Knowledge Management System Of Guangzhou Institute of Energy Conversion, CAS
| Chaotic behavior of pulsating heat pipes | |
| Song, Yanxi; Xu, Jinliang | |
| 2009-06-01 | |
| Source Publication | INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
 |
| ISSN | 0017-9310 |
| Volume | 52Issue:13-14Pages:2932-2941 |
| Corresponding Author | xujl@ms.giec.ac.cn |
| Abstract | Chaotic behavior of closed loop pulsating heat pipes (PHPs) was studied. The PHPs were fabricated by capillary tubes with outer and inner diameters of 2.0 and 1.20 mm. FC-72 and deionized water were used as the working fluids. Experiments cover the following data ranges: number of turns of 4, 6, and 9, inclination angles from 5 degrees (near horizontal) to 90, (vertical), charge ratios from 50% to 80%, heating powers from 7.5 to 60.0 W. The nonlinear analysis is based on the recorded time series of temperatures on the evaporation, adiabatic, and condensation sections. The present study confirms that PHPs are deterministic chaotic systems. Autocorrelation functions (ACF) are decreased versus time, indicating prediction ability of the system is finite. Three typical attractor patterns are identified. Hurst exponents are very high, i.e., from 0.85 to 0.95, indicating very strong persistent properties of PHPs. Curves of correlation integral versus radius of hypersphere indicate two linear sections for water PHPs, corresponding to both high frequency, low amplitude, and low frequency, large amplitude oscillations. At small inclination angles near horizontal, correlation dimensions are not uniform at different turns of PHPs. The non-uniformity of correlation dimensions is significantly improved with increases in inclination angles. Effect of inclination angles on the chaotic parameters is complex for FC-72 PHPs, but it is certain that correlation dimensions and Kolmogorov entropies are increased with increases in inclination angles. The optimal charge ratios are about 60-70%, at which correlation dimensions and Kolmogorov entropies are high. The higher the heating power, the larger the correlation dimensions and Kolmogorov entropies are. For most runs, large correlation dimensions and Kolmogorov entropies correspond to small thermal resistances, i.e., better thermal performance, except for FC-72 PHPs at small inclination angles of theta < 15 degrees. (C) 2009 Elsevier Ltd. All rights reserved. |
| Subtype | Article |
| Other Abstract | Chaotic behavior of closed loop pulsating heat pipes (PHPs) was studied. The PHPs were fabricated by capillary tubes with outer and inner diameters of 2.0 and 1.20 mm. FC-72 and deionized water were used as the working fluids. Experiments cover the following data ranges: number of turns of 4, 6, and 9, inclination angles from 5 degrees (near horizontal) to 90, (vertical), charge ratios from 50% to 80%, heating powers from 7.5 to 60.0 W. The nonlinear analysis is based on the recorded time series of temperatures on the evaporation, adiabatic, and condensation sections. The present study confirms that PHPs are deterministic chaotic systems. Autocorrelation functions (ACF) are decreased versus time, indicating prediction ability of the system is finite. Three typical attractor patterns are identified. Hurst exponents are very high, i.e., from 0.85 to 0.95, indicating very strong persistent properties of PHPs. Curves of correlation integral versus radius of hypersphere indicate two linear sections for water PHPs, corresponding to both high frequency, low amplitude, and low frequency, large amplitude oscillations. At small inclination angles near horizontal, correlation dimensions are not uniform at different turns of PHPs. The non-uniformity of correlation dimensions is significantly improved with increases in inclination angles. Effect of inclination angles on the chaotic parameters is complex for FC-72 PHPs, but it is certain that correlation dimensions and Kolmogorov entropies are increased with increases in inclination angles. The optimal charge ratios are about 60-70%, at which correlation dimensions and Kolmogorov entropies are high. The higher the heating power, the larger the correlation dimensions and Kolmogorov entropies are. For most runs, large correlation dimensions and Kolmogorov entropies correspond to small thermal resistances, i.e., better thermal performance, except for FC-72 PHPs at small inclination angles of theta < 15 degrees. |
| Keyword | Pulsating Heat Pipe Nonlinear Analysis Correlation Dimension Kolmogorov Entropy |
| WOS Headings | Science & Technology ; Physical Sciences ; Technology |
| DOI | 10.1016/j.ijheatmasstransfer.2009.02.030 |
| WOS Subject Extended | Thermodynamics ; Engineering ; Mechanics |
| URL | 查看原文 |
| WOS Keyword | FLOW ; VISUALIZATION |
| Indexed By | SCI |
| Language | 英语 |
| Funding Organization | National Natural Science Foundation of China [50825603]; Natural Science Foundation of China [50776089] |
| WOS Subject | Thermodynamics ; Engineering, Mechanical ; Mechanics |
| WOS ID | WOS:000266216700004 |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.giec.ac.cn/handle/344007/3340 |
| Collection | 中国科学院广州能源研究所 |
| Affiliation | Chinese Acad Sci, Guangzhou Inst Energy Convers, Micro Energy Syst Lab, Guangzhou 510640, Guangdong, Peoples R China |
| Recommended Citation GB/T 7714 | Song, Yanxi,Xu, Jinliang. Chaotic behavior of pulsating heat pipes[J]. INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER,2009,52(13-14):2932-2941. |
| APA | Song, Yanxi,&Xu, Jinliang.(2009).Chaotic behavior of pulsating heat pipes.INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER,52(13-14),2932-2941. |
| MLA | Song, Yanxi,et al."Chaotic behavior of pulsating heat pipes".INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER 52.13-14(2009):2932-2941. |
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