Wind tunnel simulation experiment and investigation on the electrification of sandstorms

2004 ◽  
Vol 47 (6) ◽  
pp. 529 ◽  
Author(s):  
Jianjun QU
1999 ◽  
Vol 42 (1) ◽  
pp. 49-59 ◽  
Author(s):  
Liu Xianwan ◽  
Li Sen ◽  
Shen Jianyou

2020 ◽  
Vol 12 (14) ◽  
pp. 5689 ◽  
Author(s):  
Shengbo Xie ◽  
Jianjun Qu ◽  
Qingjie Han ◽  
Yingjun Pang

The Lhasa–Linzhi Railway is located in the sandy area of the South Tibet valley, with high elevation and cold temperature. The Xierong section is a bridge section where blown sand hazards are severe. However, the disaster-causing mechanism of blown sand hazards in this section is currently unclear, thereby hindering targeted sand prevention and control. To address this problem, the wind dynamic environment of and causes of sand damage in this section are investigated through the field observation of the locale and a wind tunnel simulation experiment. Results show that the dominant sand-moving wind direction in the Xierong section is SSE. The wind speed, frequency of sand-moving wind, sand drift potential (DP), and maximum possible sand transport quantity (Q) in this section are relatively high during spring (March to May) and low during other seasons. The yearly resultant sand transport direction (RDD, RA) is SW. The angle between the route trend of this section and the sand transportation direction is 30°–45°, and the sand source is located in the east side of the railway. During spring, sand materials are blown up by the wind, forming blown sand flow and movement from the NE to SW direction. Increased wind speed area is formed between the top of the slope shoulder of the windward side of the bridge and the downwind direction of 3H, causing blown sand erosion. Meanwhile, weakened wind speed areas are formed within the distance of -3H at the upwind direction and from the downwind direction of the 3H to 20H of the bridge. These areas accumulate sand materials at the upwind and downwind directions of the bridge, thereby resulting in blown sand hazards. This research provides a scientific basis for the prevention and control of sand damage in the locale.


2018 ◽  
Vol 22 (5) ◽  
pp. 1194-1210 ◽  
Author(s):  
XX Cheng ◽  
X Chen ◽  
YJ Ge ◽  
H Jiang ◽  
L Zhao

The traditional atmospheric boundary layer wind tunnel model test practice employs wind fields, the flow characteristics of which are in accordance with the empirical formulae of the atmospheric turbulence presented in Codes of Practice and monographs. However, the empirical formulae presented in Codes of Practice and monographs cannot truthfully reflect the high variations of the realistic atmospheric turbulence which sometimes aggravates wind effects on structures. Based on model tests conducted in a multiple-fan actively controlled wind tunnel, it is found that most wind effects on large cooling towers change monotonically with the increase in free-stream turbulence, and the model test results are more unfavorable for a flow field of low turbulence intensity than for a flow field of high turbulence intensity with respect to the measured coherences. Thus, a new atmospheric boundary layer wind tunnel simulation methodology for wind effects on circular cylindrical structures is proposed to overcome the deficiency of the traditional atmospheric boundary layer wind tunnel model tests. The new simulation methodology includes the simulation of two realistic atmospheric boundary layer flow fields with the highest and the lowest turbulence intensities in the wind tunnel and the envelopment of model test results obtained in the two flow fields (e.g. the mean and fluctuating wind pressure distributions, the power spectral density, the coherence function, and the correlation coefficient). The superiority of the new atmospheric boundary layer wind tunnel simulation methodology over the traditional model test practice is demonstrated by comparing the model test results with the full-scale measurement data.


2007 ◽  
Vol 146 (1-2) ◽  
pp. 82-93 ◽  
Author(s):  
Zhibao Dong ◽  
Wanyin Luo ◽  
Guangqiang Qian ◽  
Hongtao Wang

2013 ◽  
Vol 380-384 ◽  
pp. 191-194
Author(s):  
Qin Yu Yang ◽  
Jin Bo Yao ◽  
Yue Ming Yang ◽  
Xue Wei Liu

Aircraft in flight, such as supercooled water droplets encountered icing conditions suitable for the external environment, the relevant parts of the body will freeze, making the aircraft's aerodynamic performance deterioration, severe endanger flight safety, in addition, the aircraft parked in the open winter months , there will be icing, you need to clean up before takeoff. We should grasp the mechanism of aircraft icing, environmental factors and easy to freeze parts of the body. This paper presents a simulation using the wind tunnel icing device icing wind tunnel simulations can reproduce the real situation of aircraft icing, for guiding practice and got good results.


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