| Summary: | 碩士 === 國立中興大學 === 水土保持學系所 === 98 === Abstract
Windbreak net is an important role to prevent crops and plants in Taiwan. It is used often at coastline, hills, farms, and earlier stage of a Windbreak net forest, etc. There are many types of Windbreak net, but lack of directions and researches on using them correctly. In consideration of this study analyzes 3 Windbreak net types of higher market share in Taiwan, plain weave, knitted and ribbed weave, to proceed wind tunnel simulation experiments, Compared the relative wind speed, wind speed reduction coefficient, protection index and economic benefits respectively. They’re hope for provide industrial and agricultural use on a reference to explore the effect of reducing the wind, the following results:
1. Density of the same in three different types of plain weave, knit and ribbed weave, the plain weave type stands the most affectivity, knit type woven follows, and ribbed type woven the least.
2. The maximum wind speed reduction oppeared in the leeward distance with 2H-10H of Windbreak net net height(H), then reduced with the increase of horizontal distance along the wind effect is also attenuated, wind net over a vertical height of 1.7H, the wind effect no longer reduced, and the lead role of flow acceleration , the wind net windward 2H Department, five kinds of wind because the model set net uplift caused by the flow field generated by the squeeze effect and the wind speed slightly reduced, this phenomenon consistent with the theory.
3. While the density and the knitting method are the same, wind speed reducing of triangle-shaped shelter is more effect than rectangle-shape one. Ribbed weave of 4 wefts is more effect than that of 2 wefts.
4. 3 types of knitting net are effect on wind reducing, it is suggested to choose knit and ribbed weave nets if the shading function is requested, where the ribbed weave performance a better wind reducing effect. Woven and knit woven are selected if insect function is required, and woven is the better than knit woven.
5. Windbreak net mesh model 32 mesh gauze nets in five kinds of wind just above the Windbreak net net cost model B1010, but the effect of reducing the wind effect is one of the best. This proposal is now to be without shade Windbreak net network for applications, network models should be used 32-mesh wind yarn.
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