...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Experimental Thermal and Fluid Science: International Journal of Experimental Heat Transfer, Thermodynamics, and Fluid Mechanics >Transverse recirculations in low Reynolds number mixed convective gas flow over a model heated substrate
【24h】

Transverse recirculations in low Reynolds number mixed convective gas flow over a model heated substrate

机译：低雷诺数混合对流气流在模型加热基板上的横向再循环

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Combined flow visualization and temperature measurement are conducted to investigate the structure of the buoyancy driven transverse vortex rolls (T-rolls) at low Reynolds number mixed convective gas flow through a horizontal flat duct with a 0. 3 in (12-in.) heated circular plate embedded in the bottom of the duct for the Rayleigh number ranging from 3506 to 23,485. The results suggest that the regular transverse vortices prevail in the duct core only in a certain range of Rayleigh number with very low Reynolds number (Re <= 12. 1) and the vortex flow is characterized by the moving T-rolls over the heated plate enclosed by an incomplete circular roll. More specifically, the regular transverse vortex rolls are curved at the early stage of their initiation and deformed to some degree due to the presence of the incomplete circular roll around the upstream edge of the heated plate. But in the exit half of the duct the T-rolls are nearly straight and they are almost spanwisely symmetric with respect to the vertical central plane. Besides, the transverse rolls get stronger and bigger during the downstream moving and they do not travel downstream at a constant speed. The data from the transient temperature measurement reveal that the flow oscillation of the T-rolls driven by the circular heated plate is slightly space dependent for given Ra and Re. Moreover, the frequency of the flow oscillation decays substantially with the decrease in the Reynolds number. Furthermore, the amplitude of the temperature oscillation can be reduced for a raise of Ra. These characteristics are very different from the transverse vortex rolls induced in a duct with a uniformly heated bottom plate. (c) 2007 Elsevier Inc. All rights reserved.
机译：进行了组合的流量可视化和温度测量，以研究低雷诺数混合对流气流通过加热了0. 3英寸（12英寸）的水平扁平管道中的浮力驱动的横向涡流辊（T辊）的结构。管道底部嵌入的圆形板的瑞利数范围为3506至23,485。结果表明，规则的横向涡流仅在瑞利数的一定范围内占主导地位，且雷诺数非常低（Re <=12。1），涡流的特征在于加热板上的T型辊运动被不完整的圆形卷包围。更具体地说，由于在加热板的上游边缘周围存在不完整的圆形辊，规则的横向涡旋辊在其开始的早期就弯曲并变形到一定程度。但在风管的出口一半处，T型辊几乎是笔直的，并且相对于垂直中心平面几乎在翼展方向上对称。此外，横向辊在下游移动过程中变得越来越大，并且不能以恒定的速度向下游移动。瞬态温度测量的数据表明，对于给定的Ra和Re，由圆形加热板驱动的T型辊的流动振荡在一定程度上取决于空间。而且，随着雷诺数的减少，流动振荡的频率实质上衰减。此外，可以减小温度振荡的幅度以提高Ra。这些特征与在具有均匀加热的底板的管道中引起的横向涡旋辊非常不同。 （c）2007 Elsevier Inc.保留所有权利。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号