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7 Mar 2014

The team from Milton Keynes that dominated all but the initial phase of the last regulation phase (arguably better than BrawnGP once their car had a Double Deck Diffuser installed) is struggling to convince even themselves they can take the chequered flag in Melbourne, let alone be competitive. A list longer than my body, let alone my arm awaits the technical team as they re-assemble post test.

There seems to be several key issues at play along with some rather confusing ones to talk about in regards to both the RB10 and the teams approach pre-season.

Legality

It's only a small point, but one worth making, the RB10 used at all three tests thus far would be illegal if it were to start the race in Melbourne. 


Since the RB10 was unveiled it has been devoid of the FOM camera's on the side of nosecone, now this may seem like a trivial matter but it points to the fact that the RB10 isn't being shown in a competitive guise. Can we therefore infer that Red Bull have another nose design that they aren't willing to show to their competitors until the very last moment? Or are they being considered such low performance differentiators that they'll just place them on the side of the nosecone come Melbourne? Lest we forget that Red Bull have been a team over the last few seasons to have leveraged these items for an aerodynamic advantage like no other. Placing the camera's in several locations to best suit the circuit demands (Nose tip: hammerhead position, Between the front wing pylons: taking advantage of the restricted central section of the mainplane and lastly in the most neutral position on the side of the nose) and moving the airflow in different ways.

Simplicity

When I first analysed the RB10 I remarked at how basic the rear end of the car seemed in comparison to some of the teams opposition, expecting the team to revise the concept throughout pre-season testing. This however never came to fruition with the team doing some rudimentary cut away and piping work on the original bodywork to quell the thermal issues caused by such tight packaging. 



 
The downforce losses associated with the rule changes has led to many teams taking a sledge hammer to a nail whilst Red Bull appear to be using a tack hammer. Whilst the other teams are desperately proliferating the area above the floor with aero trinkets aimed at mitigating the loss of the Beam Wing, Red Bull have a relatively sparse floor etc. What is obvious though is that everything has its place, with the shrouded halfshafts within the lower wishbone placed directly behind the lower cooling outlet. Above these outlets we find the extremely shrink wrapped section of bodywork
converging the airflow from the upper surface of the Sidepods and focusing it on manipulating the exhaust plume above it. The Rear Wing is devoid of leading edge tyre wake slots as seen on the RB9 and most of the 2014 field (with some teams increasing to two per endplates) and seemingly points at the team concentrating their efforts at outwashing the rear airflow and entwining it with the low pressure behind the rear tyres. This less complex rear end will of course likely lead to less drag and could be one of the reasons why the team have taken the strange decision of not running louvres in the upper quadrant of the Endplates. Usually used to reduce the pressure gradient at the outer portion of the wing and therefore reduce drag they have become a go to for all the teams and so it seems strange to see Endplates without them now (apart from low angles of attack setup such as Monza).

Thermal Issues

We all know that the new powerunits are insanely complex and that due to the reduction in engine capacity (2400cc V8 to 1600cc V6), inclusion of a turbocharger and the increase in performance demand from two energy recovery systems that the car's thermal footprint has increased. Cooling therefore has become a massive priority to the teams and this comes in the form of several heat exchangers too: The ICE is cooled by the conventional radiator(s) whilst the inlet charge (turbo) is taken care of by the intercooler(s), there is then a plethora of oil coolers taking care of the ICE, Turbo and Gearbox. The quantity, sizing and orientation of all these heat exchangers have an impact on the car's weight and design. Having seen the layout being utilised by Toro Rosso and Lotus (ICE radiators, Intercoolers and Oil Coolers mounted in both sidepods) it's clear that Renault have designed their Turbo to receive cooled air from two sources (an intercooler in either Sidepod) whilst the extremely tight packaging displayed by the RB10 alludes to something different, with the team likely following their usually extremely marginal arrangement. 
I'd suspect the team have tried to use an asymmetric layout with an Intercooler placed in one Sidepod and the ICE radiator in the other, with the core thickness of the intercooler being substantially larger than it's radiator counterpart it would allow for the stacking of oil radiators to be done with the ICE radiator, retaining uniform packaging. In terms of cooling this perhaps isn't too much of an issue although the pipework may cause somewhat of a conundrum when returning the charge back to the turbo.

Braking

One of the key components of the changes for 2014 and that will feature heavily in both team and driver excuses, whilst becoming a firm fixture in commentary is: Brake-by-wire. The brake-by-wire system is a legacy of the increased performance being extrapolated from the MGU-K this season and puts a demand on both the engineers and drivers in getting it right.

Brake-by-wire put simply is an electronic system that sits on top of the hydraulic braking system in order to regulate the amount of braking done by both the ERS/MGU-K and the standard mechanical braking system. This is due to the fact that the MGU-K must now harvest 5 times the amount of energy per lap than it's KERS predecessor (2mj's rather than 400kj's). This additional braking force from the MGU-K requires much more focus in terms of balancing the front to rear brake bias and so this where the electronics step in. The driver will still select the amount of bias he requires for each corner, but rather than using the old mechanical setup that you're used to seeing them reach for on the left hand side of the cockpit, they will instead make changes via the steering wheel (additional paddles or buttons). These changes are metered by the amount of MGU-K harvesting happening at that given moment, allied to the amount of pressure applied to the brake pedal.

This requires a level of compliance between the driver and the software (which has been pre-written by the teams engineers), at this stage many of the drivers are still finding problems with this and are complaining that they have a lack of feel. Red Bull are believed to be one of the teams having issues with their code and have likely been trying to push the performance envelope too early.

Energy Store (ES)

In terms of performance gains from one team to another who utilise the same powerunit there isn't perhaps huge scope in 2014, with homologation encompassing almost the whole powerunit. One area that was left open for inter powerunit gains however was the Energy Store and this is apparently where Red Bull tried to steal a march on their competitors but appear to have fell a little short. As we know over the last few seasons Red Bull have been plagued by problems associated with KERS, with the blame largely falling on Adrian Newey's shoulders for the extreme packaging he requires for aero. For the past few seasons the team have run with a split system that required a battery pack placed in the sidepod and a set of supercapacitors placed around the gearbox casing. The team did this not only for performance gains within the KERS but also to assist in the cooling and overall packaging of the system.

For 2014 however the ES has a prescribed position under the driver and will likely be encased by the fuel cell too. To continue to gain an advantage over their fellow Renault competitors and they hoped over the rest of the field the boys from Milton Keynes had decided to invest in their own battery technology. This appears to have been one of the teams biggest faux pa's and has led to the low mileage during testing and numerous stoppages throughout. When installed and allied to the Renault unit they've had a difference of opinion, this has a massive effect as not only does it affect the physical installation of the ES and associated cabling. It also has an effect on the software code that has been written, especially the way all the sub systems (Turbo, MGU-H and MGU-K) have to work in perfect harmony this season. 

For the final pre-season test in Bahrain it appears that Red Bull finally bit the bullet hard and switched to the Renault ES as used by Lotus, Toro Rosso and Caterham already and led to the increase in mileage. The problems associated with this will have led to compromises in installation and packaging though that will take some time to rectify and will likely never be quite right. Furthermore the code that had been previously written by the team to control the turbo, MGU-H, MGU-K and brake-by-wire systems will largely be classed as junk and have to be re-written. “Why so different?” I hear you say, well it was to do with the way the original Red Bull ES was able to receive, store and transfer the energy and so intrinsically led to different energy pathways and a possible performance advantage that is lost now they've had to revert to Renaults.

Conclusion

Red Bull are clearly several steps behind where they wanted to be but as they've proved in the past, they are more than capable of overcoming hurdles put up in front of them.  With so much reliable and consistent running displayed by their opponents however I wouldn't expect them to be close in the first part of the season and they may be rubbing their hands together over the prospect of a double points finish at the final race.
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20 comments:

  1. Matt, I think I did see pictures of RBR having camera mounds in a classic position on the sides of the nosecone during the second test. I will have a look at AMuS, as I think it was their picture.

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  2. Hm, Can't find it so maybe it was not a Red Bull in that picture

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    1. Had been keeping a key eye on RBR's nose throughout so was pretty sure you wouldn't find it but thanks for looking.

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  3. You should have written its, instead of it's, on numerous occasions. It's surprisingly jarring when trying to read this piece.

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    1. Having looked i've found and changed one instance. I apologize for my grammatical errors but as I'm not a full time writer I will make the occasional error.

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  4. If Red Bull used their own 'energy store' it would mean that their PUs would not match the unit homologated by Renault.

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    1. The ES is considered a separate entity by the homologation regulations. If you check the matrix the homologation only covers the weight and size of the unit. This means that each team could, if they see fit specify their own ES.

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    2. Thanks. I'd not seen mention of the ES being treated separately. Is it subject to the 5 per season limit? Do you know if other teams are using their own solutions our are they all using the one supplied with the PUs?

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  5. Most interesting!
    I haven't seen it mentioned elsewhere that some of the Red Bull's problems have originated from trying to use their own battery technology - and then switching back to Renault spec battery. Not even in the F1 Technical forum.
    Just the heat dump problems from the H unit, and switching the battery cell manufacturer to Panasonic.

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  6. Well done Matt another excellent article. Thank heavens for people like you that devote so much time and passion to informing people.
    It seems RBR have long had KERS issues Supercapacitors are a really good solution as they don't have internal resistance of Li cells and are great as a buffer in both discharge and charge modes, but they are not currently a viable solution in a tight space.

    Matt, on the subject of cooling I have a fundamental problem here with all of the discussions around so called thermal issues: conservation of energy. Simply, if the new turbo engine engine is more efficient (it is) and the power is similar (it is) and the amount of fuel burned is less (yes again) then the heat output from the PU irrespective if that heat is generated by turbo compression, electrical charge / discharge or the ICE then the total heat output MUST be less. In other words the total area given to heat exchangers must be less in 2014 than in 2013. I can understand that a large number of heat exchangers are required now, the total heat extracted must be less. 2013 F1 was burning 150 kgs of fuel and now its 100kg...QED
    Or am I missing something?

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    1. Hi Rob

      Thanks for the feedback as always, just doing what I can to keep everyone in the loop.

      You have to remember the downsizing when considering the thermal impact. They're trying to attain more power at less revs with a 1.6 V6 rather than the 2.4 V8. Although the redline is set at 15,000 rpm I'd say peak is delivered just before 10,500rpm due to the flow restrictions. This means getting roughly 670bhp from the ICE/Turbo.
      Furthermore something that has had little coverage thus far in terms of thermal demand is the heatsinks that are being used. These help bridge the gap when the electrical energy being harvested has either no direct use for either the MGU-H or K or can't be stored in the ES (either due to capacity or simply due to overflow from the change in AC/DC)
      Red Bulls rudimentary cooling options seen at the tests was in part to relieve the heat being dissipated by the heatsinks. These will also have a temperature threshold and likely caused the car to go into shutdown on many occasions when the temperatures were exceeded.

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    2. Matt,
      Isaac Newton would spin in his grave. This is simply wrong. The principle of conservation of energy means one cannot create more energy, or heat from less fuel, all things being equal. Given that the efficiency of the PU has increased from around 30% to 40% means that less fuel is burned per kw output. Electrical energy is part of that 10% gap, so you cannot count it twice! The heat produced by the conversion (in)efficiency of the electrical energy is part of the 40% efficiency rating. It's really very simple; fuel burned = Heat. 100kg of fuel at 40% efficient vs 150kg at 30%. 150 kg of fuel produces more heat but comparable energy to 100kg of fuel at 40% which means the heat output - ie 70% of the 150 kgs is converted to heat so the V8 requires more cooling.

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    3. Thanks for your reply as always Rob but all things aren't equal, we have a turbocharger cramming more air into each cylinder, direct injection providing better stratification and thats all happening at lower rpm and lower compression.

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    4. Obviously the conversation of energy applies but now an F1 car is conserving more energy. More energy is being keep within the bodywork.

      Previously much energy would disappear out the back through the exhausts. The turbo has reduced that loss significantly.

      The 'energy store' is 10x the capacity, that must get hot has it charges and discharges. There's an extra MGU in there. Each element is not 100% efficient so more heat is contained etc. etc.

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    5. Guys Let me explain why I am right.
      The worst case in any scenario where one is converting fuel is that it produces 100% heat. If you start with 150Kg of fuel as opposed to 100Kg you are creating 33% more heat. The job the engine designer has is to minimise this loss. Turbocharging increases engine efficiency because it captures some of the waste heat and turns that heat into energy and in the case of F1, this takes 2 forms. 1. Heat is converted to inlet pressure by pumping and 2. Excess energy in the turbo is captured into electrical energy by the MGU-H. It is vital to understand that this energy is already accounted for. As I have said a turbo engine is more thermodynamically efficient, unfortunately the turbo heats the charge through compression, requiring a cooler to make the charge denser. The more boost pressure required, the bigger the turbo and the greater the amount of power required from the exhaust gas. Any heat extracted by air-to-air or water-to-air heat exchangers, is waste heat that would have otherwise been expelled as exhaust heat. So a turbo is minimising energy loss by transforming heat otherwise lost in the exhaust to another form of energy. The heat expended in pumping and its consequent cooling is NOT additional to the total energy; it is merely represents a reduction in the efficiency gain: this is the law of conservation of energy.
      The law of conservation of energy (First Law) states that "THE TOTAL ENERGY OF AN ISOLATED SYSTEM IS CONSTANT; ENERGY CAN BE TRANSFORMED FROM ONE FORM TO ANOTHER, BUT CANNOT BE CREATED OR DESTROYED", so while F1 engine designers are smart they cannot defeat the laws of physics. Any system with a finite energy source (Gasoline in this case) is an isolated system.
      Let’s now take the MGU-K. This is transforming Kinetic energy – critically, this is energy already expended-into electric energy. The energy captured here is then expended both while charging and discharging both in the electronic systems and motor generators. This is why it needs to be cooled …The heat expended here needs cooling but this is NOT additional to the total energy; it is merely represents a reduction in the efficiency gain from the hybrid powertrain.
      I understand the confusion here with all of the additional coolers, but the fact is this is because of inefficiency of the heat exchangers. In particular an air-air turbo intercooler takes up a massive amount of space while a water-air one is more efficient but heavy. Have a look at a typical intercooler – they are huge and that is with a typical 1 bar max pressure over atmosphere.
      These are the challenges that Newey and other designers faced – packaging. Yes there are more things to cool but the total heat extracted is less than the V8 by a considerable margin. Assuming the power output from the closed system is the same between V8 and V6T and the input of energy is 33% less one can see that the hybrid powertrain is in fact 33% more efficient because it takes 33% less fuel to run it.

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    6. I don't think anyone is saying the power-train as a whole is less efficient. Clearly the energy is coming from less fuel so there is less energy being put into the system. However, it is clear that cooling is a significant issue with these new cars and power-trains.

      The increased performance of the MGU-K (less heat loss through the brakes), the presence of the turbo (a significant heat source itself and less lost through the exhausts), the addition of the MGU-H (a new heat source) and the 10-fold increase in the energy store and reduced noise means more of that energy is being retained under the skin. Hence the cooling issues.

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    7. Rich, thanks for your comment. I am certainly not saying they are less efficient! Matt's comments as I understood them were that there was more heat to dispose of. Clearly that cannot be true. It is the packaging of multiple sources of heat that is the issue as for example LMP1's don't have the same problem as they have more space.

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  7. Kind of a late reply, but the cooled air from an intercooler goes directly into the engine, not into the turbo. The turbo compresses it and the outlet is the thing, that either directs all of it into one sidepod or splits it (can be done with two outlets in a 180° relation to each other on the housing) to be used with two intercoolers. There is no need for a return to the turbo from an intercooler.

    As for the cooling of the power unit, you used to cool the water and oil for the N/A engine, while dumping a lot of heat through the exhaust. Point in case are the glowing exhaust all the way ot the end. Now you have a turbo, which robs the exhaust flow of a lot of energy, which more or less stays in the engine compartment in the form of a really hot turbo, that needs to be cooled. Most of that cooling is done via an oil cooler and also by the ducting to cool it with air. Some of that energy is also transfered to the compressed air in the compressor, which has to be cooled form an ICE. So all in all, it's like dumping hot exhaust from the N/A era inside the engine bay. Not fun.

    As for the KERS, you also retain a lot more kinetic energy via the KERS, so again, it's directed inside the engine compartment. Since nothing is 100 % efficient, you get heat. Before the KERS era you just dumped that energy in the form of heat through the brakes. With KERS you retained a certain percentage of 60 MJ per lap inside the engine bay. That value is now what, 400 MJ? And the percentage value, due to different power requeriements, probably isn't the same. It could be even higher.

    I hope my thinking is correct, i'm by no means an expert on the topic ;)

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    1. Bah, it's 400 kJ/2 MJ, not 400 MJ. Stupid me. But you get the idea.

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