Sard Aero Blades

I have just taken delivery of a set of Sard aero blades a.k.a Vortex generators.

 

 To explain in simple terms the benefit of vortex generators I have summarised a very good article from AutoSpeed

Airflow over a car’s surfaces can be divided into two simple types, laminar (attached) flow, and turbulent (separated) flow.

A car that is being dragged along by movement has a thin blanket of air that sits on the surface of the body. This blanket of air is called the boundary layer and varies in depth, normally getting thicker towards the rear of the car.
The thicker the boundary layer, the more easily airflow will separate from the body, leading to turbulent flow.
Flow separation is bad because it leads to a larger wake (the area of disturbed, turbulent air being dragged along behind the car) and less pressure on the rear surfaces (like sloping rear windows and spoilers), reducing pressure recovery, ie reducing the pressure of the air that can help push the car forwards

As mentioned, the further you get towards the back of the car, the harder it is to keep the flow sticking to the bodywork. Because of the increased thickness of the boundary layer, air more easily separates, resulting in a larger wake, less pressure recovery and poorer performance of rear mounted wings. In other words, the airflow close to the car has lost its flow energy.

If vortex generators are placed just ahead of the separation point, they can be used to put airspeed back into the boundary layer. The boundary layer then becomes energised and as a result, the airflow is more likely to stick to the body. The wake is reduced in size or increased in pressure, where the increased pressure acts on angled rear surfaces such as the rear wing thus giving more rear downforce.

More pictures below of the aero blade.