THERMAL SCIENCE
International Scientific Journal
HEAT TRANSFER CHARACTERISTICS OF AL2O3/WATER NANOFLUID IN LAMINAR FLOW CONDITIONS WITH CIRCULAR RING INSERT
ABSTRACT
In this experimental investigation convective heat transfer, friction factor, and thermal enhancement characteristics of straight circular duct fitted with circular ring insert of constant heat flux boundary condition under fully developed laminar flow is presented. Tests have been conducted by using 0.1% volume concentration of Al2O3 nanofluid and water. Inserts of different pitch to diameter ratios of 6.25, 8.33, 12.5, and 16.67 with center core rod were used for this investigation. The circular ring insert shows a superior thermal performance than plain tube. The experimental results demonstrated that the Nusselt number, friction factor, and thermal enhancement factor increases with decrease in pitch to diameter ratio. The circular ring inserts of lower pitch to diameter ratio of 6.25 with nanofluid increases the Nusselt number by 165.38% compared to pure water and the friction factor, found to be 7.89 times higher than that of water. Empirical correlations are develope for Nusselt number and friction factor in terms of Reynolds number, volume concentration, and pitch ratio. The thermal performance factor was found to be greater than unity for all pitch to diameter ratios.
KEYWORDS
PAPER SUBMITTED: 2015-09-06
PAPER REVISED: 2016-01-03
PAPER ACCEPTED: 2016-02-29
PUBLISHED ONLINE: 2016-11-13
THERMAL SCIENCE YEAR
2016, VOLUME
20, ISSUE
Supplement 4, PAGES [S1159 - S1168]
- Choi, S. U. S., Eastman, J. A., Enhancing Thermal Conductivity of Fluids with Nanoparticles, Proceedings, ASME International Mechanical Engineering Congress and Exposition, San Francisco, Cal., USA, 1995
- Lee, S., et al., Measuring Thermal Conductivity of Fluids Containing Oxide Nanoparticles, Journal of Heat transfer, 121 (1999), 2, pp. 280-289
- Das, S. K., et al., Temperature Dependence of Thermal Conductivity Enhancement for Nanofluids, Journal of Heat Transfer, 125 (2003), 4, pp. 567-574
- Wen, D., Ding, Y., Experimental Investigation into Convective Heat Transfer of Nanofluids at the Entrance Region under Laminar Flow Conditions, International Journal of Heat and Mass Transfer, 47 (2004), 24, pp. 5181-5188
- Heris, S., et al., Experimental Investigation of Convective Heat Transfer of Al2O3/Water Nanofluid in Circular Tube, International Journal of Heat and Fluid Flow, 28 (2007), 2, pp. 203-210
- Farajollahi, B., et al., Heat Transfer of Nanofluids in a Shell and Tube Heat Exchanger, International Journal of Heat and Mass Transfer, 53 (2010), 1, pp. 12-17
- Kim, D., et al., Convective Heat Transfer Characteristics of Nanofluids under Laminar and Turbulent Flow Conditions, Current Applied Physics, 9 (2009), 2, pp. e119-e123
- Eiamsa-ard, S., et al., Influences of Peripherally-Cut Twisted Tape Insert on Heat Transfer and Thermal Performance Characteristics in Laminar and Turbulent Tube Flows, Experimental Thermal and Fluid Science, 34 (2010), 6, pp. 711-719
- Eiamsa-ard, S., et al., Thermohydraulic Investigation of Turbulent Flow through a Round Tube Equipped with Twisted Tapes Consisting of Centre Wings and Alternate-Axes, Experimental Thermal and Fluid Science, 34 (2010), 8, pp. 1151-1161
- Eiamsa-ard, S., et al., Heat Transfer Enhancement in a Tube Using Delta-Winglet Twisted Tape Inserts, Applied Thermal Engineering, 30 (200), 4, pp. 310-318
- Sivashanmugam, P., Suresh, S., Experimental Studies on Heat Transfer and Friction Factor Characteristics of Turbulent Flow through a Circular Tube Fitted with Regularly Spaced Helical Screw-Tape Inserts, Applied Thermal Engineering, 27 (2007), 8-9, pp. 1311-1319
- Sivashanmugam, P., Suresh, S., Experimental Studies on Heat Transfer and Friction Factor Characteristics of Laminar Flow through a Circular Tube Fitted with Regularly Spaced Helical Screw-Tape Inserts, Experimental Thermal and Fluid Science, 31 (2007), 4, pp. 301-308
- Jaisankar, S., et al., Experimental Studies on Heat Transfer and Thermal Performance Characteristics of Thermosyphon Solar Water Heating System with Helical and Left-Right Twisted Tapes, Energy Conversion and Management, 52 (2011), 5, pp. 2048-2055
- Murugesan, P., et al., Heat Transfer and Friction Factor Studies in a Circular Tube Fitted with Twisted Tape Consisting of Wire-Nails, Chinese Journal of Chemical Engineering, 18 (2010), 6, pp. 1038-1042
- Eiamsa-ard, S., Kiatkittipong, K., Heat Transfer Enhancement by Multiple Twisted Tape Inserts and TiO2/Water Nanofluid, Applied Thermal Engineering, 70 (2014), 1, pp. 896-924
- Suresh, S., et al., Comparative Study on Thermal Performance of Helical Screw Tape Inserts in Laminar flow Using Al2O3/Water and CuO/Water Nanofluids, Superlattices and Microstructures, 49 (2011), 6, pp. 608-622
- Suresh, S., et al., Experimental Studies on Heat Transfer and Friction Factor Characteristics of Al2O3/Water Nanofluid Under Turbulent Flow with Spiraled Rod Inserts, Chemical Engineering and Processing: Process Intensification, 53 (2012), Mar., pp. 24-30
- Chandrasekar, M., et al., Experimental Studies on Heat Transfer and Friction Factor Characteristics of Al2O3/Water Nanofluid in a Circular Pipe under Laminar Flow with Wire Coil Inserts, Experimental Thermal and Fluid Science, 34 (2010), 2, pp. 122-130
- Kongkaitpaiboon, V., et al., Experimental Investigation of Convective Heat Transfer and Pressure Loss in a Round Tube Fitted with Circular-Ring Turbulators, International Communications in Heat and Mass Transfer, 37 (2010), 5, pp. 568-574
- Pak, B. C., Cho, Y. I., Hydrodynamic and Heat Transfer Study of Dispersed Fluids with Submicron Metallic Oxide Particles, Experimental Heat Transfer an International Journal, 11 (1998), 2, pp. 151-170
- Maxwell, J. C., Treatise on Electricity and Magnetism, Vol. 2, Reprint by Dover, Mineola, N. Y., USA, 1954
- Xuan, Y., Roetzel, W., Conceptions for Heat Transfer Correlation of Nanofluids, International Journal of Heat and Mass Transfer, 43 (2000), 19, pp. 3701-3707
- Einstein, A., Investigations on the Theory of Brownian Motion, Methuen and Co., Ltd., London, 1926, Reprint by Dover Publications, Mineola, N. Y., USA, 1956
- Shah, R. K., Thermal Entry Length Solutions for the Circular Tube and Parallel Plates, Proceedings, 3rd National Heat Mass Transfer Conference, Indian Institute of Technology, Bombay, India Vol. 1, 1975, pp. 11-75