Experimental and numerical investigation of convection heat transfer in a circular copper tube using graphene oxide nanofluid

Abstract

To able to employ nanofluids in engineering applications, it is essential to investigate heat transfer properties in addition to thermophysical characteristics. In this work, the convection heat transfer coefficient of graphene oxide-distilled water nanofluid along a circular copper tube having a constant heat flux at the outside surface has been investigated both numerically and experimentally under turbulent flow regime. While the nanofluid convection heat transfer and head loss of pressure have been evaluated in the experimental section, the tube wall surface temperature, the convection heat transfer coefficient and friction factor have been obtained by using finite volume method in the numerical part with a three-dimensional domain by assuming single-phase flow. Surface and fluid temperatures and pressure drop of the distilled water have been acquired and compared with the related output from the correlation. Besides, the variations of the tube surface temperatures and the convection heat transfer coefficients of the nanofluids have been examined as numerical and experimental comparisons. The contours of the temperatures, convection heat transfer coefficients and pressure distributions for fluids have been presented. The convection heat transfer performances of the nanofluids according to the different volumetric flow rates, concentrations and the heat flux values have been exhibited in this study. The heat transfer coefficient increment value for the nanofluid of 0.02 vol% concentration and with a flow rate of 1.5 l/min (Re = 5032) has been obtained as about 48% for 5073.244 W/m 2 (350 W) heat flux according to the distilled water.

Geçiş Metali Katkılı ZnO’in Ferromanyetizma ve Büyüme Korelasyonunun İncelenmesi

“…Particle growth is difficult to control, including optimization of particle sizes and their shapes and agglomerative formations reduce in the co-precipitation. This procedure is similar with graphene oxide nanoparticle synthesis [12].…”

Elmas-Su Nanoakışkanı Kullanılan Kanatçıklı ve Farklı Yükseklikli Birleşik Jet Akışlı Kanallarda Yüzeylerin Soğutulması

“…Bu eşitlikte, ρ akışkanın yoğunluğunu (kg/m 3 ), φ nanoparçacık konsantrasyonu ifade ederken, p, nf ve bf ise sırasıyla nanoparçacık, nanoakışkan ve su akışkanını belirtmektedir [17,18]. Nanoakışkanın Özgül Isısı [17,18,19] (1…”

Numerical Analysis of Hydraulic and Thermal Performance of Al2O3-Water Nanofluid in a Zigzag Channel with Central Winglets

“…Ajeel et al [50] numerically examined the hydraulic and thermal properties of nanofluids (ZnO-water) for turbulent flow with L-shaped baffles in a curved wavy channel and reported that the baffles and nanofluids have a considerable influence on increasing the heat transfer rate. Experimental investigations of convection heat transfer in a circular copper tube using graphene oxide nanofluid carried out by Karabulut et al [51][52][53] and Kilinc et at. [54].…”