Numerical Investigation of MHD Double-Diffusive Flow and Entropy Generation in a Corrugated Enclosure with a Star-Shaped Inner Body

Abstract

A finite element-based numerical study is conducted on MHD double-diffusive natural convection and entropy generation in an inclined, corrugated porous enclosure with a star-shaped inner body. The role of various parameters had been selected such as enclosure's angle $\left(\Phi =0^{°},{15}^{°},{30}^{°},{45}^{°}\right)$ along with various Rayleigh number$\left({10}^4\le \mathrm{Ra}\le {10}^6\right)$, buoyancy ratio $\left(N=0,2,4,6,8,10\right)$ and Lewis number $\left(\mathrm{Le}=\mathrm{0.1,1},10\right)$ while Hartmann and Darcy numbers had been kept constant at $\left(\mathrm{Ha}=20,\mathrm{Da}=0.001\right)$. The role of corrugated length had been tested as well with ranging$\left(L=0.1,0.15,0.2\right)$. The results had been presented in terms of streamlines, isotherms with four different types of entropy due to fluid friction, heat transfer, double diffusive and magnetic field. Additionally, the variation of Nusselt number, Sherwood number and Bejan number had been studied as well. The major results show a small decrease in heat transfer, approximately 2.5%, with the increment of the enclosure's angle from $\Phi =0^{°}$ to $\Phi ={45}^{°}$. The mass transfer decreased by 8. under the same enclosure angles values. It is important to note that entropy generation decreases by 10  with an increase in the enclosure's angle. The analysis also revealed that a longer corrugated length improved heat and mass transfer performance; however, this enhancement was accompanied by a rise in entropy generation. Lastly, the Bejan number is reduced as the corrugated length increases.