| dc.description.abstract | This dissertation presents a numerical simulation of three-dimensional flow and
heat transfer in a channel with a backward-facing step. Flow was considered to be steady,
incompressible, and laminar. The flow medium was treated to be radiatively
participating. Governing momentum equations, energy equation, and the radiative
equation were solved by a finite volume method. Extensive validation studies were
carried out. As part of the validation study, three-dimensional combined convection and
radiation in a rectangular channel without a backward-facing step was studied. The
SIMPLE algorithm was used to link pressure and velocity fields. The combined
convective-radiative heat transfer were studied by varying three parameters, i.e. optical
thickness ( H τ =0.1, 0.2, and 0.4) and scattering albedo ( ω=0, 0.25, 0.5, 0.75 and 1).
Variation of thermophysical properties with temperature was considered in this study. In
this work consideration was given only to cooling. Effects of those radiative parameters
on velocity, bulk temperature, and Nusselt number are presented in detail. The fluid with
a hot inlet compared to a cold wall was cooled in a relatively short distance from the channel inlet because of the radiation effect. The thermal penetration decreased with a
decrease in optical thickness and an increase in scattering albedo. Thermal penetration
increased with increasing optical thickness and decreasing scattering albedo. The
reattachment length varied with temperature due to variation of thermophysical
properties with temperature. | en |
