Sensitivity analysis of predicted convective heat transfer at internal building surfaces to diffuser modelling in CFD

As a cost-effective alternative to experiments, computational fluid dynamics (CFD) can provide new insight in airflow patterns and the related convective heat transfer (CHT). However, together with the governing equations, the description of the boundary conditions determines for a greater part the reliability and the accuracy of CFD simulations. In this study the sensitivity of the predicted CHT to diffuser modelling is studied. Numerical simulations of a modified version of test case E.2 of the IEA Annex 20-project are performed. The results show a strong influence of the applied diffuser model on the predicted CHT.