Pressure continues to pile on McLaren and Honda as their burgeoning relationship has failed to deliver in 2015 so far.
In Austria the team arrived with a raft of aerodynamic updates for the MP4-30 in order to both rectify inefficiencies and boost performance. The updates were only available for one car and so Fernando Alonso had them on his car, as Jenson Button took an upgrade earlier than him at the start of the season.
Meanwhile, Honda introduced reliability upgrades to the RA615-H but focused their attention on their current weakness: ERS, in an attempt to increase drive-ability and more importantly power.
The most prominent element of the update package is the new nose, which replaces the elongated one run since the cars launch.
Much has been made of the use of a shorter nose with the rule changes made for 2015, with many citing it as a reason for the loss in performance. However, I’m always struck by the fact that not only do Ferrari continue to run an elongated nose, there seems to be no rush from them to adopt the shorter nose either. Lest we forget they are the closest team to Mercedes in terms of race performance, calling into question the logic behind their use.
The challenge of designing a short nose is not only an aerodynamic one but also one limited by the structure itself. Shortening the nose makes it more difficult to pass the crash test, with the deceleration distance reduced. The obvious answer is to add more material into the nose, but as weight is such a key issue, the team desire the lightest version possible, making it a tough balancing act.
In terms of aerodynamic gains the most obvious advantage of running a shorter nose is improving the flow under the nose, something teams have chased extensively since 2009. A more expansive flow region under the nose obviously helps to improve flow to the splitter, floor, sidepod undercuts etc. However, if that flow isn’t dealt with efficiently it is just a waste and so changes will be made to the MP4-30 to better utilise this.
The other consideration is how the nose influences the neutral centre section of the front-wing (marked in yellow above), with this section the same up and down the grid, teams use the nose as a way of influencing it how they see fit aerodynamically.
Think of the nose as a shadow, casting the shadow over the neutral section at different points will influence its flow structure. The old nose cast an extremely long shadow, with the nose well beyond the neutral section, whilst the thumb style nose bought to Austria protrudes only slightly above it, casting much less of a shadow, therefore influencing the central section in a very different way.
FRONT-WING ALTERATIONS
Although the main focus of the McLaren upgrade was focused on the nose, alterations were also made to the front-wing, with an evolution of the upper flaps (marked in green). The changes not only focus on flap geometry and chord length but also their tips, which adjusts the vorticity along the Y250 axis. This is key to the management of the additional airflow passing under the nose. Furthermore, the team have been toying with the movement of their adjustment system over the last few races, with the adjuster moved inboard, this has been retained as a feature of the new wing.
MINOR AERODYNAMIC MODIFICATIONS
As part of a larger upgrade of the area around the sidepod, that is likely to be tested in the post race test and be used at Silverstone, the bargeboards saw a minor revision. A slot was added to the rearward slope [1], whilst a new vane [2] hangs off the bargeboard, mirroring the floors geometry behind it. These changes will help to improve the performance of the airflow moving around the sidepods undercut and the floor.
What is ‘Tyre Squirt’
Tyre squirt is the injection of airflow laterally into the diffusers path as the tyre deforms. This can be detrimental to its performance, especially at the critical cornering phase, when downforce is required the most.
At the rear of the car the team have also revised the floor ahead of the rear tyre. Having previously employed a singular dog-legged tyre squirt slot, the area has been furnished with a multitude of new slots/louvres.
The introduction of these new slots allows airflow to move between the upper and lower surfaces, improving performance, especially in transient conditions.
Analysis produced by Matthew Somerfield exclusively for Grand Prix Times. Follow Matthew on Twitter.
