Natural ventilation: calculation of discharge coefficient in a complex opening (laminar flow).

The discharge coefficient in a complex opening was studied in order to determine its value. Several experiments were set up for different external shapes of complex openings with various internal opening configurations. The openings were placed in different orientations with respect to the airflow direction. The airflow was arranged in order to achieve the fully developed laminar flow when passing through the openings. Thirty-two openings were used in the experiments with four different orientations, i.e. 30, 45, 60 and 90 degree. The shape factor was defined in order to distinguish the difference among each internal opening configuration for mathematical purpose. Data received from the experiments were then used to develop the equations for calculating the discharge coefficient of the airflow through complex opening.