What Are Vehicular Vortex Generator & Canard?

Vehicular aerodynamics is all about increasing downforce and reducing drag. There are several solutions to meet those purposes: adding wing, using diffuser, and getting help from ground effect theory are some of the ways to have optimum air flow around a car. While some aerodynamic features are popular and visible, some are not as noticeable such as canards (dive plates) and vortex generators. In this short article I am going to briefly go though these tools and the way they function.

One of the undesirable phenomena in aerodynamics is flow separation. This phenomenon occurs when the airflow detach from the solid surface of an object and distort the airflow boundary layer. The flow separation causes massive increase in drag force.

Vortex Generator Flap:

 In order to decrease the possibility of flow separation vortex flaps are used when there is a sharp edge on the vehicle's body. Those vortex flaps energize the flow by making vortices. This change in airflow characteristic makes it reluctant to leave the surface of the body. Hence the drag will reduce.

Canard:

Canard at front side of a vehicle is a common tool to generate vortices. Wheels area is susceptible to flow separation. Those winglets (canards) energize and circulate the air flow at both sides of the vehicle. Consequently, separation around wheel area is less likely to happen; also, The energized air flow act like a curtain at the sides of vehicle's body and prevent ambient high pressure from penetrating to the bottom of the vehicle. This way, at the bottom of the vehicle low pressure will form (with the help of ground effect, diffuser etc.) while on the top of the vehicle higher atmospheric pressure would push the car down.

Otherwise, if the ambient pressure goes under the vehicle and blend with low pressure passing under the car, less pressure difference would occur therefore less downforce will be generated.

At the end, I hope this article could help you understand the aerodynamic functionality of vortex generator flaps and canards.