Abstract
The Hall effect on the unsteady hydromagnetic free-convection resulting from the combined effects of thermal and mass diffusion of an electrical-conducting liquid through a porous medium past an infinite vertical porous plate in a rotating system have been analysed. The expressions for the mean velocity, mean skin friction, and mean rate of heat transfer on the plate are derived. The effects of magnetic parameterM, Hall parameterm, Ekman numberE, and permeability parameterK * on the flow field are discussed with the help of graphs and tables.
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Abbreviations
- C p :
-
specific heat at constant pressure
- C′:
-
the species concentration inside the boundary layer
- C ′w :
-
the species concentration at porous plate
- C ′∞ :
-
the species concentration of the fluid at infinite
- C :
-
dimensionless species concentration
- D :
-
chemical molecular diffusivity
- E :
-
Ekman number
- Ec:
-
Eckert number
- g :
-
acceleration due to gravity
- Gr:
-
Grashof number
- Gm:
-
modified Grashof number
- H 0 :
-
applied magnetic field
- (J x′, Jy′, Jz′):
-
components of current density
- M :
-
magnetic parameter
- m :
-
Hall parameter
- P :
-
Prandtl number
- q m :
-
mean rate of heat transfer
- Sc:
-
Schmidt number
- t′ :
-
time
- t :
-
dimensionless time
- T′ :
-
temperature of fluid
- T ′w :
-
temperature of the plate
- T ′∞ :
-
temperature of fluid at infinite
- T :
-
dimensionless temperature
- (u′, v′, w′):
-
components of the velocityq′
- w 0 :
-
suction velocity
- (x′, y′, z′):
-
Cartesian coordinates
- z :
-
dimensionless coordinate normal to the plate
- β:
-
coefficient of volume expansion
- β*:
-
coefficient of thermal expansion with concentration
- ω′:
-
frequency
- ω:
-
dimensionless frequency
- k :
-
thermal conductivity
- K * :
-
permeability parameter
- ν:
-
dinematic viscosity
- ρ:
-
density of the fluid in the boundary layer
- μ:
-
coefficient of viscosity
- μe :
-
magnetic permeability
- Ω:
-
angular velocity
- σ:
-
electrical conductivity of the fluid
- τm :
-
mean skin friction
- τmn :
-
mean skin friction in the direction ofx
- τmv :
-
mean skin friction in the direction ofy
References
Agrawal, H. L., Ram, P. C., and Singh, V.: 1983a,Astrophys. Space Sci. 91, 445.
Agrawal, H. L., Ram, P. C., and Singh, V.: 1983b,Astrophys. Space Sci. 94, 383.
Georgantopoulos, G. A., Koullias, J., Goudas, C. L., and Courogenis, C.: 1981,Astrophys. Space Sci. 74, 357.
Raptis, A.: 1983a,Int. J. Eng. Sci. 21, 345.
Raptis, A.: 1983b,Energy Research 7, 385.
Raptis, A., Perdikis, C. P., and Tzivanidis, G. J.: 1981,Acta Phys. Acad. Sci. Hungaricae 50, 373.
Soundalgekar, V. M. and Pop, I.: 1979,Acta Phys. Acad. Sci. Hungaricae 47, 313.
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Singh, T.P., Agrawal, A.K., Agrawal, H.L. et al. Unsteady free-convective flow and mass transfer in a rotating porous medium with Hall current, I. Astrophys Space Sci 181, 171–181 (1991). https://doi.org/10.1007/BF00639086
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DOI: https://doi.org/10.1007/BF00639086