Open AccessExperimental and numerical study of forced convection heat transfer in different internally ribbed tubes configuration using TiO 2 nanofluid
Author(s) -
Al Kumait Aadel A. R.,
Ibrahim Thamir K.,
Abdullah Maysoon A.
Publication year - 2019
Publication title -
heat transfer—asian research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.41
H-Index - 30
eISSN - 1523-1496
pISSN - 1099-2871
DOI - 10.1002/htj.21457
Subject(s) - nanofluid , nusselt number , materials science , heat transfer , tube (container) , mechanics , turbulence , heat transfer enhancement , turbulence kinetic energy , heat flux , reynolds number , thermodynamics , concentric tube heat exchanger , forced convection , heat transfer coefficient , composite material , physics
TiO 2 /water nanofluid is used together with a ribbed tube for heat transfer augmentation. This paper presents an experimental and numerical investigation to study the influence of the ribs' pitch distance and ribbed tube configuration on heat transfer using TiO 2 nanofluid in a turbulent regime with Reynolds numbers of 5000‐40 000. Meanwhile, the fluid properties are assumed to be constant with temperature under uniform heat flux. The average nanoparticle size is 50 nm and volume fractions of 0% to 1% are adopted. The study is accomplished by using the finite volume method, and its objective involves finding a low friction factor and high heat transfer enhancement in the presence of TiO 2 /water nanofluids. In comparison with the plain tube, a helical ribbed tube provides higher performance evaluation criteria (about 2.0%), while circumferentially ribbed tube provides 1.9% and longitudinal ribbed tube provides 1.88%. The helical ribbed tubes with a 5.89 mm pitch distance gave higher turbulent kinetic energy due to a stronger swirl intensity, resulting in a thinner thermal boundary layer and a higher Nusselt number with uniform distribution. The nonlinear models of friction factor and Nusselt number have been predicted with a maximum deviation of ±3% and ±2%, respectively.