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Wind Tunnels and Experimental Fluid Dynamics Research Part 13

Tham khảo tài liệu 'wind tunnels and experimental fluid dynamics research part 13', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 468 Wind Tunnelsand Experimental Fluid Dynamics Research Hokkaido Northern Regional Building Research Institute Fig. 4. Wind Tunnel for the snow simulations ữơB.Ã ơơ ơơơơ Ã-Ã ơơ ơ ã j ơơ Ã ơơơơơ ƠƠB Ã flỉ-ỉ- ữỢ Ã ơơ ơơơơ Ã È Ỉ S Ũ ữơơ ƠƠBÃ Fig. 5. Vertical distribution of wind velocities in the wind tunnel Public Square Design with Snow and Wind Simulations Using Wind Tunnel 469 The characteristic point between pure snow in Wakkanai and white soil are similar. Both of drifting angle and shape are similar the angle of pure snow assumes around from 45 to 50 and the angle of white soil is 46. This is the reason author adopted white soil for the snow simulations Fig. 6 . Fig. 6. Comparison the drifting angle between pure snow and white soil Drifting Angle Pure snow in Hokkaido 45 - 50 degree White soil 46 degree 2.3 Models for snow simulation experiments For the snow simulation tests block models of the target area the Wakkanai station district were made of styro-foam in the scale of 1 to 300. The size of the district is 540m in the north-south direction by 360m in the east-west direction therefore the models of the district measured 1800mm long by 1200mm wide for the snow simulation tests. The snow models were made of white soil powder 4. This soil tends to have a drifting pattern similar to that of snow in Hokkaido. It gives a static-free performance in wind tunnels therefore there was no friction between the powder particles themselves. The ground model boards were painted therefore there was no friction between the powder and the ground models. The powder for the snow models was supplied from windward side nozzles to the testing area of the tunnel by an air compressor. The cw models were made of acrylic plastic board for no friction with the snow soil powder. Photo 2. The targeted district models of Downtown .