INFLUENCE OF THE REFERENCE STATE IN THE SLW MODEL FOR FLOWS WITH STRONG TEMPERATURE AND PRESSURE GRADIENTS

摘要

Radiative heat transfer in a real case showing high temperature and pressure gradients is calculated with a global model (SLW) with and without re-scaling of the absorption coefficients to the local conditions. Changes in radiative heat flux to the walls for different reference temperatures and reference pressures are studied. Changes in reference pressure are shown to have a small influence compared to changes in reference temperature, except if the pressure is less than 10 bars for a high-pressure case. The use of the scaling does decrease the dependency on the reference condition. The highest differences obtained with strong reference temperature or pressure changes (800K and 30.10~5 Pa) are of about 15% and 7% respectively. For smaller changes, an uncertainty of 5% could be assumed.