Do you know, that… ?

On the sheet metal tab you will find the operation The vent. It allows you to make a hole with ribs and the so-called. bridges. The shape of the opening can be any, but bounded by a closed curve. The other elements can be omitted, then the flow area is 100%. By contrast, selecting the bridges, ribs and the fill border, real Flow area will decrease.

An interesting fact is this, that the operation can also be used in objects that are not brach sheets (e.g. plastic housing). Then you can additionally control (except the width) the thickness of the ribs and bridges or the slope. In sheets, the thickness must be consistent with the thickness of the sheet, there is no requirement here.