Numerical Comparison of Wind-Aligned Ventilation Cases in an Isolated Building: Analysis of Flow Field and Pollutant Dispersion

Natural ventilation is a sustainable and energy-efficient approach that improves indoor air quality by facilitating the removal of indoor pollutants. Most previous studies have focused on opening configurations perpendicular to the wind direction, as this arrangement typically provides the highest cross-ventilation performance. However, architectural constraints often prevent the use of perpendicular openings making wind-aligned configurations a practical alternative that requires further investigation. In this paper, computational fluid dynamics (CFD) is employed to analyze the flow field and gaseous pollutant distribution in an isolated building subjected to wind-driven natural ventilation. A three-dimensional steady Reynolds-averaged Navier–Stokes (RANS) model with the standard k–_x۰۰۰۳_ turbulence closure is used. Four ventilation cases are evaluated: Case ۱ (empty opening with wind perpendicular to the windows) as the reference case, Case ۲ (empty opening with wind parallel to the windows), Case ۳ (Casement), and Case ۴ (Pivot). Since the wind-aligned cases do not generate strong internal jet structures, velocity contours alone are insufficient for performance assessment. Therefore, turbulence kinetic energy and pollutant concentration fields are used for comparison. Results show that Case ۱ provides the highest ventilation effectiveness due to strong jet formation, enhanced turbulence, and efficient pollutant removal. Among the wind-aligned cases, the Casement configuration increases turbulence kinetic energy and improves mixing resulting in a significant reduction in pollutant concentration compared with the Pivot configuration. Overall, the present findings highlight the crucial role of opening type and orientation in determining natural ventilation performance.

کلیدواژه ها:

Natural Ventilation ، Wind-Aligned Ventilation ، Cross-Ventilation ، Computational Fluid Dynamics ، Pollutant Concentration Distribution