Everything you need to know about Mercedes' F-Duct and DRS System
The start of the 2012 Formula 1 season has been filled with talks in the paddock regarding the innovative Mercedes ‘Super DRS’ device. Charlie Whiting has given his decision more than once regarding the legality of the device but the debate just doesn’t seem to die down with the protest being led by Red Bull and Lotus.
The device is a very complicated one with rival teams not being able to understand the working and configuration of the device totally. As Mercedes’ rivals can’t exactly figure out, so there might be an official protest sometime in the future. If and when an official protest is held, Mercedes have to fully explain the device and hence why it is legal according to their thinking in front of the FIA and members of rival teams. That might prove to be a disadvantage to the Silver Arrows as other teams might be able to find out even more new things with the device which will negate the top speed advantage that Mercedes has now.
Let us understand the basic working of this device and why it has created such hullabaloo:-
Firstly, let us understand what is the DRS or the Drag Reduction System. The rear wings of current Formula 1 cars have two elements – the base plane and the upper flap. Current regulations let the driver open the upper flap with the pressing of a button on the steering wheel which helps in reducing the drag and hence increasing speed especially down the straights. DRS can be used anywhere around the track in free practice and qualifying sessions during the weekend. But during the race, there are specified zones on the track(may be more than one) for DRS to be used with a DRS detection line. If the car behind is within 1 second the car in front, it can use the DRS to gain straight line speed over its rival and pass it on the straight. Also, DRS is disabled during wet sessions when the visibility is not deemed satisfactory by race control.
Next is the F-Duct system. The major function of the F-Duct is to reduce the drag created by the rear wing and hence increasing the speed. There is a gap between the two elements of the rear wing.
This ‘slot gap’ has the function of allowing air to pass through it so that the airflow beneath the wing does not separate from the underside of the rear wing profile in cases of higher angles of attack. What this F-Duct system does is it stops ‘blowing’ the slot gap which means the slot gap is shut closed and this causes the wing to ‘stall’. This stalling of the wing reduces the drag and hence increases the speed.
Mercedes’ clever idea this year has been to combine the two and obtain even more speed when the DRS is open. In the rear wing endplates of the W03, there are slots which are in the shape of the side boundary of the upper flap. The most logical explanation of the working of the device which has come out until now is that air enters through the slots, passes within the endplates(they are quite thick this year), goes into the rear beam wing, and ‘stalls’ the rear wing as explained before with the help of greater airflow. Mercedes are supposed to have found a way to direct this airflow through the bodywork towards the front wing and perform a similar ‘stalling’ operation on the front wing. This is important because if there is less drag on the rear wing and the car has more front end downforce, the car will not be balanced and have oversteer. So, this ‘stalling’ of both wings helps in improving the balance of the car by reducing downforce both at the front as well as the rear of the car.
One reason for Mercedes’ much better qualifying pace compared to their race pace is this innovative system as teams can’t use DRS anytime during the lap in the race and in wet conditions. Without opening the upper flap, this system is totally ineffective.
The debate regarding the illegality of the device stems from the fact that one of FIA’s technical regulations state that the car cannot have any driver-operated or movable aerodynamic devices (apart from the DRS). Red Bull and Lotus are arguing that as DRS is driver-operated, so the Mercedes F-duct (which is an aerodynamic device) doesn’t comply with the regulations. But Charlie Whiting has said on more than one occasion that to him the system seems passive and so there is nothing illegal with the device.
This debate doesn’t seem to be ending in the near future as it will take Mercedes’ rivals quite a lot of time to figure out the path of the F-Duct system through the bodywork towards the front wing and it will be also very costly to implement. Till then, they will try to keep Ross Brawn and his team regularly under watch of the FIA regarding their innovative system.