Key parameters of a porous windbreak for high-speed railways based on porous media
Reasonable parameter matching is a key issue in the study of windbreak facilities along high-speed railways.This paper aims at the problem that the ambient wind in some sections of the concrete solid windbreak will cross the top of the wall,causing serious pantograph-catenary offline and unable to raise the bow normally,which endangers the safety of the train.This study proposed changing"blocking"to"diversion",and regulating the wind field of the line behind the windbreak wall through a certain ventilation rate,providing a new idea to alleviate the above phenomenon.The core problem lied in the precise matching of the key parameters of the ventilated windbreak and the windproof effect.Therefore,based on the characteristics of porous media,this paper proposed a new research method for the wind field of windbreak walls based on porous media,which transformed the problem of precise matching between ventilation rate and windproof effect into the relationship between the drag coefficient of porous media and the aerodynamic load of trains.First,the accuracy of the numerical simulation method used in this paper was corrected and verified by comparing the numerical simulation with the field test results of the wind field of the Lanzhou-Xinjiang high-speed railway windbreak.Then the relationship between the resistance parameters of the porous medium and the ventilation rate of the windbreak was proved through numerical research.The optimal parameter range of the windbreak for the high-speed railway was obtained.The results are drawn.Porous media can be used instead of the geometry of the windbreak wall to study the wind field of the windbreak,which can significantly improve the research efficiency.The viscous drag coefficient of the porous medium can be ignored in the study of the wind field of the windbreak,and the inertial drag coefficient of the porous medium has a power function relationship with the porosity of the windbreak.When the height of the windbreak is 3.5 m and the porosity is in the range of 24.4%～28.7%,the windproof effect on the first and second line trains is the best.
万方数据
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