Tech Talk: Who nose if the Twin Tusk concept will work for Lotus?
25 February, 2014
The Lotus team caused somewhat of a furore when they released a teaser render of the car ahead of the actual unveiling of the E22. The furore centered around their twin-tusk asymmetric nose, as for many it seemed to defy the regulations.
I had however proposed a similar solution several weeks before the car was launched having re-visited my notes made when the regulations had been released some time ago. Although the nose tip is required to be set at 185 mm from the reference plane and must contain a horizontal projection of 900 mm 250mm behind this it does not go as far to say that at 50.01 mm behind this you may not create another structure.
This is where we find Lotus carving an advantage, with the right hand (left as you view the image) tusk just over 50mm longer than the other. Whereas the rest of the field has converged on either the ‘Finger’ or ‘Anteater’ style noses the Lotus variant offers the opportunity to condition more airflow centrally.
You’ll also undoubtedly note that the E22′s nose seems longitudinally shorter than some of it’s counterparts at that, to leverage an advantage in terms of how much height can be retained between the tusks. The height retention is one of the main advantages of using this style of nose as it allows more airflow to pass under the chassis and onward to the floor.
It does however come with the drawbacks associated with asymmetry and will likely lead to some eratic airflow behaviour in yaw, the loss is probably deemed negligible enough though to warrant the better mass flow.
In terms of other teams using this idea, it could prove difficult unless they’ve already been working on it. This is due to the fact that most teams conduct their initial test phase in CFD, which is usually only done with half the car (from the centre-line outward).
Lotus must have completed their CFD runs modelling the whole car, to take in account the inconsistencies that asymmetry can produce and is further echoed by the teams use of asymmetric parts further downstream.
The regulations going forward put a much heavier restriction on the use of both CFD and Wind Tunnel testing to offset the return of in-season testing. This will undoubtedly hinder any teams wanting to assess the twin tusk concept as the computing power to process the whole car vs half of it is more than double.
Lotus are expecting other teams to ask the FIA for clarification on their nose design when the competition begins in Melbourne but thus far it has stood up to the test of the FIA’s regulations. Lotus are reportedly working on a more aggressive version of the nose for future development as well.
Lotus Technical Director Nick Chester said of the concept, “Some teams have had the luck to have visibility [of the E22] quite early and I thought one or two teams might have tried it or maybe developed it. I think one of things that’s difficult with that nose is that it’s quite hard to structurally develop it and crash test it. It might be that they were already on a path where it was too late to develop that kind of nose.
“Obviously it’s a very different structure to a standard nose and it took quite a lot of iteration to get it to a point where we were happy and it got through the crash test.”
“From the aero numbers we are getting back from the car it does seem to be performing. I’m not going to give you a number on how much better we thought it was than a standard low nose, but we did see what we thought was a significant benefit, which is why we chased it,” added Chester. (Analysis by Matt Somerfield)