对非均匀拟形冠层大气流动特征的大涡模拟研究

发布时间：2019-05-11 23:58

【摘要】：近年来,立方体拟形试验作为研究城市大气边界层扩散特征的一个手段得到了广泛的开展。随着研究的深入,对于试验用拟形块体的设计也提出了更高的要求,以使实验结果更接近实际城市冠层的情况。该文通过对不同布置形式、不同顶高差异度的立方体冠层进行大涡模拟试验,讨论了冠层内结构顶高差异度和流向上结构均匀的程度对冠层内大气流态的影响规律。结果表明,立方体冠层内的流动结构很大程度上取决于主风向上结构的均匀程度;顶高的差异性亦会造成冠层内流态改变,且流态的改变随立方体冠层布置形式的改变而改变;冠层顶部紊流对动量的有效传输效率和冠层内顶高的差异性有关,其在主流向结构不均匀程度低的冠层内较小。
[Abstract]:In recent years, cubic mimetic experiments have been widely developed as a means to study the diffusion characteristics of urban atmospheric boundary layer. With the deepening of the research, higher requirements are put forward for the design of the simulated block for the test, so that the experimental results are closer to the actual urban crown. In this paper, the effects of the top height difference and the uniformity of the upper structure on the atmospheric flow pattern in the crown are discussed by means of large vortex simulation experiments on the cube crown with different arrangement forms and different top height differences. The results show that the flow structure in the cube crown depends to a large extent on the uniformity of the upward structure of the main wind, and the difference of the top height will also cause the change of the flow pattern in the crown, and the change of the flow pattern will change with the change of the arrangement of the cube crown. The effective transport efficiency of momentum at the top of the crown is related to the difference of the height of the crown, which is smaller in the crown where the degree of inhomogeneity of the mainstream structure is low.
【作者单位】：清华大学水沙科学与水利水电工程国家重点实验室;
【基金】：国家自然科学基金项目(11472156)
【分类号】：TU119

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