| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 236970 | Powder Technology | 2012 | 6 Pages |
This paper presents an experimental investigation of rheological and heat transfer properties of Al2O3 nanofluids based on the mixture of 45 vol.% ethylene glycol and 55 vol. % water. The Al2O3 nanofluids (volume fraction φ = 0.02) over 45 °C exhibit Newtonian behaviors, below 45 °C, they will be non-Newtonian fluids. The enhanced thermal conductivity ratios of the nanofluids with the volume fraction 1.0%, 2.0% and 3.0% are 3.8%, 7.7%, and 11.6% respectively, slightly larger than those predicted by the classic theoretical models. The heat transfer coefficients of the nanofluids with 1.0 vol.% and 2.0 vol.% have been found an increase up to 57% and 106%, respectively, when the Reynolds number is 2000.
Graphical abstractHeat transfer coefficient versus Reynolds for the base fluid and nanofluids.The heat transfer coefficients of the nanofluids with 1.0 vol.% and 2.0 vol.% have been found to increase up to 57% and 106%, respectively, when the Reynolds number is 2000.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► We investigated the heat transfer properties of Al2O3 based nanofluids. ► The heat transfer coefficient of 2.0 vol.% nanofluids with Reynolds number 2000 increases up to 106%. ► Newtonian or non-Newtonian behaviors of nanofluids depend strongly on the temperatures and volume fractions. ► The large enhancement of heat transfer of the nanofluids is helpful to increase the efficiency of heat exchanger information.
