FLUID FLOW AND HEAT TRANSFER OF NATURAL CONVECTION AROUND MULTIPLE HEAT SOURCES PLACED IN THE SAME HORIZONTAL PLANE

同一水平面上多个热源周围自然对流的流体流动和传热

基本信息

批准号：
07650252
负责人：
KITAMURA Kenzo
金额：
$ 1.47万
依托单位：
TOYOHASHI UNIVERSITY OF TECHNOLOGY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07650252/
关键词：
Natural Convection Heat Transfer Plume Visualization Horizontal Plate Multiple Heat Sources Interaction

项目摘要

Interactions of natural convection plumes issued from multiple heat sources placed in the same horizontal plane have been investigated experimentaly in the present study. The special concerns were focused on the fluid flow and the heat transfer around the horizontal rows of vertical plates, horizontal cylinders and upward-facing horizontal plates, which were placed at the constant intervals and were heated with the constant heat fluxes. The test fluid is water at room temperature. The flow field around these heat sources were visualized with dye. The results demonstrate that the plumes departed from the heat sources interact with each other and gather to the symmetrical plane between the heat sources. These interactions occur even when the intervals between the heat sources are ten times larger than the dimensions of the heat sources. The influences of the plume interactions on the heat transfer characteristics of the heat sources were also investigated. The results for the vertical plates show no substantial change in the local heat transfer coefficients, while the local coefficients of the horizontal cylinders and of the horizontal plates are changed by the plume interaction. It is found from the visualization study that the separation points over the above two heat sources move toward the center of the heat sources when the interactions occur and this could cause the variations in the local coefficients. On the basis of the above discussions, the heat transfer characteristics of the upward-facing horizontal plates were investigated. It was revealed that the local heat transfer coefficients are affected seriously when the plates are placed at small intervals. However, the effect of the plume interaction on the heat transfer coefficients becomes smaller with increasing the intervals, and the over-all coefficients of the plates become the same as those of the single plate when the plate intervals exceed 50mm.

在本研究中，已经研究了从位于同一水平平面上的多个热源发出的自然对流羽相互作用。特殊问题集中在流体流量和垂直板，水平气缸和向上朝上的水平板的水平行周围的热传递，这些板以恒定的间隔放置，并用恒温通量加热。测试液是室温下的水。这些热源周围的流场用染料可视化。结果表明，与热源相互作用的羽流相互作用，并聚集到热源之间的对称平面。即使热源之间的间隔比热源的尺寸大十倍，这些相互作用也会发生。还研究了羽相互作用对热源传热特性的影响。垂直板的结果显示局部传热系数没有实质性变化，而水平气缸的局部系数和水平板的局部系数则通过羽流相互作用而改变。从可视化研究中可以发现，当相互作用发生时，分离指向上述两个热源向热源中心移动，这可能会导致局部系数的变化。在上述讨论的基础上，研究了向上的水平板的传热特性。据显示，当板以较小的间隔放置时，局部传热系数会严重影响。但是，随着间隔的增加，羽流相互作用对传热系数的影响变得较小，并且当板间隔超过50mm时，板的过度系数与单板的所有系数变得相同。