Search Results (205)

This study presents a data-driven methodology to optimize the operational efficiency of a tugboat equipped with a Voith–Schneider Propeller (VSP) based on full-scale fuel consumption and vessel performance data. The objective is to identify optimal combinations of engine RPM and propeller pitch to reduce fuel consumption during low-demand phases without compromising maneuverability. Sea trials were conducted under controlled conditions using a dual flowmeter system and onboard speed measurements. The data enabled the construction of performance curves, efficiency ratios, and interpolated maps of fuel consumption. Optimal configurations were identified across defined speed ranges, and continuous efficiency zones were visualized through iso-consumption and contour plots. The results reveal a nonlinear relationship between propeller pitch, speed, and fuel demand, with maximum efficiency occurring at medium-to-high pitch values and speeds between 3 and 6 knots. This methodology provides a replicable tool for energy management in port operations and supports informed decisions during accompanying operations and standby periods. Efficiency differences over 300% between RPM–pitch settings were found, highlighting the operational impact of informed configuration choices. Moreover, the structured dataset and visual analysis framework lay the groundwork for future digital twin models aimed at enhancing operational efficiency in VSP-powered tugboats. Full article

The high water demand of rice cultivation is mainly due to flood irrigation, which requires large volumes not only to meet evapotranspiration needs, but also due to losses from percolation, lateral seepage, and surface runoff. In addition to lowering water use efficiency, surface runoff may transport nutrients. This study aimed to calibrate and validate a daily water balance model to estimate surface runoff losses across three rice-growing seasons. During the first two seasons, different model components were calibrated by comparing simulated and observed water depths. In the final season, the calibrated model was validated using direct runoff measurements obtained from weirs and flowmeters. Results showed strong agreement between model estimates and direct measurements of water depth and surface runoff. Linear regression models showed good fit, with coefficients of determination (R²) above 0.80 for water depth and 0.79 for runoff. A validated daily water balance model, combined with periodic monitoring of water depth, proved to be a reliable tool for estimating surface runoff during the rice-growing season. Total runoff—from irrigation, rainfall, and final drainage—represented between 7.5% and 18% of the total water input. This approach offers a practical tool for improving irrigation water management and understanding runoff-driven nutrient transport. Full article

The role of weirs in flow regulation in water resources infrastructure and flood control is well known. In the meantime, the study of full-width plate weirs (FWPW), due to their wide application and lacking findings, is of great importance. In this study, experimental models were conducted at Babol Noshirvani University of Technology to investigate flow passing through FWPWs with five different heights (p = 0.07, 0.09, 0.11, and 0.15 m) under eight discharge conditions (Q = 1.4 to 6.3 L/s). The experiments were carried out in a flume measuring 4 m in length, 0.6 m in width, and 0.2 m in height. The discharges were measured with a calibrated flowmeter, and the water depths upstream of the weir (h) and the tailwater depths (h₁) were measured with a point gauge with an accuracy of 0.1 mm. For each test, the discharge coefficient (C_d), relative residual energy (E₁/E₀), and relative energy dissipation ((E₀ − E₁)/E₀) were computed. The proposed equation for calculating discharge achieved good accuracy with RMSE = 0.0002, MAE=0.0002, and R² = 0.997. Results show a reducing trend of C_d by increasing h/P, which is compatible with previous results. It was observed that at a constant discharge, relative residual energy reduces by an average of 47% by increasing weir height, and at a constant P, increasing flow discharge increases it a little. A novel accurate equation for relative energy dissipation in FWPW was proposed based on h/P that provided specific constant coefficients for each p value. Full article

Clamp-on ultrasonic flowmeters serve as an important tool for on-site testing of gas flow meters. However, its accuracy is significantly affected by the actual flow field, thus limiting its application scenarios. To address this issue, this study focuses on typical industrial disturbance structures and obtains the evolution and distribution of non-ideal flow fields downstream of disturbances through experiments and numerical simulations, as well as their effects on velocity and flow measurement errors. The results indicate that when traditional reflection or diagonal measurements were used in the downstream of disturbances, the flow deviation was largely dependent on the installation position and angle of the clamp-on ultrasonic flowmeter. This introduced significant uncertainty and bias, rendering it impossible to correct measurement results through quantitative coefficients. Utilizing a dual-channel measurement method can enhance measurement accuracy. When two sets of sensors perpendicular to each other were used to combine the reflection measurement path, the deviation fluctuation downstream of disturbances can be effectively controlled within the range of ±2%, irrespective of the installation angle. This measurement approach significantly reduced the distance limitations on the distance of the straight pipe section during the use of clamp-on ultrasonic flowmeters. Full article

This study presents a robust methodology for the indirect estimation of groundwater abstraction for irrigation at the scale of individual wells, addressing a key gap in data-scarce agricultural settings. The approach combines NDVI time series, crop water requirement modelling, and spatial analysis of irrigation systems within a GIS environment. A soil water balance model was applied to Homogeneous Units of Analysis, and irrigation requirements were estimated using an ensemble approach accounting for key sources of uncertainty related to phenology detection, soil moisture at sowing (%SAW), and irrigation system efficiency. A spatial linkage algorithm was developed to associate individual wells with the irrigated areas they supply. Sensitivity analysis demonstrated that 10% increases in %SAW resulted in abstraction reductions of up to 1.98%, while 10% increases in irrigation efficiency reduced abstractions by an average of 6.48%. These findings support the inclusion of both parameters in the ensemble, generating eight abstraction estimates per well. Values ranged from 33,000 to 115,000 m³ for the 2023 season. Validation against flowmeter data confirmed the method’s reliability, with an R² of 0.918 and an RMSE equivalent to 9.3% of the mean observations. This approach offers an accurate, spatially explicit estimation of groundwater abstractions without requiring direct metering and offers a transferable, cost-effective tool to improve groundwater accounting and governance in regions with limited monitoring infrastructure. Full article

Induction in pineapples requires the targeted delivery of specific chemical solutions into the plant’s central core to enable batch management, a task currently reliant on manual operation. This study addressed this challenge by analyzing the physical characteristics of pineapple plants and establishing a perception-based mathematical model for core position localization. An integrated hardware–software system was developed, complemented by a human–machine interface for real-time operational monitoring. Comprehensive experiments were conducted to evaluate the spraying accuracy, nozzle response time, and prototype performance. The results demonstrate that the actuation system—comprising solenoid valves, pumps, and flowmeters—achieved an average spraying error of 2.72%. The average nozzle opening/closing time was 0.111 s; with a standard operating speed of 0.5 m/s, a delay compensation distance of 55.5 mm was implemented. In human–machine comparative trials, the automated system outperformed manual spraying in both efficiency and stability, with average errors of 7.1% and 6.4%, respectively. The system reduced chemical usage by over 67,500 mL per hectare while maintaining a miss-spray rate of 5–6%. Both two-tailed tests revealed extremely significant differences (p < 0.001). These findings confirm that the developed solution meets the operational requirements for pineapple floral induction, offering significant improvements in precision and resource efficiency. Full article

Natural gas is one of the major sources of energy supply, where the measurement of natural gas is very crucial. The flowmeter fastening apparatus typically used tightened screw nuts for clamping. This study designed a clamping device for a DN300 specification gas pipe, which directly clamped the flowmeter with the flange by external force. This clamping method is more efficient compared to previous methods. Based on the fabricated flowmeter clamping experimental device, a simplified numerical model was established. A detailed analysis was conducted on several key components, including the screw nuts, flange, flowmeter, and pipe. The results indicate that the designed clamping devices can operate safely and reliably. The stress distribution is reasonable in the entire clamping device. The average stress in the flowmeter flange is significantly greater than the pressure of gas within the pipe. The stress distribution on the screw nuts generally shows a pattern of higher stress in the central area and lower stress in the surroundings. The maximum stress of the flowmeter clamping device is located on the flowmeter flange, reaching 146 MPa. The maximum stress value of the nut is the smallest, which is 117 MPa. Full article

The universalization of basic sanitation remains a challenge. For the development of sanitation infrastructure projects, it is essential to use water consumption data that accurately reflect reality, ensuring greater precision. This study aimed to determine the per capita contribution to fecal sewage (Cp) in six quilombola residences in Goiás (Brazil). The research was conducted in two phases: (a) a literature review on Cp in similar communities (CpL) and (b) the determination of Cp in six residences from different rural communities (CpP), varying in the number of inhabitants (8, 8, 5, 2, 1, and 1 persons in households R1 to R6, respectively). Flow measurements were obtained using a volumetric flowmeter (nominal flow rate of 1.5 m³/h) installed in the water pipeline supplying the toilet(s) of each household. A dearth of Cp data was observed in the literature, particularly for rural areas. Research on this topic remains in its infancy, as evidenced by the small number of publications (nine papers) published between 2006 and 2022, of which 44.4% reported on-site measurements. In the present study, the CpP ranged from 12.10 L/cap.day to 21.79 L/cap.day, with a mean of 16.22 L/cap.day (CV = 0.239). These calculated values lie within the lower (9.9 L/cap.day) and upper (51.5 L/cap.day) ranges reported in the literature. Generally, estimated data are higher than values calculated from flowrate measurements, highlighting the importance of direct measurements—which can also help reduce construction costs. Therefore, it is recommended that flowrate measurements and Cp calculations be expanded to residences with diverse demographic and geographic characteristics, also incorporating meteorological data, to obtain more accurate results. Full article

In this paper, the D3Q19 multiple-relaxation-time (MRT) lattice Boltzmann method (LBM) for large eddy simulation (LES) was employed to optimize the shape of the vortex generator in a triangular vortex flowmeter. The optimization process focused on the vortex shedding frequency, lift force per unit area, and symmetry of the vortex street. The optimal shape of the vortex generator was determined to feature a 180° incoming flow surface, a concave arc side with a curvature radius of 25 mm, and a fillet radius of 4 mm at the end. Numerical simulations revealed that the optimized vortex generator achieves a 2.72~13.8% increase in vortex shedding frequency and a 17.2~53.9% reduction in pressure drop and can adapt to the flow conditions of productivity fluctuations (6.498 × 10⁵ ≤ Re ≤ 22.597 × 10⁵) in the gas well production. The results demonstrated significant advantages, including low pressure loss, minimal secondary vortex generation, high vortex shedding frequency, and substantial lift force. These findings underscore the robustness and efficiency of the LBM-LES method in simulating complex flow dynamics and optimizing vortex generator designs. Full article

This study investigates the correlation between bluff body parameters and vortex flowmeter performance through big data modeling and machine learning techniques. Vortex flowmeters are widely used in industry due to their high accuracy and minimal pressure loss. Nonetheless, optimizing their design remains challenging due to the complex relationship between input and output parameters. Symmetry in bluff body design is crucial for vortex formation and stability. In this study, Latin Hypercube Sampling (LHS) was employed to generate 10,000 symmetry bluff bodies, and efficient serial simulations were conducted using Ansys Fluent, significantly reducing computational costs compared to traditional CFD methods. A regression model was developed using scikit-learn to map eight geometric parameters to eight performance indicators, achieving excellent fitting accuracy with residuals far smaller than the simulation accuracy of ANSYS Fluent. Through Grey Relational Analysis (GRA), objective function analysis, and in conjunction with CFD contour maps, this study has analyzed the relationships between input and output parameters and their impact on the Karman vortex street. This work has significantly improved the speed of big data collection and provided a solid theoretical foundation for data-driven optimization through big data analysis. In addition, the improvement of existing machine learning methods has achieved high-precision prediction and system parameter optimization, promoting the design of vortex flowmeters. Full article

The accurate monitoring of flow velocity is crucial in applications such as blood microcirculation and microfluidic systems. However, the high sensitivity of current hot wire flowmeters is often achieved at the expense of increasing the initial temperature, which imposes significant limitations when measuring blood or other temperature sensitive fluids. In this study, a fiber sensor probe with a plano-concave cavity, fabricated from a PbS quantum dots (QDs)-doped photoresist, is proposed for the sensitive flow velocity detection of microfluidics. In the proposed hot wire-based micro-flowmeter, the excitation laser (980 nm) is efficiently absorbed and converted into thermal energy, while minimally affecting the high-quality interference of the cavity at the C-band. The experimental results show that only a 3 °C increase in temperature is required for flow velocity monitoring, with a sensitivity of 7.7 pm/(mm/s) achieved within a linear response range of 3.82 mm/s to 16.72 mm/s. Additionally, an intensity interrogation scheme is introduced for the hot wire-based fiber sensor probe. This low initial temperature requirement makes the proposed sensor suitable for microfluidics, demonstrating promising potential for use in microcirculation measurement and drug delivery systems. Full article

This article deals with the technical and official possibilities of changing the official data on vehicle fuel consumption in the Slovak Republic. This case study analyzes various methods of measuring fuel consumption, including the use of a fuel flowmeter, OBD devices and calculation based on emission tests. The tests took place in laboratory conditions using the roller dynamometer on the Kia Ceed mildhybrid vehicle. Based on the Real Drive Emission requirements, five 1.5 h cycles were repeated in urban, suburban and highway conditions. Using multi-criteria analysis, the methods used to measure fuel consumption are evaluated from the point of view of efficiency, accuracy, and economy. This study contains a real view of the performance of these exams in the conditions of the Slovak Republic. The fuel consumption measured by the OBD device compared to the volumetric flowmeters was at a relative difference of −4.94%. The fuel consumption calculated through exhaust gas emissions was +2.83% compared to the volumetric flowmeters. Full article

The hydraulic model serves as an effective tool for operational simulation, dispatch decision-making, and engineering planning in water distribution systems (WDSs). The increasing complexity of large-scale networks and the growing number of monitoring devices present both challenges and opportunities for the online calibration of WDSs in terms of efficiency and accuracy. To address these issues, this paper introduces a novel strategy, Flowmeter-Monitoring Path-Partitioning (FMPP), for nodal demand calibration of hydraulic models. FMPP partitions nodes based on the monitoring paths of flowmeters, which include all downstream nodes of a given flowmeter. Then, a system of equations is formulated from the mass and energy conservation, and an iterative optimization process is employed to calibrate the nodal demands. This method enables the partitioning of nodes to achieve the optimal granularity, enabling each flowmeter to be calibrated individually and also reducing the calibration parameters through node grouping. The performance of the proposed method has been validated through two comprehensive case studies, demonstrating its superiority to conventional calibration techniques in terms of accuracy, computational efficiency, and practical applicability in real-time nodal demand estimation. This approach meets the requirements for the real-time calibration of nodal demand in complex large-scale pipe networks. Full article

The purpose of this study was to demonstrate the series of processes involved in designing, manufacturing, installing, and operating a practical Surface Image Flowmeter (SIF) system, complete with suitable hardware and software. By ‘practical’, we mean a system capable of automatically measuring discharges in a river 24 h a day, 365 days a year, at 2 min intervals. The equipment required for this practical SIF includes a CCTV camera, a water level gauge, a Linux-based PC for analysis, and lighting for night-time measurements. We also developed software to operate the system. Furthermore, we applied a coordinate transformation method using projective transformation to calculate the area of the measurement cross-section according to changes in water level and to adjust the positions of velocity analysis points within the image. The CCTV captured 20 s video clips every 2 min, which were then analyzed using the Spatio-Temporal Image Velocimetry (STIV) method. For the STIV method, measurement points were set at appropriate intervals on the measurement cross-section, and spatio-temporal images (STIs) were constructed at these points for analysis. The STIs were captured parallel to the main flow direction (perpendicular to the cross-section), and the resulting STIs were analyzed using the hybrid STIV method to calculate the discharge. When the constructed SIF system was tested in a steep-sloped channel at the Andong River Experiment Center, the velocity distribution showed a difference of less than 9% compared to measurements from a traditional current meter, and the discharge showed a difference of around 10% compared to measurements from an Acoustic Doppler Current Profiler (ADCP). Full article

A balanced flowmeter not only inherits the advantages of orifice plate flowmeters but also stabilizes the flow field, reduces permanent pressure loss, and effectively increases the cavitation threshold. To perform an in-depth analysis of flow characteristics through the perforated plate and achieve performance optimization for the liquid hydrogen (LH₂) measurement, a numerical calculation framework is established based on the mixture model, realizable turbulence closure, and Schnerr–Sauer cavitation model. The model is first evaluated through comparison with the liquid nitrogen (LN₂) experimental results of a self-developed balanced flowmeter as well as the measuring setup. The flow coefficient and pressure loss coefficient are especially considered, and a comparison is made with the orifice plane considering cavitation and non-cavitation conditions. The cavitation cloud and temperature contours are also presented to illustrate the difference in the upper limit of the Re between water, LN₂, and LH₂ flow. The results show that compared to LN₂ and water, LH₂ has a larger cavitation threshold, indicating a wider range of Re number measurements. Full article