• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>International Journal of Heat and Mass Transfer >Numerical simulation of liquid film formation and its heat transfer through vapor bubble expansion in a microchannel
【24h】

Numerical simulation of liquid film formation and its heat transfer through vapor bubble expansion in a microchannel

机译：液膜形成及其在微通道中通过汽泡膨胀传热的数值模拟

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

The evaporation of vapor bubbles inside a microchannel is important to realize a device with high cooling performance. The liquid film formed on the solid surface is essential for evaporative heat transfer from solid to fluid; its formation process and heat transfer characteristics need to be investigated. The expansion process of a single vapor bubble via evaporative heat transfer in microchannels was evaluated via a numerical simulation in this study. In the calculation model, the working fluid used was saturated FC-72 at 0.1013 MPa and the channel diameter was 200 gm. The superheat of the initial temperature field and wall were considered as parameters. To evaluate the heat transfer characteristics, the time variation of liquid film thickness was evaluated. The averaged liquid film thickness had a correlation with the capillary number. Additionally, the dominant heat transfer mode was estimated by decomposing the heat transfer rate into the heat-transfer rate through the liquid film, rear edge, and wake. When the superheat was low, the heat transfer mostly occurred via liquid film evaporation; the heat flux through the liquid film could be predicted using the liquid film thickness. On the other hand, in cases of higher superheat, owing to rapid expansion of the vapor bubble, no evaporative heat transfer occurred through the liquid film around the bubble head. It could be inferred from this study that the relationship between the thickness of the thermal boundary layer of the bubble and liquid film thickness is important for predicting the cooling effect of this phenomena. When the vapor bubble grows in the high superheat liquid, the rapid growth makes the liquid film thick, and the thick liquid film prevents the heat transfer between the liquid-vapor interface and heated wall. (C) 2019 Elsevier Ltd. All rights reserved.
机译：微通道内蒸气气泡的蒸发对于实现具有高冷却性能的装置很重要。固体表面上形成的液膜对于从固体到液体的蒸发热传递至关重要。其形成过程和传热特性需要研究。在本研究中，通过数值模拟评估了通过微通道中的蒸发传热产生的单个气泡的膨胀过程。在计算模型中，所使用的工作流体为0.1013 MPa的饱和FC-72，通道直径为200 gm。初始温度场和壁的过热被视为参数。为了评估传热特性，评估了液膜厚度的时间变化。平均液膜厚度与毛细管数相关。另外，通过将传热速率分解为通过液膜，后边缘和尾流的传热速率来估计主要传热模式。当过热度低时，传热主要通过液膜蒸发发生。通过液膜的热通量可以使用液膜厚度来预测。另一方面，在过热度较高的情况下，由于蒸气气泡的迅速膨胀，没有发生通过气泡头周围的液膜的蒸发热传递。从这项研究可以推断出，气泡的热边界层厚度与液膜厚度之间的关系对于预测这种现象的冷却效果很重要。当蒸汽气泡在高过热度的液体中生长时，迅速的生长会使液膜变厚，而厚的液膜会阻止液-气界面与加热壁之间的热传递。 （C）2019 Elsevier Ltd.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