Validation of DNS techniques for dynamic combined indoor air and constructions simulations using an experimental scale model

Abstract: This paper presents a study on the application of Direct Numerical Solving (DNS) techniques using an experimental scale model. The COMSOL Multiphysics software is promising in solving dynamic heat and air transport. However, the authors were not able to reproduce in 3D the experimental results using DNS, default grids and 32 GB of memory. This could mean that the current experimental scale model, with dimensions 0.64m x 0.45m x 0.39m, is practically already too big. This is also indicated by the fact that more reliable simulation results were obtained if each length scale was reduced with a factor 10 smaller than the current situation. Nevertheless, the experiments can be very useful as benchmark for CFD codes.