RESUMO

This paper deals with the theoretical investigation of the effect of dust particles on the marginal stability of a ferrofluid layer with internal angular momentum heated from below subjected to a transverse uniform magnetic field. For a flat fluid layer contained between two free boundaries, an exact solution is obtained using a linear stability analysis theory and normal mode analysis method. For the case of stationary convection, the effect of various parameters like dust particles, magnetization, coupling parameter, spin diffusion parameter, and heat conduction parameter has been analyzed. The critical magnetic thermal Rayleigh number for the onset of instability is also determined numerically for sufficiently large values of the magnetic parameter M1 and results are depicted graphically. It is observed that the critical magnetic thermal Rayleigh number is reduced because the heat capacity of clean fluid is supplemented by that of dust particles. The principle of exchange of stabilities is found to hold true for the ferrofluid with internal angular momentum in the absence of dust particles, coupling parameter, and microinertia. The oscillatory modes are introduced due to the presence of dust particles, coupling parameter, and microinertia, which were nonexistent in their absence. The sufficient conditions for the nonexistence of overstability are also obtained.