This study addresses the optimization of automated yarn handling in textile manufacturing by examining the related suction process through a combined numerical and experimental approach.In particular,a three-dimension...This study addresses the optimization of automated yarn handling in textile manufacturing by examining the related suction process through a combined numerical and experimental approach.In particular,a three-dimensional model of the suction nozzle was coupled with an equivalent linear-elastic beam representation of the yarn,and a Fluent-IDW-Abaqus weakly coupled fluid-structure interaction(FSI)framework was employed to capture the yarn’s release and dynamic response under negative-pressure suction.High-speed imaging experiments validated the simulations,demonstrating excellent agreement in displacements and velocities.According to the results,increasing the initial suction pressure from -0.04 MPa to -0.06 MPa reduces adsorption time by approximately 62% and markedly dampens yarn-end vibrations,enhancing suction performance.Pressures beyond -0.06 MPa,however,induce overshoot and nozzle collisions,increasing the risk of entanglement and mechanical damage.The outcomes of a statistical analysis are also presented to further quantify the interplay among energy consumption,suction efficiency,and operational success under varying pressures,thereby providing a rigorous foundation for the optimal selection of pressure parameters in automated yarn-handling systems.展开更多
This paper presents a simplified design tool based on semi-analytical formulations to investigate the dynamic response of an immersed composite cylinder subjected to a far-field underwater explosion.The cylinder is si...This paper presents a simplified design tool based on semi-analytical formulations to investigate the dynamic response of an immersed composite cylinder subjected to a far-field underwater explosion.The cylinder is simply supported,fully submerged and filled with air inside.A classical shell theory using a Double Fourier series solution combined with the first-order Doubly Asymptotic Approximation(DAA1)formulation is adapted to model the fluid-structure interaction.An explicit non-standard finite difference scheme is applied to solve the coupled differential equations in time domain.The validity of DAA1 model is established by comparing the LS-DYNA/USA finite element results with existing experimental data from the literature.Then the proposed semi-analytical solutions are compared to the LS-DYNA/USA results,showing good correlation with a discrepancy of 7%for peak deflections and±9%for maximum stresses at the stand-off point for cylinders with relatively small length over radius ratios.Parametric studies examining the effect of different loading conditions,areal masses,and material configurations reveal that a large charge mass located far from the composite panel turns out to be more damaging than a small mass located nearby due to a broader pressure-time profile.Finally,the proposed model demonstrates a significant reduction in computation time,being approximately 30 times faster than its numerical counterpart,LS-DYNA/USA,making it a valuable tool for the preliminary design stages.展开更多
The Hydrodynamic Ram(HRAM)effect occurs when a high kinetic energy projectile penetrates a fluid filled area,e.g.,a liquid filled tank.The projectile transfers its momentum and kinetic energy to the fluid,what causes ...The Hydrodynamic Ram(HRAM)effect occurs when a high kinetic energy projectile penetrates a fluid filled area,e.g.,a liquid filled tank.The projectile transfers its momentum and kinetic energy to the fluid,what causes a sudden,local pressure rise,further expanding as primary shock wave in the fluid and developing a cavity.It is possible that the entire tank ruptures due to the loads transferred through the fluid to its surrounding structure.In the past decades,additionally to experimental investigations,HRAM has been studied using various computational approaches particularly focusing on the description of the Fluid-Structure Interaction(FSI).This article reviews the published experimental,analytical and numerical results and delivers a chronological overview since the end of World War II.Furthermore,HRAM mitigation measures are highlighted,which have been developed with the experimental,analytical and numerical toolboxes matured over the past 80 years.展开更多
A frequent cause of unplanned and costly outages in water-cooled nuclear power plants is the premature failure of the fuel rods due to excessive flow-induced vibration in the reactor core.Turbulence and unsteadiness i...A frequent cause of unplanned and costly outages in water-cooled nuclear power plants is the premature failure of the fuel rods due to excessive flow-induced vibration in the reactor core.Turbulence and unsteadiness in the coolant water flowing through the reactor core can cause excessive vibration of the fuel rods,which in turn can result in fretting wear that eventually leads to the fuel rod cladding perforation and subsequent failure.The economic burden of unplanned reactor outages has motivated extensive research into flow-induced vibration.This perspective article provides a brief summary of recent research on flow-induced vibration of cantilever rod systems,which are simplified paradigmatic test configurations that have been instrumental to advance the fundamental physical understanding of axial-flowinduced vibration problems,and have enabled the development of cost-effective numerical methodologies for the simulation of these problems in engineering,with particular application to nuclear reactor systems.This summary covers recent experimental and numerical studies,and includes a description of a novel non-contact Hall-effect-based measuring technique specifically developed to track the vibration of the cantilever rod with gas-liquid two-phase flows.The article concludes by highlighting promising avenues for future research.展开更多
This paper proposes a novel three-directional functionally graded(3D FG)vibration energy harvesting model based on a bimorph pipe structure.A rectangular pipe has material properties that vary continuously along the a...This paper proposes a novel three-directional functionally graded(3D FG)vibration energy harvesting model based on a bimorph pipe structure.A rectangular pipe has material properties that vary continuously along the axial,width,and height directions,and a steady fluid flows inside the pipe.Two piezoelectric layers are attached to the upper and lower surfaces of the pipe,and are connected in series with a load resistance.The output electricity is predicted theoretically and validated by finite element(FE) simulation.The complex mechanisms regulating the energy harvesting performance are investigated,focusing particularly on the effects of 3D FG material(FGM) parameters,load resistance,fluid-structure interaction(FSI),and geometry.Numerical results indicate that among several material gradient parameters,the axial gradient index has the most significant impact.Increasing the axial and height gradient indices can markedly enhance the energy harvesting performance.The optimal resistances differ between the first two modes.Overall,the maximum power is generated at lower resistances.The FSI effect can also improve the energy harvesting performance;however,higher flow velocities may destabilize the system,causing failure of harvesting energy.This research is capable of providing new insights into the design of a pipe energy harvester in engineering applications.展开更多
This paper proposes 2.5-dimensional polymer micromachined insect-mimetic wings based on a fluid-structure interaction(FSI)design concept that enables natural deformations like cambering and pitching under fluid forces...This paper proposes 2.5-dimensional polymer micromachined insect-mimetic wings based on a fluid-structure interaction(FSI)design concept that enables natural deformations like cambering and pitching under fluid forces.Instead of directly employing an analysis for the FSI,an iterative structural Design Window(DW)search is used to reduce the computational cost significantly.A DW search using the iterative method refines the initial design by addressing fabrication challenges and tuning it to meet manufacturability constraints.The successful fabrication and demonstration of the final design solution for a wing demonstrates the effectiveness of the iterative DW search based on the FSI design concept.Furthermore,a pixel model is introduced to convert an unstructured to a structured mesh for the FSI analysis to further reduce the computational cost.The camber and pitching error between the unstructured and structured meshes is minimized to achieve insect-like aerodynamic performance by adjusting the elastic moduli of center and root veins.Finally,an analysis for the FSI is conducted,based on the parameters obtained from the pixel model to evaluate the flight performance on the basis of the lift,camber,and pitching required by an actual insect to maneuver and hover.展开更多
文摘This study addresses the optimization of automated yarn handling in textile manufacturing by examining the related suction process through a combined numerical and experimental approach.In particular,a three-dimensional model of the suction nozzle was coupled with an equivalent linear-elastic beam representation of the yarn,and a Fluent-IDW-Abaqus weakly coupled fluid-structure interaction(FSI)framework was employed to capture the yarn’s release and dynamic response under negative-pressure suction.High-speed imaging experiments validated the simulations,demonstrating excellent agreement in displacements and velocities.According to the results,increasing the initial suction pressure from -0.04 MPa to -0.06 MPa reduces adsorption time by approximately 62% and markedly dampens yarn-end vibrations,enhancing suction performance.Pressures beyond -0.06 MPa,however,induce overshoot and nozzle collisions,increasing the risk of entanglement and mechanical damage.The outcomes of a statistical analysis are also presented to further quantify the interplay among energy consumption,suction efficiency,and operational success under varying pressures,thereby providing a rigorous foundation for the optimal selection of pressure parameters in automated yarn-handling systems.
基金supported by French Defense Innovation Agency(AID-DGA)(Grant No.ANR-21-ASM2-0002-02)in the framework of the Astrid Maturation SUCCESS+project,a collaborative French research project.
文摘This paper presents a simplified design tool based on semi-analytical formulations to investigate the dynamic response of an immersed composite cylinder subjected to a far-field underwater explosion.The cylinder is simply supported,fully submerged and filled with air inside.A classical shell theory using a Double Fourier series solution combined with the first-order Doubly Asymptotic Approximation(DAA1)formulation is adapted to model the fluid-structure interaction.An explicit non-standard finite difference scheme is applied to solve the coupled differential equations in time domain.The validity of DAA1 model is established by comparing the LS-DYNA/USA finite element results with existing experimental data from the literature.Then the proposed semi-analytical solutions are compared to the LS-DYNA/USA results,showing good correlation with a discrepancy of 7%for peak deflections and±9%for maximum stresses at the stand-off point for cylinders with relatively small length over radius ratios.Parametric studies examining the effect of different loading conditions,areal masses,and material configurations reveal that a large charge mass located far from the composite panel turns out to be more damaging than a small mass located nearby due to a broader pressure-time profile.Finally,the proposed model demonstrates a significant reduction in computation time,being approximately 30 times faster than its numerical counterpart,LS-DYNA/USA,making it a valuable tool for the preliminary design stages.
文摘The Hydrodynamic Ram(HRAM)effect occurs when a high kinetic energy projectile penetrates a fluid filled area,e.g.,a liquid filled tank.The projectile transfers its momentum and kinetic energy to the fluid,what causes a sudden,local pressure rise,further expanding as primary shock wave in the fluid and developing a cavity.It is possible that the entire tank ruptures due to the loads transferred through the fluid to its surrounding structure.In the past decades,additionally to experimental investigations,HRAM has been studied using various computational approaches particularly focusing on the description of the Fluid-Structure Interaction(FSI).This article reviews the published experimental,analytical and numerical results and delivers a chronological overview since the end of World War II.Furthermore,HRAM mitigation measures are highlighted,which have been developed with the experimental,analytical and numerical toolboxes matured over the past 80 years.
文摘A frequent cause of unplanned and costly outages in water-cooled nuclear power plants is the premature failure of the fuel rods due to excessive flow-induced vibration in the reactor core.Turbulence and unsteadiness in the coolant water flowing through the reactor core can cause excessive vibration of the fuel rods,which in turn can result in fretting wear that eventually leads to the fuel rod cladding perforation and subsequent failure.The economic burden of unplanned reactor outages has motivated extensive research into flow-induced vibration.This perspective article provides a brief summary of recent research on flow-induced vibration of cantilever rod systems,which are simplified paradigmatic test configurations that have been instrumental to advance the fundamental physical understanding of axial-flowinduced vibration problems,and have enabled the development of cost-effective numerical methodologies for the simulation of these problems in engineering,with particular application to nuclear reactor systems.This summary covers recent experimental and numerical studies,and includes a description of a novel non-contact Hall-effect-based measuring technique specifically developed to track the vibration of the cantilever rod with gas-liquid two-phase flows.The article concludes by highlighting promising avenues for future research.
基金Project supported by the National Natural Science Foundation of China (Nos. 12372025 and 12072311)。
文摘This paper proposes a novel three-directional functionally graded(3D FG)vibration energy harvesting model based on a bimorph pipe structure.A rectangular pipe has material properties that vary continuously along the axial,width,and height directions,and a steady fluid flows inside the pipe.Two piezoelectric layers are attached to the upper and lower surfaces of the pipe,and are connected in series with a load resistance.The output electricity is predicted theoretically and validated by finite element(FE) simulation.The complex mechanisms regulating the energy harvesting performance are investigated,focusing particularly on the effects of 3D FG material(FGM) parameters,load resistance,fluid-structure interaction(FSI),and geometry.Numerical results indicate that among several material gradient parameters,the axial gradient index has the most significant impact.Increasing the axial and height gradient indices can markedly enhance the energy harvesting performance.The optimal resistances differ between the first two modes.Overall,the maximum power is generated at lower resistances.The FSI effect can also improve the energy harvesting performance;however,higher flow velocities may destabilize the system,causing failure of harvesting energy.This research is capable of providing new insights into the design of a pipe energy harvester in engineering applications.
基金supported by the Japan Society for the Promotion of Science KAKENHI under grant number 23H00475.
文摘This paper proposes 2.5-dimensional polymer micromachined insect-mimetic wings based on a fluid-structure interaction(FSI)design concept that enables natural deformations like cambering and pitching under fluid forces.Instead of directly employing an analysis for the FSI,an iterative structural Design Window(DW)search is used to reduce the computational cost significantly.A DW search using the iterative method refines the initial design by addressing fabrication challenges and tuning it to meet manufacturability constraints.The successful fabrication and demonstration of the final design solution for a wing demonstrates the effectiveness of the iterative DW search based on the FSI design concept.Furthermore,a pixel model is introduced to convert an unstructured to a structured mesh for the FSI analysis to further reduce the computational cost.The camber and pitching error between the unstructured and structured meshes is minimized to achieve insect-like aerodynamic performance by adjusting the elastic moduli of center and root veins.Finally,an analysis for the FSI is conducted,based on the parameters obtained from the pixel model to evaluate the flight performance on the basis of the lift,camber,and pitching required by an actual insect to maneuver and hover.
