scholarly journals EFFECTS OF VISCOUS DISSIPATION AND AXIAL HEAT CONDUCTION ON FORCED CONVECTION FLOW OF HERSCHEL-BULKLEY FLUID IN CIRCULAR DUCT WITH AXIALLY VARIABLE WALL HEAT FLUX

2020 ◽  
Vol 15 ◽  
Author(s):  
Rabha Khatyr ◽  
Jaafar Khalid Naciri
Keyword(s):  
Heat Flux ◽  
Heat Conduction ◽  
Forced Convection ◽  
Viscous Dissipation ◽  
Wall Heat Flux ◽  
Convection Flow ◽  
Circular Duct ◽  
Forced Convection Flow ◽  
Axial Heat ◽  
Variable Wall

scholarly journals Viscous dissipation effect on laminar forced convection in a circular duct with adiabatic walls - preliminary numerical investigation

2018 ◽  
Vol 240 ◽  
pp. 03016
Author(s):  
Tomasz Janusz Teleszewski
Keyword(s):  
Heat Flux ◽  
Forced Convection ◽  
Viscous Dissipation ◽  
Heat Flux Density ◽  
Energy Equation ◽  
Brinkman Number ◽  
Circular Duct ◽  
Nusselt Numbers ◽  
Axial Heat ◽  
Laminar Forced Convection

In this work, an analysis of laminar forced convection in a pipe with heated and adiabatic walls for a Newtonian fluid with constant properties is performed by taking the viscous dissipation into account when the axial heat conduction in the fluid is neglected. The Nusselt number versus the Brinkmann, which is based on the total wall heat flux density, have been investigated. In order to determine the temperature field, an analytical solution describing the velocity field in the pipe was used, while the energy equation was determined by the boundary element method (BEM). The results of the calculations of Nusselt numbers as a function of the Brinkman number for different thermal insulation heights to the diameter of the circular duct were presented in the form of diagrams.

Fully Developed Laminar Forced Convection in a Circular Duct for Herschel–Bulkley Fluids With Viscous Dissipation and Axial Heat Conduction

2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Rabha Khatyr ◽  
Jaafar Khalid-Naciri ◽  
Ali Il Idrissi
Keyword(s):  
Boundary Condition ◽  
Heat Conduction ◽  
Forced Convection ◽  
Viscous Dissipation ◽  
Circular Duct ◽  
Nusselt Numbers ◽  
Asymptotic Values ◽  
Axial Heat ◽  
Laminar Forced Convection ◽  
Axial Heat Conduction

The asymptotic behavior of laminar forced convection in a circular duct for a Herschel–Bulkley fluid of constant properties is analyzed. The viscous dissipation and the axial heat conduction effects in the fluid are both considered. The asymptotic bulk and mixing temperature field, and the asymptotic values of the bulk and mixing Nusselt numbers are determined for every boundary condition, enabling a fully developed region. In particular, it is proved that whenever the wall heat flux tends to zero, the asymptotic Nusselt number is zero. The obtained results are compared to other existing solutions in the literature for Newtonian and non-Newtonian cases.

Sign in / Sign up

Export Citation Format

Share Document