Experimental study of heat transfer and pressure drop characteristics of microtube condenser using R134a

In this experimental study heat transfer and pressure drop behavior of ZnO/water nanofluid flow inside a circular tube with constant wall temperature condition is investigated where the volume fractions of nanoparticles in the base fluid are 1% and 2%. The experiments? Reynolds numbers ranged roughly from 5000 to 30000. The experimental measurements have been carried out in the fully-developed turbulent regime. The results indicated that heat transfer coefficient increases by 11% and 18% with increasing volume fractions of nanoparticles respectively to 1% and 2% vol. The measurements also showed that the pressure drop of nanofluids were respectively 45% and145% higher than that of the base fluid for volume fractions of 1% and 2% of nanoparticles. However experimental results revealed that overall thermal performance of nanofluid is higher than that of pure water by up to 16% for 2% vol. nanofluid. Also experimental results proved that existing correlations can accurately estimate nanofluids convective heat transfer coefficient and friction factor in turbulent regime, provided that thermal conductivity, heat capacity, and viscosity of the nanofluids are used in calculating the Reynolds, Prandtl, and Nusselt numbers.

Download Full-text

Experimental Study of the Effects of Inclusion of Rectangular-Cut Twisted Tapes on Heat Transfer and Pressure Drop in a Round Tube

Arabian Journal for Science and Engineering ◽

10.1007/s13369-019-04047-7 ◽

2019 ◽

Vol 44 (12) ◽

pp. 10303-10312 ◽

Cited By ~ 4

Author(s):

K. Ruengpayungsak ◽

Manoj Kumar ◽

V. Chuwattanakul ◽

S. Eiamsa-ard

Keyword(s):

Heat Transfer ◽

Experimental Study ◽

Pressure Drop ◽

Round Tube ◽

Twisted Tapes

Download Full-text

Experimental Study of Internal Forced Convection of Ferrofluid Flow in Porous Media

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.348.139 ◽

2014 ◽

Vol 348 ◽

pp. 139-146 ◽

Cited By ~ 2

Author(s):

Ashkan Sehat ◽

Hani Sadrhosseini ◽

M. Behshad Shafii

Keyword(s):

Magnetic Field ◽

Heat Transfer ◽

Experimental Study ◽

Porous Media ◽

Temperature Distribution ◽

Pressure Drop ◽

Forced Convection ◽

Volume Fraction ◽

Flow In Porous Media ◽

Tetra Methyl Ammonium Hydroxide

This work presents an experimental study of the effect of a magnetic field on laminar forced convection of a ferrofluid flowing in a tube filled with permeable material. The walls of the tube are subjected to a uniform heat flux and the permeable bed consists of uniform spheres of 3-mm diameter. The ferrofluid synthesis is based on reacting iron (II) and iron (III) in an aqueous ammonia solution to form magnetite, Fe3O4. The magnetite is mixed with aqueous tetra methyl ammonium hydroxide, (CH3)4NOH, solution. The dependency of the pressure drop on the volume fraction, and comparison of the pressure drop and the temperature distribution of the tube wall is studied. Also comparison of the wall temperature distribution, convection heat transfer coefficient and the Nusselt numbers of ferrofluids with different volume fractions is investigated for various Reynolds numbers (147 < Re < 205 ). It is observed that the heat transfer is enhanced by using a porous media, increasing the volume fraction had a similar effect. The pressure coefficient decreases for higher Reynolds number. The effect of magnetic field in four strategies, named modes, on ferrofluid flow through the porous media is presented.

Download Full-text