Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN CD: 1-56700-226-9

ISBN Online: 1-56700-225-0

International Heat Transfer Conference 13
August, 13-18, 2006, Sydney, Australia

THERMAL-ENTRANCE-REGION HEAT TRANSFER FOR A NON-NEWTONIAN LAMINAR FLOW IN A CONCENTRIC ANNULUS WITH AN AXIALLY MOVING CORE

Get access (open in a dialog) DOI: 10.1615/IHTC13.p20.110
12 pages

Abstrakt

In this study the laminar heat transfer of non-Newtonian fluids flowing in a concentric annulus with an axially moving core is investigated by taking into account the effects of viscous dissipation and fluid axial heat conduction for constant wall temperature boundary condition, and the velocity field is obtained by applying the modified power-law model. The energy equation together with a constant temperature at upstream infinity, fully developed temperature profile at downstream infinity and the appropriate thermal boundary conditions at the inner and outer tubes is numerically solved by the finite difference method as an elliptic type problem.
The effects of the moving core velocity (as U*), rheological property (flow index, n), a geometrical factor of the annulus (inner/outer radius ratio), Brinkman number (Br) and Peclet number (Pe) on the temperature distribution and Nusselt number at the walls are discussed.
It is observed that the fluid temperature near the moving core is strongly affected by the velocity profile deformed owing to the moving core and that the Nusselt number at the moving core shows complicate behavior as functions of Br and Pe in the thermal entrance region.