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A wide range of applications of unsaturated hydraulic conductivity is well known in geotechnical, hydrological, and agricultural engineering fields. The standard prediction models for hydraulic conductivity function overlook the complexity of soil pore structure and employ a simplistic approach based on the bundle of capillary tubes. This study proposes an alternative approach employing pore network models calibrated to match soil water retention data to predict the hysteretic hydraulic conductivity function of granular soils. A novel approach to constructing a multidirectional pore network built on an irregular lattice with variable coordination numbers is presented for the realistic representation of soil voids. The geometric and topological parameters of the pore network model are optimized using the genetic algorithm, and adequate pore‐scale processes (piston‐like advance and corner flow during drainage and piston‐like advance, pore body filling, and snap‐off during imbibition) are modeled to get reasonable predictions of hysteretic hydraulic conductivity functions over the entire suction range of granular soils. Comparisons between the pore network model results, standard physically based models, and measured data for a variety of granular soils show that the proposed pore network has a superior performance over other models and compares favorably to the experimental data. [ABSTRACT FROM AUTHOR]

ABSTRACT The anisotropy at the grain scale significantly impacts cracking behavior of crystalline rocks. However, the anisotropy of mineral structure, especially the grain shape and orientation has been inadequately addressed in studies on hydraulic fracturing. To bridge this gap, this paper introduces a coupled hydro‐grain‐texture model (HGTM) based on discrete element model (DEM) that investigates the influence of grain shape and orientation on fluid‐driven cracking processes in crystalline rock. The HGTM can consider the different mineral grain shapes and orientations by changing the aspect ratio and rotating coordinate axes. Our studies covered six distinct in‐situ stresses, three grain shapes, and five grain orientations. Initially, we present a comprehensive examination of the microcracking processes of hydraulic fracturing. Then the influences of in‐situ stress, grain shape, and grain orientation on cracking processes were studied. The results underscore that both mineral grain and in‐situ stress interplay to influence the hydraulic fracturing of the crystalline rocks. The proposed HGTM can well mimic the propagation process of hydraulic fracturing by comparing with the experimental results and the results reveal that hydraulic fracturing in crystalline rocks is a highly complex process. This research clarifies the complex interplay between grain texture and hydraulic fracturing, offering invaluable insights for optimizing stimulation practices. [ABSTRACT FROM AUTHOR]

Flooding is one of the world's most common and costly natural hazards, inflicting billions in damages each year. However, current hydraulic models to support flood mapping are not well suited for large-scale applications or frequent updates, either due to limited accuracy of simple methods or lack of scalability (i.e., large computational requirements) for more sophisticated hydrodynamic models. This results in flood maps being decades out of date or simply nonexistent in some areas. Recent advances in generating flood maps have been made seemingly in parallel between geospatial methods and hydrodynamic models, such as the Height Above Nearest Drainage (HAND) method, hybrid 1D-2D hydrodynamic models and more efficient computing of 2D models. This study presents the Geospatially Augmented Standard Step (GASS) method, which combines a novel improvement to the HAND method, Dynamic Height Above Nearest Drainage (DHAND), with a 1D hydraulic model for rapid flood inundation mapping at large scales while maintaining the accuracy of hydrodynamic models. This method is implemented into a new modelling software package called Blackbird, and is benchmarked in two case studies, including a verification of the code and a benchmark test comparing multiple approaches in the ability to approximate 2D model results. The Blackbird model vastly outperforms the simpler HAND-Manning method and also outperforms a traditional HEC-RAS 1D model when evaluated for accuracy of approximating a 2D model benchmark. This new method is shown to reduce the incidence of falsely predicting flooded areas through improved resolution of landscape connections over HAND-based or 1D hydraulic models. Blackbird also streamlines the model development effort relative to existing 1D or 2D models while maintaining a computational speed that was 10, 000 times less than a comparable 2D model in one case study. The method also allows for future integration of hydraulic structures, ice jams and other features that are unavailable in HAND-based models. Overall, the GASS method provides a viable option for large-scale and real-time fluvial flood mapping applications. [ABSTRACT FROM AUTHOR]

The ICESat-2 and SWOT satellite earth observation missions have provided highly accurate water surface slope (WSS) observations in global rivers for the first time. While water surface slope is expected to remain constant in time for approximately uniform flow conditions, we observe time varying water surface slope in many river reaches around the globe in the ICESat-2 record. Here, we investigate the causes of time variability of WSSs using simplified river hydraulic models based on the theory of steady, gradually varied flow. We identify bed slope or cross section shape changes, river confluences, flood waves, and backwater effects from lakes, reservoirs, or the ocean as the main non-uniform hydraulic situations in natural rivers that cause time changes of WSSs. We illustrate these phenomena at selected river sites around the world, using ICESat-2 data and river discharge estimates. The analysis shows that WSS observations from space can provide new insights into river hydraulics and can enable the estimation of river discharge from combined observations of water surface elevation and WSSs at sites with complex hydraulic characteristics. [ABSTRACT FROM AUTHOR]

Multi-stage and multi-cluster hydraulic fracturing treatments of horizontal wells play a crucial role in the successful development of unconventional shale reservoirs. Completion design and optimization require a good understanding of proppant placement in multiple simultaneously propagating hydraulic fractures in horizontal wells. In this study, we simulate proppant placement in multiple hydraulic fractures in a rapid fashion by implementing an efficient proppant transport model in a rapid multi-cluster, multi-stage hydraulic fracture model. Our simulations take into account proppant settling and embedment during shut-in, critical but often overlooked aspects in proppant transport simulations. Sensitivity analyzes are performed to investigate the effects of various parameters, including pumping rate, fluid leak-off rate, number of perforations per cluster, and excess stress in the barrier layers, on the final proppant distribution, fracture residual aperture, and fracture conductivity. The simulation results reveal that increasing the pumping rate or decreasing the number of perforations per cluster can help achieve a more uniform proppant distribution among multiple hydraulic fractures. Higher fluid leak-off rates can cause the formation of proppant patches at the top of the fractures, leading to uneven proppant distribution within the fractures. In addition, higher levels of excess stress in the barrier layers may reduce the uniformity of fracture geometry and proppant distribution across multiple fractures. These findings provide valuable insights into the placement of proppant in multiple simultaneously propagating hydraulic fractures and may be helpful for the completion design and optimization of horizontal wells. Highlights: Proppant placement in multiple simultaneously propagating hydraulic fractures is simulated. Proppant settling and embedment during shut-in are taken into consideration. The effects of pumping rate, fluid leak-off rate, number of perforations per cluster, and excess stress in the barrier layers on the final proppant distribution and fracture conductivity were studied. [ABSTRACT FROM AUTHOR]

The existing one-dimensional model is inadequate in predicting the dynamic interactions between hydraulic transients and inline air pockets in water pipelines, leading to underestimated pressure dissipation in the modeling results. In this study, a one-dimensional (1D)–three-dimensional (3D) coupling model was applied to analyze and explain the interactions between the hydraulic transients and inline air pockets observed in systematic laboratory experiments. In this model, the method of characteristics provides 1D modeling of hydraulic transients in the regions without the inline air pocket and the finite-volume method with volume of fluid approach provides 3D modeling of hydraulic transient interactions at the air pocket. The coupling between 1D and 3D models is achieved using the partly overlapped coupling method. The analysis of the transient velocity profile unveils unique velocity distributions on both sides of the air pocket due to reflection and transmission processes, which contribute to the compression and movement of the air pocket. The investigations of variation in the internal energy of the air pocket using the 1D–3D model demonstrate that the internal energy reduces in the slow compression process due to greater energy fluctuations and more rapid energy transfer between air and water, especially at the front of the air–water interface directly impacted by the incident wave. This explains why the existing 1D model underestimates the pressure damping. [ABSTRACT FROM AUTHOR]

Copyright of Tecnología y Ciencias del Agua is the property of Instituto Mexicano de Tecnologia del Agua (IMTA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Hydraulic actuators are highly nonlinear when they are subjected to different types of model uncertainties and dynamic disturbances. These unfavorable factors adversely affect the control performance of the hydraulic actuator. Although various control methods have been employed to improve the tracking precision of the dynamic system, optimizing and adjusting control gain to mitigate the hydraulic actuator model uncertainties remains elusive. This study presents an adaptive back-stepping sliding mode controller (ABSMC) to enhance the trajectory tracking precision, where the virtual control law is constructed to replace the position error. The adaptive control theory is introduced in back-stepping controller design to compensate for the model uncertainties and time-varying disturbances. Based on Lyapunov theory, the finite-time convergence of the position tracking errors is proved. Furthermore, the effectiveness of the developed control scheme is conducted via extensive comparative experiments. [ABSTRACT FROM AUTHOR]

ABSTRACT Traditional photosynthesis‐driven growth models have considerable uncertainties in predicting tree growth under changing climates, partially because sink activities are directly affected by the environment but not adequately addressed in growth modelling. Therefore, we developed a semi‐mechanistic model coupling stomatal optimality, temperature control of enzymatic activities and phenology of cambial growth. Parameterized using Bayesian inference and measured data on Picea abies and Pinus sylvestris in peatland and mineral soils in Finland, the coupled model simulates transpiration and assimilation rates and stem radial dimension (SRD) simultaneously at 30 min resolution. The results suggest that both the sink and phenological formulations with environmental effects are indispensable for capturing SRD dynamics across hourly to seasonal scales. Simulated using the model, growth was more sensitive than assimilation to temperature and soil water, suggesting carbon gain is not driving growth at the current temporal scale. Also, leaf‐specific production was occasionally positively correlated with growth duration but not with growth onset timing or annual cambial area increment. Thus, as it is hardly explained by carbon gain, phenology itself should be included in sink‐driven growth models of the trees in the boreal zone and possibly other environments where sink activities and photosynthesis are both restrained by harsh conditions. [ABSTRACT FROM AUTHOR]

To endow the prey with intelligent movement behavior and improve the performance of Golden Jackal Optimization (GJO), a Q-learning Improved Gold Jackal Optimization (QIGJO) algorithm is proposed. This paper introduces five update mechanisms and proposes double-population Q-learning collaborative mechanism to select appropriate update mechanisms to improve GJO performance. Additionally, a new convergence factor is incorporated to enhance convergence capability of GJO. QIGJO demonstrates excellent performance across 23 benchmark functions, CEC2022, and three classical engineering design problems, indicating high convergence accuracy and significantly enhanced global exploration capability. The reliability optimization model of the hydraulic system for concrete pump trucks was established based on a Continuous-time Multi-dimensional T-S dynamic Fault Tree (CM-TSdFT), considering the two-dimensional factors of operating time and number of impacts. Utilizing QIGJO to optimize this model yielded excellent results, providing valuable methodological support for reliability optimization of hydraulic systems. [ABSTRACT FROM AUTHOR]

In the 465,000 km2 Canadian Prairies ecozone, robust hydrological input data for hydraulic model applications are uncommon because of the sparse monitoring network and the intermittently connected stream network. New hydrological datasets can offer a valuable advancement for making water management decisions and designing infrastructure in this water stressed region. The Prairie Hydrology Design and Analysis Product (PHyDAP) was created to address existing limitations, and provides a comprehensive regional dataset for use in hydraulic modelling applications. PHyDAP is a collection of outputs from a physically based hydrological modelling framework, run for periods ranging from 38 to 150 years, according to three climate forcing datasets. The dataset includes vertical and lateral fluxes (rainfall, snowmelt, upland runoff, and open water evaporation) and basin streamflow, at hourly or 3-hourly intervals for the >4000 small basins of approximately 100 km2 that span the region. This contribution describes the motivation for this work and methodology used to derive the data product, summarizes the data and its accessibility, and provides an overview of potential use cases. [ABSTRACT FROM AUTHOR]

A length-scale insensitive degradation function is applied to extend the cracks during hydraulic fracturing under stress boundary conditions in this study. The phase field method is an effective modeling technique that has great potential for use in hydraulic fracturing. Nonetheless, current hydraulic fracturing research is still concentrated on small scales. The phase field model employs a degradation function that is insensitive to length scale, allowing for the decoupling of the phase field length scale from the physical length scale. This facilitates the simulation of hydraulic fracturing crack extensions in larger structures with a consistent mesh density. The correctness of the phase field method is verified firstly by comparing with the experimental results, and the accuracy and efficiency of the proposed method are further verified through a series of numerical calculations. [ABSTRACT FROM AUTHOR]

The pool-type demonstrative China Fast Reactor 600 (CFR-600) adopted a series of improved safety designs, among which the hydraulic suspended passive shutdown subassembly (HS-PSS) is employed for inherent safety enhancement, especially suitable against unprotected loss of flow accident (ULOF). In this article, functional requirements for HS-PSS design in hydro-dynamic aspects are proposed, with the corresponding performance indicators discussed. To address these functional requirements, qualitative analysis on the equilibrium solution properties of the nonlinear dynamical model equation of the hydraulic moving body (HMB) in the HS-PSS are conducted, which leads to the determination of an applicable design parameter domain of the HMB for its practical design from the broad range of structural and parametric design options available for HS-PSS. Furtherly, hydraulically characterizing and modeling the constituent paths and consequent fluid network, hydraulic characteristics of the HS-PSS, as well as the coupled hydro-dynamic motion behaviors of the HMB for suspension and dropping states, were simulated and test-validated. Considering the HS-PSS hydro-dynamic behaviors, key indicators such as critical flowrate, drop time, hydraulic self-tightening performance, as well as the hydraulic characteristics curve are for fulfilling the functional requirements. Meanwhile, through sensitivity study of some structural parameters' impact on hydraulic characteristics, some most sensible structural parameters for adjusting and optimizing detailed design are observed. The work is quite significant in supporting the conceptual design of the HS-PSS as well as its engineering improvement. [ABSTRACT FROM AUTHOR]

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Urban areas continue to be affected by flooding, necessitating more sustainable and effective adaptation strategies and mitigation initiatives. This study investigates the potential flood reduction capability achieved through implementing various green infrastructures known as low-impact development (LID). The Bendung watershed, in the center of Palembang City, with a total area of 18.37 km2, is used as the study area to evaluate the performance of LID infrastructure in reducing flood parameters, including total runoff volume, peak runoff discharge, runoff coefficient, and flooding area. Five types of LID infrastructure were simulated, namely bio-retention cells, rain gardens, permeable pavements, rain barrels, and recharge wells. The flood simulations were performed using four design storms with 2-, 5-, 10-, and 25-year return periods. Hydrologic and hydraulic modeling and simulations were carried out using PCSWMM Professional 2D, and the results were integrated with ArcMap to map the flood inundation. The results of this study demonstrate that with only 9.81 percent of the area occupied by LIDs, a flood reduction of more than 30% can be achieved. In addition, implementing LIDs can help restore the watershed's hydrological condition to its natural state, as indicated by the decrease in the runoff coefficient. Thus, implementing LIDs in a sustainable urban drainage system must be widely promoted in many urban areas, especially in developed countries like Indonesia. This study can be used as a reference for the local government and authorities to create policies and regulations to establish sustainable flood mitigation measures in Palembang City. [ABSTRACT FROM AUTHOR]

A novel model is proposed for analyzing high-concentration granular flow systems comprising equally sized spherical particles within vertical, long straight pipelines. This model is specifically tailored for simulating the vertical hydraulic transport of ore particles in marine mining projects. The proposed model treats the granular system akin to a pseudo-fluid and operates through three mechanisms. First, fluid characteristics of the granular system are derived from particle–particle collisions. Second, the resistance exerted by the pipe wall on the granular system is calculated based on the momentum loss of particles during particle–wall collisions. Third, the interaction between individual particles and the surrounding fluid is transformed into an interaction between the carrier fluid and the pseudo-fluid. Additionally, the present work develops a dedicated numerical format and iterative method for solving the one-dimensional two-fluid governing equations. The one-dimensional (1D) model notably enhances computational efficiency and facilitates accurate tracking of high-concentration particles over extended distances within straight pipelines. Notably, the proposed 1D model demonstrates a high degree of predictive accuracy when compared against experimental data as well as results from computational fluid dynamics and discrete element method simulations. [ABSTRACT FROM AUTHOR]

Variation of the slag cover surface (SCS) in the oxygen-enriched top-blown molten bath smelting process is critical for the smelting efficiency of a complex Cu–S concentrate. However, capturing these variation characteristics is difficult because of the high temperature inside the molten bath and the dynamic complexity of the smelting process. In this work, machine learning (i.e., U-net algorithm and support vector machine) is combined with a skillful hydraulic model (i.e., gas–liquid two-phase top-blown agitated vessel) and an experimental measurement strategy to quantitatively explore the variation characteristics of the SCS in an oxygen-enriched top-blown molten bath smelting process. Results showed that a minimum of 30 images, with the smallest size being 900 × 600 pixels, was sufficient for the training process. The data accuracy of the training procedure ranged from 93.20% to 96.23% for identifying the SCS at the laboratory scale. The highest average height of 2.23 cm for the SCS occurred under the operational condition, with a flow rate of 160 L/h, a liquid temperature of 60 °C, and a liquid depth of 0.4 m. The chaotic systems of SCS in industry were deterministic. It was found that the proposed strategy could be used to accurately identify the variation characteristics of the SCS in the gas–liquid two-phase top-blown agitated vessel. The variation of the SCS in the industrial process could be roughly grasped by magnifying the height of the SCS obtained from the experimental data in the laboratory. Quantification of the variation characteristics of the SCS is useful to increase the smelting efficiency of the oxygen-enriched top-blown molten bath smelting process. This also provides insights for multiphase measurements in other studies related to efficient utilization of complex Cu–S concentrates. [ABSTRACT FROM AUTHOR]

The double-row hydraulic sluicing model is widely used in deep-sea mining collecting systems. However, there has been limited research focusing on its flow contributions and the relationship with particle motions. In this paper, a double-row hydraulic sluicing collector with high pickup efficiency is designed. The flow characteristics, the mechanics of the flow field, and the movement of particles in the collector are analyzed in detail through numerical calculations and experiments. The flow contributions and the collecting mechanism are clearly highlighted through aspects such as the frequency of pressure fluctuations and flow-induced vortices. The high-speed jet rolls upward after hitting the ground, forming a high-pressure area on the ground. The upwelling in the collection area is generated by the combination of the high-pressure area and the upward rolling of fluid. Regarding the particles, it is observed that particle motion can be divided into two main stages, rapid acceleration, followed by slow deceleration. Some particles may fall back when rising. Additionally, the analysis of fluid forces on the particles indicates that drag force and pressure gradient force have significant influence on particle motion. [ABSTRACT FROM AUTHOR]

Micro-vibrations during the operation of space remote sensing equipment can significantly affect optical imaging quality. To address this issue, a bellows-type viscous damper serves as an effective passive damping and vibration isolation solution. This paper introduces a bellows-type viscous damper with adjustable damping capabilities, designed for mid- to high-frequency applications. We developed a system damping model based on hydraulic fluid dynamics to examine how different factors—such as viscous coefficients, damping hole lengths, hole diameters, chamber pressures, and volumes—influence the damping characteristics. To validate the theoretical model, we constructed an experimental platform. The experimental results show that the theoretical damping curves closely match the measured data. Moreover, increasing the chamber pressure effectively enhances the damper's damping coefficient, with the deviation from theoretical predictions being approximately 4%. [ABSTRACT FROM AUTHOR]

The hydraulic calculation of column internals is crucial for their design. The various fouling effects (due to crystallization, particles, chemical reaction) influence the hydraulics of columns in different ways (capacity, separation efficiency). However, current hydraulic models are based on clean systems and do not consider fouling. By properly taking into account the geometrical parameters affected by fouling, the classical models can be used to calculate the state of internals as they evolve over time. [ABSTRACT FROM AUTHOR]

Hydrodynamic models are used to analyse water networks (water distribution, drainage, surface water, district heating, etc.). The non-linear nature of water flows necessitates the use of iterative solution methods in hydraulic modelling. This requires a relatively large computational effort. To reduce this effort, networks, network forcing and/or the flow in networks are often simplified and analysed using the Graph Theory. The simplification options depend on the network characteristics. There are many topological features to describe Graph-based networks. In this paper, these characteristics are summarised, applied on 7 urban drainage networks and discussed. As the topological features do not describe the networks in a uniform manner, a new type of topological characterisation of looped drainage networks (Network Linearisation Parameter, NLP) is proposed based on linearized hydraulics and bottlenecks identified in paths to outfalls. [ABSTRACT FROM AUTHOR]

Floods are increasingly becoming a significant concern due to climate change, global warming, and excessive urbanization. The Intergovernmental Panel on Climate Change (IPCC) has projected that global warming will continue to contribute to more frequent and severe floods and hydrological extremes. In response to these challenges, nature-based solutions (NBSs) have gained recognition as effective approaches to mitigate the adverse impacts of floods by focusing on ecosystem conservation, restoration, and sustainable utilization of natural resources. This study examines a flood that occurred in the Erkilet District of Kayseri, Türkiye on September 22, 2022, as a result of intense rainfall. It involves a thorough on-site investigation to assess the hydraulic, hydrologic, and geotechnical attributes of the study area. The findings from the field study indicate that the primary cause of the flood is attributed to excessive urbanization. To further analyze the impact of urbanization, a hydraulic model is developed considering both the physical and topographical conditions of the study area for both the year 2006 and 2022. The simulation results reveal that the extent of inundation area and water depth has increased significantly due to the excessive urbanization that occurred within a 16-year period. Additionally, the effectiveness of green roofs and permeable pavements as NBSs to mitigate urban flooding is explored. The implementation of green roofs and permeable pavements shows promising results, reducing the adverse effects of urban floods by 3% to 8%, depending on their specific locations and configurations. However, the results suggest that NBSs alone cannot fully prevent floods so they should complement gray infrastructure. The novelty of the study lies in its ability to demonstrate the impact of urbanization and the effectiveness of nature-based solutions in mitigating flood extent based. [ABSTRACT FROM AUTHOR]

Fish habitats and reproduction can be significantly altered downstream of hydroelectric power plants operated by hydropeaking and resulting in rapid and frequent changes in river hydrodynamic conditions. To mitigate the impacts, it is necessary to maintain the habitat quality through operational measures. The microhabitat method, coupling 1 D or 2 D hydraulic simulations to biological models, is a useful tool to assess the evolution of hydromorphological parameters and fish habitats and define these mitigation measures. Calibration of the hydraulic model must be carried out carefully because the model must accurately reproduce hydraulic conditions from low to high flows. The objective is therefore to evaluate the sensitivity of the habitat value as a function of the type of calibration and the friction law for shallow habitats. The analysis is performed by estimating the uncertainty in fish habitat values resulting from Strickler's law or Nikuradse's law. The study is carried out on a river in the French Pyrenees based on the modeling of 2 stations with different cross-sectional shapes, one with progressive overflow and the other without these phenomena. Thanks to field measurements at low and high flowrates, the calibration process showed that the friction coefficient can be multiplied by 2. Two dimensionnal simulations give similar results to those obtained with 1 D when the flow remains unidirectional but differ for areas with high overflows. Calibration and models can lead to different conclusions regarding the estimation of habitat modifications due to hydropeaking operation and the definition of base flow and maximum turbine discharge. [ABSTRACT FROM AUTHOR]

Fractured and cavernous rocks, as well as rocks with increased permeability, are prone to mud losses during oil and gas well drilling. Circulation subs are a promising solution to mitigate mud and technological fluid losses in intervals ranging from 5 to 40 m3/h by sealing the problematic interval. However, current circulation subs designs have notable drawbacks, including limited activation capabilities and usage scenario restrictions. This article provides a comprehensive analysis and characterization of the functional use of circulation subs, along with a qualitative comparative market analysis and patent search for devices activated by ball dropping, hydraulic, mechanical, and electromechanical means. The primary outcome of this research is the development of a functional hydraulic quick-acting activation device that addresses the shortcomings of existing designs. The device's design allow for future development of assemblies and optimization of their configurations to suit specific operating conditions. It can also serve as a protective measure for the downhole motor and telemetry system against harsh mechanical and chemical action during sealing. The device's limitations include pressure constraints and the need for flow rate adjustment. The article concludes with an overview of the developed hydraulically activated device and the results of qualitative bench tests, which demonstrate its functionality. [ABSTRACT FROM AUTHOR]

Oil temperature plays a crucial role in hydraulic closed-circuit systems (HCS), and conventional thermal equilibrium models and coupled simulation models face challenges in terms of accuracy, efficiency, and cost when calculating oil temperature. This study introduces an innovative HCS oil temperature precise prediction model and oil refilling parameter optimization method. The initial sample space was determined through a Sobol sensitivity analysis and improved Latin hypercube sampling, leading to the development of a combinatorial agent model (CAM) suitable for oil temperature prediction with superior accuracy and stability compared to other methods. Based on CAM, the optimal oil refilling flow rates under various operational conditions are computed. To validate the efficacy of the theoretical analysis, an HCS experiment platform was established. The data indicates that the temperature prediction error range of the CAM model falls between 0.30 °C and 1.05 °C, and optimizing the oil refilling flow rate can effectively enhance system efficiency while ensuring that the oil temperature remains within permissible limits. The research methodology and findings are applicable in engineering practice and can be extended to optimize the design of other hydraulic systems. [ABSTRACT FROM AUTHOR]

Copyright of Nuclear Safety is the property of Nuclear & Radiation Safety Center and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Earthwork operations are critical to construction projects, with their safety and efficiency influenced by factors such as operator skill and working hours. Pre-construction simulation of these operations is essential for optimizing outcomes, providing key training for operators and improving safety awareness and operational efficiency. This study introduces a hierarchical cumulative reward mechanism that decomposes complex operational behaviors into simple, fundamental actions. The mechanism prioritizes reward function design elements, including order, size, and form, thus simplifying excavator operation simulation using reinforcement learning (RL) and enhancing policy network reusability. A 3D model of a hydraulic excavator was constructed with six degrees of freedom—comprising the boom, arm, bucket, base, and left/right tracks. The Proximal Policy Optimization (PPO) algorithm was applied to train four basic behaviors: scraping, digging, throwing, and turning back. Motion simulation was successfully achieved using diggable terrain resources. Results demonstrate that the simulated excavator, powered by RL neural networks, can perform coordinated actions and maintain smooth operational performance. This research offers practical implications by rapidly illustrating the full operational process before construction, delivering immersive movies, and enhancing worker safety and operational efficiency. [ABSTRACT FROM AUTHOR]

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Energy dissipation of water flow is an important factor in the planning of structures such as stilling basins. One of the standards set by the USBR (United States Bureau of Reclamation) that must be considered in the planning of the stilling basin is the Froude number (F1) at the toe of the spillway. Various forms of planning can be used to meet these standards, one of which is by using a double-sill downstream of the chute channel with a certain distance and height. However, as an alternative to planning, this study aims to evaluate the level of attenuation of flow energy in a stilling basin by using a double-sill. Because this sill is more effective in breaking down and reducing the strength of the water flow. Hydraulic physical model tests were carried out in the laboratory by placing double sills in a fixed position and varying the height of the sills. Because several previous studies have shown that the shape and size of sills affect the level of energy dissipation. It is expected that the results of the hydraulic model test can provide better information about the flow behavior in the overflow system in terms of energy dissipation. [ABSTRACT FROM AUTHOR]

Climate change is a major issue in wastewater management at local and regional levels, as it affects the frequency of flooding and therefore the need to update infrastructure and design regulations. To this end, rainfall data are the main input to hydraulic models used for the design of drainage systems and, in advanced contexts, for their real-time monitoring. Field observations are of great interest and water authorities are increasing the number of existing rain gauges, but at present they are scarce and require maintenance, so their number needs to be considered with their O&M costs. Remote sensors, including both the existing satellite rain products (SRPs) and radar imagery (RI), can complete the spatial distribution of rainfall and optimise the cost of observations. While most SRPs are based on re-analysis and have a lag in availability, RI can be obtained in near real time and is becoming increasingly popular in weather forecasting applications. Unfortunately, actual rainfall forecasts from RI observations are not accurate enough for real-time monitoring of drainage systems. In this paper, the Colour Pattern Regression (CPR) algorithm is used to recalibrate the 6 h rainfall values from RI provided by the Agencia Estatal de Meteorología (AEMET) with the observed rain gauge data, using as a case study the metropolitan area of Palma (Spain). [ABSTRACT FROM AUTHOR]

Flood occurred in the Melamchi River on June 15 and recurred on July 31, 2021 have led notorious impacts in Nepal. This study has investigated these extreme flood events and their nexus with climate i.e. precipitation and temperature. The available daily and hourly hydro-meteorological data were analyzed. The regional flow during both flood events were estimated using 1-D hydraulic HEC-HMS model and the correlation among rainfall -runoff, temperature with snow water equivalent were examined. Result show that the Melamchi region found an average annual rainfall of 2610 mm during 1992–2021. Specifically, the middle section i.e. Shermathang and Tarkeghang has observed the highest daily average rainfall of 26.8 mm and 39.2 mm during the first and 61.4 mm and 66.6 mm during the second flood event, respectively. The discharge found at the Melamchi town segment was at 2893 m3/s and 1105 m3/s in the first and second events respectively in which regional contribution into discharge were found significant. The Bhemathang, which is landslide damming area where The daily average discharge observed 357 m3/s and 76 m3/s on both events, respectively. At the Nakote, the rainfall and runoff are poorly correlated while snow water equivalent and temperature showed positive correlation during summer. The snowmelt contribution to discharge was found 9.68 m3/s in the Melamchi River during the Summer season. The regional contribution to discharge and spatial variations of precipitation during flooding events showed that precipitation is the main climatic driver while temporary damming and increasing temperature also contributes to the magnitude of the Melamchi flood. [ABSTRACT FROM AUTHOR]

Accurate characterization of soil hydraulic conductivity influenced by temperature under a centrifugal environment is important for hydraulic and geotechnical engineering. Therefore, a temperature-influenced scaling law for hydraulic conductivity of soil in centrifuge modeling was deduced, and a temperature-controlled falling-head permeameter apparatus specifically designed for centrifuge modeling was also developed. Subsequently, a series of temperature-controlled falling-head tests were conducted under varying centrifugal accelerations to achieve the following objectives: (1) examine the performance of the apparatus, (2) investigate the influence of temperature and centrifugal acceleration on the hydraulic conductivity of sand and its scaling factor, and (3) validate the proposed scaling law for hydraulic conductivity. The main conclusions of the study are as follows. Firstly, the apparatus demonstrated good sealing and effectively controlled the temperature of both the soil specimen and the fluid. Secondly, the hydraulic conductivity of sand was not constant but varied over time, likely due to the presence of radial seepage in addition to vertical seepage as the test progressed. Thirdly, temperature significantly influenced the hydraulic conductivity of sand and its scaling factor under the same centrifugal acceleration. Therefore, it is essential to closely monitor the temperature of models during centrifugal tests. Finally, the measured and calculated values of the scaling factor index for the hydraulic conductivity of sand showed good agreement, verifying the proposed scaling law. [ABSTRACT FROM AUTHOR]

Cargo handling issues affect the ability of large heavy-duty Unmanned Aerial Vehicles (UAVs) to transport cargo and limit the development of large UAVs. Compared to conventional landing gear, hydraulically controlled landing gear can tilt the drone within a specified angle, facilitating smoother loading and unloading of goods. Therefore, it is important to study the hydraulic landing gear control system for a UAV to make the UAV's tilt possible. In this paper, an impedance-based parallel cooperative control method for front and rear landing gear hydraulic systems of large heavy-duty UAVs is presented, which can achieve UAV tilting within a reasonable angle during the loading and unloading of cargoes by large, heavy-duty UAVs. This paper establishes the physical model of the UAV's landing gear, the mathematical model of the hydraulic system, and the kinematic model of the airframe. Through kinematic analysis, the correlation between each hydraulic dive unit's (HDU's) extension length in the landing gear and the UAV's tilt angle is established. This paper introduces a two-fold based-loop parallel control technique, featuring angle based-loop control for the UAV's front and position based-loop control for its rear landing gear. It aims to enable the UAV to freely tilt for loading and unloading cargo at a predetermined angle, by measuring the UAV's tilting angle, the HDU's force exerted on the landing gear, and its positional parameters. Ultimately, the practicality of this technique is confirmed through simulations and experiments. [ABSTRACT FROM AUTHOR]

Seamless integration of three-dimensional (3D) terrain models and hydraulic structure models is a technical challenge in the construction of 3D virtual scenes for irrigation areas. This study proposes a level-of-detail (LOD)-based dynamic classification integration method for hydraulic structure models and 3D terrain models, called CM-D-LOD. Hydraulic structures are classified according to their point, line, and surface morphologies, as well as their dependence on or independence of the terrain into four categories: point-like hydraulic structures independent of terrain, line-like hydraulic structures dependent on terrain, surface-like hydraulic structures dependent on terrain, and surface-like hydraulic structures independent of terrain. By utilizing the proposed model classification integration method, a visualization management platform for virtual geographical environments of irrigation areas is developed, and experiments are conducted in the Zhuluo Ba Irrigation Area within the large economic zone along China's eastern coast. Results demonstrate that the integration accuracy can be controlled between 0.2 and 0.7 m and that the 3D virtual scene of the irrigation area can be updated in real time. The proposed classification integration method transforms the traditional global model integration approach into a more efficient one, significantly improving the efficiency of constructing virtual geographical scenes for irrigation areas. [ABSTRACT FROM AUTHOR]

Floods are among the most widespread and recurrent natural disasters globally. In the European region, climate change leads to an increase in the incidence and intensity of flooding. For effective management of the phenomenon, the European Union instituted Directive 2007/60/EC for the assessment and management of flood risks in order to reduce the negative consequences of flooding on human health, economic activities, the environment, and cultural heritage. Cyprus, as a member of the European Union, had to comply with the provisions of the directive. Within the second implementation of the directive, combined 1D/2D hydraulic models were conducted. These data served as a benchmark for the present research, in which the differences in the inundated area, depths, and simulation time are investigated using a full 2D hydraulic simulation. The present research examines two Areas of Potentially Significant Flood Risk, one in an urban and one in a rural area. Overall, the proposed 2D methodology was found to represent inundated areas to a good extent with almost zero deviation in comparison to the 1D/2D method. This study demonstrated the adequacy of the 2D hydraulic simulation method, which offers greater flexibility in modeling a variety of hydraulic scenarios, enabling planning and flood risk management that is vital for protecting communities, infrastructure and the environment from the devastating impacts of floods. [ABSTRACT FROM AUTHOR]

Hydraulic models are essential for predicting, estimating, analyzing, and optimizing long-distance water supply systems. Accurate calibration of these models is crucial for effectively representing the behavior of such complex systems and achieving a comprehensive understanding. However, the limited availability of measured data in actual systems often leads to an ill-posed problem characterized by more variables than equations. This paper proposes a calibration framework based on artificial neural networks (ANN) and adaptive particle swarm optimization to address this challenge. The influence of the number of measurement points and the measurement errors on the calibration results is analyzed within an actual long-distance water supply system featuring multi-branch pipelines. Results showed that ANNs can accurately reconstruct flow rates and pressures at unmeasured nodes, even with very limited measurement data. Compared to conventional calibration methods, the proposed framework can reduce the influence of measurement data uncertainty on calibration results, achieving better calibration accuracy. Additionally, by introducing regularization into the loss function, the constraints of physical laws are incorporated into the neural network's training process, further enhancing the calibration accuracy of the model. [ABSTRACT FROM AUTHOR]

The study evaluates the rain-on-grid (RoG) hydraulic model's sensitivity to digital elevation model (DEM) resolution when simulating an extreme flood in Slovenia. The RoG model is validated against a high-resolution benchmark, showing strong agreement with a Kling-Gupta efficiency of 0.913 and Pearson correlation of 0.964 for a 1 m DEM. Differences are observed in peak shapes and concentration times, attributed to rainfall propagation in RoG grids. DEM resolution significantly impacts performance, with the largest decrease between resolutions of 1 and 5 m. Coarser DEMs yielded higher depths, indicating slope decreases and terrain smoothing. The study concludes that high-resolution DEMs (<1 m) are needed for adequate RoG performance, while commercially available coarser DEMs (30 m) degraded accuracy and should be avoided using this method. Differences from semi-empirical concentration time models are also discussed, and emphasis is placed also on the impacts on water velocity and numerical stability. [ABSTRACT FROM AUTHOR]

Hydraulic modelling of natural floodplain vegetation using leaf area index (LAI) has been applied successfully for non-submerged conditions whereas its suitability for submerged conditions requires further development. This study investigates the vegetative flow resistance at low relative submergences and extends existing LAI-based approaches building upon new flume data and prior experiences from field-scale applications. We provide advanced LAI-based formulas for modelling the flow resistance from emergent to submerged conditions, with water depth up to three times higher than the vegetation height. Such low relative submergences are highly relevant in hydraulic analyses of riverbank and floodplain flows but not adequately represented in existing formulas. The use of the deflected vegetation height as the characteristic height provided the most accurate modelling results, whereas the use of undeflected height resulted in significant errors. As a new development for submerged conditions, we proposed von Kármán scaling factor for improved model predictions. Overall, the results proved that LAI-based modelling is suitable also at low relative submergences for a wide range of vegetation densities (LAI = 1–5) and mean flow velocities (0.05–1.2 m s−1). For both emergent and slightly overtopped vegetation the JAR and VAS approaches outperformed the BAPmod-LAI approach that does not account for reconfiguration. For modellers, we provide a workflow and guidance on the use of the newly developed LAI-based formulas in 1D/2D hydrodynamic models for both emergent and submerged conditions. [ABSTRACT FROM AUTHOR]

Interaction between various components of bridge scour is a complex phenomenon. Bridge submergence during high flooding leads to the scour mechanisms becoming even more complex. Thus, to find the interaction between various components of bridge scour, a detailed investigation has been conducted by using scaled-down models in a hydraulic laboratory. Scour experiments were conducted with free, submerged-orifice, and overtopping flow (OT) under clear-water conditions. The results show that the total interactive scour caused by simultaneous effects of pier, abutment and contraction scour results in a reduced equilibrium scour depth compared to the sum of all individual components acting independently. A comparison with HEC-18 methodology shows that the large bias of over-estimation has been eliminated by the suggested model in this study. However, the interaction of pier scour with vertical contraction scour remains as a sum of individual scour components with the exception of the recommendation of using Lyn's modified model to calculate vertical contraction scour. Field examples from past historical events have been used to validate the model, and they show good agreement with the suggested model. [ABSTRACT FROM AUTHOR]

To date, the traffic-induced dynamic behavior of geosynthetic-encased stone column-supported embankments (GESC) under traffic cyclic loads accompanied by embankment consolidation has not been well studied. Three-dimensional (3D) coupled mechanical and hydraulic modeling is performed using FLAC3D, which considers the fluid flow during the lifespan of three stages: (1) embankment construction (EC): (2) consolidation (C) under embankment surcharge; and (3) cyclic loading (CYC). During the simulation, excess pore pressure, stress concentration, settlement, and lateral displacement are monitored, and the total settlement and lateral displacement could be easily obtained by accumulating the components of the three stages. Parametric analyses are conducted on the reinforcement forms and cyclic loading characteristics that include the dynamic stress amplitude and loading frequency. The ordinary stone (OSC) and GESCs could reduce the settlement and lateral displacement during each stage by improving the strength of the foundation and accelerating drainage consolidation; however, GESCs outperform the columns without geoencasement. In addition, the stress concentration ratio under embankment filling decreased with the increase in the dynamic stress amplitude and loading frequency, which led to the increase in the percentage of the cyclic loading-induced settlement to total settlement. [ABSTRACT FROM AUTHOR]

One of the most perilous natural hazards is flooding resulting from dam failure, which can devastate downstream infrastructure and lead to significant human casualties. In recent years, the frequency of flash floods in the northern part of Nicosia, Cyprus, has increased. This area faces increased risk as it lies downstream of the Kanlikoy Dam, an aging earth-fill dam constructed over 70 years ago. In this study, we aim to assess potential flood hazards stemming from three distinct failure scenarios: piping, 100-year rainfall, and probable maximum precipitation (PMP). To achieve this, HEC-HMS hydrologic model findings were integrated into 2D HEC-RAS hydraulic models to simulate flood hydrographs and generate flood inundation and hazard maps. For each scenario, Monte Carlo simulations using McBreach software produced four hydrographs corresponding to exceedance probabilities of 90%, 50%, 10%, and 1%. The results indicate that all dam breach scenarios pose a significant threat to agricultural and residential areas, leading to the destruction of numerous buildings, roads, and infrastructures. Particularly, Scenario 3, which includes PMP, was identified as the most destructive, resulting in prevailing flood hazard levels of H5 and H6 in the inundated areas. The proportion of inundated areas in these high hazard levels varied between 52.8% and 57.4%, with the number of vulnerable structures increasing from 248 to 321 for exceedance probabilities of 90% and 1%, respectively. Additionally, the number of flooded buildings ranged from 842 to 935, and 26 to 34 km of roads were found to be inundated in this scenario. These findings revealed the need for authorities to develop comprehensive evacuation plans and establish an efficient warning system to mitigate the flood risks associated with dam failure. [ABSTRACT FROM AUTHOR]

Flooding represents the greatest natural threat to the UK, presenting severe risk to populations along coastlines and floodplains through extreme tidal surge and hydrometeorological events. Climate change is projected to significantly elevate flood risk through increased severity and frequency of occurrences, which will be exacerbated by external drivers of risk such as property development and population growth throughout floodplains. This investigation explores the entire flood hazard modelling chain, utilising the nonparametric bias correction of UKCP18 regional climate projections, the distributed HBV-TYN hydrological model and HEC-RAS hydraulic model to assess future manifestation of flood hazard within the Broadland Catchment, UK. When assessing the independent impact of extreme river discharge and storm surge events as well as the impact of a compound event of the two along a high emission scenario, exponential increases in hazard extent over time were observed. The flood extent increases from 197 km2 in 1990 to 200 km2 in 2030, and 208 km2 in 2070. In parallel, exponential population exposure increases were found from 13,917 (1990) to 14,088 (2030) to 18,785 (2070). This methodology could see integration into policy-based flood risk management by use of the developed hazard modelling tool for future planning and suitability of existing infrastructure at a catchment scale. [ABSTRACT FROM AUTHOR]

This paper endeavors to tackle the issue of horizontal vibrations encountered in high-speed and ultra-high-speed elevator cabins during operation. Given the limitations of traditional passive-control guide shoes in effectively mitigating these vibrations and the complexity and cost associated with active control systems, a novel approach involving passive-control rolling guide shoes (PCRGS) integrated with hydraulic damping is explored. The PCRGS incorporates a hydraulic actuator and hydraulic damping, which can be modeled by a mechanical and hydraulic co-simulation model using AMESim2020 software. The simulation reveals a substantial reduction in cabin vibrations equipped with PCRGS. Specifically, under pulse excitation, the reduction ranges from 26.2% to 27.5%; under white noise excitation, it varies between 14.3% and 17.1%; and under sine wave excitation, the reduction spans 21.2% to 24.1%. Notably, the system meets the stringent 'Excellent' (<=0.07 m/s2) performance criteria under sine wave excitation at lower frequencies, signifying its high effectiveness. These findings not only underscore the potential of hydraulic passive-control guide shoes in mitigating elevator vibrations but also provide invaluable guidance for their further development and refinement. [ABSTRACT FROM AUTHOR]

Almost all multipurpose reservoirs in Romania were put into operation 30–50 years ago or even earlier. Meanwhile, a large volume of hydrologic data has been collected, and the initial design flood should be reconsidered. Consequently, the operating rules of flow control structures (bottom gates and weir gates) should be re-examined, mainly for medium and low-frequency floods. The design flood is not unique, being characterized by different shapes and time to peak, which has consequences for flood mitigation rules. Identifying the critical design flood is an important preliminary step, although it is usually neglected in flood management. Simulating the operation of the Stânca–Costești reservoir on the Prut River, it was found that the design flood corresponding to the maximum value of the compactness coefficient is the most difficult to mitigate considering the specific conditions of the dam and the reservoir: the prescribed conservation level in the reservoir, and the design flood volume of medium and rare floods that far exceeds the flood control volume. These conditions can jeopardize both dam safety and downstream flood protection. The main steps of the proposed approach are as follows: (1) developing the hydraulic model; (2) statistical processing of the registered floods and defining critical design floods for different AEPs (Annual Exceedance Probabilities); (3) deriving optimal operation rules based on a simulation-optimization model; (4) implementing real-time adaptive operation of the mechanical outlets; and (5) critically assessing the operating rules after the event. Based on the hydrological forecast, if necessary, new outlets are put into operation while keeping the ones already activated. Based on the hydrological forecast and properly operated, the safety of the Stânca–Costești dam is guaranteed even in the event of a 0.1% CC (Climate Change) flood. However, for floods greater than 1% magnitude, the carrying capacity of the downstream riverbed is exceeded. The main gaps addressed in this paper are the following: (1) the establishment of critical design floods, and (2) the adaptive operating rules of outlet devices aimed at optimizing flood control results, using short-term flood forecasts. [ABSTRACT FROM AUTHOR]

The paper describes the implementation of internal boundary conditions in the 1D ORSADEM hydraulic model to simulate the effect of a hydraulic in-line structure. The proposed model introduces a simplified representation of the bridge geometry by imposing an equivalent narrowing, computed according to the opening size and characteristics, combined with the mass and energy balance at the structure. The model is then applied to a series of experimental tests concerning the propagation of shock waves through different types of bridges, representing different flow conditions, from free surface flow to overflow. The tests are also simulated with the original 1D ORSADEM model, including the standard head losses and the cross-section narrowing due to the presence of a structure. The comparison with the experimental measurements shows that the proposed model can simulate the shock wave flow through the bridges with a higher accuracy than the standard formulation. These findings highlight the possibility of properly evaluating the backwater effect at bridges even with a simple 1D model if the physical narrowing of the cross-section is modeled. [ABSTRACT FROM AUTHOR]

Floods are one of the most common natural calamities and the disastrous action of flood becomes stringent when the floods are caused by dam failures. It is quite difficult to predict the failure of dam however the technique of dam break analysis provides an effective way to understand the flood wave generated due to assumed failure of dam. The present work focuses on dam break analysis of Ajwa dam constructed on river Surya, a tributary of river Vishwamitri. The work is divided into two parts. The first part consists of hydrological modeling of Vishwamitri basin using SWAT model and estimates the flood for 20-year return period and further calibrating and validating the model in SWATCUP 2019 using SUFI2 algorithm. The maximum flood calculated from SWAT model is taken as lateral inflow in dam break model setup. The breach parameters have been adopted as per the guidelines provided by Central Water Commission. Time of arrival of dam break flood at important locations downstream of Ajwa dam has been identified. The results reflect the potential of such a study to encompass the emergency action plans to safeguard the public and property in case of the possible flood event due to dam break. [ABSTRACT FROM AUTHOR]

Riverbank and in-stream protection are crucial in numerous river stretches, where erosion of banks and bed material instigates river course alterations, consequently leading to land and property damage. In large Indian braided rivers like Brahmaputra, implementing tetrahedron frames commonly referred to as 'porcupines' has emerged as a cost-effective strategy for river training, yielding commendable outcomes in near bank sedimentation. Using flexible river training structures, such as porcupine, presents an appealing option for managing braided river channel networks in areas where permanent control structures like groynes or dams prove excessively costly or potentially ineffective, particularly in systems exhibiting highly dynamic flow regimes and morphology. This work aims to develop a hydrodynamic model that integrates the porcupine systems within its framework. The model's effectiveness was assessed through a field test near Nematighat, Brahmaputra River, in collaboration with Assam's Water Resources Department. The mathematical modelling provided some valuable insights regarding the flow characteristics surrounding the porcupine structure, shedding light on its hydrodynamic behaviour. [ABSTRACT FROM AUTHOR]

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