مقاله Experimental studies on heat transfer and friction factor characteristics of CuO/water nanofluid under turbulent flow in a helically dimpled tube : تی پی بین

خلاصه مقاله

An experimental investigation on the convective heat transfer and friction factor characteristics in the plain and helically dimpled tube under turbulent flow with constant heat flux is presented in this work using CuO/water nanofluid as working fluid. The effects of the dimples and nanofluid on the Nusselt number and the friction factor are determined in a circular tube with a fully developed turbulent flow for the Reynolds number in the range between 2500 and 6000. The height of the dimple/protrusion was 0.6 mm. The effect of the inclusion of nanoparticles on heat transfer enhancement, thermal conductivity, viscosity, and pressure loss in the turbulent flow region were investigated. The experiments were performed using helically dimpled tube with CuO/water nanofluid having 0.1%, 0.2% and 0.3% volume concentrations of nanoparticles as working fluid. The experimental results reveal that the use of nanofluids in a helically dimpled tube increases the heat transfer rate with negligible increase in friction factor compared to plain tube. The experimental results showed that the Nusselt number with dimpled tube and nanofluids under turbulent flow is about 19%, 27% and 39% (for 0.1%, 0.2% and 0.3% volume concentrations respectively) higher than the Nusselt number obtained with plain tube and water. The experimental results of isothermal pressure drop for turbulent flow showed that the dimpled tube friction factors were about 2–10% higher than the plain tube. The empirical correlations developed for Nusselt number and friction factor in terms of Reynolds number, pitch ratio and volume concentration fits with the experimental data within ±15%.

نویسندگان

S. Suresh [ Department of Mechanical Engineering, National Institute of Technology, Tiruchirappalli 620 015, India ]

M. Chandrasekar [ Department of Mechanical Engineering, National Institute of Technology, Tiruchirappalli 620 015, India ]

S. Chandra Sekhar [ Department of Mechanical Engineering, National Institute of Technology, Tiruchirappalli 620 015, India ]

کلمات کلیدی

Nanofluid Helically dimpled tube Heat transfer enhancement Nusselt number Pressure drop

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مشاهده مقالات

Experimental Thermal and Fluid Science 2011

International Journal of Experimental Heat Transfer, Thermodynamics, and Fluid Mechanics Experimental Thermal and Fluid Science provides a forum for research emphasizing experimental work that enhances basic understanding of heat transfer, thermodynamics and fluid mechanics, and their applications. In addition to the principal areas of research, the journal covers research results in related fields, including combined heat and mass transfer, micro and nanoscale systems, multiphase flow, combustion, radiative transfer, porous media, cryogenics, turbulence, contact resistance, and thermophysical property measurements and techniques.

حوزه های تحت پوشش : heat transfer, thermodynamics and fluid mechanics , micro and nanoscale systems