Numerical simulation of conjugate heat transfer and surface radiative heat transfer using the P 1 thermal radiation model: Parametric study in benchmark cases.
Journal article, 2016
A parametric investigation of radiative heat transfer is carried out, including the effects of conjugate heat
transfer between fluid and solid media. The thermal radiation is simulated using the P1 -model. The
numerical model and the thermal coupling strategy, suitable for a transient solver, is described. Such
numerical coupling requires that the radiative equation is solved several times at each iteration; hence,
the computational cost of the radiative model is a crucial issue. The P1 -model is adopted because of its
particularly fast computation. First, a collection of benchmark cases is presented and used to carefully
validate the radiation model against literature results and to analyse the model prediction limits.
Despite the simplicity of the model, it satisfactorily reproduces the thermal radiation effects. Some lack
of accuracy is identified in particular cases. Second, a number of benchmark cases are described and
adopted to investigate fluid–solid thermal interaction in the presence of radiation. Three cases are
designed, to couple radiation with: pure conduction, conduction and forced convection, conduction
and natural convection. In all the cases, the surface radiative heat transfer strongly influences the system
thermodynamics, leading to a significant increase of the fluid–solid interface temperature. The main non-
dimensional numbers, related to the mutual influence of the different heat transfer modes, are intro-
duced and employed in the analyses. A new conduction-radiation parameter is derived in order to study
the conductive boundary layer in absence of convective heat transfer.
Surface radiative heat transfer
Conjugate heat transfer