

EDIT 04/01/16 - Before you get your teeth into this article I can now verify I've seen a Technical Directive issued by Charlie Whiting that rules out the concept. (Although it's still worth a read as it not only explains my thoughts behind this concept but also the previous use of DRD and the F-Duct)



It's about that time when changes to the regulations cause us to have a good old look at what might now be possible. The implementation of wastegate exhausts has got us all wondering what advantage the teams can possibly glean. Unfortunately their positioning along the cars centreline rules out any edge of floor/diffuser blowing tomfoolery. However, how they're used along the centreline could yield some interesting applications in any case



Before we get going, make sure you're sitting comfortably and have a drink as this is going to be a long one. Let's start with a little history lesson.... (If you want to cut to the chase and/or don't need the history lesson skip to the end of the article where I've added a brief version of the Active-DRD concept) EDIT 04/01/16 - Before you get your teeth into this article I can now verify I've seen a Technical Directive issued by Charlie Whiting that rules out the concept. (Although it's still worth a read as it not only explains my thoughts behind this concept but also the previous use of DRD and the F-Duct)It's about that time when changes to the regulations cause us to have a good old look at what might now be possible. The implementation of wastegate exhausts has got us all wondering what advantage the teams can possibly glean. Unfortunately their positioning along the cars centreline rules out any edge of floor/diffuser blowing tomfoolery. However, how they're used along the centreline could yield some interesting applications in any caseBefore we get going, make sure you're sitting comfortably and have a drink as this is going to be a long one. Let's start with a little history lesson.... (If you want to cut to the chase and/or don't need the history lesson skip to the end of the article where I've added a brief version of the Active-DRD concept)





Back in 2010 McLaren arrived to pre-season testing with what they code named the RW80, but was latterly dubbed the F-Duct by the mainstream media.

McLaren's blown rear wing concept was known in-house as the RW80 but when the media noted the chassis duct had the 'F' from Vodafone emblazoned on it, it became known as the F-Duct.



The shark fin engine cover connected the pipework to the upper flap The flaps were hollow, allowing the airflow ducted to them to pass air through slots on their rear face The slots on the rear face of the wing were placed differently depending on how the team wanted the wing to 'stall' Under normal conditions airflow passing through the airbox duct would pass down through the engine cover outlet. In order that the wing 'stalled' / drag reduction took place the driver would place his hand/knee (dependent on the car) over a hole in the cockpit, which in-turn created a switching effect at the junction (fluidic switch) causing the airflow to pass down the pipework to the rear wing through the slots on the rear wing, interrupting the normal flow pattern and 'stalling' the wing.

Here's an overview of how the F-Duct system worked. When not in operation air flowed through the duct astride the cockpit and into the cockpit via the aperture, the pipework at the junction was shaped that when inactive the airflow from the airbox passes down through the neutral feed. When activated by the driver (places his hand/knee/leg over the cockpit aperture) the airflow moves down toward the junction and the airflow switches, to supplying the rear wing. NB Green denotes active airflow, whilst Yellow denotes no supply. The system, whatever you choose to call it, had a scoop mounted on the upper surface of the chassis, with ductwork passing through the monocoque to the rear of the car. Meanwhile the air box was divided, with some pipe work responsible for the usual task of intake air and cooling whilst the another made its way toward a junction. This junction split, with pipework feeding both the rear wing and the outlet just above the beam wing. This was made possible by the connecting engine cover and slots placed on the rear face of either the mainplane or top flap (each team chose differently dependent on how they wanted to stall the rear wing).Under normal conditions airflow passing through the airbox duct would pass down through the engine cover outlet. In order that the wing 'stalled' / drag reduction took place the driver would place his hand/knee (dependent on the car) over a hole in the cockpit, which in-turn created a switching effect at the junction (fluidic switch) causing the airflow to pass down the pipework to the rear wing through the slots on the rear wing, interrupting the normal flow pattern and 'stalling' the wing.

Outlawed by the FIA in 2011 owing to the danger of driver interaction it was replaced by DRS (Drag Reduction System), which was initially, during qualifying, unlimited in its use, whilst in race conditions it can only be used in 'activation' zones and only when a driver is 1 second behind the one he trails at the detection point. It's use has been somewhat diluted since its introduction in my opinion, with the length of zones increased/decreased throughout race weekends in the past in order to facilitate better racing. This often led to teams carrying numerous flap sizes and having to test their vMax in order to decide which way to go for qualifying and the race. With the zones rigid in their length throughout race weekends it has become somewhat of a formality that the chasing car will overtake and is now moreover a tool to return the drivers to their status quo dependent on the tyre wear, rather than a tool to create overtaking opportunities.





In 2012 Lotus looked into another option to reduce drag, which they simply dubbed the 'device', I decided to call it DRD (Drag Reduction Device) as the mainstream media (Sky and the BBC) had begun confusing fans by calling it Double DRS (DDRS), an acronym already in use with Mercedes employing a drag reducing device that used DRS to 'stall' the front wing.

The Lotus drag reduction device seen implemented on the E20 here with flo-viz applied. You'll note the flow separation in the centre of the wing caused by airflow being blown laterally out of the slots in the pylon

DRD was tested repeatedly by Lotus throughout 2012 and others joined them, with Mercedes, Sauber and Red Bull all trialling their own versions (albeit I was never really convinced that Red Bull were doing the same thing). However, it never really reached its potential and featured in just one race, when Kimi Raikkonen gave it an outing at Silverstone. The problem with DRD was it was passive, unlike the RW80/F duct it relied solely on air speed to create the switch, which made it difficult to tune. The problem was speed, set the threshold too low and it would create an imbalance during cornering, too high and its effect was nullified by the additional weight and complexity of the components.





So, come on Matt, why are you dragging all this up again?..





Well, if we take a mixture of both the RW80 switchable concept and DRD blown pylon it is entirely plausible the introduction of wastegate exhausts may have inadvertently reopened the door to the blown wing. There are undoubtedly several ways in which this could work (trust me I've drawn several), but I've chosen perhaps the easiest to explain in order that we get the idea out on the table.





Firstly let's talk about the wastegates function, which is to relieve boost from the turbine when it exceeds the requirement. F1 Powerunits have electronically controlled wastegates, of which the ECU are in command of and can specify changes based on differing parameters. Therefore it is entirely plausible that you could utilize a low speed wastegate and high speed wastegate, with the low speed wastegate opened up until a given rpm or a steering wheel override command is deployed by the driver. Furthermore, as the Turbo is supplemented by the MGU-H whilst the wastegate is in operation you can still keep the turbo in the optimum operational window.



