Investigation of wind-induced natural ventilation in buildings

In this thesis, the cross-ventilation conditions of building models with different window opening shapes, building models with different roof pitches, building models with different inlet and outlet opening dimensions, and building models with varying window opening positions are numerically analyzed. Numerical analyses have shown that the highest positive pressure coefficient occurs on the upwind wall due to the wind force on the building wall in building models with different roof pitches. Increasing the roof pitch from 15° to 35° decreases the internal pressure, which is related to Bernoulli's principle. The enlargement of the inlet openings decreased the internal air velocity and increased pressure. The highest pressure was observed in model C1 and the lowest in model C5. Among the buildings with different window opening geometries, rectangular windows provided the highest ventilation rate with 0.004212 m³/s and triangular windows provided the lowest ventilation rate with 0.002158 m³/s. The building with α=35° slope had the highest ventilation rate with 0.003040 m³/s and the building with α=15° slope had the lowest ventilation rate with 0.003024 m³/s. These findings reveal that the roof slope directly affects ventilation efficiency. In the analysis with fixed outlet and variable inlet window sizes, the G5 building model provided the highest ventilation rate with 0.004089 m³/s and the G1 building model achieved the lowest ventilation rate with 0.000418 m³/s. In the analysis of the exit openings, the C5 model achieved the highest ventilation rate with 0.003814 m³/s and the C1 model achieved the lowest ventilation rate with 0.000467 m³/s. For the cases with different window openings, the ventilation rate was found to be 0.003021 m³/s for the Lower-Upper model with a fixed inlet opening of 20 mm and 0.002932 m³/s for the Lower-Lower model. In the Mid-Upper model with 40 mm inlet opening, 0.003065 m³/s and 0.002959 m³/s were calculated in the Mid-Lower model. With a 60 mm inlet opening, the highest rate was 0.003129 m³/s in the Top-Lower model, and the lowest rate was 0.003012 m³/s in the Top-Upper model. The opening positions affect the efficiency of ventilation, and it was determined that the high position of the upwind opening increases the air flow.