Korean GP: Lotus abandons DDRS and introduces Coanda-style exhaust
By Berthold Bouman
Lotus will not further develop their Double DRS system, Technical Director James Allison said ahead of the Korean Grand Prix. “We haven’t had the happiest of introductions with the system. It’s been harder than I anticipated to make it switch effectively with only the limited opportunity afforded in Free Practice. We’re going to take it away, have another think and most likely give it another go in the Abu Dhabi young drivers’ test,” Allison explained.
Instead Lotus will introduce their version of the Coanda-style exhaust system. “Once we saw the potential gain of the Coanda system surpass that of our current design it was clear that we needed to implement it, both for the benefit we could get in the last quarter of this season and also for learning experience it presents us for next year. We will run our first version of this style of exhaust in Korea,” said Allison
As the blown diffuser and the blown floor are now banned, teams have been searching for another ways to lead the exhaust gasses through the diffuser, while the exhaust outlet is still in the place where the FIA wants it to be. Last year Nick Heidfeld’s car went up in flames twice due to the hot exhaust gasses that were led through the floor and diffuser, but the Coanda exhaust is a complete different system according to Allison.
“The Coanda system is a little more indirect, and the [exhaust] jet has cooled a little before it impinges on the floor which makes things a little easier to manage. There’s still a fair amount of rearrangement including new Coke panels, new exhausts, new exhaust exit panels, some fire proofing of the floor and so on.”
But what is the Coanda effect? The Coanda effect is the tendency of a fluid jet to be attracted to a nearby surface, the effect was named after Romanian aerodynamics pioneer Henri Coanda, who used it for his Coanda aircraft in the 1920s. It’s now the magic word in Formula One, but it must be said, it is not as powerful as the 2011 blown diffuser, but every tenth of a second counts in Formula One and thus the Coanda-style exhaust is the latest toy of the Formula One engineers.