Experimental Investigation of Laminar Convective Heat Transfer and Pressure Drop of Al2O3/Water Nanofluid in Circular Tube Fitted with Twisted Tape Insert

Yıl 2017, Cilt: 4 Sayı: 2, 73 - 86, 10.08.2017

LAITH JAAFER Al-saady Fouad A. Saleh Bassim M. Maajel

Öz

In the present study, convective heat transfer coefficient
and pressure drop of Al₂O₃/water nanofluid in laminar flow
regime under constant inlet temperature conditions inside a circular finned-tube
with a typical twisted tape was experimentally investigated. For this purpose,
Al₂O₃ nanoparticles of 20 nm size were synthesized,
characterized and dispersed in distilled water to formulate Al₂O₃/water
nanofluid containing 3 and 5% volume concentration of nanoparticles. The
thermophysical properties like thermal conductivity and viscosity of Al₂O₃
nanofluid is determined through experiments at different volume
concentrations and validated. Experiments are conducted in the Reynolds number
range of (678–2033) with tape of twist ratio (H/D = 1.85). The effect of
different volume concentrations on convective heat transfer coefficient and
friction factor was studied. The results emphasize that increasing of particle volume
concentration leads to enhance convective heat transfer coefficient.
Measurements show the average heat transfer coefficient enhanced about 21-51 %
with 5% volume concentration and increased about 19-38 % with 3% volume
concentration compared to distilled water. In addition, the average ratio of (f_nf/f_bf)
was about 2.3 for 5% volume concentration. Therefore, there is a significant
increase in friction factor for nanofluids. A generalized regression equation
is developed for the estimation of Nusselt number and friction factor valid for
nanofluid. 

Anahtar Kelimeler

Typical twisted tape, Heat transfer

Kaynakça

• [1] Bergles, A. E. "Handbook of Heat Transfer", McGraw-Hill, New York, NY, USA, 3rd edition, 1998.
• [2] Adrian B. and Allan K. D. "Heat transfer enhancement" In Heat Transfer Handbook, Chapter 14, pg.1033, -1101, Wiley- 2003.
• [3] Khaled A. R., Abdulhafiz N. I., and Boukhary A. Y., "Recent Advances in Heat Transfer Enhancements", Hindawi Publishing Corporation InternationalJournal of Chemical Engineering Volume 2010, Article ID 106461.
• [4] Whitham, J. M., "The Effects of Retarders in Fire Tubes of Steam Boilers", Street Railway.1896, 12(6), 374.
• [5] Khwanchit Wongcharee, Smith Eiamsa-ard, 2011,"Enhancement of Heat Transfer Using CuO/water Nanofluid and Twisted Tape with Alternate Axis", International Communications in Heat and Mass Transfer., 38:742–748.
• [6] E. Esmaeilzadeh, H. Almohammadi, A. Nokhosteen, A. Motezaker and A. N. Omrani, "Study on Heat Transfer and Friction Factor Characteristics of γ-Al2O3/water Through Circular Tube with Twisted Tape Inserts with Different Thicknesses", International Journal of Thermal Sciences, 82 (2014) 72-83.
• [7] Naik M. T., Ranga Janardana G., Syam Sundar L., "Experimental Investigation of Heat Transfer and Friction Factor with Water–Propylene Glycol Based CuO Nanofluid in a Tube with Twisted Tape Inserts", International Communications in Heat and Mass Transfer, 46, (2013), 13–21.
• [8] L. Syam Sundar and K.V. Sharma, "LAMINAR CONVECTIVE HEAT TRANSFER AND FRICTION FACTOR OF AL2O3 NANOFLUID IN CIRCULAR TUBE FITTED WITH TWISTED TAPE INSERTS", International Journal of Automotive and Mechanical Engineering (IJAME), 3, (2011), 265-278.
• [9] Suresh S, Venkitaraj KP, Selvakumar P., "Comparative study on thermal performance of helical screw tape inserts in laminar flow using Al2O3/water and CuO/water nanofluids". Super lattices and Microstructures 2011; 49:608–22.
• [10] Suresh S, Venkitaraj KP, Selvakumar P, Chandrasekar M., "A comparison of thermal characteristics of Al2O3/water and CuO/water nanofluids in transition flow through a straight circular duct fitted with helical screw tape inserts", Experimental Thermal and Fluid Science 2012;39:37–44.