At higher downforce circuits you're
sure to find a winglet placed in the middle of the rear wing you've
often heard referred to as the Monkey Seat. Contrary to popular
belief the Monkey Seat (Y100 Winglet) doesn't produce a huge amount
of downforce by itself, its role is to assist in the performance of
the diffuser and rear wing. That's not to say that their design is
not crucial, as any airflow coming off it can aid or disturb elements
like the diffuser and rear wing. It's design needs to complement its
surroundings and so you'll see variation between each team, just as
we do other components. (as one Monkey Seat might not work with
someone elses Rear Wing design). It's design depends on what the
team are trying to achieve, whether it be more low speed, peak
downforce or a larger window of opportunity. The array of winglets
that proliferate this area can only extend 100mm either side of the
cars centreline (Y100) and with the exception of the regulations
pertaining to the exhaust the area is fairly free in terms of design
constraints.
To create more downforce at a lower
speed the team retain the rear wings usual angle of attack (AoA), but
due to the upwash created by the Monkey Seat the airflow makes the
wing work harder.
As we can see in the image above the at
low speeds there isn't sufficient airflow for the top flap to work at
its full potential, the spirals represent airflow detachment which is
when the airflow separates from the wing resulting in a loss of
downforce.
The use of a Y100 Winglet / Monkey Seat
as pictured above can remedy the airflow inconsistencies resulting in
more low speed downforce.
Of course these images are only to show
you how it works and aren't directly representative of any of the
teams solutions, as each approaches the solution differently
depending on their current configuration and when they want peak
downforce. We are of course seeing teams using Monkey Seats all the
time this season, that's because they are trying to utilise the
exhaust plume that is within the vicinity, increasing the net effect
and mitigating the loss of the beam wing.
Mercedes WO5
Mercedes arrived in Monaco with a new
Y100 Winglet / Monkey Seat, designed to extract further performance,
downforce and balance from the WO5. Their new Monkey Seat is a
further development from the one tested by the team after the Spanish GP.
Above: The team tested a new Monkey
Seat at the post Spanish GP test, as we can see there are changes to
the endplates (curved at their base) whilst the addition of two extra
winglets above the exhaust to invoke the exhaust plume to upwash and
are covered in high temperature paint.
For Monaco the team have made further
revisions with the Monkey Seat featuring much taller endplates and an
additional horizontal winglet placed at the top of it which help to
control how the airflow upwashes and interacts with the rear wing
(without this the upwash may be too steep and interact with the rear
wing too early).
This season the teams are using the
centreline exhaust in conjunction with the Monkey Seat in order to
extract more downforce, it's a design principle that McLaren followed
from the start of their campaign and many have assimilated. The idea
is that the exhaust plumes low pressure high energy flow pulls the
airflow through or past any bodywork that's placed within it's
proximity. (In the case of McLaren their Venturi shaped pylon
support which surrounds the exhaust) Mercedes have designed their
new endplates with a curvature at the bottom of them in order to
condition and isolate the flow to do similar, this is important as
they've now extended their sidepod outlets to exit inline with the
main central cooling outlet (amended for the Spanish GP).
The additional winglets added above the
exhaust that the team tested at Barcelona have been covered in high
temperature paint (likely Zircotec) as these will invariably get hot
due to their continuous interaction with the exhaust plume.
All of these changes were made in order
to create flow structures that allow the diffuser and rear wing to
work in unison and create more low speed downforce.
Red Bull RB10
The chase for downforce is still on for
the team that everyone else believes to have the most in hand, with
the team adding a new upper winglet to complement the lower one the
team have been using so far this season. Having decided to run a
Y100 winglet under the exhaust and just below where the old beam wing
used to run the team were/are clearly looking to enhance the way in
which the diffuser interacts with the exhaust.
Lotus
The introduction of the higher Y100
winglet which sits astride their regular one looks to create further
interaction with the underside of the rear wing, whilst undoubtedly
utilising the exhaust plume as it exits below it.
Lotus
Having added a Monkey Seat at the
Spanish GP the team revised its design for Monaco, introducing a
secondary tier. The two winglet approach is used to discern extra
upwash, with the slot between the two winglets helping the upper one
overcome the more extreme angle of attack of the upper winglet.
Toro Rosso
Toro Rosso converged on McLaren's
singular mounting pylon (Y-Lon) as few races ago with the intention
of using the cylindrical section that wraps around the exhaust to
pull airflow through and over the Sidepods (amendments were made to
these too, in order to exploit this). Continuing along the same path
as McLaren the team arrived in Monaco with a new Monkey Seat which
hung off the rear of the cylindrical exhaust cover. The double tier
winglet looks to exploit the airflow in this region, creating up wash
that would help both the Diffuser and Rear Wing work more effectively
together.
You'll note however that Toro Rosso's design features
endplates on each of the winglets, these are usually used to increase
the aspect ratio of the winglets and further condition the airflow.
Sauber
The Swiss team had a plethora of
updates for the C33 in Spain, not all of which can be seen as
successful with the team still struggling. Monaco provides a vast
difference in terms of aero balance when compared to Barcelona and so
the team ploughed on with the same parts, trying to further
understand where they'd gone wrong.
Like all of the teams mentioned above
Sauber decided to run with a Monkey Seat for Monaco, which although
they were chasing performance I'm quite sure it would have offered
the drivers a little more balance too.
It's awesome to read about the small tweaks that each team has been making. Thanks for discussing this and providing the details.
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