Appropriate CFD Turbulence Model for Improving Indoor Air Quality of Ventilated Spaces

Abstract

Accurate assessment of air-flow in ventilated spaces is of major importance for achieving healthy and comfortable indoor environment conditions. The CFD (Computational Fluid Dynamics) technique is nowadays one of the most used approaches in order to improve the indoor air quality in ventilated environments. Nevertheless, CFD has still two main challenges: turbulence modeling and experimental validation. As a result, the objective of this study is to evaluate the performance of different turbulence models potentially appropriate for the prediction of indoor airflow. Accordingly, results obtained with 6 turbulence models (standard k-ε model, RNG k-ε model, realizable k-ε model, LRN SST k-ω model, transition SST k-ω model and low Reynolds Stress-ω model) are thoroughly validated based on detailed experimental data. The configuration taken into account in this work corresponds to isothermal and anisothermal airflows produced by mixing ventilation systems in small enclosures at low room air changes per hour. In general, the transition SST k-ω model shows the better overall behavior in comparison with measurement values. Consequently, the application of this turbulence model is appropriate for air flows in ventilated spaces, being an interesting option to more sophisticated LES (Large Eddy Simulation) models as it requires less computational resources.

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“…Furthermore, the best behavior for internal convective airflows among k- models has been established by using SST k-ω turbulence models . Finally, SST k-ω turbulence models have shown the better overall prediction of the airflow among 6 turbulence models investigated, in comparison with detailed experimental data for similar configurations to that in our study: airflows generated by mixing ventilation system in small rooms at low air changes per hour (Teodosiu et al, 2014). M a n u s c r i p t 11…”

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“…(3) example, the influence of the turbulence model on accuracy for simulation of wind turbine wakes [20], for improving indoor air quality [21], and of gas and liquid pool fires [22].…”

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