多孔介质森林模型中流场分布特征的研究

	多孔介质森林模型中流场分布特征的研究
Alternative Title	Research of the Characteristics of Flow Field in a Porous Medium Forest Model
	毛泽魁
Thesis Advisor	武建军
	2016-05-31
Degree Grantor	兰州大学
Place of Conferral	兰州
Degree Name	硕士
Keyword	森林风场湍流特性多孔介质欧拉双流体模型
Abstract	本文利用FLUENT软件数值模拟了风场以及粉尘穿过森林时的流场分布特征。1.首先介绍了多孔介质模型的基本理论，利用体积平均法对时均N-S方程进行空间平均，得到风场控制方程，给出了模型中计算参数的选取；然后推导了欧拉双流体模型的基本理论，给出了控制方程中计算参数的选取；2.把森林部分看作是均匀的多孔介质区域，利用FLUENT中的多孔介质模型，数值模拟了风场穿过森林时的风场分布特征，并与前人的实验结果和数值模拟结果作比较，结果基本吻合，从而验证了森林多孔介质模型的正确性。森林的阻风效果十分明显，在森林冠层位置，沿流场方向10m长度内风速减小了10.48%，50m内风速降低了27.21%；风场进入森林后，湍流强度在森林高度以下湍流强度先是增大，然后慢慢减小，并且在森林高度的二分之一处达到最大，森林高度以上，湍流强度变化趋势迅速减小；3.粉尘体积浓度在接近地面的很短距离内急剧减小，随后缓慢减降低；在森林内部，粉尘体积浓度迅速降低，在森林冠层部位，粉尘体积浓度有所增加，在森林高度以上，粉尘体积浓度又逐渐降低。输沙量在森林高度内迅速减小，在森林上方迅速增大，至森林二倍高度处，增至最大，最后又逐渐减小至0；森林对大粒径颗粒的阻挡效果更好。
Other Abstract	Commercial software FLUENT is used in this paper to study the characteristics of flow field when the wind and dust goes through the forest.1. The space-average method was used to transform the time-averaged N-S equations to obtain the control equation of flow field. Then the basic theory of the euler two-phase model was derived.2. The results were compared with the results of the previous work and showed good agreement. When wind entered the forest, turbulence intensity below the height of forest increased first, and then decreases slowly, which reached maximum in half of the forest height. Turbulence intensity variation trend is decreasing rapidly above the forest.3. The results show that the dust volume concentration decrease rapidly within a short distance near the ground. The dust volume concentration decrease rapidly in the forest. The mass flux decreases rapidly under the forest, then increases rapidly above the forest and it increases to the maximum at two times the height of the forest, at last it gradually reduced to 0.The forest has better resisting effect for the large particle size.
URL	查看原文
Language	中文
Document Type	学位论文
Identifier	https://ir.lzu.edu.cn/handle/262010/226555
Collection	土木工程与力学学院
Recommended Citation GB/T 7714	毛泽魁. 多孔介质森林模型中流场分布特征的研究[D]. 兰州. 兰州大学,2016.

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