Transient heat transfer due to exponentially increasing heat inputs for turbulent flow of FC-72 in small diameter tubes
Transient heat transfer due to exponentially increasing heat inputs for turbulent flow of FC-72 in small diameter tubes
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DOI：
10.1016/j.ijheatmasstransfer.2017.03.022
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发表时间：
2017-07
影响因子：
5.2
通讯作者：
Yantao Li;K. Fukuda;Qiusheng Liu
中科院分区：
文献类型：
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作者：
Yantao Li;K. Fukuda;Qiusheng Liu
对FC-72在不同的流速、入口液体温度和指数增加的热输入周期等参数组合下的湍流传热过程进行了示意性研究。雷诺数Red和普朗特数Pr的范围分别为23，400 - 81，800和8.4-10.8。在这项研究中使用的测试加热器是圆形的SUS 304管，小内径为1，1.8和2.8毫米，壁厚为0.5毫米，加热长度约为30，40和50毫米。详细讨论了流速、指数周期和管径对瞬态湍流传热过程的影响。通过引入无量纲时间傅立叶数Fo，可以分析热输入指数增加引起的瞬态湍流传热。基于Fo、流速和管径的影响，建立了小管径管内指数增加热输入引起的瞬态湍流换热的经验关联式。经验关联式给出的实验数据在± 25%以内。
The transient heat transfer process due to exponentially increasing heat inputs for turbulent flow of FC-72 was schematically investigated for different combinations of parameters such as flow velocity, inlet liquid temperature and period of exponentially increasing heat inputs. The ranges of Reynolds number,Red, and Prandtl number,Pr, were 23,400–81,800 and 8.4–10.8, respectively. The test heaters used in this study were circular SUS304 tubes with small inner diameters of 1, 1.8 and 2.8 mm, wall thickness of 0.5 mm, and heated lengths around 30, 40 and 50 mm. The effects of flow velocity, exponential period and tube inner diameter on transient turbulent heat transfer process were discussed in detail. It was clarified that the transient turbulent heat transfer due to exponentially increasing heat inputs could be analyzed by introducing a dimensionless time, Fourier number,Fo. An empirical correlation for transient turbulent heat transfer caused by exponentially increasing heat inputs on small diameter tubes was developed based on the effects ofFo, flow velocity and tube inner diameter. The empirical correlation presents the experimental data within ±25%.