Pub Date : 2025-12-29DOI: 10.1016/j.flowmeasinst.2025.103165
Hsun-Chuan Chan , Hsin-Kai Yang , Po-Wei Lin , Jung-Tai Lee
{"title":"Corrigendum to ‘Discharge formula for flows over open-check dams’ [Flow Meas. Instrum. 72 (2020) 101690]","authors":"Hsun-Chuan Chan , Hsin-Kai Yang , Po-Wei Lin , Jung-Tai Lee","doi":"10.1016/j.flowmeasinst.2025.103165","DOIUrl":"10.1016/j.flowmeasinst.2025.103165","url":null,"abstract":"","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"108 ","pages":"Article 103165"},"PeriodicalIF":2.7,"publicationDate":"2025-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146076918","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 : 2025-12-27DOI: 10.1016/j.flowmeasinst.2025.103175
Yongkang Li, Guangyao Shen
Numerous problems lead to high water-based motor being seriously damaged, mainly manifested as moving pairs rusting due to internal leakage and rotor cavitation in the valve plate pair. To quantitatively predict its leakage rate and explore the failure mechanism, the formula for contact area and transient model of the valve plate pair were derived, and the dynamic coupling method between the flow simulation and the valve plate movement was proposed. In addition, a dynamic film testing system was established to verify effectiveness. The results show that the periodic intersection and separation of different holes contribute to fluctuation in the high-pressure area and hydraulic separation force, which act as the primary factors in the film fluctuates within the range of 8.8–10.2 μm, this is the primary cause of the evident internal leakage. The instantaneous velocity can reach 51.2 m/s when the holes begin to connect, which is the direct cause of rotor cavitation. The trends in simulation are consistent with the experiment results, and their deviation is less than 8.5 %. The inlet pressure and liquid style have significant effects on the gap and leakage of the valve plate pair, but the influence of rotational speed is not obvious. The motor with a valve plate structure will inevitably leak, especially when inlet pressure changes caused by the load. Only by innovating the valve plate structure can prevent the problem of premature failure.
{"title":"Transient film characteristic of valve plate friction pair and failure mechanism in high water-based motor","authors":"Yongkang Li, Guangyao Shen","doi":"10.1016/j.flowmeasinst.2025.103175","DOIUrl":"10.1016/j.flowmeasinst.2025.103175","url":null,"abstract":"<div><div>Numerous problems lead to high water-based motor being seriously damaged, mainly manifested as moving pairs rusting due to internal leakage and rotor cavitation in the valve plate pair. To quantitatively predict its leakage rate and explore the failure mechanism, the formula for contact area and transient model of the valve plate pair were derived, and the dynamic coupling method between the flow simulation and the valve plate movement was proposed. In addition, a dynamic film testing system was established to verify effectiveness. The results show that the periodic intersection and separation of different holes contribute to fluctuation in the high-pressure area and hydraulic separation force, which act as the primary factors in the film fluctuates within the range of 8.8–10.2 μm, this is the primary cause of the evident internal leakage. The instantaneous velocity can reach 51.2 m/s when the holes begin to connect, which is the direct cause of rotor cavitation. The trends in simulation are consistent with the experiment results, and their deviation is less than 8.5 %. The inlet pressure and liquid style have significant effects on the gap and leakage of the valve plate pair, but the influence of rotational speed is not obvious. The motor with a valve plate structure will inevitably leak, especially when inlet pressure changes caused by the load. Only by innovating the valve plate structure can prevent the problem of premature failure.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"108 ","pages":"Article 103175"},"PeriodicalIF":2.7,"publicationDate":"2025-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883510","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 : 2025-12-26DOI: 10.1016/j.flowmeasinst.2025.103173
D. Venkatesan , T.S. Krishna , M. Karthikeyan , V. Naveen Sahith , J. Aravind Kumar
Ammonium Diuranate (ADU) powder is a compound that requires effective energy management in the process of nuclear fuel fabrication because it is toxic, radioactive, and agglutinates easily. The present paper forms a pneumatic conveying system of ADU powder with two methods of vacuum generation: a blower and an air-ejector. A surrogate material (silica sand) was subjected to experiments both in fluidized and non-fluidized environment to determine salting velocity, pressure gradient and conveying performance. The findings demonstrate that the air-ejector works with a much low salting velocity and pressure drop than the blower, meaning that the particles are less degraded and the pipeline is less eroded. Cost comparison with 10 years further shows that air-ejector system has significant savings in terms of operation as compared to blower based pneumatic conveying and mechanical transfer. The originality of this work is that it has formed a comparative framework of the performance of the ADU powder transportation, as well as given an insight into the efficiency of the operations, the system design parameters, and process safety of the advanced nuclear fuel cycle.
{"title":"Design of pneumatic powder transfer (conveying) system using air-ejector and vacuum unit for energy management","authors":"D. Venkatesan , T.S. Krishna , M. Karthikeyan , V. Naveen Sahith , J. Aravind Kumar","doi":"10.1016/j.flowmeasinst.2025.103173","DOIUrl":"10.1016/j.flowmeasinst.2025.103173","url":null,"abstract":"<div><div>Ammonium Diuranate (ADU) powder is a compound that requires effective energy management in the process of nuclear fuel fabrication because it is toxic, radioactive, and agglutinates easily. The present paper forms a pneumatic conveying system of ADU powder with two methods of vacuum generation: a blower and an air-ejector. A surrogate material (silica sand) was subjected to experiments both in fluidized and non-fluidized environment to determine salting velocity, pressure gradient and conveying performance. The findings demonstrate that the air-ejector works with a much low salting velocity and pressure drop than the blower, meaning that the particles are less degraded and the pipeline is less eroded. Cost comparison with 10 years further shows that air-ejector system has significant savings in terms of operation as compared to blower based pneumatic conveying and mechanical transfer. The originality of this work is that it has formed a comparative framework of the performance of the ADU powder transportation, as well as given an insight into the efficiency of the operations, the system design parameters, and process safety of the advanced nuclear fuel cycle.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"108 ","pages":"Article 103173"},"PeriodicalIF":2.7,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883507","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 : 2025-12-26DOI: 10.1016/j.flowmeasinst.2025.103178
Wei Pu , Leilei Ji
To enhance particle flow within the pump, this study employed CFD-DEM (Computational Fluid Dynamics - Discrete Element Method) to investigate the solid-liquid two-phase flow characteristics of a centrifugal pump. It began by examining the changes in the external characteristics of the impeller before and after cutting the back cover. The analysis then focused on the distribution of particles within the pump. The study revealed that the introduction of solid particles significantly degraded the hydraulic performance of the centrifugal pump, with head and efficiency dropping by 12.76 % and 27.22 %, respectively, under design conditions. However, after the impeller was cut, hydraulic performance showed improvement, characterized by increased particle velocity and enhanced flow capability. Cutting the back cover reduced collisions of particles with the impeller's back cover wall, blade pressure surface, and the outer wall of the volute. The primary force acting on particles shifted from pressure gradient force to normal force following the cut. After the modification, both translational and rotational kinetic energies of the particles increased, although rotational kinetic energy decreased with the rise in pressure gradient force. A positive correlation was observed between translational kinetic energy and pressure gradient force, while the total positional potential energy of the particles decreased after cutting the impeller's back cover. The research results provide reference for further improving the solid-liquid two-phase flow characteristics of centrifugal pumps.
为了增强泵内的颗粒流动，本研究采用CFD-DEM （Computational Fluid Dynamics - Discrete Element Method）对离心泵固液两相流动特性进行了研究。它首先检查了切割后盖前后叶轮外部特性的变化。然后，分析集中在泵内粒子的分布上。研究表明，固体颗粒的引入显著降低了离心泵的水力性能，在设计条件下扬程和效率分别下降了12.76%和27.22%。而切割叶轮后，水力性能有所改善，表现为颗粒速度增加，流动能力增强。切割后盖减少了颗粒与叶轮后盖壁、叶片压力面和蜗壳外壁的碰撞。在切割后，作用在颗粒上的主要力由压力梯度力转变为法向力。修正后，颗粒的平动动能和旋转动能均增加，但旋转动能随压力梯度力的增大而减小。平动动能与压力梯度力之间存在正相关关系，而切割叶轮后盖后颗粒的总位置势能减小。研究结果为进一步改善离心泵固液两相流特性提供了参考。
{"title":"Influence of arc cutting of impeller back cover on particle characteristics of solid-liquid two-phase flow in centrifugal pump","authors":"Wei Pu , Leilei Ji","doi":"10.1016/j.flowmeasinst.2025.103178","DOIUrl":"10.1016/j.flowmeasinst.2025.103178","url":null,"abstract":"<div><div>To enhance particle flow within the pump, this study employed CFD-DEM (Computational Fluid Dynamics - Discrete Element Method) to investigate the solid-liquid two-phase flow characteristics of a centrifugal pump. It began by examining the changes in the external characteristics of the impeller before and after cutting the back cover. The analysis then focused on the distribution of particles within the pump. The study revealed that the introduction of solid particles significantly degraded the hydraulic performance of the centrifugal pump, with head and efficiency dropping by 12.76 % and 27.22 %, respectively, under design conditions. However, after the impeller was cut, hydraulic performance showed improvement, characterized by increased particle velocity and enhanced flow capability. Cutting the back cover reduced collisions of particles with the impeller's back cover wall, blade pressure surface, and the outer wall of the volute. The primary force acting on particles shifted from pressure gradient force to normal force following the cut. After the modification, both translational and rotational kinetic energies of the particles increased, although rotational kinetic energy decreased with the rise in pressure gradient force. A positive correlation was observed between translational kinetic energy and pressure gradient force, while the total positional potential energy of the particles decreased after cutting the impeller's back cover. The research results provide reference for further improving the solid-liquid two-phase flow characteristics of centrifugal pumps.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"108 ","pages":"Article 103178"},"PeriodicalIF":2.7,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883506","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 : 2025-12-26DOI: 10.1016/j.flowmeasinst.2025.103176
Madhu V , Suresh M , Umapathy M , Ezudheen P , Vishakh Prakash
Flow regime information helps provide insight into complex interaction between phases in two-phase flow. The phase distribution and flow pattern significantly impact behaviour of pressure drop at any section of flow conduit. In the study, experimental investigations were undertaken at a 100 mm NB air-water test loop for fully developed horizontal flow for the regimes slug, plug and stratified flow and further the regimes slug, churn flow regimes in vertical flow. Measurements for pressure loss were obtained using high response differential pressure sensors coupled with high speed sampling measurements at the Data Acquisition System.
The acquired time-series differential pressure signals were assessed for patterns using machine learning approaches. Techniques like Random Forest, non-linear regression models did not yield resolvable results for a range of tests. Three machine learning approaches namely, Gated Recurrent Unit(GRU), Long Short Term Memory (LSTM) and Shapelet Transform Classifier (STC) were attempted that reveal reasonably good prediction for flow regimes.
As per analysis, the STC model yielded accuracy in the range 71–73 % for horizontal flow regimes viz., stratified flow, slug flow and plug flow, based on pressure loss in horizontal line and venturimeter. For the vertical flow regimes slug flow and churn flow, the LSTM and GRU indicate similar performance (72–73 % prediction accuracy). LSTM and GRU however yielded prediction accuracy of the order of 89–91 % for differential pressure at the venturimeter located about 10D downstream of the bend. The study indicates feasibility for wider use of machine learning approaches on time varying pressure drop information for assessment and prediction of flow regimes in two phase gas liquid flow.
{"title":"Gas-liquid flow regime information in horizontal and vertical pipes using machine learning approach on time varying pressure drop signals","authors":"Madhu V , Suresh M , Umapathy M , Ezudheen P , Vishakh Prakash","doi":"10.1016/j.flowmeasinst.2025.103176","DOIUrl":"10.1016/j.flowmeasinst.2025.103176","url":null,"abstract":"<div><div>Flow regime information helps provide insight into complex interaction between phases in two-phase flow. The phase distribution and flow pattern significantly impact behaviour of pressure drop at any section of flow conduit. In the study, experimental investigations were undertaken at a 100 mm NB air-water test loop for fully developed horizontal flow for the regimes slug, plug and stratified flow and further the regimes slug, churn flow regimes in vertical flow. Measurements for pressure loss were obtained using high response differential pressure sensors coupled with high speed sampling measurements at the Data Acquisition System.</div><div>The acquired time-series differential pressure signals were assessed for patterns using machine learning approaches. Techniques like Random Forest, non-linear regression models did not yield resolvable results for a range of tests. Three machine learning approaches namely, Gated Recurrent Unit(GRU), Long Short Term Memory (LSTM) and Shapelet Transform Classifier (STC) were attempted that reveal reasonably good prediction for flow regimes.</div><div>As per analysis, the STC model yielded accuracy in the range 71–73 % for horizontal flow regimes viz., stratified flow, slug flow and plug flow, based on pressure loss in horizontal line and venturimeter. For the vertical flow regimes slug flow and churn flow, the LSTM and GRU indicate similar performance (72–73 % prediction accuracy). LSTM and GRU however yielded prediction accuracy of the order of 89–91 % for differential pressure at the venturimeter located about 10D downstream of the bend. The study indicates feasibility for wider use of machine learning approaches on time varying pressure drop information for assessment and prediction of flow regimes in two phase gas liquid flow.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"108 ","pages":"Article 103176"},"PeriodicalIF":2.7,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883594","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 : 2025-12-24DOI: 10.1016/j.flowmeasinst.2025.103166
Desheng Chen , Wei Shi , Caihua Zhou , Xuejin Zhu , Jingyu Jiang , Zhe Lin
The piston pump is widely used in petrochemical, coal chemical, and offshore engineering applications due to its high-pressure delivery capability and adaptability to various media. However, the presence of solid particles in the conveyed fluid often leads to unstable delivery performance, severe erosion, and reduced structural reliability. In this study, the internal erosion characteristics of a piston pump during solid–liquid two-phase transport were investigated using a dynamic-mesh CFD–DPM approach. The model was qualitatively validated by comparing the predicted erosion distribution with experimental observations, confirming its capability for erosion location prediction. The particle motion distribution and wall erosion patterns under different operating conditions were analyzed. Results showed that erosion caused by particle impact mainly occurs on the valve seat's sealing interface, the inflow-facing region of the valve core, the inner wall of the valve cover, and the outer surface of the outlet elbow. The particle diameter exhibits a nonlinear relationship with the extent of erosion: as particle size increases, the corresponding kinetic energy becomes greater, but the impact angle relative to the wall changes accordingly. The curvature of the sealing surface significantly affects erosion intensity, which increases with larger curvature.
{"title":"Study on erosion characteristics of piston pump during discharge","authors":"Desheng Chen , Wei Shi , Caihua Zhou , Xuejin Zhu , Jingyu Jiang , Zhe Lin","doi":"10.1016/j.flowmeasinst.2025.103166","DOIUrl":"10.1016/j.flowmeasinst.2025.103166","url":null,"abstract":"<div><div>The piston pump is widely used in petrochemical, coal chemical, and offshore engineering applications due to its high-pressure delivery capability and adaptability to various media. However, the presence of solid particles in the conveyed fluid often leads to unstable delivery performance, severe erosion, and reduced structural reliability. In this study, the internal erosion characteristics of a piston pump during solid–liquid two-phase transport were investigated using a dynamic-mesh CFD–DPM approach. The model was qualitatively validated by comparing the predicted erosion distribution with experimental observations, confirming its capability for erosion location prediction. The particle motion distribution and wall erosion patterns under different operating conditions were analyzed. Results showed that erosion caused by particle impact mainly occurs on the valve seat's sealing interface, the inflow-facing region of the valve core, the inner wall of the valve cover, and the outer surface of the outlet elbow. The particle diameter exhibits a nonlinear relationship with the extent of erosion: as particle size increases, the corresponding kinetic energy becomes greater, but the impact angle relative to the wall changes accordingly. The curvature of the sealing surface significantly affects erosion intensity, which increases with larger curvature.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"108 ","pages":"Article 103166"},"PeriodicalIF":2.7,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145839857","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 : 2025-12-24DOI: 10.1016/j.flowmeasinst.2025.103171
Jiadi Lian , Zijian Zheng , Hong Zang , Yibin Li , Jing Xu
An innovative vacuum mixed transfer pump with mixed transfer function - the worm shaft pump was proposed. The geometric model of the eccentric helical worm shaft rotor and the multi-objective parameters of the rotor helix, taper ratio, rotational speed, eccentricity and baffle were established. The flow characteristics of the worm shaft pump under different objective parameters were discussed. The stirring, mixing and conveying functions of the worm shaft pump were quantitatively evaluated by using the CFD numerical simulation method. By analyzing the velocity dead zone of the flow field in the inlet cavity of the worm shaft pump and the volume fraction of the oil phase in the outlet cavity, the structural design parameters that meet the mixing performance of the worm shaft pump were obtained. Through the flow-head and flow-efficiency curves, the optimal design parameters of the conveying structure were determined as an eccentricity of 11.5 mm, a rotational speed of 3000 rpm, 4 screws, a taper ratio of any one of the set parameters, and a structural design with baffles. Combining the mixing characteristics and conveying characteristics, the comprehensive optimized design parameters of the worm shaft pump were finally proposed as an eccentricity of 11.5 mm, a rotational speed of 3000 rpm, 4 screws, a taper ratio of 0.30, and a structural design with baffles, in order to meet the requirements of the mixing characteristics and conveying characteristics of the cutting fluid. This research can be applied to the performance improvement and structural optimization design of vacuum mixed transfer pumps.
{"title":"Simulation and study of flow field characteristics of oil-water two-phase flow worm shaft pump","authors":"Jiadi Lian , Zijian Zheng , Hong Zang , Yibin Li , Jing Xu","doi":"10.1016/j.flowmeasinst.2025.103171","DOIUrl":"10.1016/j.flowmeasinst.2025.103171","url":null,"abstract":"<div><div>An innovative vacuum mixed transfer pump with mixed transfer function - the worm shaft pump was proposed. The geometric model of the eccentric helical worm shaft rotor and the multi-objective parameters of the rotor helix, taper ratio, rotational speed, eccentricity and baffle were established. The flow characteristics of the worm shaft pump under different objective parameters were discussed. The stirring, mixing and conveying functions of the worm shaft pump were quantitatively evaluated by using the CFD numerical simulation method. By analyzing the velocity dead zone of the flow field in the inlet cavity of the worm shaft pump and the volume fraction of the oil phase in the outlet cavity, the structural design parameters that meet the mixing performance of the worm shaft pump were obtained. Through the flow-head and flow-efficiency curves, the optimal design parameters of the conveying structure were determined as an eccentricity of 11.5 mm, a rotational speed of 3000 rpm, 4 screws, a taper ratio of any one of the set parameters, and a structural design with baffles. Combining the mixing characteristics and conveying characteristics, the comprehensive optimized design parameters of the worm shaft pump were finally proposed as an eccentricity of 11.5 mm, a rotational speed of 3000 rpm, 4 screws, a taper ratio of 0.30, and a structural design with baffles, in order to meet the requirements of the mixing characteristics and conveying characteristics of the cutting fluid. This research can be applied to the performance improvement and structural optimization design of vacuum mixed transfer pumps.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"108 ","pages":"Article 103171"},"PeriodicalIF":2.7,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883596","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 : 2025-12-23DOI: 10.1016/j.flowmeasinst.2025.103174
Li Nie , Jin Jin , Yongyong Ma , Kaiqiang Geng , Qingquan Fu , Yu Han
Suspended sediment present in open-channel flows significantly alters the vertical velocity distribution, thereby impairing the accuracy of cross-sectional mean velocity estimation. To examine the effects of sediment concentration on flow structure, a series of controlled flume experiments was conducted in a rectangular glass channel. Representative combinations of flow discharge and sediment concentration were tested, and vertical velocity profiles were acquired at five transverse positions across multiple cross sections using an Acoustic Doppler Velocimeter (ADV). The results indicate that increasing sediment concentration induces a substantial reduction in free-surface velocity and causes the velocity peak to shift downward to a position located about 0.75 of the local flow depth above the bed. This results in the transformation of the classical logarithmic velocity profile into an asymmetric structure, with reduced surface velocity gradients and enhanced near-bed velocities, which together indicate the emergence of a distinct velocity dip. Building upon the log–dip–wake framework, a predictive model for cross-sectional mean velocity in sediment-laden open-channel flows was developed. Structural parameters were inferred from measured profiles to identify the vertical location of mean velocity, enabling the construction of a functional relationship between mean and free-surface velocities. Sediment concentration–dependent response functions were further incorporated to facilitate parameter adaptation. Model validation demonstrates strong predictive performance across a wide concentration range (R2 > 0.933), significantly outperforming conventional linear empirical models (R2 ~ 0.85).
{"title":"Vertical velocity profiles and mean flow prediction in rectangular open channels under various sediment concentrations","authors":"Li Nie , Jin Jin , Yongyong Ma , Kaiqiang Geng , Qingquan Fu , Yu Han","doi":"10.1016/j.flowmeasinst.2025.103174","DOIUrl":"10.1016/j.flowmeasinst.2025.103174","url":null,"abstract":"<div><div>Suspended sediment present in open-channel flows significantly alters the vertical velocity distribution, thereby impairing the accuracy of cross-sectional mean velocity estimation. To examine the effects of sediment concentration on flow structure, a series of controlled flume experiments was conducted in a rectangular glass channel. Representative combinations of flow discharge and sediment concentration were tested, and vertical velocity profiles were acquired at five transverse positions across multiple cross sections using an Acoustic Doppler Velocimeter (ADV). The results indicate that increasing sediment concentration induces a substantial reduction in free-surface velocity and causes the velocity peak to shift downward to a position located about 0.75 of the local flow depth above the bed. This results in the transformation of the classical logarithmic velocity profile into an asymmetric structure, with reduced surface velocity gradients and enhanced near-bed velocities, which together indicate the emergence of a distinct velocity dip. Building upon the log–dip–wake framework, a predictive model for cross-sectional mean velocity in sediment-laden open-channel flows was developed. Structural parameters were inferred from measured profiles to identify the vertical location of mean velocity, enabling the construction of a functional relationship between mean and free-surface velocities. Sediment concentration–dependent response functions were further incorporated to facilitate parameter adaptation. Model validation demonstrates strong predictive performance across a wide concentration range (R<sup>2</sup> > 0.933), significantly outperforming conventional linear empirical models (R<sup>2</sup> ~ 0.85).</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"108 ","pages":"Article 103174"},"PeriodicalIF":2.7,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145839855","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}
Accurate gas flow measurement in transmission systems is strongly affected by contamination, with black powder, a corrosive by-product of pipeline degradation, representing a major challenge for turbine meters. In this study, a validated Computational Fluid Dynamics (CFD) framework combining a moving reference frame (MRF) and a two-way coupled discrete phase model (DPM) is employed to evaluate meter performance under four representative scenarios: (1) single-phase gas flow (reference case), (2) particle-laden flow, (3) deposition, and (4) combined deposition–erosion. Model predictions were benchmarked against full-scale calibration data, yielding a mean absolute error of 1.2 %. Results demonstrate that suspended particles alone exert negligible impact on rotor dynamics, whereas deposition of fine particles systematically alters blade geometry, intensifies turbulence, and induces a persistent positive bias in flow measurement. Incorporating erosion further destabilizes the flow, increases rotor speed, and results in a systematic over-reading of up to +2.5 %. These findings highlight that the dominant mechanism of measurement deviation is cumulative surface modification rather than instantaneous particle loads. The outcomes provide new mechanistic insights into contamination-induced bias in custody-transfer metering and establish a foundation for predictive correction strategies and advanced contamination-control practices in natural gas transmission systems.
{"title":"Black powder contamination in turbine gas meters: A comprehensive numerical study of particle transport, deposition, and erosion impacts on measurement accuracy","authors":"Mahdi Esmaeili , Farhad Shahraki , Mohammad Reza Sardashti Birjandi , Hamed Khosravi-Bizhaem","doi":"10.1016/j.flowmeasinst.2025.103172","DOIUrl":"10.1016/j.flowmeasinst.2025.103172","url":null,"abstract":"<div><div>Accurate gas flow measurement in transmission systems is strongly affected by contamination, with black powder, a corrosive by-product of pipeline degradation, representing a major challenge for turbine meters. In this study, a validated Computational Fluid Dynamics (CFD) framework combining a moving reference frame (MRF) and a two-way coupled discrete phase model (DPM) is employed to evaluate meter performance under four representative scenarios: (1) single-phase gas flow (reference case), (2) particle-laden flow, (3) deposition, and (4) combined deposition–erosion. Model predictions were benchmarked against full-scale calibration data, yielding a mean absolute error of 1.2 %. Results demonstrate that suspended particles alone exert negligible impact on rotor dynamics, whereas deposition of fine particles systematically alters blade geometry, intensifies turbulence, and induces a persistent positive bias in flow measurement. Incorporating erosion further destabilizes the flow, increases rotor speed, and results in a systematic over-reading of up to +2.5 %. These findings highlight that the dominant mechanism of measurement deviation is cumulative surface modification rather than instantaneous particle loads. The outcomes provide new mechanistic insights into contamination-induced bias in custody-transfer metering and establish a foundation for predictive correction strategies and advanced contamination-control practices in natural gas transmission systems.</div></div>","PeriodicalId":50440,"journal":{"name":"Flow Measurement and Instrumentation","volume":"108 ","pages":"Article 103172"},"PeriodicalIF":2.7,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145839956","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 : 2025-12-22DOI: 10.1016/j.flowmeasinst.2025.103169
Jian Zhang, Zeyang Su, Shenghao Chen, Jianian Li, Shihong Chen, Jun Wu
Conventional fertigation systems often exhibit poor water-fertilizer mixing uniformity, which degrades the proportioning accuracy of the fertilizer solution and compromises both nutrient use efficiency and environmental safety. In this study, an online automatic water-fertilizer mixing device was developed to address these problems. Metering pumps were employed to accurately inject the fertilizer stock solution, and a cone-type vortex-guided static mixer was designed, based on vortex diversion principles and fluid mechanics, to enhance water-fertilizer mixing. The pipeline structure was analyzed using CFD to evaluate flow characteristics, wall pressure, and pressure loss. A fuzzy logic control strategy, combined with concentration–conductivity models established for six straight fertilizers (R2 > 0.99), was used to dynamically regulate stock solution injection under a constant water source flow rate and time-split fertilizer application. Simulation and experimental results showed that the mixing uniformity exceeded 80 % for all tested water-fertilizer combinations, with RSD (Relative Standard Deviation) values all below 10 %. The pipeline system experienced a maximum static wall pressure of 0.307 MPa (within the rated pressure) and a total pressure drop of 0.07 MPa (well below the pump specification), and no backflow occurred at the junction between the main pipe and the stock solution pipe, ensuring continuous and stable dosing. The device achieved an average fertilizer injection accuracy of 98 %, an average settling time of 37.81 s, and an average proportioning accuracy of 97.47 %. Under continuous 6 h operation or during multiple nutrient formulation switches, the fertilizer solution concentration fluctuated by less than 5 %, confirming precise and stable fertilizer proportioning. Overall, the developed device outperformed both literature-reported systems and existing practically applied water-fertilizer integration devices. This study provides theoretical and technical foundations for precise and stable water-fertilizer regulation and offers a viable solution for advanced fertigation applications.
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