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Particle shape effect on heat transfer performance in an oscillating heat pipe.

Ji Y, Wilson C, Chen HH, Ma H - Nanoscale Res Lett (2011)

Bottom Line: A binary mixture of ethylene glycol (EG) and deionized water (50/50 by volume) was used as the base fluid for the OHP.Experimental results show that the alumina nanoparticles added in the OHP significantly affect the heat transfer performance and it depends on the particle shape and volume fraction.In addition, even though previous research found that these alumina nanofluids were not beneficial in laminar or turbulent flow mode, they can enhance the heat transfer performance of an OHP.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, MO 65211, USA. mah@missouri.edu.

ABSTRACT
The effect of alumina nanoparticles on the heat transfer performance of an oscillating heat pipe (OHP) was investigated experimentally. A binary mixture of ethylene glycol (EG) and deionized water (50/50 by volume) was used as the base fluid for the OHP. Four types of nanoparticles with shapes of platelet, blade, cylinder, and brick were studied, respectively. Experimental results show that the alumina nanoparticles added in the OHP significantly affect the heat transfer performance and it depends on the particle shape and volume fraction. When the OHP was charged with EG and cylinder-like alumina nanoparticles, the OHP can achieve the best heat transfer performance among four types of particles investigated herein. In addition, even though previous research found that these alumina nanofluids were not beneficial in laminar or turbulent flow mode, they can enhance the heat transfer performance of an OHP.

No MeSH data available.


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Performance enhancement efficiency of nanofluid in an OHP at a filling ratio of 50% and an operating temperature of (a) 20°C and (b) 60°C.
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Figure 5: Performance enhancement efficiency of nanofluid in an OHP at a filling ratio of 50% and an operating temperature of (a) 20°C and (b) 60°C.

Mentions: where, is the average thermal resistance of the OHP charged with base fluid, and is the average thermal resistance of the OHP charged with nanofluid. Using the definition shown above, η can be determined as shown in Figure 5. It can be seen that at the volume fraction of 0.3%, all the nanofluids used in this study can enhance the heat transfer performance of the OHP. For other volume fractions, it largely depended on the operation temperature. At an operating temperature of 20°C, η tends to decrease as the volume fraction increases except cylinder-like particle (P3). The highest (37.3%) and lowest (-98.3%) values of η were found when the OHP was charged with P3V1 and P2V5, respectively. At an operating temperature of 60°C, all nanofluids except P1V3, P2V3, and P1V5 can enhance the heat transfer performance of the OHP. For blade-like particles (P2), cylinder-like particles (P3), and brick-like particles (P4), η decreases first and then increases as the volume fraction increases. For platelet-like particles (P1), η decreases as the volume fraction increases. When the OHP was charged with P3V03 and P1V5, the highest (75.8%) and lowest (-79.0%) values of η were found, respectively.


Particle shape effect on heat transfer performance in an oscillating heat pipe.

Ji Y, Wilson C, Chen HH, Ma H - Nanoscale Res Lett (2011)

Performance enhancement efficiency of nanofluid in an OHP at a filling ratio of 50% and an operating temperature of (a) 20°C and (b) 60°C.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211362&req=5

Figure 5: Performance enhancement efficiency of nanofluid in an OHP at a filling ratio of 50% and an operating temperature of (a) 20°C and (b) 60°C.
Mentions: where, is the average thermal resistance of the OHP charged with base fluid, and is the average thermal resistance of the OHP charged with nanofluid. Using the definition shown above, η can be determined as shown in Figure 5. It can be seen that at the volume fraction of 0.3%, all the nanofluids used in this study can enhance the heat transfer performance of the OHP. For other volume fractions, it largely depended on the operation temperature. At an operating temperature of 20°C, η tends to decrease as the volume fraction increases except cylinder-like particle (P3). The highest (37.3%) and lowest (-98.3%) values of η were found when the OHP was charged with P3V1 and P2V5, respectively. At an operating temperature of 60°C, all nanofluids except P1V3, P2V3, and P1V5 can enhance the heat transfer performance of the OHP. For blade-like particles (P2), cylinder-like particles (P3), and brick-like particles (P4), η decreases first and then increases as the volume fraction increases. For platelet-like particles (P1), η decreases as the volume fraction increases. When the OHP was charged with P3V03 and P1V5, the highest (75.8%) and lowest (-79.0%) values of η were found, respectively.

Bottom Line: A binary mixture of ethylene glycol (EG) and deionized water (50/50 by volume) was used as the base fluid for the OHP.Experimental results show that the alumina nanoparticles added in the OHP significantly affect the heat transfer performance and it depends on the particle shape and volume fraction.In addition, even though previous research found that these alumina nanofluids were not beneficial in laminar or turbulent flow mode, they can enhance the heat transfer performance of an OHP.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, MO 65211, USA. mah@missouri.edu.

ABSTRACT
The effect of alumina nanoparticles on the heat transfer performance of an oscillating heat pipe (OHP) was investigated experimentally. A binary mixture of ethylene glycol (EG) and deionized water (50/50 by volume) was used as the base fluid for the OHP. Four types of nanoparticles with shapes of platelet, blade, cylinder, and brick were studied, respectively. Experimental results show that the alumina nanoparticles added in the OHP significantly affect the heat transfer performance and it depends on the particle shape and volume fraction. When the OHP was charged with EG and cylinder-like alumina nanoparticles, the OHP can achieve the best heat transfer performance among four types of particles investigated herein. In addition, even though previous research found that these alumina nanofluids were not beneficial in laminar or turbulent flow mode, they can enhance the heat transfer performance of an OHP.

No MeSH data available.


Related in: MedlinePlus