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With the rapid growth of the global population and increasing pressures on freshwater resources, water scarcity has become one of the most pressing challenges worldwide. Agriculture accounts for approximately 70% of global freshwater consumption, making the efficient use of water in agricultural irrigation systems essential for sustainable water management. Irrigation valves, as key components in precision agricultural irrigation systems, critically influence the efficiency and reliability of water delivery through their hydraulic performance. This study presents a comprehensive quantitative review of the hydraulic characteristics and optimization of irrigation valves based on research published from 2005 to 2024, drawing from CNKI and Web of Science (WOS) databases. The review identifies research hotspots and evolving trends over time and systematically examines the evaluation indices used to assess hydraulic performance, including core parameters such as flow capacity, pressure loss, and cavitation, alongsi

The article presents a comprehensive analysis of the hydraulic characteristics of ash suspensions, in particular the removal of ash from the Dnieper Hydroelectric Station. The importance of this research is justified by the relevance of understanding hydrodynamic processes in suspensions, which is crucial for the efficiency of mineral resource processing. The study focuses on the investigation of the physico-chemical properties of suspensions, which is fundamental for the development and optimization of technological processes. The main goal of the article is to determine the discrepancies between theoretical calculations and experimental data in the context of the hydraulic characteristics of ash suspensions. Focusing on this issue, the research aims to make an important contribution to the accuracy of prediction and calculation of the behavior of suspensions, which has important practical applications. The research methodology includes a series of experiments to measure various hydraulic parameters of the suspension, including suspension density, solid phase weight content, and porosity. The experiments are based on a detailed analysis of ash samples collected from the Dnieper Hydroelectric Station. It is established that theoretical formulas for determining hydraulic characteristics are well confirmed experimentally. The difference is due to the accuracy of measuring the density of the solid phase and errors in measuring weight and volume; it is sufficiently small and does not have a fundamental character.

Fault rock is a typical hazardous material of water–silt inrush during the excavation in underground mines. To investigate hydraulic characteristics of fault rock during the water–silt inrush, a one-dimensional radial three-phase flow model of water–rock–silt was established in this study. In the proposed model, the mass conservation and continuity equations of the three-phase flow were obtained; the rock particle migration and the momentum conservation of the three-phase fluid migration were described by erosion constitutive equations and non-Darcy flow equations, respectively. The laboratory tests of porosity and the evolution of volume discharge rate were compared, and the accuracy of the proposed three-phase model was verified by the comparison results. From the test and numerical results, a high standard deviation of repeated results is observed in the case with high silt concentrations, and the erosion effect is inhibited by the silt flow. Last but not least, the temporal–spatial distribution of hydraulic properties is obtained by the numerical simulation: With the progress of the three-phase flow, rock particles near the fluid outlet are first fluidized and constantly migrate outward, resulting in an increase of the porosity and permeability in fault rock. Subsequently, water-conducting pathways are gradually formed inside the fault rock, and then more fluidized rock particles flow out. Finally, the fluidized rock particles have completely migrated, and the porosity and permeability tend to be stable with the more significant non-uniform spatial distribution.HighlightsA one-dimensional radial three-phase flow model of water-rock-silt is established.Mass conservation, continuity, erosion constitutive and non-Darcy flow relations are considered.Laboratory tests are designed to verify the proposed model from porosity and volume discharge rate.Temporal-spatial distribution of hydraulic properties during water-silt inrush is obtained.

Measuring open channel flows has been a major challenge at the field level. Because of the fact that the measuring devices are to be made from procedures and materials prescribed in standard codes. Weirs over a period of time had been used to measure discharges in open channel systems. But non-availability of standard material at village level proves to be a major bottleneck in implementing weirs as field measurement devices. The present experimental study is an attempt to prove the good hydraulic performance of weirs made of locally available metal sheets. That use of complicated material and machining is not necessary in the fabrication of rectangular weir. A discharge formula for the rectangular weir of different sizes is extensively studied. From the experimental study it is concluded that the Cd value for each weir is nearly same. Also material and slight variation in thickness has no effect on the Cd value in case of rectangular sharp crested weir.

Integrated vertical flow constructed wetland (IVCW) is a new type of ecological wastewater treatment, and its internal hydrodynamic characteristics are crucial for the efficiency of pollutant removal. To enhance the hydrodynamic characteristics and pollutant removal efficiency of IVCWs, this study systematically investigated the influence mechanisms of substrate arrangement, layer thickness ratio, and hydraulic load on the internal flow field and hydrodynamic characteristics of the IVCW system using CFD technology. Based on these findings, an optimized IVCW system was proposed, and its pollutant removal performance was examined through field measurements. The results showed that the highest hydraulic efficiency within the system (λ = 0.835) was achieved when the substrate was arranged in descending order of resistance coefficient from top to bottom (medium, high, low), with a layer thickness ratio of 1:4:1 and a hydraulic load of 0.7 m/d. Compared to the control group, the optimized IVCW exhibited significantly higher average removal rates for COD (Chemical Oxygen Demand), TP (Total Phosphorus), and TN (Total Nitrogen).This study provides technical support for the improvement and application of the IVCW system and holds significant implications for ecological wastewater treatment.

The cemented soils by trench cutting re-mixing deep (TRD) wall or trench cutting assembled diaphragm (TAD) wall are a mixture of various soils. The physical and mechanical properties of these cement-stabilized soils are thus not only affected by construction technologies but also significantly controlled by cement content and soil texture. Three typical soils, including clay soil, silty soil, and fine sand, were used to prepare samples of cement-stabilized soils with different combinations of cement content and soil texture. Then, the workability (including fluidity, cohesion, and water retention), strength, hydraulic, and microstructure characteristics of different cement-stabilized soils were investigated by depth compression, permeability, and microstructural tests. Results indicate that there should be a higher water-cement ratio for clay soil while a low value for fine sand to achieve the required compactness. The unconfined compressive strength of cement-stabilized soils increased linearly with cement content, while their permeability had an approximate power relationship with cement content. The permeability magnitude of cement-stabilized composite soils was greatly affected by the proportion of the soil with high permeability. The clay soil could partly improve the pore structure of cement-stabilized composite soils and reduce permeability due to fine particles’ high activity, which was further confirmed by the microstructural analysis. The relationship between unconfined compressive strength and permeability coefficient was approximately consistent with a power function. The unconfined compressive strength of cement-stabilized soils decreased linearly with porosity, and the logarithm to base 10 of permeability coefficients of cement-stabilized soils increased with porosity.

Dump slopes have experienced severe rill erosion and threaten the safety of the ecological environment. Although vegetation restoration has improved the ecological environments of mining areas, because dump slopes have unique soil properties, the mechanism by which roots impact rill erosion on dump slopes remains unclear. Based on the in-situ runoff scouring experiment of the dump slope and the use of bare land as the control (CK), the influence of roots on rill erosion characteristics (RECs) of the dump slopes were analyzed for three root types of vegetation, specifically, tap root–Artemisia ordosica (AO), fibrous root–Elymus dahuricus (ED) and tap + fibrous root–Artemisia ordosica + Elymus dahuricus (AE). The results indicated that, compared to the CK, the roots reduced the rill erosion rate (Ts) by 75.61%–86.64% and the rill depth (Rd) by 64.62%–81.06% on the dump slopes. However, they increased the runoff depth (h) and Reynolds number (Re) by 2.02%–37.14% and 36.1%–172.0%. Among them, AO significantly increased Manning roughness coefficient (n), Darcy–Weisbach friction factor (f) and shear stress (τ), whereas ED and AE were most effective in reducing h and Ts, respectively. 59.9% of the RECs of dump slopes were explained by roots and hydraulic characteristics together. Furthermore, PLS-SEM analysis revealed that roots affect hydraulic characteristics by changing surface roughness and runoff friction resistance, ultimately leading to differences in the RECs of dump slopes, which explained 98.5% of the RECs on dump slopes with a 72.2% goodness-of-fit. The above results further enhance the understanding of the role of roots in controlling rill erosion on dump slopes. •Hydrodynamic and rill erosion were influenced by roots on the dump slopes.•Roots and hydrodynamics explain 59.9 % of the rill erosion of dump slopes.•The influence mechanism of the root on rill erosion of dump slopes was revealed.

The improved iterative method for the simultaneous determination of the hydraulic properties of growing media from One-Step experiment by Bibbiani, is performed and compared with simplified equations by Valiantzas and Londra. Brooks and Corey equation for water retention, and Kozeny power equation for hydraulic conductivity characterized the hydraulic properties of the porous media. The iterative procedure is applied on pure peat, pumice, and their mixes. The One- Step method has been previously optimized: processing the mean cumulative outflow curves recorded versus time, an estimation of diffusivity, and therefore of the hydraulic functions, is derived. Estimated water retention curve is compared with nine experimental data, and with the estimation of the Van Genuchten model, via the RETC code. Bibbiani’s and Van Genuchten’s models overlap except for the “very wet” range near saturation, whereas the Valiantzas and Londra’s procedure didn’t get satisfactory results. In regard to diffusivity, a good similarity between Bibbiani’s and Van Genuchten-Mualem’s curves can be assessed, while Valiantzas and Londra’s procedure generally results in higher values. Due to the lack of estimation of the water retention curve, Valiantzas and Londra’s procedure fails to estimate the hydraulic conductivity function, whereas Bibbiani’s and Van Genuchten-Mualem’s curves match together in most cases.

This study investigated the hydraulic characteristics of stormwater sumps and their design optimization for sediment retention using physical experiments. Particle image velocimetry was utilized to measure the flow field, and the use of internal structures was investigated for improving solids retention. Results indicate that these internal structures can significantly improve the sediment removal efficiency of suspended solids with an average size of 125 μm, resulting in an efficiency improvement of 20–30%. Additionally, a modified Péclet number was proposed to more accurately evaluate the sediment removal efficiency of stormwater sumps, and recommendations were provided for further improving and optimizing sump design. This study provides insights into the hydraulic characteristics of stormwater sumps and has important implications for optimizing and designing particle removal systems for various industrial and environmental applications.

A microchannel heat sink (MCHS) is a potential solution for chip and battery thermal management. The new microchannel structure is beneficial for further improving the thermal-hydraulic performance of MCHSs. Inspired by leaf veins, six new channel structures were designed, and the effects of the channel structures (three parallel structures named PAR I, II, and III and three pinnate structures named PIN I, II, and III), channel depths (0.4, 0.8, and 1.6 mm), and heat fluxes (20, 50, and 80 kW/m2) were investigated via numerical simulation. The cooling medium was water, and the heating area was 40 × 40 mm2. Both PAR II and PIN III exhibit superior overall performance, characterized by the highest Nusselt number and the lowest heating wall temperature. Moreover, PIN III demonstrates the lowest standard deviation in heating wall temperature, while PAR II exhibits the lowest friction factor. The greater the channel depth is, the larger the solid–liquid contact area is, leading to a reduced wall temperature at the interface under identical conditions of inlet Reynolds number and heating wall heat flux. Consequently, an increase in the Nusselt number corresponds to an increase in the friction factor. The maximum value and standard deviation of the heating wall temperature increase with increasing heat flux, while the Nusselt number and friction factor remain unaffected. The overheating near the two right angles of the outlet should be carefully considered for an MCHS with a single inlet–outlet configuration.