HAAS GOES OFF THE BEATEN PATH
While most teams use deflectors to customize their Halo, Haas chose to place vortex generators on the VF18 driven by Romain Grosjean and Kevin Magnussen.
These small triangular pieces create a pressure difference between each of their faces, producing a vortex. These vortices re-energize the flux boundary layer and delay its separation from the surface, presumably to "clean" as much as possible the airflow going to the rear wing. This could explain the astonishing presence of vortex generators also on the central pillar (see the red arrows on the middle image).
However, the orientation and positioning of the triangles relative to the airflow suggests that their role could also be to supply the roll-hoop air intake, under the main air intake. As always when we discuss the details of the aerodynamic elements, we are limited to conjectures...
Finally, a notched adhesive is placed in front of the triangles (see the yellow arrow on the first image). In recent years Mercedes has been using a similar adhesive on the underside of the main plane of the rear wing, in order to keep the airflow attached.
When the car is in the garage, a tarpaulin protects these parts, both fragile and blunt (follow the blue arrow).
