Towards eddy resolving CFD in room ventilation: A comparative precursor study of LES and SAS models

¹ FH Münster University of Applied Sciences, Department for Energy, Building Services and Environmental Engineering, Stegerwaldstraße 39, 48565 Steinfurt, Germany
² Technical University Darmstadt, Faculty of Mechanical Engineering, Institute for Fluid Mechanics and Aerodynamics, Peter-Grünberg-Straße 10, 64287 Darmstadt, Germany
³ Ruhr-University Bochum, Department of Mechanical Engineering, Chair of Hydraulic Fluid Machinery, Universitätsstraße 150, 44801 Bochum, Germany

Abstract

The building sector’s increasing focus on energy conservation, driven by climate change concerns, necessitates innovations in construction practices. In Germany, where the building sector contributes significantly to the overall energy consumption, reducing energy losses through well-insulated, airtight constructions has emerged as a viable option. However, this approach introduces challenges, such as potential mould growth due to inadequate moisture removal. Ventilation systems, especially those employing unsteady ventilation concepts, are gaining prominence for their potential to enhance air quality, comfort, and energy efficiency. This study employs computational fluid dynamics (CFD), specifically Large Eddy Simulation (LES) and Scale Adaptive Simulation (SAS), to analyse and compare the precursor simulations for eddy-resolving techniques. The LES method directly resolves large turbulent structures, utilizing the Wall-Adapting Local Eddy-viscosity (WALE) model for improved near-wall behaviour. Meanwhile, SAS combines elements of LES and Reynolds Average Navier-Stokes (RANS), offering a computationally efficient approach to capture turbulent structures. A Reynolds scaled model room with PIV measurements provides experimental validation data. Preliminary precursor results indicate first good results with both models. In the next step, the model room, investigated with PIV, will be simulated with both approaches with constant boundary conditions.