TY - JOUR
TI - Mixed convection in an eccentric annulus filled by copper nanofluid
AU - El-Maghlany Wael
AU - Abo Elazm Mohamed Mahmoud
AU - Shahata Ali
AU - Eldrainy Yehia
JN - Thermal Science
PY - 2016
VL - 20
IS - 5
SP - 1597
EP - 1608
PT - Article
AB - A numerical study of mixed convection flow and heat transfer of Copper  (Cu)-water nanofluid inside an eccentric horizontal annulus is presented. The  inner and outer cylinders are kept at constant temperatures as Th and Tc,  respectively. The inner cylinder rotates to generate the forced convection  effect. The numerical work was carried out using an in-house CFD code written  in FORTRAN. Different scenarios were explored to explain the effects of  different parameters on the studied problem. These parameters are Richardson  number, eccentricity ratio, and solid volume fraction. The range of the  Richardson number Ri, solid volume fraction of the nanoparticles ζ, and the  eccentricity ratioe, are 0.01 ≤ Ri ≤ 100 (natural convection), 0 ≤ ζ ≤ 0.05,  0 ≤ e ≤ 0.9 respectively. All results were performed with thermal Grashof  number Gr, and radius ratio Rr, equaled to 104 and 2, respectively. The  effects of eccentricity, nanoparticles volume fraction, and Richardson number  on the average Nusselt number, streamlines and isotherms were investigated.  Results were discussed, and were found to be in good agreement with previous  works. It was also found that, the eccentricity has a positive remarkable  effect on the average Nusselt number, while the effect of nanoparticles  concentration was more pronounced at mixed convection region (Ri=1).