The elongating of cable-stayed bridge brings a series of aerodynamic problems. First of all,geometric nonlinear effect of extreme long cable is much more significant for cable-stayed bridge spanning over one thousand ...The elongating of cable-stayed bridge brings a series of aerodynamic problems. First of all,geometric nonlinear effect of extreme long cable is much more significant for cable-stayed bridge spanning over one thousand meters. Lateral static wind load will generate additional displacement of long cables,which causes the decrease of supporting rigidity of the whole bridge and the change of dynamic properties. Wind load,being the controlling load in the design of cable-stayed bridge,is a critical problem and needs to be solved. Meanwhile,research on suitable system between pylon and deck indicates fixed-fixed connection system is an effective way for improvement performance of cable-stayed bridges under longitudinal wind load. In order to obtain aerodynamic parameters of cable-stayed bridge spanning over one thousand meters,identification method for flutter derivatives of full bridge aero-elastic model is developed in this paper. Furthermore,vortex induced vibration and Reynolds number effect are detailed discussed.展开更多
Indoor temperature is a critical environmental factor for piglets that affects the health,welfare,and production efficiency of domesticated pigs.However,there are limited reports about wireless intelligent thermal con...Indoor temperature is a critical environmental factor for piglets that affects the health,welfare,and production efficiency of domesticated pigs.However,there are limited reports about wireless intelligent thermal control and management system for piglets in largescale pig farms,and evaluation energy saving.This paper presents an Automatic Thermal Control and Management System(ATCMS)of micro-environment for piglets,that could provide a suitable production environment and reduce the energy consumption.ATCMS includes automatic temperature control system(ATCS),multipoint temperature management system(MTMS)and remote access.The infrared heating lamps are chosen in the ATCS for their good performance in heating rate and heating distribution.In order to meet a scientific temperature requirements of piglet growth,the suitable thermal ranges of each growth-stage(STREG)are employed as intelligent control strategies to generate an automatic and precise heating control.MTMS is responsible for communicating with ATCSs and transmitting information to database server for record based on wireless technology.Remote access offers information services for remote administrators by smart phones and clients via Internet.The experiments of ATCMS were carried out both in winter and summer at Binsheng Breeding Piggery Farm,Acheng City,Heilongjiang Province,China.Results showed that the temperature provided by ATCS had been kept in STREG of piglets during the whole winter period.When the indoor temperature during summer period were in or above STREG,heating lamps were turned off by ATCS for a long time.The energy consumption of ATCS were 63.60%in winter and 39.35%in summer with continuous heating system operation.Therefore,ATCMS could take the suitable thermal ranges of each growth-stage as an intelligent control principle to give an automatic and precise control to heating devices in order to meet a scientific temperature requirements of piglet growth.展开更多
文摘The elongating of cable-stayed bridge brings a series of aerodynamic problems. First of all,geometric nonlinear effect of extreme long cable is much more significant for cable-stayed bridge spanning over one thousand meters. Lateral static wind load will generate additional displacement of long cables,which causes the decrease of supporting rigidity of the whole bridge and the change of dynamic properties. Wind load,being the controlling load in the design of cable-stayed bridge,is a critical problem and needs to be solved. Meanwhile,research on suitable system between pylon and deck indicates fixed-fixed connection system is an effective way for improvement performance of cable-stayed bridges under longitudinal wind load. In order to obtain aerodynamic parameters of cable-stayed bridge spanning over one thousand meters,identification method for flutter derivatives of full bridge aero-elastic model is developed in this paper. Furthermore,vortex induced vibration and Reynolds number effect are detailed discussed.
基金supported by the project of National Natural Science Foundation of China(NSFC)(32072787)the project of scholar plan at Northeast Agriculture University(19YJXG02),China+1 种基金the Earmarked Fund for China Agriculture Research System(CARS-35),Chinathe Key Laboratory of Swine Facilities Engineering,Ministry of Agriculture,P.R.China.
文摘Indoor temperature is a critical environmental factor for piglets that affects the health,welfare,and production efficiency of domesticated pigs.However,there are limited reports about wireless intelligent thermal control and management system for piglets in largescale pig farms,and evaluation energy saving.This paper presents an Automatic Thermal Control and Management System(ATCMS)of micro-environment for piglets,that could provide a suitable production environment and reduce the energy consumption.ATCMS includes automatic temperature control system(ATCS),multipoint temperature management system(MTMS)and remote access.The infrared heating lamps are chosen in the ATCS for their good performance in heating rate and heating distribution.In order to meet a scientific temperature requirements of piglet growth,the suitable thermal ranges of each growth-stage(STREG)are employed as intelligent control strategies to generate an automatic and precise heating control.MTMS is responsible for communicating with ATCSs and transmitting information to database server for record based on wireless technology.Remote access offers information services for remote administrators by smart phones and clients via Internet.The experiments of ATCMS were carried out both in winter and summer at Binsheng Breeding Piggery Farm,Acheng City,Heilongjiang Province,China.Results showed that the temperature provided by ATCS had been kept in STREG of piglets during the whole winter period.When the indoor temperature during summer period were in or above STREG,heating lamps were turned off by ATCS for a long time.The energy consumption of ATCS were 63.60%in winter and 39.35%in summer with continuous heating system operation.Therefore,ATCMS could take the suitable thermal ranges of each growth-stage as an intelligent control principle to give an automatic and precise control to heating devices in order to meet a scientific temperature requirements of piglet growth.
