Showing papers by "Kumbakonam R. Rajagopal published in 1985"

Flow of a non-Newtonian fluid between heated parallel plates

Abstract: The flow of a fluid of grade three between heated parallel plates is examined for two cases. In the first instance we postulate constant heat flux at the walls and via a similarity transformation calculate the Nusselt number as a function of both Γ, the parameter controlling viscous dissipation, and Λ, the non-Newtonian parameter. In the second case we restrict the temperature to change only normal to the plates; solutions in this case are obtained for two temperature-viscosity models, μ = μ ( θ ).

Natural convection flow of a non-Newtonian fluid between two vertical flat plates

Abstract: The natural convection of a homogeneous incompressible fluid of grade three is investigated between two infinite parallel vertical plates. The effect of the non-Newtonian nature of fluid on the skin friction and heat transfer are studied.

Asymmetric flow above a rotating disk

Abstract: In this paper we generalize the von Karman solution for flow above a single rotating disk, to include non-axisymmetric solutions. These solutions contain an arbitrary parameter; for zero value of the parameter the asymmetric flow degenerates into the classical von Karman solution. Thus the classical solution is never isolated when considered within the scope of the full Navier–Stokes equations; there are asymmetric solutions in every neighbourhood of the von Karman solution. Calculations are reported here for s = 0, 0.02 and 0.06, where s represents the ratio of angular velocity of the fluid at infinity to the angular velocity of the disk. A subset of the solutions obtained here corresponds to flow induced by the rotation of a disk when the latter is placed in a fluid that is moving with a constant uniform velocity.

Flow of viscoelastic fluids between plates rotating about distinct axes

Abstract: We discuss the flow of BKZ fluids in an orthogonal rheometer. Some analytical results are proved, and numerical solutions are obtained for the Currie model. These solutions show a boundary layer behavior at high Reynolds numbers and the possibility of discontinuous solutions or nonexistence at high Weissenberg numbers.

A universal relation in torsion for a mixture of solid and fluid

Abstract: In his study of combined finite extension and torsion of a nonlinear, incompressible, isotropic elastic circular cylinder, Rivlin [1] established a relation for the torsional stiffness which depends only on the axial force, the axial extension ratio and the radius of the undeformed cylinder, in the case of small twist. The relationship did not depend on the structure of the stored energy function and is hence a “universal relation”. In this paper, we extend Rivlin's result to the case of combined extension and torsion of a cylindrical mixture of a nonlinear elastic solid and fluid.

A boundary integral equation method for the study of some laminar forced convection problems

Abstract: A boundary integral method ideally suited for the study of forced convection problems involving laminar fully developed flows in channels of arbitrary cross sections is discussed. After developing the appropriate boundary integral equations and the numerical procedure for arbitrary cross sections, results based on this method are compared with those available for circular, elliptical, rectangular, and triangular cross sections.