Mc Laren’s innovative rear wing system ( F-duct)
Mc Laren constructed its 2010 condenter , the MP4/25 , equipped with a new innovative system , called the F-duct which helped the car to achieve higher top speed at straights without loosing downforce at corners .
Official name of the system :
While press and media called the system “The F-duct” , Mc Laren officially coded the system as “RW80” meaning Rear Wing version 80
What is the benefit from such a system :
The driver at will can blow a high velocity airstream to the rear wing at straights , causing the it to stall , gaining a significant greater top speed for the MP4/25 up to 7-12 km/h according to the tuning of the system and the track characteristics . The system was found to be within the rules by the FIA .
Why the system was considered to be legal :
Several teams protested against the legality of the system when it gained publicity but FIA had already gave the green light to Mc Laren to develop such a system because the non movable-flexing wing plane principle is not violated as the system alters only the airflow around the wing and not the wing’s flexibility . Rival teams rushed to copy the system with the first one to be Sauber , while Ferrari , Red Bull , Williams , Force India and much later Renault and Toro Rosso also launched their own versions of the system .
For 2011 the rear wing stalling system was ruled out of the regulations in favor of the new rear wing attack angle adjustment mechanism .
How the system is activated :
The air entering the nose snorkel can be blocked by the drivers left leg at will and as a result the airflow inside the engine cover is forced by changed pressure to circulate via a certain tube to reach the rear wing causing it to stall .
Parts of the system :
The system functions with the combination of three different air inlets which are :
(A) a nose duct ( spotted where the F letter of the Vodafone logo exists and so called F-duct ) – (Number 4 )
(B) an inlet located behind the driver’s helmet under the primary airbox inlet to receive airflow – (Number 3 )
(C) airbox second upper inlet – (Number 1 )
[The number 2 inlet feeds the engine with air and has nothing to do with the system]
The received airflow from the nose duct is directed via a tube inside and around the cockpit ending inside the engine cover . There it meets a second richer airflow coming from the (B) inlet. The summoned airflows then enter a system of tubes housed inside the engine cover . The airflow coming from the (C) airbox upper inlet also enters this system of tubes
How the system functions :
When the system is active ( at driver will ) the airflow entering the (C) airbox inlet circulates via a certain tube , gaining gradually velocity with the help of a venturi effect , to reach a hole located on the centre zone of the rear wing profile ( yellow arrow ) . The airflow hits the wing and exits behind the wing’s profile via a small additional pair of wavy shaped slits , disrupting airflow and causing the wing to stall . As a result the wing’s drag production is significantly decreased in favor of top speed .
wing blown aiflow exits behind the wing’s profile via a small additional pair of wavy shaped slits
When system is inactive the air inside the engine cover flows into a second tube exiting above the beam wing leaving the rear wing unaffected .
Pre-2010 season variations of the system :
The system is much complicated and the team tested various versions before launching it at Bahrain . The visual variations regarding the nose snorkel are the following .
Developments during 2010 season of the system
During season Mc Laren developed further the system . The season developments regarding the system’s activation way ,which was revised from driver’s knee to driver’s hand and the different system’s tuning and air exiting ways , are going to be described in future posts .