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Sunday, May 06, 2012
Firstly I'd like you to take this blog
post with a pinch of salt, it's something I've been thinking about
and wanted to get down on paper, so seeing as I had a little spare time this afternoon I thought I would. I'm not saying it's legal (although
I see no reason it wouldn't be) or cost effective in terms of running
the CFD, Simulations & Wing Tunnel in order to gain what could be
a small amount of time on track. However if it's viable it should
give a small performance jump in qualifying and make the car quicker for
overtaking opportunities in the race and also return some additional downforce at all other times.
When the FIA deemed the use of
additional systems employed by DRS legal in the Mercedes/Lotus
dispute the FIA made the following statement:
2. The modifications on Cars 7 and 8 are examples of the above.
3. The Mercedes design complies with all bodywork geometric and stiffness regulations.
4. The design is entirely passive and has no moving parts whatsoever.
5. The sole purpose of the "DRS" (or the "system" as referred to in the regulations) as stated in Article 3.18.3, is to improve overtaking. The Mercedes design is completely consistent with this objective.
6. . Noting the agreement of Lotus that "if the hole currently located in the rear end plate was located elsewhere and permanently exposed, this would be acceptable", there is no reason why the locating of the hole is the current position on Cars 7 and 8 should not also be acceptable. 7. In relation to the 5 questions posed by Lotus, all 5 of which Lotus assert (and the Stewards agree) if answered in the affirmative, would rule the vehicles ineligible;
(i) Article 3.15 does not apply because it does not directly use driver movement, as a means of altering the aerodynamic characteristics of the car. The alteration is indirectly (and not directly) consequential to the movement of the driver adjustable bodywork ("DRS")
(ii) The second question posed is not relevant in light of (i) above
(iii) The Mercedes design is not a "system" or "device" in its own right, it is part of a design made to take advantage of the change in airflow caused by the activation of the DRS (refer 1 above)
(iv) The Mercedes design is not activated by driver movement. It is a consequence of a change of position of the driver adjustable bodywork, which is permitted under the regulations.
(v) The Mercedes design does appear to alter the aerodynamic characteristics of the car by reducing the drag, however this is consistent with the intent of the regulations.
Taking all of this into account we can
also surmise that should another passive aero device be influenced by
a slot under the DRS wing the FIA would concede that it be legal too.
This brings into question what is also achievable in terms of duct
style bodywork when using DRS as the fluidic switch.
The Mercedes system relies heavily on
being designed at the same time as the chassis with enough space
having been left in and around the cockpit and the bulkhead for the
tubing. Perhaps then we abandon the idea of using the front wing and
look in other regions of bodywork that could be prudent for blowing
or stalling. As with anything aero related in F1 the exhaust region
would offer the biggest gain in this area but it's perhaps not the
only region you could/would want to affect.
With the 2012 regulations requiring a
periscope design exhaust we have seen many variations on
location/orientation/position of exhausts in order to manipulate
exhaust gas. The teams know due to it's velocity the exhaust offers
an airflow that if channeled correctly can provide significant
downforce. McLaren's exhaust position may at first seem a little
cumbersome but it attains what the other teams are now trying to
copy. Using the Coanda effect it manipulates the airflow from both
on top and the side of the sidepod allowing the airflow to stay
attached for longer and converging on the rear floor helping to seal
the diffuser below. Adjusting the angle of exhaust exit will have an
effect on how the manipulation occurs like opening/closing a window
for more or less airflow.
Each engine type will have different
demands on the tuning lengths required for the exhausts so
manipulating their positioning will have a push and pull effect in
terms of engine and aerodynamic effect. The openings available for
the exhausts to exhale into are also mandated in the regulations in
terms of surface area. This can also limit the potential extraction
of more aerodynamic effect.
So why am I talking about exhausts I
hear you say when we could be talking about DRS ducts, well I’m
getting there.
In modern F1 the consensus has been to
duct the airflow created internally in the sidepods inbound and out
of the cooling duct at the rear of the engine cover. Ferrari and
Sauber are this year exhausting the air slightly inbound of this with
Ferrari using their 'Acer Ducts' and Sauber a similar solution.
As a requirement of cooling, this air
needs to move through the car so why not use it? As that’s the
case why don't we use it to aerodynamically influence somewhere else?
It's obviously not going to provide the same force as an exhaust
would but by manipulating space with tuned tubing you can speed up
the flow. Due to the regulations you can't simply place holes in any
position you so desire and would have to have to open up an area of
bodywork at the rear of the sidepod. I'm not saying any of this
definitively legal I'm just proposing a situation if it were (Mercedes have used some cooling louvres in a similar position this season).
If we use the image I have mocked up
below I'll try to explain my theory.
In RED is the area of the floor which
relates to the diffuser below. In order to better utilise the
diffuser you want to get as much air as possible traveling over this
area.
The GREEN section highlights the most
neutral position you could put the exhaust in but this comes with a
compromise as the air cascades over the top of the Sidepod it
converges with the flow that comes from around the side of the
sidepod. The 2 flows won't interact with one another very well as
they will differ in speed and the airflow contra rotates against the
sidepod as it trys to escape into the lower area of pressure (Behind
the Sidepod)
The ORANGE section represents the
position being most commonly used this season in order to help manage
both the downwash over the sidepod and the sideflow from around the
sidepod accelerating and converging the two flows into a more uniform
flow whilst also manipulating their direction both down and inward
toward the RED section of floor.
The YELLOW section represents the open
section of bodywork I mention to blow out the air from the
sidepod/radiator entry. (Many options of shape/orientation/position could be used here to utilise the ejected airflow) This would have the effect of reattaching
the flow around the bodywork for longer toward the exhaust outlet
allowing the position to be angled further toward the GREEN section
in turn pushing more directional flow over the RED section of the
floor.
This of course could be used in a
passive way just like Ferrari are trying to do with the Acer Duct or
it could be tied to Super DRS, using DRS as part of the fluid switch
the airflow would travel down the Rear Wing Endplates, through the
Beam Wing, through the tubing inside the bodywork to the fluid switch
where it will redirect the flow from the sidepod exit to the rear end
cooling outlet. The net result of this will be a net gain in
downforce until DRS is activated at which point the airflow from
around the side of the sidepod will no longer interact / stay
attached to the sidepod for as long and so the diffuser's downforce
level would drop reducing the amount of drag.
In Summary
There are many ways in which using DRS
as a means of turning bodywork on or off could be effective. If a
team decides to utilise the system in a region that is effected by
exhaust gas the results could be much larger. The decision now that a
Super DRS / DDRS system is legal is, is it worth the cost and time to
develop a system that can give a huge difference on track?
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