In this work,the deformation of free interface during water entry and exit of a circular cylinder is investigated numerically by using the two-dimensional(2D)immersed boundary-multiphase lattice Boltzmann flux solver(...In this work,the deformation of free interface during water entry and exit of a circular cylinder is investigated numerically by using the two-dimensional(2D)immersed boundary-multiphase lattice Boltzmann flux solver(IB-MLBFS).The fluid domain is discretized by finite volume discretization,and the flux on the grid interface is evaluated by lattice Boltzmann equations.Both the implicit velocity correction and the surface flux correction are implemented by using the immersed boundary-method to consider the fluid-structure interaction and the contact interface between the multiphase fluids and the structure.First,the water entry of a circular cylinder is simulated and the results are compared with the experiment,which considered the length-diameter ratio of the circular cylinder.The reliability of 2D simulation is verified and the deformation of the free interface is well investigated.Afterward,the water exit of a circular cylinder with constant velocity is simulated,which is less researched.In addition,the results show the advantage of present IB-MLBFS to some extent.Finally,the water exit and re-entry of a circular cylinder are presented,and the results present the complex deformation of the free interface and the dynamic response of the moving structure.Based on the numerical results,the free interface of the multiphase fluids is well captured,and the contact interface on the boundary of the moving structure is accurately presented by the IB-MLBFS.展开更多
In this paper, we consider a unidirectional highway road with one entry/exit uniformly distributed on the road interval. One road side unit (RSU) is located on the position of the entry/exit. We build an analytical mo...In this paper, we consider a unidirectional highway road with one entry/exit uniformly distributed on the road interval. One road side unit (RSU) is located on the position of the entry/exit. We build an analytical model to study the network connectivity problem. In building the analytical model, we take into account several parameters, such as vehicle arrival rate, vehicle moving speed, vehicle communication radius, RSU communication radius, highway road length and the probability of vehicles driving through the entry/exit. The analytical model is verified by using simulation tools.展开更多
Based on extensive micro data sets, this paper examines the relationship among large-scale entry and exit, competition and total factor productivity （TFP） growth of China＇s industry during economic transition and m...Based on extensive micro data sets, this paper examines the relationship among large-scale entry and exit, competition and total factor productivity （TFP） growth of China＇s industry during economic transition and market opening. We have arrived at these findings： market opening spurs entry and exit of large numbers of non-state-owned enterprises （non-SOEs） and facilitates dynamic competition; through the stimulation effect of competition, entry and exit push TFP growth on the part of enterprises; through the resource reallocation effect, entry and exit promote growth of the aggregate TFP. However, results indicate that the resource allocation efficiency remains very low in capital-intensive industries where the government intervenes a lot. To conclude, promoting open competition is significant to the growth of industrial sectors ＇productivity.展开更多
基金Supported by the National Natural Science Foundation of China(52061135107)the Fundamental Research Fund for the Central Universities(DUT20TD108,DUT20LAB308)the Liao Ning Revitalization Talents Program(XLYC1908027),and Dalian Innovation Research Team in Key Areas(2020RT03).
文摘In this work,the deformation of free interface during water entry and exit of a circular cylinder is investigated numerically by using the two-dimensional(2D)immersed boundary-multiphase lattice Boltzmann flux solver(IB-MLBFS).The fluid domain is discretized by finite volume discretization,and the flux on the grid interface is evaluated by lattice Boltzmann equations.Both the implicit velocity correction and the surface flux correction are implemented by using the immersed boundary-method to consider the fluid-structure interaction and the contact interface between the multiphase fluids and the structure.First,the water entry of a circular cylinder is simulated and the results are compared with the experiment,which considered the length-diameter ratio of the circular cylinder.The reliability of 2D simulation is verified and the deformation of the free interface is well investigated.Afterward,the water exit of a circular cylinder with constant velocity is simulated,which is less researched.In addition,the results show the advantage of present IB-MLBFS to some extent.Finally,the water exit and re-entry of a circular cylinder are presented,and the results present the complex deformation of the free interface and the dynamic response of the moving structure.Based on the numerical results,the free interface of the multiphase fluids is well captured,and the contact interface on the boundary of the moving structure is accurately presented by the IB-MLBFS.
文摘In this paper, we consider a unidirectional highway road with one entry/exit uniformly distributed on the road interval. One road side unit (RSU) is located on the position of the entry/exit. We build an analytical model to study the network connectivity problem. In building the analytical model, we take into account several parameters, such as vehicle arrival rate, vehicle moving speed, vehicle communication radius, RSU communication radius, highway road length and the probability of vehicles driving through the entry/exit. The analytical model is verified by using simulation tools.
文摘Based on extensive micro data sets, this paper examines the relationship among large-scale entry and exit, competition and total factor productivity （TFP） growth of China＇s industry during economic transition and market opening. We have arrived at these findings： market opening spurs entry and exit of large numbers of non-state-owned enterprises （non-SOEs） and facilitates dynamic competition; through the stimulation effect of competition, entry and exit push TFP growth on the part of enterprises; through the resource reallocation effect, entry and exit promote growth of the aggregate TFP. However, results indicate that the resource allocation efficiency remains very low in capital-intensive industries where the government intervenes a lot. To conclude, promoting open competition is significant to the growth of industrial sectors ＇productivity.
