The pre-gate suction vortex,gate-bottom-edge transverse vortex,gate-slot vertical vortex,and downstream-of-gate return vortex are important factors affecting the flow instability of flat gates,which may lead to fatigu...The pre-gate suction vortex,gate-bottom-edge transverse vortex,gate-slot vertical vortex,and downstream-of-gate return vortex are important factors affecting the flow instability of flat gates,which may lead to fatigue failure in severe cases.This study used the volume of fluid(VOF)model and large eddy simulation(LES)method to accurately capture the transient turbulence characteristics of flow under different water flow conditions and reveal the flow field and vortex structure.The Q—criterion,Omega(Ω)method,and latest third-generation Liutex vortex identification method were used to analyze and compare the pre-gate suction vortex,gate-slot vertical vortex,and downstream-of-gate return vortex,focusing on the ability of each vortex identification method to capture the flow field information and vortex characteristics.The results reveal that theΩmethod and Liutex method are less dependent on the threshold value,and the Liutex method captures a wide range of pre-gate vortices.Different flow conditions cause changes in the vortex structure of over-gate flow.When the relative opening of the gate is smaller,the intensity of the vortices in the flow field around the gate is greater,the return vortices downstream of the gate are more disordered,and the vortex changes are more violent,which in turn affects the efficient and stable operation of the gate.展开更多
Fishway research is important for mitigating the fragmentation of river habitats caused by hydraulic projects.The vertical slit fishway is a broadly used fishway type because of its high efficiency and adaptability to...Fishway research is important for mitigating the fragmentation of river habitats caused by hydraulic projects.The vertical slit fishway is a broadly used fishway type because of its high efficiency and adaptability to water levels.However,the resulting vortex current disrupts the fish passage hence directly affecting fish migration.This study aims to accurately capture the vortex structure in the fishway and analyze the effect of vortex elements(vortex structure,vortex intensity,etc.)on fish.We conducted an analysis of the 3-D current flow field in the fishway through the utilization of an experimental model and the large eddy simulation(LES)method.Moreover,we captured the vortex information in the fishway at different flow rates using the Liutex vortex identification method and investigated the effect of the vortex on fish migration.The results revealed that the structures inside the fishway pool occupy most of the room,however,the areas with higher vortex strength were primarily located in the vortex near the vertical seam and the mainstream,the vortex strength inside the fishway gradually increases with increasing flow,suppressing fish migration.Fish experienced significantly increased resistance when encountering strong vortices.This suggests that the vortex may act as a physical barrier to fish migration.These findings highlight the potential negative effects of vortex on fish movement and reiterate the importance of understanding vortex dynamics for aquatic environmental management.As an effective tool for identifying vortices in fluid flow,the Liutex method demonstrates features of vortex within the fishway,thereby providing important insights into the interaction between fluid dynamics and aquatic organisms.展开更多
There are two main approaches when discussing living green walls:an ecological one and an artistic one.Ecological thinking mainly considers environmental aspects,comfort enhancement and energy consumption and oversees...There are two main approaches when discussing living green walls:an ecological one and an artistic one.Ecological thinking mainly considers environmental aspects,comfort enhancement and energy consumption and oversees human interaction and actual proximity to plants.In opposition,art or architecture installations that involve vegetation,lack technical and ecological aspects,aiming to raise awareness on environmental issues using human interaction either physically(direct)or emotionally(indirect).The present paper aims to analyze methods of combining the two directions,in a functional,ecological,yet aesthetically pleasing composition.In order to further develop previous experiences gathered by the team members,authors of this article,a green installation concept made out of interactive modular systems unites all the knowledge into a new,living,moving,dynamic,interactive structure whose inspiration is taken from nature while using biomimicry as main principle for its development.This new concept responds and is influenced by both external,natural stimuli and by the human factor.Multidisciplinarity is a key element in developing this project,involving architecture,art,interior and landscape design,botany,geometry,mechanical and electrical engineering,leading towards new research directions and innovative approaches in greenery-interior environment connections.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.52069009,51369013).
文摘The pre-gate suction vortex,gate-bottom-edge transverse vortex,gate-slot vertical vortex,and downstream-of-gate return vortex are important factors affecting the flow instability of flat gates,which may lead to fatigue failure in severe cases.This study used the volume of fluid(VOF)model and large eddy simulation(LES)method to accurately capture the transient turbulence characteristics of flow under different water flow conditions and reveal the flow field and vortex structure.The Q—criterion,Omega(Ω)method,and latest third-generation Liutex vortex identification method were used to analyze and compare the pre-gate suction vortex,gate-slot vertical vortex,and downstream-of-gate return vortex,focusing on the ability of each vortex identification method to capture the flow field information and vortex characteristics.The results reveal that theΩmethod and Liutex method are less dependent on the threshold value,and the Liutex method captures a wide range of pre-gate vortices.Different flow conditions cause changes in the vortex structure of over-gate flow.When the relative opening of the gate is smaller,the intensity of the vortices in the flow field around the gate is greater,the return vortices downstream of the gate are more disordered,and the vortex changes are more violent,which in turn affects the efficient and stable operation of the gate.
基金supported by the National Natural Science Foundation of China(Grant Nos.52069009,51369013).
文摘Fishway research is important for mitigating the fragmentation of river habitats caused by hydraulic projects.The vertical slit fishway is a broadly used fishway type because of its high efficiency and adaptability to water levels.However,the resulting vortex current disrupts the fish passage hence directly affecting fish migration.This study aims to accurately capture the vortex structure in the fishway and analyze the effect of vortex elements(vortex structure,vortex intensity,etc.)on fish.We conducted an analysis of the 3-D current flow field in the fishway through the utilization of an experimental model and the large eddy simulation(LES)method.Moreover,we captured the vortex information in the fishway at different flow rates using the Liutex vortex identification method and investigated the effect of the vortex on fish migration.The results revealed that the structures inside the fishway pool occupy most of the room,however,the areas with higher vortex strength were primarily located in the vortex near the vertical seam and the mainstream,the vortex strength inside the fishway gradually increases with increasing flow,suppressing fish migration.Fish experienced significantly increased resistance when encountering strong vortices.This suggests that the vortex may act as a physical barrier to fish migration.These findings highlight the potential negative effects of vortex on fish movement and reiterate the importance of understanding vortex dynamics for aquatic environmental management.As an effective tool for identifying vortices in fluid flow,the Liutex method demonstrates features of vortex within the fishway,thereby providing important insights into the interaction between fluid dynamics and aquatic organisms.
基金supported by research grant GNaC2018 ARUT,no.1347/01.02.2019financed by Politehnica University of Timisoara.
文摘There are two main approaches when discussing living green walls:an ecological one and an artistic one.Ecological thinking mainly considers environmental aspects,comfort enhancement and energy consumption and oversees human interaction and actual proximity to plants.In opposition,art or architecture installations that involve vegetation,lack technical and ecological aspects,aiming to raise awareness on environmental issues using human interaction either physically(direct)or emotionally(indirect).The present paper aims to analyze methods of combining the two directions,in a functional,ecological,yet aesthetically pleasing composition.In order to further develop previous experiences gathered by the team members,authors of this article,a green installation concept made out of interactive modular systems unites all the knowledge into a new,living,moving,dynamic,interactive structure whose inspiration is taken from nature while using biomimicry as main principle for its development.This new concept responds and is influenced by both external,natural stimuli and by the human factor.Multidisciplinarity is a key element in developing this project,involving architecture,art,interior and landscape design,botany,geometry,mechanical and electrical engineering,leading towards new research directions and innovative approaches in greenery-interior environment connections.
