A new thread was created in the F1 Technical Forum concerning grooved surfaces. A user asked whether grooved surfaces would be beneficial for channelling air around the car. But soon the question became whether grooved surfaces would reduce drag. The question concerns both longitudinal grooves and lateral grooves. So I decided to carry out a CFD test to answer the question. I tested a body with lateral grooves, longitudinal grooves and no grooves at all.
The body has a teardrop shape, it is 320 mm long and 100 mm thick on its thickest part. I tested it at 42 m/s and found the drag produced by each body.
Drag: 0.27 N
Drag: 0.95 N
The longitudinal grooves reduce the thickening of the boundary layer. Also because of the increased surface area the body produces much more drag.
Drag: 3.68 N
The drag increased too much here partly because of the grooved shape of the front of the body.
Lateral Grooves V2:
Drag: 2.57 N
I smoothed out the front of the body that created a lot of drag, but still the drag figure for the body with lateral grooves is too high.