The flow pattern at low Reynolds number in the neighborhood of a sudden contraction is very sensitive to the mechanical behavior of the flowing fluid. A large extensional viscosity leads to vortex enhancement in the corner region of the flow of a non-Newtonian fluid in such geometry. In the corresponding flow of a Newtonian fluid, these vortices are much weaker and smaller. Moreover, the extension-thickening behavior of most polymeric liquids leads to higher viscous dissipation effects in the predominantly extensional flow, as compared to typical shear flows. The flow and temperature fields for this problem have been obtained from numerical integration of the conservation equations, aiming at applications related to extrusion and capillary rheometry of polymeric liquids. To account for the flow dependence of the stress tensor, a generalized Newtonian model has been employed, including the dependence of the viscosity function on both the second and the third invariants of the rate-of-deformation tensor. The numerical solutions have been obtained via a finite-volume method. The case of a 4:1 circular contraction was investigated, with uniform temperature distribution at the solid boundaries. The fluid inlet temperature is equal to the temperature at the walls, so that thermal gradients in the fluid are due to viscous dissipation effects only. Comparisons between Newtonian and non-Newtonian results showed that the combined effect of viscous dissipation and enhancement of vortex activity significantly affects the temperature field. The practical significance of the results is discussed for extrusion processes and capillary rheometry.
Skip Nav Destination
Article navigation
Research Papers
Heat Transfer in the Non-Newtonian Axisymmetric Flow in the Neighborhood of a Sudden Contraction
M. S. Carvalho,
M. S. Carvalho
Department of Mechanical Engineering, Pontificia Universidade Cato´lica—RJ, Rio de Janeiro, RJ 22453, Brazil
Search for other works by this author on:
P. R. Souza Mendes
P. R. Souza Mendes
Department of Mechanical Engineering, Pontificia Universidade Cato´lica—RJ, Rio de Janeiro, RJ 22453, Brazil
Search for other works by this author on:
M. S. Carvalho
Department of Mechanical Engineering, Pontificia Universidade Cato´lica—RJ, Rio de Janeiro, RJ 22453, Brazil
P. R. Souza Mendes
Department of Mechanical Engineering, Pontificia Universidade Cato´lica—RJ, Rio de Janeiro, RJ 22453, Brazil
J. Heat Transfer. Aug 1992, 114(3): 582-588 (7 pages)
Published Online: August 1, 1992
Article history
Received:
March 1, 1991
Revised:
December 1, 1991
Online:
May 23, 2008
Citation
Carvalho, M. S., and Souza Mendes, P. R. (August 1, 1992). "Heat Transfer in the Non-Newtonian Axisymmetric Flow in the Neighborhood of a Sudden Contraction." ASME. J. Heat Transfer. August 1992; 114(3): 582–588. https://doi.org/10.1115/1.2911321
Download citation file:
Get Email Alerts
Cited By
Related Articles
Non-Newtonian Flow and Heat Transfer in an Obstructed Channel With Radio-Frequency Heating
J. Heat Transfer (November,1995)
Fluid Flow and Mixed Convection Transport From a Moving Plate in Rolling and Extrusion Processes
J. Heat Transfer (August,1988)
Similarity Solution of Combined Convection Heat Transfer From a Rotating Cone or Disk to Non-Newtonian Fluids
J. Heat Transfer (November,1990)
Experimental Study of the Convective Cooling of a Heated Continuously Moving Material
J. Heat Transfer (February,1994)
Related Proceedings Papers
Related Chapters
Laminar Fluid Flow and Heat Transfer
Applications of Mathematical Heat Transfer and Fluid Flow Models in Engineering and Medicine
Plate Exchangers
Heat Exchanger Engineering Techniques
Mathematical Background
Vibrations of Linear Piezostructures