title: Unloading Characteristics of Sand-drift in Wind-shallow Areas along Railway and the Effect of Sand Removal by Force of Wind.
abstract: Wind-shield walls decrease the velocity of wind-drift sand flow in transit. This results in sand accumulating in the wind-shadow zone of both windshield wall and track line, causing severe sand sediment hazard. This study reveals the characteristics of sand accumulation and the laws of wind-blown sand removal in the wind-shadow areas of three different types of windshield walls, utilizing three-dimensional numerical simulations and wind tunnel experiments and on-site sand sediment tests. The results revealed the formation of apparent vortex and acceleration zones on the leeward side of solid windshield walls. For uniform openings, the vortex area moved back and narrowed. When bottom-opening windshield walls were adopted, the track-supporting layer at the step became a conflux acceleration zone, forming a low velocity vortex zone near the track line. At high wind speeds, windshield walls with bottom-openings achieved improved sand dredging. Considering hydrodynamic mechanisms, the flow field structure on the leeward side of different types of windshield structures is a result of convergence and diffusion of fluids caused by an obstacle. This convergence and diffusion effect of air fluid is more apparent at high wind velocities, but not obvious at low wind velocities.
authors.affiliation: College of Water Resources and Architectural Engineering, Shihezi University, Shihezi Xinjiang 832003, China.
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: Cheng
authors.affiliation: College of Water Resources and Architectural Engineering, Shihezi University, Shihezi Xinjiang 832003, China.
authors.forename: Guo-Wei
authors.initials: GW
authors.lastname: Xin
authors.affiliation: College of Water Resources and Architectural Engineering, Shihezi University, Shihezi Xinjiang 832003, China.
authors.forename: Ling-Yan
authors.initials: LY
authors.lastname: Zhi
authors.affiliation: Northwest Research Institute Co., Ltd. of China Railway Engineering Corporation, 365 Minzhu East Road, Lanzhou 730000, China.
authors.forename: Fu-Qiang
authors.initials: FQ
authors.lastname: Jiang