Introduction

The F-Duct was an aerodynamic development by the McLaren F1 Team in 2009, as a form to reduce drag by manipulating the airflow to the rear wing by the driver.

It is actually quite an ingenious development, as it circumvented FIA (the governing body) regulations on movable aerodynamic devices. Technically, the duct was legal as it was operated by the driver, and not by any other mechanical device.

Rationale

The structure of a rear wing actually consists of a few plates, as seen below:

To maximise downforce, the entire area of the rear wing is required. However, at the straights, it is not required, and is instead even detrimental to the performance of the Formula One car.

Structure

The F-duct consists of an inlet at the front of the vehicle, which passes to the cockpit of the car, where the driver’s leg manipulates the airflow leading to the rear wing of the car.

The redirection of the airflow through a conduit will disrupt the nominal airflow over the rear wing, such that it would stall the rear wing and save drag.

Stalling

The following diagram shows how the airflow detaches from the wing and ‘stalls’. For more information on finding the downforce, please find it here.

References

http://www.formula1-dictionary.net/f_duct.html