Effective viscosities and thermal conductivities of aqueous nanofluids containing low volume concentrations of Al2O3 nanoparticles |
| |
| Authors: | Ji-Hwan Lee Kyo Sik Hwang Seok Pil Jang Byeong Ho Lee Jun Ho Kim Stephen U.S. Choi Chul Jin Choi |
| |
| Affiliation: | 1. Department of Mechanical Engineering of Agricultural Machinery, University of Tehran, Mesbah Cross, Karaj, Iran;2. Nanotechnology Research Center, Research Institute of Petroleum Industry (RIPI), West Blvd. Azadi Sport Complex, Tehran, Iran;1. Department of Mechanical Engineering, Islamic Azad University, Mashhad Branch, Mashhad, Iran;2. Young Researchers and Elite Club, Islamic Azad University, Mashhad Branch, Mashhad, Iran;3. Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur 50630, Malaysia;4. Heat and Thermodynamics Division, Department of Mechanical Engineering, Faculty of Mechanical Engineering, Yildiz Technical University (YTU), Yildiz, Besiktas, Istanbul 34349, Turkey;5. Fluid Mechanics, Thermal Engineering and Multiphase Flow Research Lab. (FUTURE), Department of Mechanical Engineering, Faculty of Engineering, King Mongkut’s University of Technology Thonburi, Bangmod, Bangkok 10140, Thailand |
| |
| Abstract: | Aqueous nanofluids containing low volume concentrations of Al2O3 nanoparticles in the 0.01–0.3 vol.% range were produced and characterized. Measurements of zeta potential and TEM micrograph of the alumina nanoparticles in the Al2O3–water nanofluids show that the alumina nanoparticles can be best dispersed and stabilized in DI water with little evidence of aggregation at 5 h of ultrasonic vibration. Viscosity measurements show that the viscosity of the Al2O3–water nanofluids significantly decreases with increasing temperature. Furthermore, the measured viscosities of the Al2O3–water nanofluids show a nonlinear relation with the concentration even in the low volume concentration (0.01%–0.3%) range, while the Einstein viscosity model clearly predicts a linear relation, and exceed the Einstein model predictions. In contrast to viscosity, the measured thermal conductivities of the dilute Al2O3–water nanofluids increase nearly linearly with the concentration, agree well with the predicted values by the Jang and Choi model, and are consistent in their overall trend with previous data at higher concentrations. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
