Flow of a generalized second grade fluid between heated plates
Summary
We examine the fully developed flow of a generalized fluid of second grade between heated parallel plates, due to a pressure gradient along the plate. The constant coefficient of shear viscosity of a fluid of second grade is replaced by a shear dependent viscosity with an exponentm. If the normal stress coefficients are set equal to zero, this model reduces to the standard power-law model. We obtain the solution for the case when the temperature changes only in the direction normal to the plates for the two most commonly used viscosity models, i.e. (i) when the viscosity does not depend on temperature, and (ii) when the viscosity is an exponentially decaying function of temperature.
Keywords
Viscosity Fluid Dynamics Pressure Gradient Normal Stress Shear ViscosityList of symbols
Alphanumeric
- A1,A2
Kinematical tensor
- b
Body force
- C
Dimensionless parameter related to the pressure gradient
- h
Separation between the plates
- L
Velocity gradient
- m
Power-law index
- M
Constant appearing in the Reynolds viscosity model
- p
Pressure field
- \(\hat p,\hat \bar p\)
Modified pressure field
- q
Heat flux vector
- r
Radiant heating
- T
Cauchy's stress tensor
- l
Unit tensor
- v
Velocity vector
- V
Characteristic velocity
- x
Axis along the plate
- y
Axis perpendicular to the plate
Greek
- α1, α2
Normal stress coefficient
- ε
Specific internal energy
- Γ
Dimensionless parameter related to the viscous dissipation
- ϕ
Conservative body force field
- η
Specific entropy
- κ
Thermal conductivity
- μ
Coefficient of viscosity
- μ0
Reference viscosity
- Π
Second invariant of the stretching tensor
- θ
Temperature
- θ1
Temperature of the lower plate
- θ2
Temperature of the upper plate
- ϱ
Density
- ψ
Specific Helmholtz free energy
Operators
- div
Divergence
- grad
Gradient
- tr
Trace
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