侧向局部加热腔体内对流时空结构的研究

发布时间：2018-05-29 14:33

  本文选题：侧向局部加热 + 破碎扰动　； 参考：《应用力学学报》2016年03期

【摘要】：通过二维流体力学基本方程组的数值模拟,研究了普朗特数Pr=6.949时侧向局部加热腔体内水平温差驱动的自然对流。仔细观察腔体内水平流的入侵过程,发现在冷热流体交接面的上下部位同时出现了冷入侵流和热入侵流,并且在交汇处有破碎扰动波出现。揭示了周期性双局部对流结构,并发现在右壁面温度高于左壁面温度区域顶部有对流卷生成,对流卷随时间沿侧壁面向腔体下部移动,最后消失,同时又有新对流卷在该区域顶部生成,这种现象重复循环着。结果表明:在右壁面温度高于左壁面温度区域,热边界层厚度(θδ)随腔体高度增加而增大;在右壁面温度等于左壁面温度区域,θδ值随腔体高度增加而减小;并且格拉晓夫数(Gr)越大,θδ值越小。
[Abstract]:Based on the numerical simulation of the basic equations of two-dimensional hydrodynamics, the natural convection driven by horizontal temperature difference in a laterally heated cavity with Plantt number pr = 6.949 is studied. After careful observation of the invasion process of horizontal flow in the cavity, it is found that the cold intrusion flow and the thermal intrusion flow occur simultaneously in the upper and lower parts of the interface of the cold and hot fluid, and there are broken disturbance waves at the junction. The periodic bi-local convection structure is revealed, and it is found that convection rolls are generated at the top of the region where the temperature of the right wall is higher than that of the left wall, and the convection rolls move along the sidewall to the lower part of the cavity with time, and finally disappear. At the same time, a new convection roll is formed at the top of the region, and this phenomenon repeats itself. The results show that the thickness of the thermal boundary layer (胃 未) increases with the increase of the height of the cavity in the region where the temperature of the right wall is higher than that of the left wall, and decreases with the increase of the height of the cavity when the temperature of the right wall is equal to the temperature of the left wall. And the larger the Gre number of Gracoff is, the smaller the value of 胃 未 is.
【作者单位】： 西安理工大学西北旱区生态水利工程国家重点实验室培育基地;
【基金】：国家自然科学基金(10872164) 陕西省重点学科建设专项资金项目(00X901)
【分类号】：O35
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本文编号：1951226