The
new power units of 2014 have caused controversy since the FIA
originally announced their intentions to drive development in the
area. Many had a twinkle of nostalgia in their eye when they first
heard F1 was revisiting turbo's with the 1980's providing the
backdrop to simply awe inspiring power. Unlike the 1980's however
the agenda for this engine regulation change is one of
responsibility, whereas the 80's turbo cars were weak, inefficient
and could be tuned for maximum qualifying attack. The new engines
have been introduced to help drive sustainability, be more efficient
and require exacting strategies to utilise the restricted
capabilities at hand.
The
FIA's initial intention to move to an inline 4 engine was quashed by
the teams (mainly Ferrari) who simply couldn't understand why F1
should provide the backdrop for such a stark reach toward the
consumer market. They finally settled on a V6 configuration which
lends itself to the world of F1 and helps the likes of Ferrari to
engage with it's consumer products.
The
V6 units themselves will of course be shorter than their older V8
counterparts but both the weight and composition of the power units
inclusive of ERS will exceed that of the older units. The FIA have
also raised the position of the unit/crankshaft for 2014 to 90mm
above the reference plane whereas the V8 has been at 58mm (32mm
difference). Inline with this the centre of gravity of the engine
previously lay at a point no higher than 165mm from the reference
plane whilst in 2014 this is raised to 200mm. Furthemore the centre
of gravity will be further effected by the overall weight for which
the minimum has been raised from 95KG to 145KG (50KG increase).
Heat
and Fuel management will be essential for the new engines and its
widely reported the manufacturers are seeing upto 40% thermal
efficiency from the V6 with engine revs having been reduced from
18,000rpm to 15,000rpm. It's widely agreed that with the fuel flow
restrictions in place (5.1.4 Fuel
mass flow must not exceed 100kg/h. & 5.1.5
Below
10500rpm the fuel mass flow must not exceed Q (kg/h) = 0.009 N(rpm)+
5.5.) that the 2014's redline will however
probably be closer to 12,000 rpm.
The
original rules allowed for direct injection and a supply of fuel
(25%) via port injection upto 8333rpm meanwhile the latest draft of
the regulations only allow for direct injection, This is probably
one of the areas the WMSC/FIA believed teams/manufacturers would look
toward to extrapolate extra performance to the detriment of cost
control. The original regulation draft also insisted on FIA specified
injectors and fuel pumps but the latest draft omits this cavaet
allowing teams to source and cost control their own components.
The
expected output of the engine is somewhere in the region of
600-650bhp but it'll be the delivery of torque that far supersedes
it's V8 counterpart with the engine giving a linear power delivery
all the way to 10,500rpm where the fuel supply drops with increased
revs. This increase in torque will make for great viewing as the
drivers try to grapple with the extra low end power. Furthermore the
challenge will extend to Pirelli who will be required to provide
tyres that are capable of more horizontal movement. With the V6
engine and pressure charging system being down on power compared to
the V8 the new power unit will be supplemented by a much more powerful
Energy Recovery System (ERS):
Energy
Recovery System – ERS
Since
the FIA introduced KERS in 2009 the sport has half heartedly had it's
toe planted in green credentials with the drivers able to recover
400KJ's of energy per lap and dispense it at 60kw via a motor
attached to the crankshaft. The result is roughly 80bhp for around
6.6 Seconds which can obviously be adjusted to anywhere from 0-80bhp
for use over a longer time period. KERS is the older brother to a
much more technologically advanced younger sibling who has much more
power at his fingertips:
2014
will see KERS replaced by ERS as both kinetic and thermal energy can
be recovered, energy can still be recovered at the crank (KERS) but
instead of the measly 400kj's per lap available now 5 times the power
can be harvested (2MJ's) presenting an entirely different challenge
in terms of brake balance. Although only 2MJ's can be recovered
4MJ's can be released each lap meaning that not only have the FIA
increased the output to 120KW (roughly 160bhp) at peak power it can
be used for 33.33 seconds. An interesting aside is F1 car's
currently operate within the optimum KERS dispense range for around
50-60 seconds, this optimum range will obviously change with the new engines due to their linear power delivery.
Having
read over the last paragraph you may be confused as to how you can
harvest 2MJ but use 4MJ well this is where the other aspect of ERS
comes into play (TERS). TERS or Thermal Energy Recovery System
encompasses the recovery of energy from the pressure charging system.
An MGUH (Motor
Generator Unit – Heat) is attached to the turbo compressor and
recovers energy otherwise wasted by the compressor. This recovery is
done either when the driver is backing off the throttle (normally
taken care of by a wastegate) or when the pressure being produced
supersedes the engines requirements. In either case that energy can
then either be sent to the ES (Energy Store / Batteries) or
symbiotically shared with the MGUK via the MGU control unit.
The
Energy Store can hold upto 4MJ of energy (10 times the current KERS battery capacity) which can be be utilsed
either by the MGUH to spin the compressor (reducing lag) or by the
MGUK at a rate of upto 120kw (roughly 160bhp). As I mentioned earlier
if this 4MJ of energy were to be dispensed solely by the MGUK at
120kw it would equate to 33.33 seconds of peak power. However we can
also see from the Flux diagram in the technical regulations that the
MGUH and MGUK share a symbiotic relationship whereby energy recovered
by one source can be dispensed by the other without the need to send
it to the ES. It would be possible to recover energy from the MGUK
during braking and release it simultaneously through the MGUH giving
instantaneous power when the driver returns to the throttle without
the need of exceeding the 4MJ storage limit.
Storage
will be taken care of by a battery unit of prescribed weight (No less
than 20KG's and no more than 25KG's) stored under the driver in the
safety cell just as the KERS batteries of today's cars are. Battery
Storage is one of the single largest challenges in the ERS system as
being able to provide storage for a high quantity of electricity at
rapid rates is difficult. The KERS systems in use since 2009 are
only required to store 400KJ's of energy which is 10 times less than
the new Energy Store. This will require planning in order to achieve
the right balance between storage capacity and charge/discharge
rates. It's widely regarded that the current KERS battery consists
of Lithium Ion cell(s) whilst Lithium Ion Polymer cell(s) may give
another option in 2014 due to their quicker charge rates and easier
packaging.
Battery
tech doesn't stop there, as an important aspect of the electric cars
quest to replace the combustion engine better storage methods must be
found. The future presently lies in the application of nanowire
batteries (silicone nanowires cover a stainless steel anode rather
than a graphite one, increasing power and storage capabilities) and
the use of Lithium Air batteries which for all intents and purposes
will revolutionize the market once they can be applied.
The
other area that can be utilised is the combination of the different
battery technologies as Red Bull Racing have been doing. Red Bull
utilise Supercapacitors within their KERS system in order to manage
the flow of electricity and storage and raises an important question
for 2014. Their recent association with Infiniti as title sponsor
allied the two in the research and development of KERS technology and
although the teams will purchase their Power Units from their
respected engine partners (Ferrari, Mercedes & Renault) they are
free to supply their own ES. Working with Infiniti may provide Red
Bull with access to an advantage that other teams have not considered
outside of their Engine manufacturers scope. This is especially important as the ES is the only part of the power unit that won't be homoglated (From the 1st March 2014 the units consisting of Engine, Turbine, Compressor, MGUH & MGUK all will classified as a power unit and development froze)
So
now you know a little more about how ERS will work in unison with the
engine perhaps we should turn our attention to the physical
components and assess how they may be applied to the new units.
The
MGUH converts the excess rotational forces between the turbine and
compressor and so will most likely sit between the two making for a
larger unit. There are several ways in which this can be introduced
to the packaging of the engines with the most obvious selections
already having been shown by Magnetti Marelli, RenaultSportF1 &
Mercedes-Benz HPP below:
Above:
Magnetti Marelli recently showcased an example of their product with the 2014 power
plants in mind. As we can see the MGUH sits between the Turbine and
Compressor housings converting waste energy into electricity to be
sent either directly to the MGUK for additional power or to the ES
for storage for later use.
Above:
When Mercedes-Benz HPP invited journalists to visit their factory at
Brixworth recently the image above was also released. This is a mock
up of the Mercedes unit but will probably in reality bear no
resemblence to the 2014 power unit. As we can see Mercedes took the
opportunity to showcase a similar concept to the Magnetti Marelli one
seen above. The image shares a symmetry with the image previously
released by RenaultSportF1 (below) however in their mockup they also
present the option of intercooling the charge air
These
images released by the manufacturers are simply to create imagery for
the fans and the final product will likely be wide of the
specification shown. Somewhere in the midst of their deceit and the
reading of the regulations reveals that there are many options open
to the designers in terms of packaging this technology:
I
did a few sketches of my own a while ago (please be aware these were
to get idea's down and so are far from any kind of scale or correct
angles) based on a few ideas I had in regard to the placement of the
ERS system:
.JPG)
Above:
In this image we can see that when I separated the Turbine from the
Compressor in order to place the MGUH in between I extended the shaft
through the central V. This would allow the hot side of the unit
(turbine) to be at the furthest point from the cold side (compressor)
resulting in less heat soak from the turbo and shorter lengths for
the exhaust and inlet manifolds. However the problem with this would
be the shaft from the Turbine to the Compressor is increased in
length and weight potentially increasing the chance of
vibration/failure. The potential issue that struck me with this
configuration most of all though was the requirement for ambient air
at the compressor end would now sit directly below the airbox. This
results in a 90o
turn
from the airbox down to the compressor which may be considered
undesirable in performance terms. The other option would be to have
the Turbine at the front of the engine giving the exhaust a 90o
angle to turn (twice) and head under the block (which is raised from
the 2013 position by a further 32mm from the reference plane)
.JPG)
Above:
This image is really a variation upon the previous with the Turbine
and compressor sitting at either end of the engine's V. This time
however I’ve incorporated intercoolers either side of the engine in
order to cool the inlet charge further. Conflicting information has
been given out by the engine suppliers in regard to the usage of
intercooling (Renault saying it's inevitable and Mercedes not) As in
the variation above the engine could face in the opposite direction
(turbine forward) with the exhaust going underneath the engine.
.JPG)
Above:
In the last sketch we see that the turbine is mounted at the rear of
the engine block. Using the Magnetti Marelli unit as a reference
I’ve placed the compressor between the V. (Of course this is all
very dependent on unit size) This allows a direct route from the
compressor to the inlet manifold which is donut shaped to allow for
the airbox to pass through. The concept is similar to the one now
seen in the Renault rendering only they have the MGUH on the other
end of the compressor shaft.
Sizing of the Turbine and Compressors used will be vital to the way in
which power is both used and extracted (TERS) making for decisions by
the engine manufacturers at this stage that will provide a differential
between the suppliers power units.
In summary far from looking at the new power units as doom and gloom I
see the potential for some great racing whilst also passing
technology down the line to the road car industry. The utilisation
of the pressure charging system and ERS the cars won't suffer from
being underpowered and will still have a very F1 distinctive sound
(even if it is demonstrably different from their V8 counterparts.