Numerical investigation of non‐Newtonian nanofluid mixed convection in a two‐opposite direction lid‐driven cavity with variable properties

Abstract

The mixed convection fluid flow in a square cavity filled with AL2O3‐water non‐Newtonian nanofluid is numerically analyzed. The left and right vertical boundaries of the enclosure have been kept in the constant temperature. Remaining walls of the cavity have been considered to have adiabatic boundary condition. Two different cases have been considered. In the first case, left and right side walls have been moved vertically with constant speed Vb in opposite directions. In the second case, the directions of their motions have been reversed. The transport equations, written in terms of the primitive variables for the non‐Newtonian nanofluid, have been solved numerically using the finite volume method. The shear stresses were calculated using the Ostwald‐de Waele model for the shear‐thinning nanofluid. The model introduced by Patel et al was used to obtain the thermal conductivity of the nanofluid. The variation of the fluid flow with respect to the Richardson number and volume fraction of the nanoparticles was investigated through a parametric study. Even though increasing the volume fraction of nanoparticles leads to heat transfer enhancement, for the second case of this study, for Ri = 1, the average Nusselt number initially drops sharply by increasing the volume fraction of nanoparticles, then remains constant.

Modeling the effective thermal conductivity of nanofluids using full factorial design analysis

“…They are produced by conventional methods and are more stable than metallic nanoparticles . Three types of oxide metal nanoparticles are studied: Aluminum oxides (Alumina), Al 2 O 3 ; Titanium oxides (Titania), TiO 2 ; and Copper oxides, CuO . The corresponding thermophysical properties of the base fluid (water) and solid phases are given in Table .…”

Numerical investigation of mixed convection of non‐Newtonian fluid in a vented square cavity with fixed baffle

“…The findings showed an inverse relationship between $$N{u}_{\mathrm{avg}}$$ and Ri . Non‐Newtonian mixed convective nanofluid flow of Al 2 O 3 –H 2 O in an enclosure driven by lid whose walls were exposed to different temperature boundary conditions was analyzed by Nazari and Akbari 47 . The simulation employed the finite volume scheme using different parameters which includes Ri $$({10}^{-2}\le {Ra}\le {10}^{2})$$, nanoparticle volume percentage $$(0\le \varnothing \le 0.04)$$.…”

“…Non-Newtonian mixed convective nanofluid flow of Al 2 O 3 -H 2 O in an enclosure driven by lid whose walls were exposed to different temperature boundary conditions was analyzed by Nazari and Akbari. 47 The simulation employed the finite volume scheme using different parameters which includes Ri ≤ ≤ Ra (10 10 )…”

Numerical investigation of natural convection of a non‐Newtonian nanofluid in an F‐shaped porous cavity

“…Nevertheless, he generally showed that the heat transfer decreases with the increase in the index (), especially at Ra = . Nazari and Akbari 23 also used a lid‐driven cavity filled by a non‐Newtonian nanofluid to investigate mixed convection by using the FVM. Nazari and Akbari showed that the increase in nanoparticle volume fraction ( ϕ ), at natural convection, has no noticeable influences on average Nusselt numbers ( Nu ave ) at Rayleigh number ( Ra ) < 10.…”