从层状流向流的过渡界限 微封装相变材料泥-实验结果
Krzysztof Dutkowski1, Marcin Kruzel1, Martyna Kochanowska1
1Department of Mechanical and Power Engineering, Koszalin University of Technology, Raclawicka Street 15-17, 75-620 Koszalin, Poland.
Materials (Basel, Switzerland)
|January 8, 2025
概括
微封装相变材料 (mPCM) 的流动行为随着mPCM度及其相位的变化而变化. 更高的度和固态mPCM降低了临界雷诺兹数,影响了流量计算.
科学领域:
- 流体动力学 流体动力学
- 材料科学 材料科学 材料科学
- 热传递热量转移的方法
背景情况:
- 隐性功能热流体 (LFTF) 使用相变材料 (PCM) 进行增强的传热.
- 微封装PCM (mPCM) 提供先进的热流体性能.
- 了解mPCM泥中的流量模式转换对于热系统设计至关重要.
研究的目的:
- 为了确定mPCM泥中流量状态转换的临界雷诺兹数 (Re_cr).
- 为了研究mPCM度对Re_cr.的影响.
- 分析PCM相位状态 (固体,相位变化,液体) 在微囊中的对Re_cr.的影响.
主要方法:
- 在直管中实验确定mPCM泥的Re_cr.
- 不同的mPCM度 (重量为4.30%~17.20%). 和泥的温度 (7°C,24°C,44°C).
- 使用微封装的抛,点在24°C左右.
主要成果:
- mPCM度显著影响临界雷诺兹数.
- 微囊中PCM的相位状态会影响流动模式的转换.
- 在mPCM泥中的层状流在较低的Re_cr以增加mPCM度结束.
- 固态mPCM的结果是,与液态或相变态相比,Re_cr较低.
结论:
- 假设纯液体的普遍临界雷诺斯数 (例如,Re=2300) 不适用于mPCM泥.
- 精确的流电阻和传热计算需要考虑mPCM度和相位状态.
- 在mPCM泥中的流动行为与纯液体的流动行为有所不同,因此需要特定的计算方法.
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