Natural Convection and Entropy Generation in a Nanofluid-Filled Semi-Circular Enclosure with Heat Flux Source

Abstract

The effect of presence of nanoparticles on natural convection and entropy generation in a semi-circular enclosure with present heat flux is investigated numerically in the present work. The enclosure is filled with nanofluids (Cu-water). The heat flux is supplied partly in the center of the base wall, and the other parts of base wall of the enclosure are assumed adiabatic. The center of the circular arc (-45°≤γ≤+45°) is assumed at constant cold temperature and the other parts of the circular arc are adiabatic. Finite element method based on the variational formulation is employed to solve momentum and energy as well as post-processing streamfunctions. The results are based on visualization of isotherms, streamfunction and entropy generation. Comparison with previously published work is performed and the results are found to be in a good agreement. The influence of pertinent parameters such as Rayleigh number (10 4 ≤Ra≤10 7 ) and solid volume fraction of nanoparticles (0≤Φ≤0.15 step 0.05) on the flow, temperature, and entropy generation are examined in the present paper. The results show that the heat transfer rate increases with an increase of the Rayleigh number and the nanoparticles volume fraction. The system irreversibility increases as nanoparticles fraction increase.

Thermal analysis of nanofluid saturated in a semicircular hot enclosure cooled by a rotating half‐immersed active circular cylinder subject to a convective condition

“…The rate of heat transfer process can be described using the local Nusselt number of a heating element (i.e., length of the enclosure) as follows 2,5,23 :…”

Natural convection heat transfer for adiabatic circular cylinder inside trapezoidal enclosure filled with nanofluid superposed porous-nanofluid layer

“…Results showed that the addition of Ag-water nanofluid clearly increased the convection, and the inclination angle of the cavity variation had an important effect on heat transfer rate. The effect of nanoparticles on natural convection and entropy generation in a semicircular enclosure filled with nanofluid (Cu water) was presented in Al-Zamily and Amin [18]. Results showed that the heat transfer rate increased with an increase in Rayleigh number and nanoparticle volume fraction.…”

Entropy generation analysis of mixed convection with considering magnetohydrodynamic effects in an open C-shaped cavity

“…A parametric analysis and entropy generation minimization of unsteady MHD flow over a stretch rotating disk was completed by Rashidi et al [34], using an artificial neural network and particle swarm optimization algorithm. Al-Zamily and Ruhul Amin [35] investigated natural convection and entropy generation in nanofluid-filled semi-circular cavity with a heat flux source. Chamkha et al [36] studied the entropy generation and natural convection of CuO-water nanofluid in a C-shaped cavity under magnetic field.…”