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Integrated Mechanistic Analysis and Machine Learning Prediction of Slug Flow in Oil-Gas-Water Three-Phase Pipelines 认领 引用 被引量：1
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作者 Miao Li Ying Zhang +2 位作者 Yan Wang Haiyan Zhao Yonghu Zhang 《Fluid Dynamics & Materials Processing》 EI 2026年第3期150-171,共22页
Slug flow represents one of the most critical and operationally challenging regimes in oil-gas-water multiphase pipelines.To advance both mechanistic understanding and predictive capability,this study integrates physi... Slug flow represents one of the most critical and operationally challenging regimes in oil-gas-water multiphase pipelines.To advance both mechanistic understanding and predictive capability,this study integrates physical analysis with data-driven modeling to elucidate the conditions governing slug formation and to enable its rapid and accurate prediction.A systematic review of existing research is first undertaken to clarify the mechanisms responsible for slug initiation.The influences of gas superficial velocity,liquid velocity,liquid viscosity,liquid surface tension,and the axial component of gravity are examined to characterize their roles in interfacial instability and flow transition.Then,the effects of temperature,total flow rate,water cut,gas-liquid ratio,and pipeline inclination angle are quantitatively assessed,revealing the dominant trends that promote or inhibit slug development.Building on this foundation,a comprehensive three-phase oil-gas-water flow model is constructed.Numerical simulations are performed for 243 operating conditions encompassing a broad range of temperatures,water cuts,gas-liquid ratios,liquid flow rates,and inclination angles.These simulated cases constitute the training dataset for nine machine learning algorithms.To evaluate generalization performance,108 additional randomly generated operating conditions are predicted,covering temperatures of 80–150◦C,water cuts of 40–90%,gas-liquid ratios of 3–30,liquid flow rates of 100–200 t/d,and inclination angles of 5–15.Comparative validation reveals marked differences in predictive accuracy.The BP neural network achieves the highest accuracy,95%,substantially outperforming XGBoost,83.3%,Random Forest and Decision Tree,81.5%,Logistic Regression and Support Vector Machine,80.6%,K-Nearest Neighbor and Naive Bayes 78.7%,and K-Means,63%.Overall,the BP neural network demonstrates superior robustness and precision in predicting previously unseen operating conditions,effectively combining the physical consistency of mechanistic modeling with the efficiency and adaptability of machine learning approaches. 展开更多
关键词 Oil-gas-water multiphase flow undulating pipeline slug flow formation mechanism machine learning
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CT-derived fractional flow reserve combined with atherosclerotic extent to determine long-term outcomes in diabetic patients with coronary artery disease 认领 引用 被引量：2
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作者 Zhi-Qiang WANG Zhen-Nan LI +1 位作者 Zhi-Hui HOU Bin LU 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2026年第1期27-35,共9页
Background There is still limited data on predictive value of coronary computed tomography angiography(CCTA)–derived fractional flow reserve(CT-FFR) for long term outcomes. We examined the long-term prognostic value ... Background There is still limited data on predictive value of coronary computed tomography angiography(CCTA)–derived fractional flow reserve(CT-FFR) for long term outcomes. We examined the long-term prognostic value of CT-FFR combined with CCTA–defined atherosclerotic extent in diabetic patients with coronary artery disease(CAD).Methods A retrospective pooled analysis of individual patient data was performed. Deep-learning-based vessel-specific CTFFR was calculated. All patients enrolled were followed-up for at least 5 years. Predictive abilities for major adverse cardiac events(MACE) were compared among three models(model 1), constructed using clinical variables;model 2, model 1+CCTA–derived atherosclerotic extent(Leiden risk score);and model 3, model 2+CT-FFR.Results A total of 480 diabetic patients [median age, 61(55–66) years;52.9% men] were included. During a median follow-up time of 2197(2126–2355) days, 55 patients(11.5%) experienced MACE. In multivariate-adjusted Cox models, Leiden risk score(HR: 1.06;95% CI: 1.01–1.11;P = 0.013) and CT-FFR ≤ 0.80(HR: 6.54;95% CI: 3.18–13.45;P < 0.001) were the independent predictors. The discriminant ability was higher in model 2 than in model 1(C-index, 0.75 vs. 0.63;P < 0.001) and was further promoted by adding CT-FFR to model 3(C-index, 0.81 vs. 0.75;P = 0.002). Net reclassification improvement(NRI) was 0.19(P = 0.009) for model 2 beyond model 1. Of note, adding CT-FFR to model 3 also exhibited significantly improved reclassification compared with model 2(NRI = 0.14;P = 0.011).Conclusion In diabetic patients with CAD, CT-FFR provides robust and incremental prognostic information for predicting longterm outcomes. The combined model exhibits improved prediction abilities, which is beneficial for risk stratification. 展开更多
关键词 fractional flow reserve ct ffr coronary artery disease cad methods tomography angiography ccta derived coronary artery disease atherosclerotic extent fractional flow reserve diabetic patients coronary computed tomography angiography
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Optimization of throttling windows to improve flow control of three-way control combiner valves 认领 引用 被引量：1
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作者 Jin-yuan QIAN Zhe-hui MA +7 位作者 Shi-jie LIN Chuang LIU Yu-wei WANG Fei LING Liang ZHANG Man-man CUI Tian-zuo QU Zhi-jiang JIN 《Journal of Zhejiang University-SCIENCE A》 SCIE EI CAS CSCD 2026年第3期275-287,共13页
Three-way control combiner valves(TCCVs)are critical components used in nuclear power plants to regulate the concentration of boron acid for neutron absorption and reactor safety.However,current TCCV designs often suf... Three-way control combiner valves(TCCVs)are critical components used in nuclear power plants to regulate the concentration of boron acid for neutron absorption and reactor safety.However,current TCCV designs often suffer from suboptimal control performance and high flow resistance,leading to control deviations and reduced operational efficiency.In this paper,a numerical model based on the standard K–ωturbulence model is established and validated against experimental data to analyze the flow characteristics and local flow resistance of a TCCV.A parametric design method for the throttling windows is proposed,establishing relationships between shape parameters and performance indexes,including control performance and flow resistance.The adaptive non-dominated sorting genetic algorithm(ANSGA-II)is used to optimize the shape parameters of the throttling windows.The optimization results show an improvement in the performance indexes of the TCCV,with the adjustable operating range increasing by 31.0%and the maximum local resistance decreasing by 18.3%.We also introduce the concepts of effective and controllable domains to characterize the inlet backflow phenomena and regulation dead zones,which are crucial for ensuring the reliability and effectiveness of control valves.These findings provide insights for enhancing the design and performance of TCCVs in nuclear power plants. 展开更多
关键词 Three-way valve Intersection flow Throttling windows Multi-objective optimization
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Influence of Multiple Electromagnetic Sources for Heat Transfer Improvement of Ferrofluid Flow inside the Serpentine Tube:A Computational Study 认领 引用 被引量：1
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作者 M.Barzegar Gerdroodbary S.Valiallah Mousavi Seyyed Amirreza Abdollahi 《Computer Modeling in Engineering & Sciences》 SCIE EI 2026年第2期624-641,共18页
This study investigates the enhancement of convective heat transfer in a serpentine pipe using ferrofluid flow influenced by dual non-uniform magnetic sources.The primary objective is to improve thermal performance in... This study investigates the enhancement of convective heat transfer in a serpentine pipe using ferrofluid flow influenced by dual non-uniform magnetic sources.The primary objective is to improve thermal performance in compact cooling systems,such as those used in heat exchangers.A two-dimensional,steady-state Computational Fluid Dynamic(CFD)model is developed in ANSYS Fluent to simulate the behavior of an incompressible ferrofluid under applied constant heat flux and magnetic fields.The magnetic force is modeled using the Kelvin force,which acts on magnetized nanoparticles in response to spatially varying electromagnetic fields generated by two strategically positioned current-carrying wires.The effects of magnetic field strength,quantified by the magnetic number(Mn),on flow behavior and temperature distribution are thoroughly analyzed.The results indicate that increasing Mn leads to higher Nusselt numbers,demonstrating enhanced convective heat transfer.Secondary vortices induced by magnetic forcing improve fluid mixing,particularly in curved regions of the pipe.A mesh-independence study and model validation with benchmark data support the reliability of the numerical framework.This work highlights the potential of magnetic-field-assisted thermal control in energy-efficient cooling applications and provides a foundation for the further development of advanced ferrofluid-based heat transfer systems. 展开更多
关键词 Ferrofluid flow heat transfer CFD serpentine pipe heat exchangers
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A numerical study on wind-driven runback characteristics of a thin water film flow over a solid surface 认领 引用 被引量：1
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作者 Jincheng Wang Ping He Hui Hu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第1期64-72,共9页
An unsteady numerical simulation is conducted to examine the dynamic runback characteristics of a water film flow driven by a boundary layer airflow over a solid surface pertinent to the dynamic glaze ice accretion pr... An unsteady numerical simulation is conducted to examine the dynamic runback characteristics of a water film flow driven by a boundary layer airflow over a solid surface pertinent to the dynamic glaze ice accretion process over aircraft wing surfaces.The multiphase flow simulation results of the wind-driven water runback(WDWR)flow are compared quantitatively with the experimental results in terms of the time-dependent variations of the water film thickness profiles and evolution of the front contact point of the runback water film flow.The underlying mechanism of the intermittent water runback behavior is elucidated by analyzing the time evolution of the airflow velocity and vorticity fields above the runback water film flow over the solid surface.To the best knowledge of the authors,the work presented here is the first successful attempt to numerically examine the transient runback characteristics of WDWR flows.It serves as an excellent benchmark case for the development of best practices to model the important micro-physical processes responsible for the transient water transport over aircraft wing surfaces. 展开更多
关键词 Multiphase flow simulation Water transport over wing surfaces Glaze ice accretion process Volume of fluid method
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Three-dimensional heat transfer model of oil-water two-phase stratified flow 认领 引用
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作者 Hui-Shu Liu Ji-Miao Duan +4 位作者 Yong-Xiang Huang Hao-Nan Li Shuo Xu Shi-Ming Chen Hui-Rong Huang 《Petroleum Science》 SCIE EI CAS CSCD 2026年第4期2120-2135,共16页
Oil-water stratified flow,a fundamental pattern in multiphase pipe flow,is commonly encountered in offshore petroleum production and transportation.Although hydraulic characteristics of this flow regime have been exte... Oil-water stratified flow,a fundamental pattern in multiphase pipe flow,is commonly encountered in offshore petroleum production and transportation.Although hydraulic characteristics of this flow regime have been extensively studied,accurate prediction of its heat transfer behavior under nonisothermal conditions remains a challenge.In this study,we develop a three-dimensional heat transfer model for oil-water stratified flow by integrating the energy conservation equation with established flow models and coupling it with momentum conservation.Turbulence is resolved using a lowReynolds-number k-ε model.The phase interface is captured via a minimum energy model,and the irregular physical domain is transformed into a regular rectangular region using bipolar coordinates to simplify grid generation and numerical solution.The model was validated against experimental measurements of average outlet temperatures for both phases,showing relative errors within 5%.Results further reveal how water cut influences the axial temperature distribution and highlight threedimensional temperature profiles during non-isothermal flow.This model provides theoretical insights and practical tools for optimizing thermal management and ensuring safety in offshore petroleum pipeline operations. 展开更多
关键词 Oil-water two-phase flow Stratified flow Heat transfer characteristics Numerical model
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RH refining behavior affected by swirling flow nozzles combined with electromagnetic stirring 认领 引用
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作者 Feng-Sheng Qi De-Qiang Li +3 位作者 Liang-Yu Zhang Zhong-Qiu Liu Sherman-C.-P.Cheung Bao-Kuan Li 《Journal of Iron and Steel Research International》 SCIE EI CSCD 2026年第1期341-358,共18页
A 3D mathematical model was established to investigate the gas-liquid two-phase flow in Ruhrstahl-Heraeus(RH)vacuum refining process.The flow characteristics of molten steel were calculated using the coupled standard... A 3D mathematical model was established to investigate the gas-liquid two-phase flow in Ruhrstahl-Heraeus(RH)vacuum refining process.The flow characteristics of molten steel were calculated using the coupled standard k-εmodel and volume of fluid model.The bubble distribution was tracked by discrete phase model.Electromagnetic field was applied in the up-leg snorkel to enhance the effect of vacuum refining.The effect of swirling flow nozzles combined with electromagnetic stirring(EMS)on the flow characteristics of molten steel and bubble distribution was analyzed.The erosion of the up-leg snorkel was compared.The results show that when the swirling flow nozzles are used,the bubbles exhibit a distinct adherent rising behavior,and the refining efficiency decreases.In addition,the electromagnetic field can significantly improve the refining efficiency,but it brings stronger erosion to the up-leg snorkel.Nevertheless,when using the swirling flow nozzles combined with EMS,the refining performance is further optimized,and the erosion of the up-leg snorkel is also reduced due to its characteristic of bubble distribution.Compared to conventional nozzles,the mixing time was shortened by 16.2%,the recirculation rate increased by 12.5%.and the swirling intensity was strengthened by 8.9%. 展开更多
关键词 Ruhrstahl-Heraeus refining Swirling flow nozzle Electromagnetic stirring Bubble distribution Multiphase flow
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Reconstructing flow fields from sparse measurements using a convolutional autoencoder integrated with an Informer model 认领 引用
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作者 Yulu Liu Jiakun Long +2 位作者 Bofu Wang Tienchong Chang Xiang Qiu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第7期116-130,共15页
This paper explores the use of sparse time-series data from flow systems,acquired through sensors or other means,to predict flow fields using deep learning techniques.This area of research holds substantial scientific... This paper explores the use of sparse time-series data from flow systems,acquired through sensors or other means,to predict flow fields using deep learning techniques.This area of research holds substantial scientific significance and practical application value.The time-series data measured from different points typically contain spatial correlation and temporal features,which,when utilized effectively,can contribute to reconstructing flow fields.In this study,a convolutional autoencoder is applied to reduce the dimensionality of the flow field.Subsequently,an Informer neural network and a convolutional neural network are employed to extract low-dimensional representations of the flow field from the measurement data.A specially designed loss function bridges these latent features to establish a mapping between measurement point sequences and flow fields.The hybrid model is validated using data from both numerical simulations and experimental measurements.Results demonstrate that this method effectively predicts velocity and pressure fields from sparse data,showcasing its potential for practical flow field reconstruction tasks. 展开更多
关键词 Flow around cylinder Flow prediction Neural network
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A method of characteristics for supersonic viscous flows 认领 引用
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作者 Bo ZHANG Yuxin ZHAO Shihe YI 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第3期282-293,共12页
This paper develops a method of characteristics for supersonic viscous flows.The proposed method removes the inviscid and isentropic assumptions of the classical method of characteristics.The characteristic equations ... This paper develops a method of characteristics for supersonic viscous flows.The proposed method removes the inviscid and isentropic assumptions of the classical method of characteristics.The characteristic equations and compatibility equations are derived from the governing equations for compressible viscous flow.By combining the characteristic lines,the triangular interior unit process,quadrilateral interior unit process,and direct sonic point unit process are developed.The unit processes make up the characteristic net.The numerical algorithms consider the path of flow signal propagation.The inviscid terms are solved along characteristic lines,while the viscous terms are corrected through iterative whole-field computations.The proposed method has been applied to supersonic flat-plate boundary layer and verified by the similarity solution.The errors of velocity and temperature profiles are on the order of 0.1%,while the computation efficiency is the same as the classical method of characteristics.The accuracy and efficiency make the proposed method potential to become a basic tool of analysis and design for supersonic viscous flows. 展开更多
关键词 Characteristic line Compatibility equation Compressible flow Method of characteristics Supersonic flow Viscous flow
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Flow analysis of asymmetric clearance and optimization of pressure equalization grooves to mitigate hydraulic spool valve sticking 认领 引用
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作者 Zhen-hao LIN Yu-wei WANG +3 位作者 Zhe-hui MA Tian-xiao ZHANG Zhi-jiang JIN Jin-yuan QIAN 《Journal of Zhejiang University-SCIENCE A》 SCIE EI CAS CSCD 2026年第5期493-505,I0022-I0025,共13页
The hydraulic spool valve is a critical control component in aerospace hydraulic systems.However,complex working environments can cause the valve core to become stuck,thus severely restricting the performance of such ... The hydraulic spool valve is a critical control component in aerospace hydraulic systems.However,complex working environments can cause the valve core to become stuck,thus severely restricting the performance of such valves.This in turn can hinder the precise control of hydraulic oil,reduce the stability of the hydraulic system,and lead to serious accidents in aerospace systems.The unbalanced radial force and solid particle intrusion into the fit clearance are the main factors behind this sticking.To better understand these issues,in this study,we simulated the fluid dynamics and particle behavior within the clearance of the valve core and analyzed the effects of inclination angle,clearance size,particle diameter,and pressure equalization groove(PEG)properties.The mechanism behind valve core sticking was revealed,and it was found that the PEG has an inhibitory effect on the unbalanced radial force and particle intrusion.Furthermore,we proposed an optimized structure for a triangular pressure equalization groove with an arc-shaped bottom(Tri-PEG).The structural parameters were determined through multi-objective optimization,with the objectives of minimizing the leakage at the clearance and maximizing the particle volume fraction at the bottom of the Tri-PEG.The optimal parameters were an arc-shaped radius of 0.200 mm,a groove depth of 0.392 mm,and a half groove width of 0.215 mm.Comparing Tri-PEG with a rectangular PEG,the leakage was reduced by 12%,and the particle concentration was increased by 6%.Overall,these findings serve as an important reference for alleviating spool valve sticking. 展开更多
关键词 Spool valve Flow characteristics Multi-objective optimization Solid-liquid two-phase flow Aerospace hydraulic systems Valve sticking
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Heterogeneity Performance of Cross-border Development Under the Influence of High-speed Rail Flow and Information Flow in Yangtze River Delta Region,China 认领 引用
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作者 DUAN Wei WANG Shaobo +1 位作者 ZHOU Yutao WANG Xinyu 《Chinese Geographical Science》 SCIE CAS CSCD 2026年第3期524-540,共17页
In the knowledge economy era,the rapid flow channels represented by high-speed rail(HSR)and online information flow promote cross-border development between cities.This study constructed a conceptual model of cross-bo... In the knowledge economy era,the rapid flow channels represented by high-speed rail(HSR)and online information flow promote cross-border development between cities.This study constructed a conceptual model of cross-border development from the perspective of flow space.Taking the Yangtze River Delta Region(YRDR),China,as a case study,we apply the Speaker-listener Label Propagation Algorithm(SLPA)to detect the heterogeneity patterns of cross-border development shaped by HSR flow and information flow in 2021.Results show that cross-border development among cities is more evident under information flows compared to HSR flow.Furthermore,intra-provincial cross-border development predominates under HSR flow,whereas inter-provincial cross-border development is more frequent under in-formation flow.Additionally,information flow leads to more shared or competitive nodes in cross-border development across different communities.In the future,leveraging these nodes'intermediary role will be the key to driving the next phase of regional integration.This research will enhance and broaden the theoretical frameworks for cross-border integrated development,flow space,and regional coordinated development. 展开更多
关键词 flow space cross-border development high-speed rail(HSR)flow information flow Yangtze River Delta Region(YRDR),China
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Characteristics of wind-sand flow in longitudinal slope embankment section of desert highway 认领 引用
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作者 LI Liangying ZHANG Yu +3 位作者 XIN Guowei WANG Zhenqiang JI Shuai WANG Xu 《Journal of Mountain Science》 SCIE CSCD 2026年第1期270-281,共12页
Investigating the wind-sand flow response regularity in the longitudinal slope sections of desert highways provides a scientific basis for selecting the slope of desert roads.This study uses the Tengger Desert section... Investigating the wind-sand flow response regularity in the longitudinal slope sections of desert highways provides a scientific basis for selecting the slope of desert roads.This study uses the Tengger Desert section of the Wuhai-Maqin Expressway as a case study,employing CFD numerical simulation methods to calculate and analyze the wind-sand flow field distribution characteristics in different longitudinal slope sections.The results show that:(1)Along with the direction of the incoming flow,the windward and leeward slope toes of the embankment are low-wind-speed zones,with the wind speed at the leeward slope toe being even lower.The higher the embankment,the larger the low-wind-speed zone at the windward and leeward slope toes.As the longitudinal slope increases,the extent of the lowwind-speed zone at the same location along the route also increases.(2)Along the route direction,the wind speed at the windward and leeward slope toes decreases as embankment height increases.At the embankment toe,sand particles are transported from the top to the bottom of the longitudinal slope,and the greater the longitudinal slope,the stronger the transport effect.(3)Along the route direction,the sand accumulation around the embankment gradually gathers toward the bottom of the longitudinal slope as the slope increases.When the longitudinal slope is 3%and 4%,the trend of sand accumulation moving from the windward side at the end of the route to the leeward side at the start of the route is more significant.When the longitudinal slope is less than or equal to 3%,severe sand accumulation within the embankment range is reduced by 86.4%or more compared to when the slope is 4%.(4)Under the same longitudinal slope,the higher the embankment height,the smaller its transport rate.When the embankment height is the same,the greater the longitudinal slope,the greater the embankment transport rate. 展开更多
关键词 Desert highway Wind-sand flow Longitudinal slope gradient Flow field structure Sand accumulation law Numerical simulation
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Impact of multiscale flow structures on mixing and losses in turbine blade tip region 认领 引用
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作者 Zhengping ZOU Lin HUANG Yifan WANG 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第2期44-79,共36页
Multiscale mixing of the turbine blade tip leakage and mainstream flows causes considerable aerodynamic loss.Understanding it is crucial to correctly estimating the mixing loss and thus improving the turbine's per... Multiscale mixing of the turbine blade tip leakage and mainstream flows causes considerable aerodynamic loss.Understanding it is crucial to correctly estimating the mixing loss and thus improving the turbine's performance.The multiscale mixing phenomenon in a typical high-pressure turbine rotor flow was studied in this work.The contributions of various scale flows to entropy production and mixing properties were identified.The corresponding physical mechanisms at different scales were explored.It is shown that the large-scale and time-averaged flow contributions to mixing are significant,accounting for approximately 37.1% and 25% of the total.Time-averaged and large-scale flows cause the majority of the fluid deformation of the material surface,while mesoand small-scale flows just generate finer deformations.It raises the area stretch coefficient and the virtual concentration gradient.Thus,mixing is enhanced.Furthermore,time-averaged and large-scale flows account for the majority of the losses in the upstream and downstream regions of the blade tip respectively,accounting for approximately 53.8%and 33.5%of the total.The sheet-like structures—rather than the tip leaking vortex—are the primary source of the loss.High-dissipation regions are produced by the sheet-like structures via the pressure Hessian term and the self-amplification terms. 展开更多
关键词 Entropy production analysis Mixing Multiscale flows Tip leakage flow Turbine
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Multiscale Single-Phase Flow Mechanisms of Shale Oil Revealed by High-Pressure Nuclear Magnetic Resonance Experiments 认领 引用
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作者 Maolei Cui Zengmin Lun +2 位作者 Jie Zhang Jun Niu Pufu Xiao 《Fluid Dynamics & Materials Processing》 EI 2026年第2期253-264,共12页
To clarify fluid flow mechanisms and establish effective development conditions in continental shale oil reservoirs,a high-temperature,high-pressure steady-state flow system integrated with nuclear magnetic resonance(... To clarify fluid flow mechanisms and establish effective development conditions in continental shale oil reservoirs,a high-temperature,high-pressure steady-state flow system integrated with nuclear magnetic resonance(NMR)technology has been developed.The apparatus combines sample evacuation,rapid pressurization and saturation,and controlled displacement,enabling systematic investigation of single-phase shale oil flow under representative reservoir conditions.Related experiments allow proper quantification of the activation thresholds and relative contributions of different pore types to flow.A movable fluid index(MFI),defined using dual T2 cutoff values,is introduced accordingly and linked to key flow parameters.The results reveal distinct multi-scale characteristics of single-phase shale oil transport,namely micro-scale graded displacement and macro-scale segmented nonlinear behavior.As the injection-production pressure difference increases,flow pathways are activated progressively,beginning with fractures,followed by large and then smaller macropores,leading to a pronounced enhancement in apparent permeability.Although mesopores and micropores contribute little to direct flow,their indirect influence becomes increasingly important,and apparent permeability gradually approaches a stable limit at higher pressure difference.It is also shown that the MFI exhibits a strong negative correlation with the starting pressure gradient and a positive correlation with apparent permeability,providing a rapid and reliable indicator of shale oil flow capacity.Samples containing through-going fractures display consistently higher MFI values and superior flowability compared with those dominated by laminated fractures,highlighting the pivotal role of well-connected fracture networks generated by large-scale hydraulic fracturing in improving shale oil production. 展开更多
关键词 Shale oil laminated fractures steady-state flow Nuclear Magnetic Resonance(NMR) nonlinear flow
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Control of Base Pressure in Supersonic Separated Flows over Axisymmetric Bodies Using Triangular Rib Actuators 认领 引用
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作者 Abdul Aabid Renita Sharon Monis +2 位作者 Ambareen Khan Sher Afghan Khan Muneer Baig 《Fluid Dynamics & Materials Processing》 EI 2026年第5期1-24,共24页
Separated flow at a blunt base remains a critical topic in both automotive and aerospace engineering,particularly in the context of high-speed and supersonic vehicles such as modern fighter aircraft.In the separated r... Separated flow at a blunt base remains a critical topic in both automotive and aerospace engineering,particularly in the context of high-speed and supersonic vehicles such as modern fighter aircraft.In the separated region,characterized by a recirculation zone,the local pressure is typically lower than the ambient back pressure.This reduced base pressure can account for up to 70 percent of the total drag acting on an axisymmetric body.The present study focuses on regulating the base pressure within the recirculation region to reduce base drag and thereby enhance the operational range of rockets,missiles,and related aerospace vehicles.The analysis considers key inertial and geometric parameters,including a Mach number of M=1.8,different expansion levels,an area ratio of 6.25,and duct lengths ranging from L/D=1 to 6.A triangular rib is introduced as a passive flow-control device to modulate the pressure within the duct.In the numerical simulations,the rib base is fixed at 3 mm,while its height varies from 1 mm to 5 mm.The results indicate that increasing the rib height enhances the base pressure,with the largest height producing the greatest pressure rise.A rib height of 3 mm is sufficient to raise the base pressure close to the back pressure.For applications requiring a more substantial increase in base pressure,ribs with heights of 4 or 5 mm are recommended,depending on mission constraints.Optimal performance is achieved when the rib is positioned at L/D=3 or 4,where the maximum pressure gain is observed. 展开更多
关键词 Triangular rib base drag compressible flow steady flow effect of area ratio
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Improvement of Stability of a High-Loaded Axial Flow Compressor by a Combined Flow Control Method 认领 引用
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作者 MENG Dejun YIN Haibao LIU Jie 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2026年第2期286-300,共15页
This study investigates a high⁃loaded axial compressor in which flow instabilities in the rotor and the stator occur almost concurrently.Under these conditions,conventional stability enhancement methods prove to be in... This study investigates a high⁃loaded axial compressor in which flow instabilities in the rotor and the stator occur almost concurrently.Under these conditions,conventional stability enhancement methods prove to be ineffective.The paper proposes a combined rotor-stator flow control technique.This study reveals that the flow field deterioration stems from combined flow blockage at the rotor tip region and the near-hub region of the stator.Research on flow control methods finds that self-recirculating casing treatment can effectively improve flow capacity in the rotor tip region,but simultaneously reduce flow capacity in the near-hub zone.This makes the hub flow field more susceptible to breakdown and ultimately triggers compressor instability.Thus,the self-recirculating casing treatment fails to enhance stall margin.By contrast,hub suction significantly improves the hub-region flow field.Yet without suppressing the rotor-tip flow blockage,it achieves limited stability enhancement.The integrated solution combining self-recirculating casing treatment with hub suction simultaneously addresses flow blockage at both the rotor tip and the stator near-hub regions.This combined flow control method delivers effective stability enhancement,achieving 6.78%increase in compressor stall margin. 展开更多
关键词 axial flow compressor high load stability combined flow control method flow mechanism
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Porous Functional Nanomaterials for Continuous Flow Catalysis 认领 引用
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作者 Yingguo Li Hao Chen +7 位作者 Zhiyao Li Minghao Liu Mengmeng Fu Xiaoyi Yue Danfeng Jiang Xiao Chen Chao Yu Wei Gong 《Nano-Micro Letters》 SCIE EI CAS CSCD 2026年第9期93-138,共46页
With the advancement of green chemistry and process intensification,continuous flow technology has emerged as a powerful tool in the manufacturing of fine chemicals and pharmaceuticals.Owing to their highly regular po... With the advancement of green chemistry and process intensification,continuous flow technology has emerged as a powerful tool in the manufacturing of fine chemicals and pharmaceuticals.Owing to their highly regular porous architectures,diverse chemical compositions,and excellent catalytic activity,porous materials have proven to be ideal supports and catalytic platforms for continuous flow catalysis.This review systematically summarizes the recent progress in the design and application of porous materials in continuous flow catalysis,with a focus on several major structural categories,including metal–organic frameworks,covalent organic frameworks/polymers,cages,porous silicates,monoliths,and polymeric carbon nitrides.It also covers various reactor types,including fixed bed,packed bed,and microreactors.Special emphasis is placed on elucidating the relationships among pore structure,electronic structure,active sites,and reaction–diffusion kinetics of porous catalysts within flow reactors.Their practical applications are outlined in areas such as selective catalysis of small molecules,photocatalysis,photothermal catalysis,and multistep cascade reactions in bioconversion processes.Furthermore,focusing on the technical challenges encountered during the industrial scale-up of continuous flow systems based on porous catalysts,this review examines key issues such as insufficient precise control over structure and function,limitations in the compatibility of particle and overall morphology design,difficulties in regulating low-pressure-drop fluid dynamics,and the challenge of maintaining high catalytic stability over extended operation.It also provides a systematic analysis of potential solutions to these problems.Finally,current challenges and future directions in the field are discussed,underscoring the pivotal role of porous materials in flow chemistry.It is hoped that this review will stimulate further research on the application of porous materials in continuous flow catalysis and facilitate the rational design of novel heterogeneous porous catalysts for industrial applications. 展开更多
关键词 Porous materials Continuous flow Process intensification Photocatalysis Heterogeneous catalysis
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Flow control of a surface-mounted finite-length square cylinder using synthetic jets 认领 引用
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作者 Shiqing Li Meihua Xia +3 位作者 Shuxuan Cai Yan Han Peng Hu Lingwei Zeng 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第3期489-503,共15页
This paper studied the effect of synthetic jets on active flow control around a finite-length square cylinder using the large eddy simulation method.Based on the oncoming flow velocity(U∞)and the model width d,the... This paper studied the effect of synthetic jets on active flow control around a finite-length square cylinder using the large eddy simulation method.Based on the oncoming flow velocity(U∞)and the model width d,the corresponding Reynolds number is 2.78×104.We explored the impact of the momentum coefficient(Cμ)and the dimensionless jet frequency(f*)on a finite-length square cylinder’s aerodynamic forces and flow field characteristics.The square cylinder has an aspect ratio of 5,with one end mounted on a wall and the other end free.The synthetic jet outlet is deployed at the windward leading edge of the square cylinder.It is found that synthetic jets positioned at the top can effectively suppress the cylinder’s aerodynamic forces.Both the momentum coefficient and dimensionless jet frequency influence the control effectiveness.The maximum reductions in total mean drag coefficients(Cd,mean)and fluctuating lift coefficient(Cl,rms)are 4.01%and 50.7%,respectively.With synthetic jet control,the shear flow at the free end of the square cylinder is significantly suppressed,the separation bubble on the top surface disappears,the shear layer at the free end approaches the top surface of the square cylinder,and the turbulent kinetic energy near the free end is significantly enhanced.This study may offer valuable guidance for related engineering applications. 展开更多
关键词 Square cylinder Active flow control Synthetic jet LES
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Hydrogeological flow patterns and hydrochemical driving forces of groundwater in a typical coastal hilly region of the Jinjiang watershed,Southeast China:Recommendations for water pollution control and management 认领 引用 被引量：1
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作者 Zhong-shuang Cheng Chen Su +4 位作者 Wen-zhong Wang Bing-yan Li En-de Zuo Yu-meng Tian Zhao-xian Zheng 《China Geology》 CAS CSCD 2026年第2期316-332,共17页
Coastal groundwater(CGW)systems in rapidly urbanizing regions face critical challenges in achieving Sustainable Development Goal(SDG),where anthropogenic pressures intersect with hydrogeological vulnerability.This stu... Coastal groundwater(CGW)systems in rapidly urbanizing regions face critical challenges in achieving Sustainable Development Goal(SDG),where anthropogenic pressures intersect with hydrogeological vulnerability.This study employs coupled isotopic-hydrogeochemical analysis and geostatistics to unravel hydrochemical driving forces compromising groundwater quality in the Jinjiang Downstream Watershed(DJW),Southeast China.The results indicated that groundwater was predominantly recharged from local atmospheric precipitation and lateral recharge from the adjacent boundaries.Hydrochemical distributions exhibited a distinct pattern,transitioning from HCO3-Ca to HCO3·Cl-Ca,and then to Cl-Mg·Ca/Na·Ca,reflecting processes ranging from freshwater recharge to seawater intrusion(SWI).Elevated nitrates were primarily attributed to domestic sewage leakage and septic tank leaching.Additionally,preferential flow posed a risk to deep groundwater quality,by facilitating the rapid transport of contaminants through rock fractures.Key driving forces of hydrochemistry included silicate dissolution with local runoff paths,SWI,and human activities.The study advocates for a governance paradigm integrating electrochemical sensor networks with machine learning-driven contaminant prediction and phased membrane bioreactor deployment,which synergistically reduce nitrate fluxes while maintaining aquifer freshening processes.This integrated approach establishes a scalable model for SDG-aligned groundwater management in vulnerable coastal zones,demonstrating how process-based insights can bridge scientific discovery and water security implementation. 展开更多
关键词 Groundwater flow pattern Atmospheric precipitation Hydrochemistry Nitrate Driving forces Seawater intrusion Electrochemical sensor networks Machine learning Coastal area Sustainable Development Goal(SDG) Groundwater management Hydrogeological survey engineering
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Non-Newtonian rivulet flows on an inclined planar surface applying the 2nd Stokes problem 认领 引用
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作者 S.V.ERSHKOV E.S.BARANOVSKII A.V.YUDIN 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2026年第1期153-164,共12页
The newly formulated non-Newtonian rivulet flows streaming down an inclined planar surface,with additional periodic perturbations arising from the application of the 2nd Stokes problem to the investigation of rivulet ... The newly formulated non-Newtonian rivulet flows streaming down an inclined planar surface,with additional periodic perturbations arising from the application of the 2nd Stokes problem to the investigation of rivulet dynamics,are demonstrated in the current research.Hereby,the 2nd Stokes problem assumes that the surface,with a thin shared layer of the fluid on it,oscillates in a harmonic manner along the x-axis of the rivulet flow,which coincides with the main flow direction streaming down the underlying surface.We obtain the exact extension of the rivulet flow family,clarifying the structure of the pressure field,which fully absorbs the arising perturbation.The profile of the velocity field is assumed to be Gaussian-type with a non-zero level of plasticity.Hence,the absolutely non-Newtonian case of the viscoplastic flow solution,which satisfies the motion and continuity equations,is considered(with particular cases of exact solutions for pressure).The perturbed governing equations of motion for rivulet flows then result in the Riccati-type ordinary differential equation(ODE),describing the dynamics of the coordinate x(t).The approximated schematic dynamics are presented in graphical plots. 展开更多
关键词 rivulet flow non-Newtonian fluid creeping viscoplastic flow 1st/2nd Stokes problem
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