HB Window Opening - fract_area_oper

Hi all,

Can anyone explain how to define fract_area_oper for an awning window similar to this please?
Which term does it refer to - free area, equivalent area or effective area?


@Zuzana I think you need discharge coefficient to simualtion this case. Regularly in the elevation, we calculate the opening area / window area and it means the fraction of the window which is exposed to wind.
But it the other hand you need to simulate the change in pressure because of the opening form and it related to discharge coeficient
The discharge coefficient, which ranges from 0 to 1 , is a measure of the amount of pressure that the air loses as it goes through every opening of flow resistance. For reference, the discharge coefficient for sliding windows is of the order of 0.65.