Abstract
A similarity analysis was performed to investigate the laminar boundary-layer flow in the presence of a transverse magnetic field over a down-pointing and spinning cone with mixed thermal boundary conditions. Boundary layer velocity and temperature profiles were determined numerically for various values of the magnetic and spin parameters and the Prandtl number. The spin of the cone compresses the velocity profiles towards the surface by inducing an upward flow and decreases the surface temperature. The magnetic field suppresses the velocity profiles and increases the surface temperature. A transformation relating the similarity solutions of the boundary-layer velocity and temperature profiles associated with different values of the mixed thermal boundary condition parameter was obtained.
Similar content being viewed by others
Abbreviations
- B :
-
Magnetic field strength
- F :
-
Boundary layer stream function
- G :
-
Boundary layer rotational velocity
- g :
-
Gravitational acceleration
- Gr :
-
Grashof number
- H :
-
Boundary layer temperature
- L :
-
Characteristic length
- M :
-
Magnetic parameter
- m :
-
Transformation scale for the magnetic parameter
- Pr :
-
Prandtl number
- r :
-
Local radius of the cone
- Re :
-
Reynolds number
- T :
-
Temperature
- U :
-
Reference velocity
- u :
-
Velocity component in the x direction
- v :
-
Velocity component in the y direction
- w :
-
Velocity component in the θ direction
- x :
-
Coordinate measured along the surface
- y :
-
Coordinate normal to the surface
- α :
-
Thermal diffusivity of the fluid
- β :
-
Coefficient of thermal expansion of the fluid
- Γ :
-
Transformation scale for the temperature
- Δ :
-
Transformation scale for the stream function
- δ :
-
Transformation scale for the normal coordinate
- ε :
-
Mixed thermal boundary condition
- η :
-
Boundary layer normal variable
- Θ :
-
Dimensionless temperature ratio
- Λ :
-
Magnetic field function
- κ :
-
Transformation scale for the spin parameter
- λ :
-
Spin parameter
- ν :
-
Kinematic viscosity of the fluid
- Ω :
-
Angular speed of the cone
- ρ :
-
Density of the fluid
- φ :
-
Vertex half angle
- θ :
-
Angular coordinate
- σ :
-
Electrical conductivity of the fluid
- ψ :
-
Dimensionless stream function
- *:
-
Dimensional variable
- r :
-
Reference value
- o :
-
Ambient value
References
Ece MC (2005) Free-convection flow about a wedge under mixed thermal boundary conditions and a magnetic field. Heat Mass Transf 41:291–297
Ece MC (2005) Free-convection flow about a cone under mixed thermal boundary conditions and a magnetic field. Appl Math Model 29:1121–1134
Ozturk A, Ece MC (1995) Unsteady forced convection heat transfer from a translating and spinning body. Trans ASME J Energy Resour Technol 117:318–323
Ozturk A, Ece MC (1999) Buoyancy effects on unsteady laminar and rotational symmetric boundary layer. Trans Can Soc Mech Eng 23:397–434
Bayram M, Ece MC (2002) Unsteady laminar boundary layer flow over a spinning body in free convection. Trans Can Soc Mech Eng 26:121–135
Ozturk A (2005) Unsteady laminar mixed convection about a spinning sphere with a magnetic field. Heat Mass Transf 41:864–874
Takhar HS, Nath G (2000) Self similar solution of the unsteady flow in the stagnation point region of a rotating sphere with a magnetic field. Heat Mass Transf 36:89–96
Takhar HS, Chamkha AJ, Nath G (2001) Unsteady laminar MHD flow and heat transfer in the stagnation region of an impulsively spinning and translating sphere in the presence of buoyancy forces. Heat Mass Transf 37:397–402
Takhar HS, Singh AK, Nath G (2002) Unsteady MHD flow and heat transfer on a rotating disk in an ambient fluid. Int J Therm Sci 42:147–155
Takhar HS, Chamkha AJ, Nath G (2003) Unsteady mixed convection flow from a rotating vertical cone with magnetic field. Heat Mass Transf 39:297–304
Roy S, Takhar HS, Nath G (2004) Unsteady MHD flow on a rotating cone in a rotating fluid. Meccanica 39:271–283
Chamkha AJ, Al-Mudhaf A (2005) Unsteady heat and mass transfer from a rotating vertical cone with a magnetic field and heat generation or absorption effects. Int J Therm Sci 44:267–276
Abo-Eldahab EM, El Aziz MA (2004) Hall current and ohmic heating effects on mixed convection boundary layer flow of a micropolar fluid from a rotating cone with power-law variation in surface temperature. Int Commun Heat Mass Transf 31:751–762
Ozturk A (1995) Development of the thermal boundary layer over a translating and spinning rotational symmetric body. PhD thesis, Yıldız Technical University, İstanbul, Turkey
Hoffman JD (1992) Numerical methods for engineers and scientists. McGraw Hill, New York
Ramanaiah G, Malarvizhi G (1992) Free convection about a wedge and a cone subjected to mixed thermal boundary conditions. Acta Mech 93(1–4):119–123
Gorla RSR, Nakamura S (1995) Mixed convection of a micropolar fluid from a rotating cone. Int J Heat Fluid Flow 16:69–73
Ece MC (2001) Free convection to power-law fluids from a vertical cone of variable surface temperature. Int J Energy Res 25(4):1221–1232
Ece MC (1999–2000) Free convection laminar boundary-layer flow of a power-law fluid about a vertical cone of variable surface heat flux. J Theor Appl Fluid Mech 2(1):1–11
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Ece, M.C., Öztürk, A. Boundary-layer flow about a vertical spinning cone under mixed thermal boundary conditions and a magnetic field. Meccanica 44, 177–187 (2009). https://doi.org/10.1007/s11012-008-9159-x
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11012-008-9159-x