Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 3

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: Oldroydian viscoelastic fluid

Sortuj według:

Ogranicz wyniki do:

On the onset of thermal convection in a layer of Oldroydian visco-elastic fluid saturated by Brinkman–Darcy porous medium

Chand R.

Studia Geotechnica et Mechanica

2015

Vol. 37, nr 4

3--10

Thermal instability in a horizontal layer of Oldroydian visco-elastic fluid in a porous medium is investigated. For porous medium the Brinkman–Darcy model is considered. A linear stability analysis based upon perturbation method and normal mode technique is used to find solution of the fluid layer confined between two free-free boundaries. The onset criterion for stationary and oscillatory convection is derived analytically. The influence of the Brinkman–Darcy, Prandtl–Darcy number, stress relaxation parameter on the stationary and oscillatory convection is studied both analytically and graphically. The sufficient condition for the validity of PES has also been derived.

Effect of magnetic field on thermal instability of Oldroydian viscoelastic rotating fluid in porous medium

Thakur R. C., Rana G. C.

International Journal of Applied Mechanics and Engineering

2013

Vol. 18, no. 2

555--569

In this paper, we investigate the effect of a vertical magnetic field on thermal instability of an Oldroydian visco-elastic rotating fluid in a porous medium. By applying the normal mode analysis method, the dispersion relation governing the effects of rotation, magnetic field and medium permeability is derived and solved analytically and numerically. For the case of stationary convection, the Oldroydian viscoelastic fluid behaves like an ordinary Newtonian fluid and it is observed that rotation has a stabilizing effect while the magnetic field and medium permeability have a stabilizing/destabilizing effect under certain conditions on thermal instability of the Oldroydian viscoelastic fluid in a porous medium. The oscillatory modes are introduced due to the presence of rotation, the magnetic field and gravity field. It is also observed that the ‘principle of exchange of stability’ is invalid in the presence of rotation and the magnetic field.

Hall current effect on thermosolutal instability in a viscoelastic fluid flowing in a porous medium

Singh M.

International Journal of Applied Mechanics and Engineering

2011

Vol. 16, no 1

69-82

The thermosolutal instability in a layer of an electrically conducting Oldroydian viscoelastic fluid in a porous medium is studied to include the effect of Hall current. For the case of stationary convection, the Oldroydian fluid behaves like an ordinary Newtonian fluid. The magnetic field and the stable solute gradient are found to have stabilizing effects whereas Hall currents and medium permeability are found to have destabilizing effects on the system. Graphs are plotted by giving numerical values to the parameters to depict the stability characteristics. The sufficient conditions for the non-existence of overstability are also obtained.