE). However, few universities provide access to both integrated domain science/CSE cross-training and Top-500 High-Performance Computing (HPC) facilities. National laboratories offer internship opportunities capable of developing these skills. Purpose: This student presents an evaluation of federally-funded postgraduate internship outcomes at a national laboratory. This study seeks to answer three questions: 1) What computational skills, research skills, and professional skills do students improve through internships at the selected national laboratory. 2) Do students gain knowledge in domain science topics through their internships. 3) Do students' career interests change after these internships? Design/Method: We developed a survey and collected responses from past participants of five federally-funded internship programs and compare participant ratings of their prior experience to their internship experience. Findings: Our results indicate that participants improve CSE skills and domain science knowledge, and are more interested in working at national labs. Participants go on to degree programs and positions in relevant domain science topics after their internships. Conclusions: We show that national laboratory internships are an opportunity for students to build CSE skills that may not be available at all institutions. We also show a growth in domain science skills during their internships through direct exposure to research topics. The survey instrument and approach used may be adapted to other studies to measure the impact of postgraduate internships in multiple disciplines and internship settings.

HUANG Zexi, SUN Wei, CHEN Xinlin et al.

This study took the“22·6”flood event at the Gaodao Station along the Lianjiang River in the middle and upper reaches of the Beijiang River in Guangdong Province as an example to explore the flow prediction method combining physical models with deep learning, aiming to improve the accuracy of hydrological predictions under extreme weather conditions. The study adopted a combination of the hydrologic engineering center-hydrologic modeling system (HEC-HMS) distributed hydrological model and the long short-term memory (LSTM) network to construct three types of coupled models, namely the HEC-LSTM model based on error correction, the HECo1-LSTM model based on single-station flow, and the HECo2-LSTM model based on multi-sub-basin output. Through prediction experiments with forecast periods of three hours, six hours, and 12 hours, the performance of each coupled model and the single hydrological model in runoff forecasting and extreme flood events was compared. The results show that the HEC-HMS model has limitations when the flow fluctuates greatly; the error correction-based HEC-LSTM model significantly improves the prediction accuracy in the short and medium term, with the root mean square error (RMSE) reduced by approximately 46% in the training set and 25% in the validation set. The HECo1-LSTM and HECo2-LSTM models perform outstandingly in long-term forecast periods, with the HECo2-LSTM model reducing the RMSE by 58% in the training set and 33% in the validation set and maintaining a high prediction accuracy (Nash-Sutcliffe model efficiency coefficient of 0.91) even in the 12-hour forecast period. This study provides a new coupling method for hydrological simulation and prediction in river basins, which is expected to significantly improve the accuracy and reliability of hydrological forecasts under extreme weather conditions.

Douglas M. Smith, D. Hua, W. Earl

Alessio Dallabona, Patrik Schermann, Mogens Blanke et al.

The application of nonlinear control schemes to electro-hydraulic actuators often requires several alterations in the design of the controllers during their implementation. This is to overcome challenges that frequently arise in such control algorithms owing to model nonlinearities. Moreover, advanced control solutions for this type of systems often introduce input algebraic loops that pose significant design and tuning difficulties. Conventional methods to avoid such loops introduce chatter, which considerably degrade tracking performance and has oil degradation and wear as side effects. This study presents a nonlinear control architecture for hydraulic actuators that comprises low-complexity modules that facilitate robust high performance in tracking and avoids the drawbacks of chatter. The salient feature is a dynamic input-mapping inversion module that avoids algebraic loops in the control input and is followed by dedicated position control. The stability of the closed-loop system is analyzed using arguments from Lyapunov theory for cascaded non-autonomous nonlinear systems. The effectiveness of the proposed solution is evaluated on a high-fidelity simulator of a wind turbine pitch system, and validated on a full-scale laboratory setup that includes a hydraulic pitch system and blade bearing. Appropriate quantitative metrics are used to evaluate the closed-loop system performance in comparison to a state-of-the-art nonlinear design.

Lei Zhang, Andriy Miranskyy

A flaky test yields inconsistent results upon repetition, posing a significant challenge to software developers. An extensive study of their presence and characteristics has been done in classical computer software but not quantum computer software. In this paper, we outline challenges and potential solutions for the automated detection of flaky tests in bug reports of quantum software. We aim to raise awareness of flakiness in quantum software and encourage the software engineering community to work collaboratively to solve this emerging challenge.

Siegmund Nuyts, Eugene J. Farrell, Sheena Fennell et al.

Remote video imagery using shoreline edge detection is widely used in coastal monitoring in order to acquire measurements of nearshore and swash features. Some of these systems are constrained by their long setup time, positioning requirements and considerable hardware costs. As such, there is a need for an autonomous low-cost system (~EUR 500), such as Timex cameras, that can be rapidly deployed in the field, while still producing the outcomes required for coastal monitoring. This research presents an assessment of the effect of the sampling strategy (time-lapse intervals) on the precision of shoreline detection for two low-cost cameras located in a remote coastal area in western Ireland, overlooking a dissipative beach–dune system. The analysis shows that RMSD in the detected shoreline is similar to other studies for sampling intervals ranging between 1 s and 30 s (i.e., RMSD_mean for Camera 1 = 1.4 m and Camera 2 = 0.9 m), and an increase in the sampling interval from 1 s to 30 s had no significant adverse effect on the precision of shoreline detection. The research shows that depending on the intended use of the detected shorelines, the current standard of 1 s image sampling interval when using Timex cameras can be increased up to 30 s without any significant loss of accuracy. This positively impacts battery life and memory storage, making the systems more autonomous; for example, the battery life increased from ~10 days to ~100 days when the sampling interval was increased from 1 to 5 s.

Lihua ZHAO, Zhiyun WU, Zhiqiang YAN et al.

Objective Due to the significant greenhouse effect of SF₆ circuit breakers, research on circuit breakers using new environmentally friendly gases has garnered considerable attention. Existing studies on the C₄F₇N/CO₂ gas mixture primarily focus on arc extinguishing and insulation performance, yet investigations into its temperature rise characteristics remain insufficient. However, these characteristics are crucial for designing the current-carrying capacity and monitoring the operational condition of the circuit breaker. Therefore, this study investigates the temperature rise characteristics of environmentally friendly gas circuit breakers based on a 40.5 kV porcelain column circuit breaker prototype.Methods The internal structure of the interrupter chamber in the porcelain column circuit breaker is disassembled to analyze the current path and the mechanisms of heat generation and transfer. The thermal process primarily occurs inside the interrupter chamber, with the primary heat sources being the conductor circuit and the contact points between the movable and static contacts. Based on this, a temperature rise experimental platform is constructed. The arrangement of temperature sensors and the testing scheme are established, providing a data foundation for further studies on temperature rise characteristics. This research develops a simulation model of electromagnetic-thermal-fluid multi-physical field coupling based on the experimental prototype at a 1∶1 scale to explore the temperature rise mechanism. It employs the finite element method to calculate the temperature rise and fluid field distribution inside the interrupter chamber. The simulation’s material parameters and boundary conditions are consistent with those in the experiment.Results and Discussions The experimental and simulation temperature rise curves are closely aligned, with the temperature rise error at designated measurement points, such as the primary contact, arc contact, and nozzle, not exceeding 10%. Thus, the experiment validates the simulation model. This simulation provides a method for studying the overall temperature rise and flow field distribution of the circuit breaker, addressing the limitation of experimental measurements to only certain parts of the circuit breaker. By integrating experiments and simulations, this study also identifies the significant heating at the contact surface between the primary and arc contacts due to high current and power density. This is attributable to the small cross-section of the load current and high film resistance at the contact surface. This study indicates the temperature rise characteristics and flow field distribution of the new environmentally friendly gas circuit breaker using two analytical methods: experimental testing and simulation calculation. It also analyzes the temperature rise field and flow field distribution characteristics of the 40.5 kV porcelain column circuit breaker regarding current magnitude, insulating gas type, and gas mixture components.Conclusions The results showed that the temperature rise within the circuit breaker interrupter is symmetrical, exhibiting a step-like distribution with higher temperatures at the top and lower temperatures at the bottom. The heat is primarily concentrated in the conductor and the top of the internal insulating gas. The flow field distribution inside the interrupter remains relatively stable, with the gas near the conductor experiencing natural convection due to heat. The gas flow rate increases with the temperature, reaching its maximum at the nozzle. Under certain conditions, the temperature rise in the conductor circuit of the porcelain column circuit breaker, the porcelain casing shell, the nozzle, and other typical measurement points increases with the rise in load current. The temperature rise rate at the nozzle and conductor is significantly higher than at the porcelain casing shell. The temperature rise field of the porcelain column circuit breaker, when utilizing different gases, follows a similar distribution law. The C₄F₇N/CO₂ gas mixture shows good heat dissipation properties. As the proportion of C₄F₇N gas in the mixture increases, the temperature rise of the conductor gradually decreases. The flow field distribution inside the interrupter chamber is also similar across various gas environments. The gas flow velocity is closely related to the interrupter’s temperature and the gas’s viscosity. The results of this study provide a theoretical basis for applying the new environmentally friendly gas C₄F₇N in porcelain column circuit breakers. This is of great significance for replacing SF₆ with new environmentally friendly insulating gases in managing the temperature rise of high-voltage circuit breakers.

Nadia Ouyahia, Abdelhamid Saou, Mustapha Maza et al.

Understanding the critical relationship between the Soummam River and its alluvial aquifer is crucial for the protection of this vital water resource. The approach is based on monitoring the spatial and temporal evolution of physico-chemical parameters and identifying their origin through correlation with the geology and piezometry of the alluvial aquifer; this will be achieved using differential gauging and hydrogeochemical tracing. This will provide valuable information for the management and protection of this precious water resource. The case study focuses on the alluvial aquifer of the lower Soummam Valley in Bejaia, Algeria, where a unique natural barrier upstream creates a close hydraulic relationship between the river and the aquifer. This allows for water exchange, which we investigated through two sampling campaigns (high and low water) at 32 water points (boreholes, wells and stations). By tracking the movement of special chemical tracers in both the Soummam River and the underlying alluvial aquifer, this study confirms a direct hydraulic connection between them. This means that water can flow from the river into the aquifer, highlighting the potential risk of water pollution. This has helped us to identify areas where pollution from the river could seep into the groundwater, threatening the drinking water supply. HIGHLIGHTS Determination of the existing exchanges between the river and the alluvial aquifer.; Monitoring of the spatial and temporal evolution of physico-chemical parameters.; Identification of the origin of the physico-chemical parameters.; Selection of differential gauging methods and hydrogeochemical tracing.; Identification of areas vulnerable to water pollution in the alluvial aquifer of the lower Soummam Valley.;

Luis Romero-Ben, Paul Irofti, Florin Stoican et al.

In this paper, we present a nodal hydraulic head estimation methodology for water distribution networks (WDN) based on an Unscented Kalman Filter (UKF) scheme with application to leak localization. The UKF refines an initial estimation of the hydraulic state by considering the prediction model, as well as available pressure and demand measurements. To this end, it provides customized prediction and data assimilation steps. Additionally, the method is enhanced by dynamically updating the prediction function weight matrices. Performance testing on the Modena benchmark under realistic conditions demonstrates the method's effectiveness in enhancing state estimation and data-driven leak localization.

Camille Jorge, Amélie Chardac, Alexis Poncet et al.

Viscous flows are laminar and deterministic. Robust linear laws accurately predict their streamlines in structures as complex as blood vessels, porous media and pipe networks. However, biological and synthetic active fluids defy these fundamental laws. Irrespective of their microscopic origin, confined active flows are intrinsically bistable, and therefore non-linear. As a consequence, their emergent patterns in channel networks are out of reach of available theories, and lack quantitative experiments. Here, we lay out the basic laws of active hydraulics. We show that active hydraulic flows are non-deterministic and yield degenerate streamline patterns ruled by frustration at nodes with an odd coordination number. More precisely, colloidal-roller experiments in trivalent networks reveal how active-hydraulic flows realize dynamical spin ices. The resulting streamline patterns split into two distinct classes of self-similar loops, which reflect the fractionalization of topological defects at the subchannel scales. Informed by our measurements, we formulate the laws of active hydraulics as a double spin model. A series of mappings on loop O(n) models then allow us to exactly predict the geometry of the degenerate streamlines. We expect our fundamental understanding to provide robust design rules for active microfluidic devices, and to offer unanticipated avenues to understand the motion of living cells and organisms in complex habitats.

Gongcheng Wu, Kanghua Zhang, Chonglang Wang et al.

The loading rate of tectonic stress is not constant during long-term geotectonic activity and significantly affects the earthquake nucleation and fault rupture process. However, the mechanism underlying the loading rate effect is still unclear. In this study, we conducted a series of experiments to explore the effect of the loading rate on earthquake nucleation and stick–slip characteristics. Through lab experiments, faults were biaxially loaded at varying rates to produce a series of earthquakes (stick–slip events). Both shear strain and fault displacement were monitored during these events. The findings indicate a substantial effect of the loading rate on the recurrence interval and the shear stress drop of these stick–slip events, with the recurrence interval inversely proportional to the loading rate. The peak friction of the fault also decreases with the increasing loading rate. Notably, prior to the dynamic rupture of earthquakes, there exists a stable nucleation phase where slip occurs in a quasi-static manner. The critical nucleation length, or the distance required before the dynamic rupture, diminishes with both the loading rate and normal stress. A theoretical model is introduced to rationalize these observations. However, the rupture velocity of these lab-simulated earthquakes showed no significant correlation with the loading rate. Overall, this study enhanced our comprehension of earthquake nucleation and rupture dynamics in diverse tectonic settings.

Wenpeng Wang, Ming Tang, Yanlei Li et al.

Although regional and seasonal water scarcity occurs frequently in China, and the contradiction among domestic, production and ecological water is prominent in some watersheds, the Chinese government still attaches great importance to the determination and implementation of ecological flow of rivers or lakes. Practitioners have been seeking methods to determine the ecological flow of rivers or lakes and how to ensure its implementation. Taking the Dingnan River watershed as a case, drawing on the experience of ‘Hedging rule’, the ‘Determination-Assessment-Reduction’ for the ecological flow nexus approach (the D-A-R approach) is introduced, which includes the determination of the annual ecological flow process through the river section, the assessment of water scarcity degree of the watershed and various water reduction strategies, respectively, and respond to the three scenarios of ‘general type, saving type and constrained type’ during the gap period. The results show that it is possible to use the D-A-R approach to proactively and dynamically adjust the ecological flow according to the probability estimate of that amount of water inflow per month, which the adjusted ecological flow threshold can better adapt to water scarcity at different levels and alleviate the contradiction among domestic, production and ecological water in the watershed during the dry period. HIGHLIGHTS Drawing on the experience of the ‘Hedging rule’, the ‘synchronous reduction strategy’ about the demand for domestic, production and ecological water is proposed.; The D-A-R approach is an ecological flow determination approach combined with assessment and reduction.; The new approach is proposed to strengthen water allocation to water users with potential future water scarcity to degrade the probability of suffering more serious water scarcity events in the later stage.;

ZHA Yingdong, HOU Peng, LIU Zeyuan et al.

【Objective】 This paper aims to study the optimal layout of inclined pipes in sedimentation basins in attempts to improve sediment removal efficiency in the Yellow River. 【Method】 Three different layouts of inclined pipes were compared: a single layer (Fs), and two double-layer layouts (Fv1, Fv2), in a gravity-operated sedimentation basin. Sediment distribution of three typical particle sizes in the upstream (Su), middle stream (Sm), and downstream (Sd) was measured. Sediment tests were conducted under a low (Qq) and a high (Qs) flow rate to compare the impact of pipe inclination on sedimentation in the three layouts. 【Result】 The large granular sediment settled prior to entering the inclined pipes, while the fine particle sediment (<75 µm) was effectively captured by the inclined pipe. These resulted in an outlet sediment content of 0.342~1.354 kg/m3 and a sand content of 0~0.018 kg/m3. Among the different inclined pipe layouts, Fv2 exhibited the lowest sediment and related sand, silt, and clay content at the outlet, followed by Fv1 and Fs. The Fv2 effectively controlled the outlet sediment content at 0.342~0.991 kg/m3, showing a reduction of 10.01%~20.95% and 26.82%~38.83%, compared to Fv1 and Fs, respectively. Furthermore, different Yellow River sections showed variations in sediment content, with the Su section exhibiting the lowest sediment and related sand, silt, and clay content. 【Conclusion】 The sediment treatment capacity varied significantly among the three inclined pipe layouts for different Yellow River sediments (P<0.05). The V-shaped inclined pipe layout was superior to the conventional layout, with the Fv2 (inclination angles of 60° and 45°) being most effective.

H. Hosseiny, F. Nazari, V. Smith et al.

Solving river engineering problems typically requires river flow characterization, including the prediction of flow depth, flow velocity, and flood extent. Hydraulic models use governing equations of the flow in motion (conservation of mass and momentum principles) to predict the flow characteristics. However, solving such equations can be substantially expensive, depending upon their spatial extension. Moreover, modeling two- or three-dimensional river flows with high-resolution topographic data for large-scale regions (national or continental scale) is next to impossible. Such simulations are required for comprehensive river modeling, where a system of connected rivers is to be simulated simultaneously. Machine Learning (ML) approaches have shown promise for different water resources problems, and they have demonstrated an ability to learn from current data to predict new scenarios, which can enhance the understanding of the systems. The aim of this paper is to present an efficient flood simulation framework that can be applied to large-scale simulations. The framework outlines a novel, quick, efficient and versatile model to identify flooded areas and the flood depth, using a hybrid of hydraulic model and ML measures. To accomplish that, a two-dimensional hydraulic model (iRIC), calibrated by measured water surface elevation data, was used to train two ML models to predict river depth over the domain for an arbitrary discharge. The first ML model included a random forest (RF) classification model, which was used to identify wet or dry nodes over the domain. The second was a multilayer perceptron (MLP) model that was developed and trained by the iRIC simulation results, in order to estimate river depth in wet nodes. For the test data the overall accuracy of 98.5 percent was achieved for the RF classification. The regression coefficient for the MLP model for depth was 0.88. The framework outlined in this paper can be used to couple hydraulics and ML models to reduce the computation time, resources and expenses of large-scale, real-time simulations, specifically for two- or three-dimensional hydraulic modeling, where traditional hydraulic models are infeasible or prohibitively expensive.

Shuwei Zhou, X. Zhuang, T. Rabczuk

Abstract Phase field model (PFM) is an efficient fracture modeling method and has high potential for hydraulic fracturing (HF). However, the current PFMs in HF do not consider well the effect of in-situ stress field and the numerical examples of porous media with stress boundary conditions were rarely presented. The main reason is that if the remote stress is applied on the boundaries of the calculation domain, there will be relatively large deformation induced on these stress boundaries, which is not consistent with the engineering observations. To eliminate this limitation, this paper proposes a new phase field method to describe quasi-static hydraulic fracture propagation in porous media subjected to stress boundary conditions, and the new method is more in line with engineering practice. A new energy functional, which considers the effect of initial in-situ stress field, is established and then it is used to achieve the governing equations for the displacement and phase fields through the variational approach. Biot poroelasticity theory is used to couple the fluid pressure field and the displacement field while the phase field is used for determining the fluid properties from the intact domain to the fully broken domain. In addition, we present several 2D and 3D examples to show the effects of in-situ stress on hydraulic fracture propagation. The numerical examples indicate that under stress boundary condition our approach obtains correct displacement distribution and it is capable of capturing complex hydraulic fracture growth patterns.

Xin-Yi Gao, Yongjiang Guo, Wen-Rui Shan

Abstract Water waves, one of the most common phenomena in nature, play an important role in the marine/offshore engineering, hydraulic engineering, energy development, mechanical engineering, etc. Hereby, for the shallow water waves near an ocean beach or in a lake, we study a Boussinesq-Burgers system. With respect to the water-wave horizontal velocity and height deviating from the equilibrium position of water, we find out (1) two hetero-Backlund transformations via the Bell polynomials and symbolic computation, and (2) a set of the similarity reductions via symbolic computation, to a known ordinary differential equation, for which we also construct some solutions. The results rely on the oceanic water-wave dispersive power. We hope that our hetero-Backlund transformations and similarity reductions could help the researchers investigate certain modes of the shallow water waves near an ocean beach.

Xin-Yi Gao, Y. Guo, Wen-Rui Shan

Water waves are one of the most common phenomena in nature, the studies of which help energy development, marine/offshore engineering, hydraulic engineering, mechanical engineering, etc. Hereby, symbolic computation is performed on the Boussinesq–Burgers system for shallow water waves in a lake or near an ocean beach. For the water-wave horizontal velocity and height of the water surface above the bottom, two sets of the bilinear forms through the binary Bell polynomials and N-soliton solutions are worked out, while two auto-Bäcklund transformations are constructed together with the solitonic solutions, where N is a positive integer. Our bilinear forms, N-soliton solutions and Bäcklund transformations are different from those in the existing literature. All of our results are dependent on the water-wave dispersive power.