Numerical Simulation Of Aeolian Sediment And Wind-sand Barrier’s Parameters Optimization Base On FLUENT

This article using the Fluent software simulate the wind-sand flow get through the barrier and embankment in whole process. By adjusting the structure size parameters of the barrier, this article evaluate wind and sand blocking effect. Provides a comprehensive numerical simulation for the parameter optimization of barrier with qualitative or quantitative technical basis. It is guarantee train under strong wind desert environment running, and has more important significance for the safety of railway operation.The main research results are as follows:(1) Obstacles in the flow field, including the embankment and the barrier can significantly change the distribution of airflow. Obstacles distribute air flow mainly formed tight uplift zone, collecting acceleration zone, deceleration zone and recovery zone.(2) From the perspective of the development of the time, the the wind-sand flow through the sand bed at some stage in the cross section, with the air joint movement of sand will pass "supplement - supersaturate - consumption - dynamic balance" of the process. After dynamic balance, sand volume fraction in close to the ground with a high degree of distribution meet the index law. Compared with the coarse particle size of grains of sand, fine particle size distribution of the volume fraction of the sand along the height is relatively high. And coarse particle sizes of sand grains due to the gravity effect mainly in the surface of sand bed creep movement, so only a few grains of sand in the upper wind-sand flow movement.(3) Average wind erosion depth of embankment slope six arrises brick, from top to toe, the overall trend is gradually reduce; Because of the wind speed of windward slope large than the leeward slope, windward slope of six arrises brick wind erosion depth on the whole more than leeward slope; For a piece of six arrises brick, brick with six arrises in the upper two vertices wind erosion is most serious, and located in the six arrises brick’s underside two vertices almost no wind erosion phenomenon.(4) Leeward side barrier against the windshield sand transport rate along the horizontal distribution of overall trend is the same. Its distribution features and the wind speed distribution characteristics are same, fully embodies the airflow and the sand in characteristics of the mutual coupling.(5) In embankment windward side of the close-grained wind wall and the outside of the embankment with a range of porosity of high vertical barrier, two types of protective structure is different. The former windproof efficiency is better, suitable for setting in the embankment shoulder; The latter blocking sand efficiency is better, at the same time can guarantee a long effective windproof distance, suitable for laying on the outer edge of the embankment. Therefore, the two types of high vertical protective measures have their own advantages and disadvantages, the selection of its parameters need to be according to the object of protection combined with the actual situation of the field to a reasonable choice.