Fluid Flow and Heat Transfer of Mixed Convection and Its Application to Thin Film Formation by CVD

混合对流流体流动和传热及其在CVD薄膜形成中的应用

基本信息

批准号：
18560198
负责人：
KITAMURA Kenzo
金额：
$ 2.37万
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：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18560198/
关键词：
Heat Transfer Convective Heat Transfer Mixed Convection Forced Convection Natural Convection Upward-Facing Plate Stagnation Flow Buoyancy Effect

项目摘要

Fluid flow and heat transfer of mixed convection over upward-facing horizontal heated plates placed in a uniform downward flow of forced convection were investigated experimentally. The experiments were carried out with air and with the test plates of 50 and 100mm wide, which were heated with uniform heat flux. The Reynolds and modified Rayleigh numbers ranged as: Rew =37-2000 and Raw^*=6.2x10^4-5.3x×10^7.The flow fields over heated plates were visualized with smoke. The results showed that the laminar wedge flow from the center to the edges of the plate appears when the heat fluxes are small, while that the flow turns its direction from the edges to the center with increasing the heat flux, and, finally, the flow detaches from the center of the plate as a buoyant plume when the heat fluxes are high enough. The local heat transfer coefficients from the plates were also measured. The results showed that the coefficients under the fixed velocity of the forced flow are increased monotonously with the heat fluxes. It was also found that the overall Nusselt numbers of the plates, Nun, were predicted well with the non-dimensional parameter, (GrW^*/d/Num Rew^2.5), where Grw^* stands for the Grashof numbers. Moreover, the parameter well classify the regions of the forced, mixed and natural convection, and the mixed convection region is determined as : 0.3< (Grw^*/Num Rew^<2.5>) <15

对放置在向上的水平加热板上的均匀向下的强制对流中的流体流动和混合对流传热进行了实验研究。实验在空气中进行，并使用 50 和 100mm 宽的测试板进行加热。雷诺数和修正瑞利数范围为：Rew =37-2000 和 Raw^*=6.2x10^4-5.3x×10^7。加热板上的流场。结果表明，当热通量较小时，出现从板的中心到边缘的层流楔形流动，而随着热通量的增加，流动方向从边缘转向中心，并且最后，当热通量足够高时，流动以浮力羽流的形式从板的中心分离。还测量了板的局部传热系数。结果表明，在强制流动的固定速度下的系数。单调增加还发现板块的整体努塞尔数 Nun 可以用无量纲参数 (GrW^*/d/Num Rew^2.5) 很好地预测，其中 Grw^* 代表 Grashof此外，该参数很好地对强制对流、混合对流和自然对流区域进行了分类，混合对流区域确定为： 0.3< (Grw^*/Num)鲁^<2.5>) <15