热传递系数测量LN2和GN2在微通道中的低雷诺兹流量
Seungwhan Baek1, Peter E Bradley1, Ray Radebaugh1
1Material Measurement Laboratory, National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, USA.
International journal of heat and mass transfer
|May 7, 2025
概括
这项关于微通道热传递的研究表明,热传递系数在层状流程中是均的 (雷诺德数<2000). 这一发现解决了先前研究中的不一致性,因为它考虑了非线性温度概况.
科学领域:
- 流体动力学 流体动力学
- 热传递是一种热传递.
- 微尺度上的运输现象.
背景情况:
- 几十年来对单相流体层流热传递系数的研究产生了不一致的结果.
- 观察到的雷诺兹数依赖性与已建立的层流传热理论相矛盾.
- 微通道壁中的轴导是影响实验测量的可疑因素.
研究的目的:
- 实验研究微通道中流的传热性能.
- 开发一种分析微通道热传递的模型.
- 调和实验数据和传热理论之间的差异.
主要方法:
- 通过微通道 (液压直径110和180微米) 进行气态和液态气流的实验研究.
- 开发一个数值模型来模拟微通道内的热传输.
- 分析沿微通道长度的流体和壁面温度概况.
主要成果:
- 在低流速 (雷诺德数<1000) 的微通道长度上观察到非线性温度概况.
- 这种非线性概况与传统的努塞尔特数估计中的线性概况假设相冲突.
- 实验和数值结果验证了层流传热系数的统一性 (雷诺德数<2000).
结论:
- 对于微通道,热传递系数在层流模式 (雷诺德数<2000) 中保持一致.
- 低流速的非线性温度概况解释了先前观察到的雷诺兹数依赖性.
- 这项研究提供了实验发现和微通道传热理论预期之间的一致性.
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