카본나노튜브 나노유체의 동점성계수 증가로 인한관내 유동에서의 항력 감소
Drag Reduction Induced by Increased Kinematic Viscosity of Nanofluids Containing Carbon Nanotubes in A Horizontal Tube
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This article reports the drag reduction phenomenon of aqueous suspensions containing carbon nanotubes (CNTs)flowing through horizontal tubes. Stable nanofluids were prepared by using a surfactant. It is found that the dragforces of CNT nanofluids were reduced at specific flow conditions compared to the base fluid. It is found that thefriction factor of CNT nanofluids was reduced up to approximately 30 % by using CNT nanofluids. Increasedkinematic viscosities of CNT nanofluids are suggested to the key factors that cause the drag reduction phenomenon. In addition, transition from laminar to turbulent flow is observed to be delayed when CNT nanofluids flow in ahorizontal tube, meaning that drag reduction occurs at higher flow rates, that is, at higher Reynolds numbers.
Abstract
This article reports the drag reduction phenomenon of aqueous suspensions containing carbon nanotubes (CNTs)flowing through horizontal tubes. Stable nanofluids were prepared by using a surfactant. It is found that the dragforces of CNT nanofluids were reduced at specific flow conditions compared to the base fluid. It is found that thefriction factor of CNT nanofluids was reduced up to approximately 30 % by using CNT nanofluids. Increasedkinematic viscosities of CNT nanofluids are suggested to the key factors that cause the drag reduction phenomenon. In addition, transition from laminar to turbulent flow is observed to be delayed when CNT nanofluids flow in ahorizontal tube, meaning that drag reduction occurs at higher flow rates, that is, at higher Reynolds numbers.
참고문헌 (19)
- Barnes, H. A., "An introduction to rheology" (1989), Elsevier Science Publishers
- Berber, S., "Unusually high thermal conductivity of carbon nanotubes", Physics Review Letter, 84, pp.4613~4616 (2000)
- Cho, J., "Improved thermal stability of LiCoO2 by nanoparticle AlPO4 coating with respect to spinel Li1.05Mn1.95O4", Electrochemistry Communications, 5, pp.146~148 (2003)
- Choi, S. U. S., "Anomalous thermal conductivity enhancement in nanotube suspensions", Applied Physics Letters, 79, pp.2252~2254 (2001)
- Ding, Y. L., "Heat transfer of aqueous suspensions of carbon nanotubes (CNT nanofluids)", International Journal of Heat and Mass Transfer, 49, pp.240~250 (2006)
- Draad, A. A., "Laminar‐turbulent transition in pipe flow for Newtonian and non‐Newtonian fluids", Journal of Fluid Mechanics, 377, pp.267~312 (1998)
- Eastman, J. A., "Anomalously increased effective thermal conductivities of ethylene glycol‐based nanofluids containing copper nanoparticles", Applied Physics Letters, 78, pp.718~720 (2001)
- Hirata, A., "Sliding friction properties of carbon nanotube coatings deposited by microwave plasma chemical vapor deposition", Tribology International, 37, pp.893~898 (2004)
- Hone, J., "Thermal conductivity of single‐walled carbon nanotubes", Physics Review B, 59, pp.R2514~R2516 (1999)
- Jang, S. P., "Role of Brownian motion in the enhanced thermal conductivity of nanofluids", Applied Physics Letters, 84, pp.4316~4318 (2004)
- Kim, P., "Thermal transport measurements of individual multiwalled nanotubes", Physics Review Letter, 8721 (2001)
- Ko, G. H., "An experimental study on the pressure drop of nanofluids containing carbon nanotubes in a horizontal tube", International Journal of Heat and Mass Transfer, 50, pp.4749~4753 (2007)
- Lee, S., "Measuring thermal conductivity of fluids containing oxide nanoparticles", Journal of Heat Transfer, 121, pp.280~289 (1999)
- Potschke, P., "Rheological behavior of multiwalled carbon nanotube", polycarbonate composites, 2002, pp.43, 3247~3255
- Suhr, J., "Viscoelasticity in carbon nanotube composites", Nature Materials, 4, pp.134~137 (2005)
- White, F. M, "Fluid Mechanics" (2003), Macgraw‐ Hill
- Xie, H., "Thermal conductivity of suspensions containing nanosized SiC particles", International Journal of Thermophysics, 23, pp.571~580 (2002)
- Xie, H. Q., "Nanofluids containing multiwalled carbon nanotubes and their enhanced thermal conductivities", Journal of Applied Physics, 94, pp.4967~4971 (2003)
- Xuan, Y. M., "Heat transfer enhancement of nanofluids", International Journal of Heat Fluid Flow, 21, pp.58~64 (2000)