Natural Convection Enhancement in the Annuli Between Two  Homocentric Cylinders by Using Ethylene Glycol / Water  Based Titania Nanofluid

Fateh Mebarek-Oudina; Ahmed Kadhim Hussein; Obai Younis; Sara Rostami; Rasoul  Nikbakhti

Authors

Fateh Mebarek-Oudina Department of Physics, Faculty of Sciences, University 20 août 1955 - Skikda, B.P 26 Route El-Hadaiek, Skikda 21000, Algeria
Ahmed Kadhim Hussein 2 College of Engineering -Mechanical Engineering Department, University of Babylon, Babylon City, Hilla, Iraq
Obai Younis Department of Mechanical Engineering, College of Engineering at Wadi Addwaser, Prince Sattam Bin Abdulaziz University, Wadi Addwaser, Saudi Arabia
Sara Rostami Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam
Rasoul Nikbakhti School of Engineering, College of Science and Engineering, University of Tasmania, Tasmania, Australia

Keywords:

Natural convection, coaxial cylinders, annular region, numerical modelling, nanofluid, ethylene glycol / water mixture

Abstract

The natural convection heat transfer in annulate region confined between two homocentric cylinders were numerically studied in the present work. The annulus was filled by ethylene glycol / water-based Titania nanofluid. Both internal and external cylinders are preserved at an isothermal hot and cold temperatures respectively, whereas, the upper and lower walls are adiabatic. The numerical solution is obtained by applying the finite volume method along with the SIMPLER, and TDMA algorithms. In the current study, the solid volumetric fraction is varied as (0 % ≤ φ ≤ 3 %), the volume ratios of EG to water are varied as (0:100 %, 40: 60 %, 100:0 %), while both the Rayleigh number and radii ratio are considered fixed at (Ra = 104 and λ = 2). The obtained results indicated that the average Nusselt number increases as the solid volumetric fraction and the volume ratio of ethylene glycol in the base fluid increase. Moreover, the velocity profiles reach their maximum value in the half region adjacent the internal hot wall when TiO2-water nanofluid is used. Also, the temperature profiles decrease along the radial distance for all considered values of volume ratios of EG to water