Testing and evaluation of a locally developed boundary layer wind tunnel for assessing single-sided ventilation with and without wing walls for Philippine applications

This study investigates the effectiveness of wing walls in enhancing natural ventilation in typical Philippine residential units with single-sided openings. Wind tunnel experiments were conducted to evaluate the impact of wing wall geometry and wind direction on airflow distribution and air change rate (ACH). The results indicate a significant improvement in ACH, with airflow increasing by 297% at a 45° wind angle compared to the baseline configuration without wing walls. The wing wall configuration with a length equal to the window width achieved a 95.44% increase in ACH. While wind speed was identified as the primary driver of ventilation, the presence of wing walls rendered ACH more responsive to variations in wind direction. The R2 values for the wing wall configurations ranged from 0.3648 to 0.5092, in contrast to 0.2366 for the no-wing-wall case, highlighting the influence of wing walls on airflow predictability. The results show that diagonal wind angles (22.5° and 45°) provided optimal performance for Cases 2, 3 and 4, while perpendicular wind angles (67.5° and 90°) favoured Case 5. Additionally, the study examined both inlet and outlet airflow patterns, revealing that wing walls generate significant pressure differences, which enhance inlet velocity but also induce rapid air exit through the outlet, limiting internal circulation. These findings quantitatively demonstrate that wing walls, particularly those matching the window width, can substantially improve natural ventilation and airflow efficiency in tropical residential buildings.