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Kango, S. K.
- Triple-Diffusive Convection in a Micropolar Rotating Ferrofluid
Authors
1 Government College, Barsar (Hamirpur)-174305, Himachal Pradesh, IN
2 Government College, Darang (Mandi), Himachal Pradesh, IN
3 Government College, Sujanpur (Hamirpur), Himachal Pradesh, IN
Source
International Journal of Technology, Vol 6, No 2 (2016), Pagination: 123-132Abstract
This paper deals with the theoretical investigation of the triple-diffusive convection in a micropolar ferrofluid layer heated and soluted below subjected to a transverse uniform magnetic field in the presence of uniform vertical rotation. For a flat fluid layer contained between two free boundaries, an exact solution is obtained. A linear stability analysis theory and normal mode analysis method have been carried out to study the onset convection. The influence of various parameters like rotation, solute gradients, and micropolar parameters (i.e. coupling parameter, spin diffusion parameter and micropolar heat conduction parameter) has been analyzed on the onset of stationary convection. The critical magnetic thermal Rayleigh number for the onset of instability is also determined numerically for sufficiently large value of buoyancy magnetization parameter M1(ratio of the magnetic to gravitational forces). The principle of exchange of stabilities is found to hold true for the micropolar fluid heated from below in the absence of micropolar viscous effect, microinertia, solute gradient and rotation. The oscillatory modes are introduced due to the presence of the micropolar viscous effect, microinertia, solute gradient and rotation, which were non-existent in their absence.Keywords
Triple-Diffusive Convection, Micropolar Ferrofluid, Solute Gradient, Vertical Magnetic Field, Rotation, Magnetization.
- Triple-Diffusive Convection in a Layer of Viscoelastic Nanofluid
Authors
1 Department of Mathematics, NSCBM Govt. College, Hamirpur-177005, Himachal Pradesh, IN
2 Department of Mathematics, Govt. College, Nurpur-177 103, District Kangra, Himachal Pradesh, IN
3 Department of Mathematics, Govt. College, Barsar, District Hamirpur, Himachal Pradesh, IN
Source
International Journal of Technology, Vol 6, No 2 (2016), Pagination: 71-80Abstract
Triple-diffusive convection in a horizontal layer of nanofluid heated from below and salted from above and below is considered. The Rivlin-Ericksen type fluid model is used to describe the rheological behavior of viscoelastic nanofluid. The effects of thermophoresis and Brownian diffusion parameters are also introduced through Buongiorno model in the governing equations. By using linear stability analysis and normal modes analysis method, the dispersion relation accounting for the effect of various parameters is derived. The influences of solute-Rayleigh number, analogous solute-Rayleigh number, thermo-nanofluid Lewis number, modified diffusivity ratio and nanoparticle Rayleigh number on the stability of stationary convection are presented analytically and graphically.Keywords
Convection, Triple-Diffusive, Nanofluid, Nanoparticles, Rayleigh Number.- Thermal Instability of Ferromagnetic Fluid in the Presence of Hall Effect and Suspended Particle under Varying Gravity Field
Authors
1 Department of Mathematics, Govt. College, Haripur (Manali) (H,P.) – 175136, IN
2 Department of Mathematics, Jwalaji Degree College, Jwalamukhi (H,P.) – 176031, IN
Source
International Journal of Technology, Vol 4, No 1 (2014), Pagination: 1-9Abstract
In this paper we consider theoretical investigation of the effect hall current and the suspended particle under varying gravity field on the thermal instability of ferromagnetic fluid heated from below. For a fluid layer between two free boundaries and exact solution is obtained using a linearized stability theory and normal mode analysis. A dispersion relation governing the effect of hall current and the suspended particle is obtained. For the case of stationary convection it is found that the magnetic field has a stabilizing the system when the gravity is increasing upward i.e. (λ>0), where as the hall current and suspended particle are found to have the destabilizing effect on the system when the gravity is increasing upward i.e. (λ>0). The critical Rayleigh numbers and wave numbers of the associated disturbances for the onset of stability as stationary convection are obtained. The principle of exchange of stabilities is not valid for the problem under consideration, whereas in the absence of Hall currents hence magnetic field, it is valid under certain conditions.
Keywords
Hall Currents, Suspended Particles, Ferromagnetic Fluid and Varying Gravity Field.- Effect of Hall Currents on Thermosolutal Instability in Non-Newtonian Fluid in Non-Porous Medium
Authors
1 Jawaharlal Nehru Government College, Haripur (Manali), HP – 175136, IN
2 Vallabh Government PG College, Mandi, Himachal Pradesh, IN
Source
International Journal of Technology, Vol 4, No 1 (2014), Pagination: 240-247Abstract
The thermosolutal instability of a layer of Rivlin-Ericksen elastico-viscous fluid (a Non-Newtonian fluid) is considered in the presence of uniform horizontal magnetic field to include the Hall currents in non-porous medium. For the case of stationary convection, the Hall currents hasten the onset of convection, the magnetic field postpones the onset of convection, whereas the kinematic viscoelasticity has no effect on the onset of convection. The Hall currents, kinematic viscoelasticity, magnetic field and the solute parameter introduce oscillatory modes in the system, which were non-existent in their absence. The case of overstability is also considered wherein the sufficient conditions for the non-existence of overstability are obtained. The results are also shown graphically.