Pub Date : 2025-12-19DOI: 10.1016/j.flowmeasinst.2025.103168
Eglė Jotautienė , Davut Karayel , Vaidas Bivainis
Uniform seed distribution is essential for optimizing crop yield and enhancing seeding quality in modern agricultural practices. The helicoidal seed tube was developed to regulate seed flow within seed drills just before seeds are dispensed into the furrow, addressing challenges in consistent seed placement. This study presents a Discrete Element Method (DEM)-based approach for measuring the motion characteristics of wheat seeds within such a helicoidal tube, with the goal of enhancing measurement precision in evaluating seed velocity, spacing, and flow consistency. The DEM model was calibrated against experimental data, achieving strong agreement, including a particle flow rate of 1.34 g s−1 and a total discharge of 17.37 g over 20 s. Sensitivity analyses were performed on pitch size, tube inclination, and input flow rate, revealing their influence on seed velocity (0.40–1.30 m s−1), spacing, and the occurrence of flow interruptions. Larger pitch sizes (36 mm and 40 mm) supported smoother flow without blockage even at higher rates. This study offers a validated methodology for quantifying dynamic particle behavior in confined geometries using simulation and bench-scale testing. It contributes to measurement science by providing a structured framework to analyze, validate, and optimize seed flow systems, which can be extended to broader granular flow measurement applications.
在现代农业实践中，种子均匀分布对优化作物产量和提高种子质量至关重要。螺旋形种管的开发是为了在种子被分配到犁沟之前调节播种机内的种子流动，解决种子一致放置的挑战。本文提出了一种基于离散元法（DEM）的小麦种子在螺旋管内运动特性测量方法，旨在提高种子速度、间距和流动一致性的测量精度。DEM模型与实验数据进行了校准，得到了较好的一致性，颗粒流速为1.34 g s−1，总流量为17.37 g / 20 s。对螺距尺寸、管倾角和输入流量进行了敏感性分析，揭示了它们对种子速度（0.40-1.30 m s−1）、间距和流动中断的影响。更大的螺距尺寸（36mm和40mm）即使在更高的速率下也支持更顺畅的流动而不会堵塞。这项研究提供了一种有效的方法来量化动态颗粒的行为在有限的几何形状使用模拟和实验规模的测试。它为测量科学提供了一个结构化的框架来分析、验证和优化种子流系统，这可以扩展到更广泛的颗粒流测量应用。
{"title":"Development and validation of a DEM-based measurement method for analyzing seed motion dynamics in helicoidal seed tubes","authors":"Eglė Jotautienė , Davut Karayel , Vaidas Bivainis","doi":"10.1016/j.flowmeasinst.2025.103168","DOIUrl":"10.1016/j.flowmeasinst.2025.103168","url":null,"abstract":"<div><div>Uniform seed distribution is essential for optimizing crop yield and enhancing seeding quality in modern agricultural practices. The helicoidal seed tube was developed to regulate seed flow within seed drills just before seeds are dispensed into the furrow, addressing challenges in consistent seed placement. This study presents a Discrete Element Method (DEM)-based approach for measuring the motion characteristics of wheat seeds within such a helicoidal tube, with the goal of enhancing measurement precision in evaluating seed velocity, spacing, and flow consistency. The DEM model was calibrated against experimental data, achieving strong agreement, including a particle flow rate of 1.34 g s<sup>−1</sup> and a total discharge of 17.37 g over 20 s. Sensitivity analyses were performed on pitch size, tube inclination, and input flow rate, revealing their influence on seed velocity (0.40–1.30 m s<sup>−1</sup>), spacing, and the occurrence of flow interruptions. Larger pitch sizes (36 mm and 40 mm) supported smoother flow without blockage even at higher rates. This study offers a validated methodology for quantifying dynamic particle behavior in confined geometries using simulation and bench-scale testing. It contributes to measurement science by providing a structured framework to analyze, validate, and optimize seed flow systems, which can be extended to broader granular flow measurement applications.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"108 ","pages":"Article 103168"},"PeriodicalIF":2.7,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145839880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The hydrodynamic entry length is a critical parameter in internal pipe flows, directly influencing pressure drop, wall shear stress, and heat transfer characteristics. While classical correlations typically estimate the entry length as a function of Reynolds number, the role of inlet turbulence intensity has not been systematically quantified. In this study, a combined numerical and experimental investigation is conducted to quantify the dependence of hydrodynamic entry length on inlet turbulence intensity over a wide range of Reynolds numbers as a function of turbulence intensity. Numerical simulations are performed using ANSYS Fluent for Reynolds numbers spanning from 5000 to 150,000 and inlet turbulence intensities ranging from 2 % to 10 %. The entry length is quantified based on the axial development of mean velocity profiles, wall shear stress, and centerline velocity overshoot criteria. The results demonstrate that inlet turbulence intensity has a pronounced influence on the hydrodynamic entry length, especially at low turbulence levels. For inlet turbulence intensities of approximately 2–3 %, the entry length significantly exceeds conventional estimates, reaching values greater than 80–100D, whereas at higher turbulence intensities (8–10 %), the entry length reduces substantially to below 30–40D, depending on the Reynolds number. The influence of pipe diameter on entry length is also examined, revealing consistent scaling behavior with the numerical simulation. Experimental validation using hot-wire anemometry confirms an inlet turbulence intensity of approximately 4.5 %, which agrees well with numerical predictions. An alternative methodology for estimating entry length, independent of conventional velocity-profile-based criteria, is also proposed. The findings provide quantitative guidance for designing pipe flow systems, flow measurement installations, and jet-based thermal and fluid applications.
{"title":"Numerical investigation of entry length dependence on inlet turbulence intensity in pipe flow","authors":"Kuldhir Singh Bhati , Lata Pangtey , Vijai Laxmi , Nagendra Kumar , Harekrishna Yadav","doi":"10.1016/j.flowmeasinst.2025.103170","DOIUrl":"10.1016/j.flowmeasinst.2025.103170","url":null,"abstract":"<div><div>The hydrodynamic entry length is a critical parameter in internal pipe flows, directly influencing pressure drop, wall shear stress, and heat transfer characteristics. While classical correlations typically estimate the entry length as a function of Reynolds number, the role of inlet turbulence intensity has not been systematically quantified. In this study, a combined numerical and experimental investigation is conducted to quantify the dependence of hydrodynamic entry length on inlet turbulence intensity over a wide range of Reynolds numbers as a function of turbulence intensity. Numerical simulations are performed using ANSYS Fluent for Reynolds numbers spanning from 5000 to 150,000 and inlet turbulence intensities ranging from 2 % to 10 %. The entry length is quantified based on the axial development of mean velocity profiles, wall shear stress, and centerline velocity overshoot criteria. The results demonstrate that inlet turbulence intensity has a pronounced influence on the hydrodynamic entry length, especially at low turbulence levels. For inlet turbulence intensities of approximately 2–3 %, the entry length significantly exceeds conventional estimates, reaching values greater than 80–100D, whereas at higher turbulence intensities (8–10 %), the entry length reduces substantially to below 30–40D, depending on the Reynolds number. The influence of pipe diameter on entry length is also examined, revealing consistent scaling behavior with the numerical simulation. Experimental validation using hot-wire anemometry confirms an inlet turbulence intensity of approximately 4.5 %, which agrees well with numerical predictions. An alternative methodology for estimating entry length, independent of conventional velocity-profile-based criteria, is also proposed. The findings provide quantitative guidance for designing pipe flow systems, flow measurement installations, and jet-based thermal and fluid applications.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"108 ","pages":"Article 103170"},"PeriodicalIF":2.7,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145839856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-18DOI: 10.1016/j.flowmeasinst.2025.103159
Yanchao Li , Ruichuan Li , Junru Yang , Jiangcheng Hu
The high-frequency response pilot-operated electro-hydraulic proportional directional valve (HFRPPV) is a hydraulic component with high response speed and high precision, which is widely used in construction machinery, agricultural machinery equipment and large-scale power platforms. Given the nonlinearity, uncertainty, and susceptibility to interference inherent in HFRPPV, the active disturbance rejection control (ADRC) strategy exhibits excellent control performance. To address the problems of traditional ADRC, including poor compensation effect, large system errors caused by mismatch, and the contradiction between dynamic performance and steady-state error, this paper designs a disturbance estimation dynamic integral module and proposes an error-enhanced adaptive disturbance rejection control (EEADRC) strategy. First, the working principle of HFRPPV is analyzed. Then, the mathematical models and simulation models of both HFRPPV and the EEADRC are established. Subsequently, a comparative analysis of ADRC and EEADRC is conducted in terms of control precision and anti-interference ability, and experiments are carried out to verify the accuracy and reliability of the simulation models. The results show that during continuous step changes, the displacement errors of EEADRC were reduced by 1.40 %, 0.34 % and 0.6 % respectively, and the relative displacement error decreased by 78 %, 50.75 % and 42.86 % respectively. Following the application of identical external disturbances, EEADRC is more anti-interference than ADRC. Moreover, when the external disturbance is removed, EEADRC can restore the main spool displacement to its pre-disturbance position, demonstrating stronger anti-interference and adaptive capabilities. Both simulation and experimental results confirm the effectiveness of the proposed control strategy. Since this control strategy does not rely on the mathematical model of the controlled object, it is universally applicable to various controlled objects. The control strategy proposed in this paper effectively solves the inherent defects of traditional ADRC and holds significant theoretical innovation and application value.
{"title":"Error-enhanced aadaptive disturbance rejection control for high-frequency response pilot-operated electro-hydraulic proportional directional valve","authors":"Yanchao Li , Ruichuan Li , Junru Yang , Jiangcheng Hu","doi":"10.1016/j.flowmeasinst.2025.103159","DOIUrl":"10.1016/j.flowmeasinst.2025.103159","url":null,"abstract":"<div><div>The high-frequency response pilot-operated electro-hydraulic proportional directional valve (HFRPPV) is a hydraulic component with high response speed and high precision, which is widely used in construction machinery, agricultural machinery equipment and large-scale power platforms. Given the nonlinearity, uncertainty, and susceptibility to interference inherent in HFRPPV, the active disturbance rejection control (ADRC) strategy exhibits excellent control performance. To address the problems of traditional ADRC, including poor compensation effect, large system errors caused by mismatch, and the contradiction between dynamic performance and steady-state error, this paper designs a disturbance estimation dynamic integral module and proposes an error-enhanced adaptive disturbance rejection control (EEADRC) strategy. First, the working principle of HFRPPV is analyzed. Then, the mathematical models and simulation models of both HFRPPV and the EEADRC are established. Subsequently, a comparative analysis of ADRC and EEADRC is conducted in terms of control precision and anti-interference ability, and experiments are carried out to verify the accuracy and reliability of the simulation models. The results show that during continuous step changes, the displacement errors of EEADRC were reduced by 1.40 %, 0.34 % and 0.6 % respectively, and the relative displacement error decreased by 78 %, 50.75 % and 42.86 % respectively. Following the application of identical external disturbances, EEADRC is more anti-interference than ADRC. Moreover, when the external disturbance is removed, EEADRC can restore the main spool displacement to its pre-disturbance position, demonstrating stronger anti-interference and adaptive capabilities. Both simulation and experimental results confirm the effectiveness of the proposed control strategy. Since this control strategy does not rely on the mathematical model of the controlled object, it is universally applicable to various controlled objects. The control strategy proposed in this paper effectively solves the inherent defects of traditional ADRC and holds significant theoretical innovation and application value.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"108 ","pages":"Article 103159"},"PeriodicalIF":2.7,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-17DOI: 10.1016/j.flowmeasinst.2025.103167
Haozhe Jin , Zheng Xu , Chunyu Wang , Xiaofei Liu , Chao Wang , Lite Zhang , Pengxuan Li , Genfu Xu
In the coal gasification industry, the black water flash system, as a critical link between the gasifier and solid-liquid separation unit, subjects its valves to long-term extreme operating conditions. This study investigates the flow dynamics and damage characteristics of coal gasification blackwater valves at 25 %–85 % opening degrees using combined erosion and electrochemical models. The systematic examination of opening degree and particle size effects reveals that particles in the midstream region exhibit trajectory deflection toward the valve inlet side, forming annular paths around the valve core. This phenomenon is identified as the primary mechanism responsible for the intensified wear observed on the rear surfaces of both the valve core and body. The wear reaches a local peak at 25 % opening, while demonstrating a marked reduction at 40 % opening. At 85 % opening, the valve body and core exhibit the lowest iron ion concentration and the highest surface potential, indicating minimal electrochemical corrosion risk. A correlation between surface potential magnitude and iron ion concentration was also observed. Comprehensive analysis demonstrates that operating at 85 % valve opening reduces both mechanical wear and electrochemical corrosion. This research provides novel insights for predictive failure analysis and structural optimization of black water valves in solid-liquid two-phase flow systems.
{"title":"Tribocorrosion damage characteristics of blackwater valves under solid-liquid two-phase flow conditions","authors":"Haozhe Jin , Zheng Xu , Chunyu Wang , Xiaofei Liu , Chao Wang , Lite Zhang , Pengxuan Li , Genfu Xu","doi":"10.1016/j.flowmeasinst.2025.103167","DOIUrl":"10.1016/j.flowmeasinst.2025.103167","url":null,"abstract":"<div><div>In the coal gasification industry, the black water flash system, as a critical link between the gasifier and solid-liquid separation unit, subjects its valves to long-term extreme operating conditions. This study investigates the flow dynamics and damage characteristics of coal gasification blackwater valves at 25 %–85 % opening degrees using combined erosion and electrochemical models. The systematic examination of opening degree and particle size effects reveals that particles in the midstream region exhibit trajectory deflection toward the valve inlet side, forming annular paths around the valve core. This phenomenon is identified as the primary mechanism responsible for the intensified wear observed on the rear surfaces of both the valve core and body. The wear reaches a local peak at 25 % opening, while demonstrating a marked reduction at 40 % opening. At 85 % opening, the valve body and core exhibit the lowest iron ion concentration and the highest surface potential, indicating minimal electrochemical corrosion risk. A correlation between surface potential magnitude and iron ion concentration was also observed. Comprehensive analysis demonstrates that operating at 85 % valve opening reduces both mechanical wear and electrochemical corrosion. This research provides novel insights for predictive failure analysis and structural optimization of black water valves in solid-liquid two-phase flow systems.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"108 ","pages":"Article 103167"},"PeriodicalIF":2.7,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145839879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-17DOI: 10.1016/j.flowmeasinst.2025.103161
Yanzhao Shang , Ruichuan Li , Yanchao Li , Hui Chen , Feng Liu
The viscous heating effect caused by the throttling action at the valve port may lead to the throttling groove of the valve core expanding due to heat, resulting in phenomena such as jamming and seizing. This work is closely aligned with international research on thermal–structural coupling and clearance variation in hydraulic spool valves, providing insights relevant to the global effort to improve the thermal reliability of high-pressure hydraulic components. This paper presents a novel U-shaped throttling groove, with a slope set at its outlet and wedge-shaped slopes added on both sides to establish a three-dimensional steady-state thermal analysis model and a structural analysis numerical model of the new U-shaped throttling groove. The corresponding thermal conduction analysis of the valve core throttling groove was carried out, and the temperature distribution of the valve core throttling groove was obtained. The influence laws of the valve port opening degree and back pressure value on the temperature distribution of the valve core between the new U-shaped throttling groove and the common U-shaped throttling groove were discussed. The structural deformations of two types of valve cores caused by heating were analyzed, revealing the thermal deformation trends of the valve cores under different opening degrees and different back pressure values. The research results show that the temperature distribution of the new U-shaped throttling groove is superior to that of the common U-shaped throttling groove. Both types of valve cores undergo thermal expansion as a whole, and the main deformation area is concentrated at the throttling groove. The inlet wall deforms along the axial direction, while the outlet semi-circular wall mainly expands along the radial direction. The new U-shaped throttling groove proposed in this paper performs better than the common U-shaped throttling groove in terms of maximum deformation and radial direction, thereby reducing the failure rate of jamming and seizing caused by thermal expansion. This study provides relevant theoretical support for explaining the jamming formation mechanism and suppression methods of spool valves.
{"title":"Simulation analysis of temperature rise and thermal deformation of the core of the new U-shaped throttle groove slide valve","authors":"Yanzhao Shang , Ruichuan Li , Yanchao Li , Hui Chen , Feng Liu","doi":"10.1016/j.flowmeasinst.2025.103161","DOIUrl":"10.1016/j.flowmeasinst.2025.103161","url":null,"abstract":"<div><div>The viscous heating effect caused by the throttling action at the valve port may lead to the throttling groove of the valve core expanding due to heat, resulting in phenomena such as jamming and seizing. This work is closely aligned with international research on thermal–structural coupling and clearance variation in hydraulic spool valves, providing insights relevant to the global effort to improve the thermal reliability of high-pressure hydraulic components. This paper presents a novel U-shaped throttling groove, with a slope set at its outlet and wedge-shaped slopes added on both sides to establish a three-dimensional steady-state thermal analysis model and a structural analysis numerical model of the new U-shaped throttling groove. The corresponding thermal conduction analysis of the valve core throttling groove was carried out, and the temperature distribution of the valve core throttling groove was obtained. The influence laws of the valve port opening degree and back pressure value on the temperature distribution of the valve core between the new U-shaped throttling groove and the common U-shaped throttling groove were discussed. The structural deformations of two types of valve cores caused by heating were analyzed, revealing the thermal deformation trends of the valve cores under different opening degrees and different back pressure values. The research results show that the temperature distribution of the new U-shaped throttling groove is superior to that of the common U-shaped throttling groove. Both types of valve cores undergo thermal expansion as a whole, and the main deformation area is concentrated at the throttling groove. The inlet wall deforms along the axial direction, while the outlet semi-circular wall mainly expands along the radial direction. The new U-shaped throttling groove proposed in this paper performs better than the common U-shaped throttling groove in terms of maximum deformation and radial direction, thereby reducing the failure rate of jamming and seizing caused by thermal expansion. This study provides relevant theoretical support for explaining the jamming formation mechanism and suppression methods of spool valves.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"108 ","pages":"Article 103161"},"PeriodicalIF":2.7,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145839877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-16DOI: 10.1016/j.flowmeasinst.2025.103162
Rui Chen, Song Lu, Hui Shi, Qiyong Zhou, Heping Zhang
Accurate concentration detection technology for binary blend fire extinguishing agents is critical for advancing halon replacement and evaluating the performance of binary fire suppression systems, but the concentration measurement of binary fire extinguishing agents remains unknown. Based on the differential pressure principle, this study established a general theoretical expression for the differential pressure model of binary fire extinguishing agents. The calculated differential pressure values derived from this expression were basically consistent with the theoretical values. To validate the model's accuracy, concentration measurement experiments were conducted at various volume ratios. These experiments demonstrated strong agreement between the normalized experimental and theoretical values. Furthermore, partial correlation analysis revealed that the volume ratio exerted a greater influence on the correction coefficient between the theoretical and experimental models than the concentration. To assess practical applicability, discharge test was performed. Consequently, this study proposed a concentration measurement model for binary fire extinguishing agents based on the differential pressure principle, achieving precise concentration measurement.
{"title":"The established differential pressure model for binary fire extinguishing agent enables accurate concentration measurement","authors":"Rui Chen, Song Lu, Hui Shi, Qiyong Zhou, Heping Zhang","doi":"10.1016/j.flowmeasinst.2025.103162","DOIUrl":"10.1016/j.flowmeasinst.2025.103162","url":null,"abstract":"<div><div>Accurate concentration detection technology for binary blend fire extinguishing agents is critical for advancing halon replacement and evaluating the performance of binary fire suppression systems, but the concentration measurement of binary fire extinguishing agents remains unknown. Based on the differential pressure principle, this study established a general theoretical expression for the differential pressure model of binary fire extinguishing agents. The calculated differential pressure values derived from this expression were basically consistent with the theoretical values. To validate the model's accuracy, concentration measurement experiments were conducted at various volume ratios. These experiments demonstrated strong agreement between the normalized experimental and theoretical values. Furthermore, partial correlation analysis revealed that the volume ratio exerted a greater influence on the correction coefficient between the theoretical and experimental models than the concentration. To assess practical applicability, discharge test was performed. Consequently, this study proposed a concentration measurement model for binary fire extinguishing agents based on the differential pressure principle, achieving precise concentration measurement.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"108 ","pages":"Article 103162"},"PeriodicalIF":2.7,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-15DOI: 10.1016/j.flowmeasinst.2025.103163
Fuyou Wang , Hongfei Tao , Xingchen Guo , Yumin Yang , Mahemujiang Aihemaiti , Qiao Li , Youwei Jiang , Peng Jin , Junbo Li
Accurate measurement of water discharge in open channels is essential for advancing water-saving agriculture. Investigating the hydraulic performance of flow measurement devices and optimising their structure can significantly enhance water resource utilisation efficiency in irrigation districts. The portable triangular central baffle flume (TCBF), characterized by its simple design and ease of promotion is a practical solution for open-channel flow measurement. However, the optimal structural parameters for its operation and the significance order of factors influencing its hydraulic performance remain underexplored. This study selected head loss, backwater height, and upstream Froude number as evaluation criteria. A comprehensive physical experiment was conducted with six flow rates (0.031–0.093 m3/s), four guide wall entrance angles (45°–90°), and three shrinkage ratios (0.375–0.625). The experimental data were analysed using range and variance analyses. Prediction models for head loss, backwater height, and upstream Froude number were developed using both Buckingham's π-theorem of quantitative analysis and backpropagation (BP) neural network methods. The optimal structural parameters for TCBF were determined by integrating the non-dominated sorting genetic algorithm-II (NSGA-II) with the technique for order of preference by similarity to the ideal solution (TOPSIS) method. The results reveal that the significance order of factors affecting head loss, backwater height, and upstream Froude number is consistent: shrinkage ratio > flow rate > guide wall entrance angle. Compared to Buckingham's π-theorem of quantitative analysis, the BP neural network-based prediction models demonstrated superior performance for the three evaluation criteria, with higher coefficient of determination (R2), lower root mean square error (RMSE), and reduced mean relative error (MRE). Within the experimental scope, the optimal structural parameters for TCBF were identified as a shrinkage ratio of 0.55 and a guide wall entrance angle of 60°. These findings provide valuable insights for predicting flowmeter performance and optimising its structure, contributing significantly to the advancement of water-saving agriculture.
{"title":"Structural optimization study of portable triangular central baffle flume based on backpropagation neural network and non-dominated sorting genetic algorithm II","authors":"Fuyou Wang , Hongfei Tao , Xingchen Guo , Yumin Yang , Mahemujiang Aihemaiti , Qiao Li , Youwei Jiang , Peng Jin , Junbo Li","doi":"10.1016/j.flowmeasinst.2025.103163","DOIUrl":"10.1016/j.flowmeasinst.2025.103163","url":null,"abstract":"<div><div>Accurate measurement of water discharge in open channels is essential for advancing water-saving agriculture. Investigating the hydraulic performance of flow measurement devices and optimising their structure can significantly enhance water resource utilisation efficiency in irrigation districts. The portable triangular central baffle flume (TCBF), characterized by its simple design and ease of promotion is a practical solution for open-channel flow measurement. However, the optimal structural parameters for its operation and the significance order of factors influencing its hydraulic performance remain underexplored. This study selected head loss, backwater height, and upstream Froude number as evaluation criteria. A comprehensive physical experiment was conducted with six flow rates (0.031–0.093 m<sup>3</sup>/s), four guide wall entrance angles (45°–90°), and three shrinkage ratios (0.375–0.625). The experimental data were analysed using range and variance analyses. Prediction models for head loss, backwater height, and upstream Froude number were developed using both Buckingham's π-theorem of quantitative analysis and backpropagation (BP) neural network methods. The optimal structural parameters for TCBF were determined by integrating the non-dominated sorting genetic algorithm-II (NSGA-II) with the technique for order of preference by similarity to the ideal solution (TOPSIS) method. The results reveal that the significance order of factors affecting head loss, backwater height, and upstream Froude number is consistent: shrinkage ratio > flow rate > guide wall entrance angle. Compared to Buckingham's π-theorem of quantitative analysis, the BP neural network-based prediction models demonstrated superior performance for the three evaluation criteria, with higher coefficient of determination (<em>R</em><sup><em>2</em></sup>), lower root mean square error (<em>RMSE</em>), and reduced mean relative error (<em>MRE</em>). Within the experimental scope, the optimal structural parameters for TCBF were identified as a shrinkage ratio of 0.55 and a guide wall entrance angle of 60°. These findings provide valuable insights for predicting flowmeter performance and optimising its structure, contributing significantly to the advancement of water-saving agriculture.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"108 ","pages":"Article 103163"},"PeriodicalIF":2.7,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-13DOI: 10.1016/j.flowmeasinst.2025.103160
Hong Hua , Chenzhuo Ning , Lihao Li , Jiaxing Lu , Tingyi Shen , Xiaobing Liu
Pelton turbines are widely recognized as a primary form of high-head hydraulic machinery crucial for sustainable energy production. This research aims to investigate the influence of water film characteristics on the hydraulic performance and structural integrity of Pelton turbines through numerical simulation. The accuracy of the numerical simulation method was initially validated through experimental verification. Subsequently, the flow pattern of the water film during bucket rotation was examined, and the effects of parameters such as coverage area and thickness of the water film on bucket torque were analyzed. Meanwhile, the relationship between the shape of the water film, the velocity of the jet and the direction of the flow in the bucket and the pressure pulsation of the key nodes on the surface of the bucket was established. Ultimately, the results of unsteady flow were loaded onto the solid surface of the runner to explore the water film and solid interaction through fluid-structure coupling, which is revealed that the most prone to crack and break part of the bucket is the top of the bucket, providing valuable basis for the design and maintenance of Pelton turbine.
{"title":"Investigation of the runner water film hydraulic instability and structural crack on the Pelton turbine runner","authors":"Hong Hua , Chenzhuo Ning , Lihao Li , Jiaxing Lu , Tingyi Shen , Xiaobing Liu","doi":"10.1016/j.flowmeasinst.2025.103160","DOIUrl":"10.1016/j.flowmeasinst.2025.103160","url":null,"abstract":"<div><div>Pelton turbines are widely recognized as a primary form of high-head hydraulic machinery crucial for sustainable energy production. This research aims to investigate the influence of water film characteristics on the hydraulic performance and structural integrity of Pelton turbines through numerical simulation. The accuracy of the numerical simulation method was initially validated through experimental verification. Subsequently, the flow pattern of the water film during bucket rotation was examined, and the effects of parameters such as coverage area and thickness of the water film on bucket torque were analyzed. Meanwhile, the relationship between the shape of the water film, the velocity of the jet and the direction of the flow in the bucket and the pressure pulsation of the key nodes on the surface of the bucket was established. Ultimately, the results of unsteady flow were loaded onto the solid surface of the runner to explore the water film and solid interaction through fluid-structure coupling, which is revealed that the most prone to crack and break part of the bucket is the top of the bucket, providing valuable basis for the design and maintenance of Pelton turbine.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"108 ","pages":"Article 103160"},"PeriodicalIF":2.7,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145790703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-11DOI: 10.1016/j.flowmeasinst.2025.103158
Shiqi Zhao , Jiashuo Tan , Haodong Wang , Jun Yuan , Ting Zeng , Tengfei Tang
Efficient mixing is crucial for process intensification in microchannel reactors, yet it remains notoriously difficult to achieve under laminar flow conditions, where mixing relies solely on slow molecular diffusion. While passive micromixers offer a practical solution, their empirical designs are fundamentally limited by predefined geometries. To overcome this limitation, we present a topology optimization-based framework that automatically generates optimal flow paths by coupling the Navier-Stokes and advection-diffusion equations. The optimization objective was to maximize the mixing quality factor (MQ) under a specified pressure drop constraint (ΔP). The resulting native 3D topology-optimized mixer achieves a near-perfect mixing quality of 99.824 % at ΔP = 30 Pa—a performance nearly five times greater than a conventional baffle-type mixer (17 % MQ). Furthermore, the 3D-reconstructed model from 2D optimization yields a four-fold improvement (68.251 % MQ), demonstrating a computationally efficient pathway to significant performance gains. This work establishes a novel collaborative 2D/3D design strategy that moves beyond trial-and-error paradigms, providing a systematic foundation for the design of next-generation micromixers.
{"title":"Topology optimization-driven enhancement of mass transfer and mixing performance in microchannel reactors","authors":"Shiqi Zhao , Jiashuo Tan , Haodong Wang , Jun Yuan , Ting Zeng , Tengfei Tang","doi":"10.1016/j.flowmeasinst.2025.103158","DOIUrl":"10.1016/j.flowmeasinst.2025.103158","url":null,"abstract":"<div><div>Efficient mixing is crucial for process intensification in microchannel reactors, yet it remains notoriously difficult to achieve under laminar flow conditions, where mixing relies solely on slow molecular diffusion. While passive micromixers offer a practical solution, their empirical designs are fundamentally limited by predefined geometries. To overcome this limitation, we present a topology optimization-based framework that automatically generates optimal flow paths by coupling the Navier-Stokes and advection-diffusion equations. The optimization objective was to maximize the mixing quality factor (MQ) under a specified pressure drop constraint (ΔP). The resulting native 3D topology-optimized mixer achieves a near-perfect mixing quality of 99.824 % at ΔP = 30 Pa—a performance nearly five times greater than a conventional baffle-type mixer (17 % MQ). Furthermore, the 3D-reconstructed model from 2D optimization yields a four-fold improvement (68.251 % MQ), demonstrating a computationally efficient pathway to significant performance gains. This work establishes a novel collaborative 2D/3D design strategy that moves beyond trial-and-error paradigms, providing a systematic foundation for the design of next-generation micromixers.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"108 ","pages":"Article 103158"},"PeriodicalIF":2.7,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145737282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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