Abstract:

When high-speed trains are running,the windbreak can guarantee their safety.And meanwhile，it has to suffer strong air fluctuating pressure caused by the high-speed train-induced wind.In this paper,based on the STAR-CCM + software and by taking the CRH3 high-speed train and the windbreak as the research objects，the change of the air fluctuating pressure caused by the train-induced wind during the whole process of the high-speed train passing through the windbreak area is simulated by combining the sliding mesh method and the porous medium model that can effectively reduce the amount of grids in hole plates.Then,the time history changes of the air fluc- tuating pressure with such parameters as the train speed and the terrain clearance are analyzed,and the peak and gradient of the fluctuating pressure in the position of the windbreak are put forward,thus obtaining the frequency domain characteristics of the fluctuating pressure.The results show that (1) when the high-speed train passes through the windbreak area,the alternating loads,which are positive-negative-negative-positive,form on each part of the windbreak; (2) the fluctuating pressure peak decreases in the order of the positive pressure on the head train,the negative pressure on the head train,the negative pressure on the tail train and the positive pressure on the tail train,and the fluctuating pressure gradient becomes more obvious with the increase of the train speed; (3) as the terrain clearance decreases,the fluctuating pressure increases and reaches up to a maximum value in the bottom area of the windbreak; and (4) the power spectrum density peaks of the fluctuating pressure are con- centrated below 25Hz,and the impact energy of the train-induced wind increases by nearly 100% when the train speed increases by 50km/h.

Key words: high-speed train, windbreak, porous media, sliding mesh, numerical simulation