Stability analysis of mixed convection in a porous horizontal channel filled with a Newtonian Al2O3/Water nanofluid in presence of magnetic field and thermal radiation

This paper investigates a stability analysis of mixed convection of Al2O3/Water nanofluid in a horizontal porous channel heated from below and cooled from above. Certain effects such as magnetic field and thermal radiation are taken into consideration. The permeability of the porous medium is described by Darcy's model. Starting from the Navier-Stokes equations to which the energy and Maxwell equations are coupled and under the assumption of an analysis in normal mode, a system of differential equations with eigenvalues governing the stability of the flow is derived and solved numerically by the spectral collocation method. The effects of the magnetic field, thermal radiation, volume fraction of nanoparticles, permeability of the medium and many other important parameters are presented and analyzed. The results show that the introduction of the nanoparticles into the base fluid increases the inertia of the fluid, which dampens the dis-turbances. Among the different geometric shapes of nanoparticles, the blade shape has a more stabilizing effect on the stability of the convective flow. It is also shown that oxide-type nano -particles have a more stabilizing effect compared to metallic-type nanoparticles on small wave number disturbances. In the case of large wave numbers, the opposite is observed. Parameters such as Prandtl number and Richardson number maintain instabilities in convective flow. On the other hand, the magnetic field, the thermal radiation and the permeability of the porous medium affect the stability of the convective flow and all have stabilizing effects, which makes it possible to control the mixed convection of nanofluid.

Automated summary

This paper investigates the stability of mixed convection of Al2O3/Water nanofluid in a horizontal porous channel with consideration of factors like magnetic field and thermal radiation. The effects of various parameters on flow stability, such as nanoparticle volume fraction and medium permeability, are analyzed. The results show that introducing nanoparticles into the base fluid increases fluid inertia and dampens disturbances. The shape of nanoparticles has an impact on flow stability, with blade-shaped particles having a more stabilizing effect. Oxide-type nanoparticles have a stronger stabilizing effect on small wave number disturbances compared to metallic-type nanoparticles.