On the Feasibility of CFD for Transient Air Flow Simulations in Buildings

The rapidly growing computational capacity hasmade CFD simulations an attractive tool for indoorenvironmental applications. The ability of CFD toperform transient simulations could be incorporatedinto model predictive control systems for buildings inorder to correctly reproduce prompt disturbances inthe air field, such as opening doors and windows orchanges in occupants behaviour. In this work, twocharacteristic configurations which mimic typical air-flow patterns inside buildings are studied using dif-ferent grid sizes and turbulence models. Case one isa tall turbulent differentially heated cavity and casetwo is the turbulent mixed convection in a ventilatedsquare cavity. The Spearman’s rank correlation coef-ficient for transient simulations is compared againstcomputational time for different CFD approaches,and the possibility of performing real-time simula-tions is evaluated. Among different turbulence mod-els studied, the no-model approach with symmetrypreserving discretization has shown the best overallperformance in terms of computational cost and ac-curacy of the results.