TY  - EJOU
AU  - Khatyr, Rabha 
AU  - Naciri, Jaafar Khalid 

TI  - EFFECTS OF VISCOUS DISSIPATION AND AXIAL HEAT  CONDUCTION ON FORCED CONVECTION DUCT FLOW OF  HERSCHEL-BULKLEY FLUID WITH UNIFORM WALL TEMPERATURE  OR CONVECTIVE BOUNDARY CONDITIONS
T2  - Frontiers in Heat and Mass Transfer

PY  - 2022
VL  - 19
IS  - 1
SN  - 2151-8629

AB  - The aim is to study the asymptotic behavior of the temperature field for the laminar forced convection of a Herschel-Bulkley fluid flowing in a circular 
duct considering both viscous dissipation and axial heat conduction. The asymptotic bulk and mixing Nusselt numbers and the asymptotic bulk and 
mixing temperature distribution are evaluated analytically in the cases of uniform wall temperature and convection with an external isothermal fluid. 
In particular, it has been proved that the fully developed value of Nusselt number for convective boundary conditions is independent of the Biot number 
and is equal to the value of fully developed Nusselt number for uniform wall temperature. The analytical results obtained in the fairly general case of 
Herschel-Bulkley fluid, which considers both the existence of a yield shear-stress as well as a variable viscosity as a function of shear, are compared 
with solutions available for the simpler cases of Newtonian fluid and some non-Newtonian fluids with viscous dissipation and/or axial heat conduction 
taken into account.
KW  - <i>Laminar Forced Convection
KW  -  Viscous Dissipation
KW  -  Axial Heat Conduction
KW  -  Asymptotic Behavior
KW  -  Analytical Methods.</i>

DO  - 10.5098/hmt.19.23