基于OpenFOAM的正弦形沙丘表面流场特性研究

发布时间：2017-12-31 13:28

本文关键词：基于OpenFOAM的正弦形沙丘表面流场特性研究　出处：《上海理工大学学报》2017年04期 　论文类型：期刊论文

【摘要】：基于开源计算流体力学软件OpenFOAM,对沙丘表面流场进行数值模拟,将所得到的沙丘表面风速分布与野外观测结果进行对比,验证数值模拟的准确性.在此基础上,获得了距沙丘表面不同高度的速度分布曲线和沙丘表面上的速度矢量场,探讨了数值模拟结果对计算网格的敏感性,考察了沙丘宽高比对流场特性的影响.结果表明:OpenFOAM的标准k-ε模型能够预测低矮正弦形沙丘表面流场的速度转变特性;在贴近沙丘表面的内层,沙丘表面特定高度处的速度分布曲线相对于沙丘轮廓存在相位提前,随着高度的增加,相位提前量减少,速度变化趋于平缓;网格数目对外层速度分布影响较小,但对内层的速度分布则有重要影响;足够多的网格数目是获得精确的沙丘表面流场信息的必要条件,在沙丘流场数值模拟中应当引起重视;保持沙丘宽度不变,随着沙丘宽高比的减小,沙丘表面速度分布曲线的相位提前量变大,背风坡出现回流区,宽高比越小,回流区的长度与强度越大.
[Abstract]:Open source based on computational fluid dynamics software OpenFOAM, numerical simulation of the surface flow of sand dunes, dune surface wind velocity distribution are compared with the field observation results, verify the accuracy of numerical simulation. On this basis, obtained from the dune surface of different height speed distribution curve and the sand dunes on the surface of the velocity vector field, are discussed the results of numerical simulation on the sensitivity of the computing grid, the effects of aspect ratio on flow field characteristics of the sand dunes. The results show that the speed of the standard k- e OpenFOAM model can predict the low sinusoidal surface flow of sand dunes change characteristics; in the inner layer close to the surface of sand dunes, dune surface specific height velocity distribution curve relative to the dune contour phase in advance, with the increase of height, reduce the amount of phase advance, speed change gently; the outer layer of grid number velocity distribution has little influence, but It has an important effect on the velocity distribution of the inner layer; enough grid number is a necessary condition to obtain accurate information on surface flow of sand dunes, dune field in numerical simulation should be paid more attention; keep the dune width is constant, with the decrease of the width of the sand dunes, dune surface phase velocity distribution curve ahead of quantity, Lee appeared the recirculation zone, the aspect ratio is small, the length and strength of recirculation zone increases.

【作者单位】：上海理工大学能源与动力工程学院;上海理工大学上海市动力工程多相流动与传热重点实验室;
【基金】：国家自然科学基金资助项目(51206113,51176128,51576130) 上海市科委科研计划项目(13DZ2260900)
【分类号】：O35
【正文快照】： 2.上海理工大学上海市动力工程多相流动与传热重点实验室,上海200093)沙丘是指由于沙粒在流场中相互作用所形成的堆积体,常见于海岸、河谷和干旱沙漠地带.沙丘表面流场决定着局地沙粒输运的强度,从而影响沙丘的形态,在沙丘演变动力学研究中占据重要地位,因而备受研究者关注[1-

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