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Showing posts with label Degredation. Show all posts
Showing posts with label Degredation. Show all posts
23 Mar 2013
28 Sept 2012
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I hear a lot of fans and media alike claiming that Hamilton's move to Mercedes is intrinsically linked to the new V6 Turbo engines that will befall the formula in 2014. I fail to see the connection behind this theory, yes this will be the first time since 2006 F1 has been without the V8 engines but Mercedes will allow their engine partners the same engines as the works teams. So with the same engine as McLaren & Force India in 2014 surely there are no advantages to being at the Silver Arrows?

However it's not the core engine that could make the difference for Mercedes it's the rise of the new ERS (Energy Recovery System) within the 2014 regulations. With core power from the V6 Turbo engines being down on the current V8 engines more focus has been shifted toward energy recovery and this is something that Mercedes may not include in their engine partnership deals.

This comes in two forms:

MGUK - Recovery and Usage via the drivetrain as KERS uses now will be upped from 60kw's to 120kw's maximum output. The current power allowed per lap is 400kj's and this has been raised to 2mj's (5 times the amount) at the current 60kw's this gives around 30 seconds of power per lap

MGUH – The pressure turbine (Turbo) is allowed a mechanical link, this is used to extract thermal energy from the turbo that can be repurposed at lower RPM via the same mechanical link. At high power outputs the turbo will create more pressure than can be used by the limitation of fuel flow within the regulations. This will be regulated by controlling the compressor speed for both harvesting and dispensing of energy. No limit has been placed on the amount of energy that can be harvested or dispensed by this system with the battery storage capacity being the limiting factor.

ES (Energy Store) – There is a minimum weight of 20kg's and maximum of 25kg's weight for the ES, based on current Lithium Ion Polymer Batteries 1MJ can be stored per KG giving a maximum of 25MJ available. You also have to consider packaging and battery degradation into the life of the ES which means more likely the ES could store somewhere around 15-20MJ's of power with 2Mj's attributed to the MGUK this leaves a sizable chunk to be proportioned to the MGUH. Assuming they wish to create roughly 160BHP permanently through the MGUH (average laptime of 1.40.00) they would need around 16.8MJ's of storage or 16.8KG's.

I believe Mercedes are pinning their 2014 hopes on the basis of an ERS system that is vastly superior to many other designs with them maybe only selling the core engine to their engine partners (McLaren & Force India) they may be able to steal a march on them. Having based my crude assumptions for power output and battery life on Lithium Ion Polymer batteries Mercedes may also have other technology up their sleeve. With a leap needed to be made by car manufacturers in order to make electric road cars more viable Mercedes may be looking to use Lithium Air batteries which can store around 9Mj's per Kg making the thirst for more power even more accessible.

EDIT 29/09/12

Listening to feedback on the article I'd like to add that MBHPP (Mercedes Benz High Performance Powertrains) currently supply their works team (Mercedes), McLaren & Force India with 2.4 Litre V8 Engines and KERS.  However as Red Bull have proven this year even if you're supplied something the team can adopt a different solution.  Red Bull are supplied their KERS as part of their engine package from RenaultSport but have this season also run with Supercapacitors on the floor in order to alter the way in which power is distributed and used.  Mercedes (GP) could indeed re manufacturer their own components in house not utilising all the components sent to them by their sister company MBHPP giving them an advantage over McLaren & Force India.  That's not to say that those two teams couldn't do the same and gain an advantage but the cost / R&D would be much larger.

I won't bang on about Mercedes short comings over previous years (already covered that in my article: The Trouble at Mercedes - http://somersf1.blogspot.co.uk/2012/08/the-trouble-at-mercedes.html ) but it's safe to say that Lewis' decision wasn't based upon the teams poor performances since their inception in 2010 or their slow development rate throughout each season (2012 being a prime example with it taking them to race 12 to bring the 'Coanda' style exhaust even though it's been clear it has an advantage from an early stage).  If Lewis has made his decision to race for Mercedes on a technical ground it is that he will be the focus of each car build and development plan each season coupled with the opportunity for Mercedes to steal a march in the regulation changes of 2014.  Where this logic may fall down is McLaren can take a poor car and by season end have arguably the best car on the grid, Mercedes have yet to show this ability and moreso seem to fall back throughout a campaign.

The Brackley based team have however been quietly amassing an arsenal of technical minds amongst their ranks with most recently Mike Elliot previously of Lotus nee Renault joining them as head of Aerodynamics, with John Owen reshuffling to Technical Director.  They have Aldo Costa previously of Ferrari as Engineering director, Geoff Willis previously of RBR/HRT as technology director and Bob Bell as Technical Director (Although this is a position John Owen now holds so I'm unsure if Bell has been reshuffled) who has worked for McLaren, Bennetton, Jordan and Renault in all sorts of aero capacities. Ross Brawn oversees all of these as Team Principal. 

I think 2013 will be a difficult year for Mercedes and Lewis as they try to adapt to each others styles, it is however an opportunity for them to build their 2014 challenger around their new star.
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29 Jun 2012
Part Throttle Exhaust Blowing via Cylinder Deactivation


I talked briefly about Red Bull's apparent usage of 'Off Throttle' blowing in Valencia (although they have been doing this since the start of the season) in the latest edition of the #TechF1Show. In my previous articles I looked at the aerodynamic gains Red Bull had taken at Valencia when the team finally got the Sidepod Tunnel to work: http://somersf1.blogspot.co.uk/2012/06/red-bull-valencia-gp-technical-analysis.html this leads us back to the topic of Throttle Blowing which helps to maintain a continuous exhaust flow over the vital aerodynamic components at the rear of the car.

My theory leads me to believe that Red Bull are utilising cylinder deactivation in order to attain a continuous exhaust flow which in turn leads to more downforce and better overall balance. The advantage of using exhaust gas whilst off throttle can be huge in terms of aerodynamic influence, utilising exhaust gas whilst cornering stabilizes the car and gives a continuous airflow to the key aerodynamic elements at the rear of the car.


The video above highlights the 'Off Throttle' sound of the RB8 at Valencia. 

The FIA's amendments to the rules for 2012 were designed to stop the teams running their exhaust solutions internally giving them the maximum area of coverage above the diffuser. As always the teams have engineered ways to continue using the exhaust effect to gain rear end downforce.  The more difficult aspect however has been losing the effect of 'Off Throttle Blowing'.  During the 2011 season you will have become accustomed to the in corner 'cackle' sound the cars produced. What this sound was a sign of was the blown effect generated by the exhaust continuing to be used even when the driver was off throttle. To achieve this effect the ECU would cut the ignition but continue to send more fuel to be exhausted during the off throttle moment creating blow through. This continued the blowing effect even when the driver was fully lifted out of the throttle giving a seamless/continuous amount of rear downforce from the exhaust gasses exiting above the diffuser.
The FIA redefined many of the protocols available for mapping the ECU during the off throttle period and so many are now wondering how Red Bull are achieving the effect. Red Bull are not on their own in the search for the off throttle effect and all the teams are pushing the boundaries of the new regulations placed upon them. However I believe that Red Bull are utilising Cylinder Deactivation during part throttle in order to attain the continuous blowing effect. Cylinder Deactivation is a process that the teams normally use in Safety Car periods in order to save fuel, this is controlled by movement in the camshafts and can probably be best visualized by watching this short video:


Thanks to the Audi video above we can see how cylinder deactivation can be utilized in different driving conditions


This will allow the driver to stay at part throttle where as previously he would be off throttle, as when using cylinder deactivation it's like driving a vehicle with a smaller displacement engine. This will effectively give better driveability and traction at lower rpm's allowing the driver to stay partly on throttle giving a continuous exhaust plume. This creates downforce irrespective of throttle position (except at possible absolute zero) which in turn gives the driver more balance.  The sound generated is simply a byproduct of deactivating those cylinders. This will help Red Bull achieve more downforce without the loss of the sealing effect at the diffuser. This is important due to the impact of tyre squirt and it's lateral flow into the diffuser channel, removing Tyre Squirt from influencing the diffuser aerodynamically will result in less movement at the rear of the car.  Although the theory is the same as the term EBD or Exhaust Blown Diffuser it can't be held in the same regard as it's effect is not as great.  We shall perhaps have to coin a new term along the lines of CDBD (Cylinder Deactivated Blown Diffuser) although I'm sure someone will come up with a more apt acronym. 

Combining all of these elements (Cylinder Deactivation, Exhaust position, Exhaust plume trailing path and Diffuser design) results in better balance, faster lap times and less tyre degradation. Either the FIA will have to clarify it's position on the usage of cylinder deactivation during racing conditions or we will see all of the teams using the method. As usually occurs in these situations one engine manufacturer's ability to control/benefit from this will far outweigh anothers and so I’m sure we will see a protracted battle to utilise or ban it's use.

Lastly I'd like to leave you with Sebastian's onboard lap, we can see from this how smoothly his transitions between on and off throttle are how much quicker he is able to pick the throttle up.

 
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17 May 2012
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Much has been written already about the issue of tyre degradation the teams face. Thermal degradation is this seasons buzz word(s) but I'll go onto explain that it's not only the tyres affecting the closeness of this years racing.


Aerodynamic Influence


The loss of EBD (exhaust blown diffusers) has been a massive hammer blow for most of the leading teams. As we all know energized airflow created by the exhaust gases above the diffuser area used to generate massive amounts of downforce.
This downforce generated at the rear needed to be carefully counter balanced by the equal amount of front downforce. With EBD banned the teams are trying more ways in which to gain back the lost downforce. Some of the teams have adopted neutral exhaust positions where as others are using bodywork and angling of the exhausts to promote flow toward the floor. Due to the inaccurate nature of this flow in open atmosphere an element of tyre warming is inevitable. This may well be accelerating some of the rear tyre degredation we have been seeing.


Suspension


Bearing in mind the loss of additional pressure generated on the rear suspension by the loss of EBD this needs to be balanced up front and so the suspension yo-yo effect begins. Each aerodynamic update presented to the car requires the suspension settings to be tweaked to gain improved traction.
McLarens new higher nose can be seen as the largest representation of this so far this season with a big aero balance shift. Their new nose allows more air to flow toward the leading edge of the floor and then onward to the diffuser. This will require the team to adjust their suspension settings to counteract the additional downforce being generated at the front combined with the loss of some front end downforce.
We all saw last year how far Red Bull were willing to go in terms of pushing the limits of the Pirelli's at Spa when they were adding a pretty serious amount of 'camber' to their setup. (Adding camber leans the tyre in at the top toward the car). This has the benefit of giving a larger 'contact patch' (more surface area of the tyre touching the ground) however the further you lean the tyre the more chance you have of tyre failure and/or changing the character of the tyre as you are effectively using the sidewall of the tyre to do a job it wasn't designed to do. I haven't heard much so far this year about the amount of camber being used but I'd pretty much guarantee the teams are pushing the limits of what is viable.


Weight Distribution


The FIA added the following rule for the 2011 / 2012-2013 seasons:

4.2 For 2012 and 2013 only, the weight applied on the front and rear wheels must not be less than 291kg and 342kg respectively at all times during the qualifying practice session.
If, when required for checking, a car is not already fitted with dry-weather tyres, it will be weighed on a set of dry-weather tyres selected by the FIA technical delegate.

This effectively narrowed the operating window of many teams who were perhaps running more exotic suspension setups in order to attain better aerodynamic advantage. Rake is an important element in adjusting the area available in the diffuser as the rake increases so does the volume available in the diffuser. EBD allowed considerably more air to flow through the diffuser last year and thus many teams are running with much less rake this year. This is not the only reason though, when running more rake you are effectively pointing the car nose down. This will tilt the weight distribution forward and as we can see from the new rules this is something the FIA is trying to minimize. With those 2 mandated minimum weights combined (633kg's) this only leaves 7kg's of 'free weight' Due to the minimum car weight of 640kg's. This allows the teams a little more than a bag of sugar to distribute weight how and where they want. Rearward weight should give better traction where as weight placed forward may help those who can generate more airflow to the diffuser gain rear downforce. The weight distribution rule narrows the window available for the teams and so as far as I can tell this rule is much more of a contributing factor to the closeness in racing than the tyres themselves.

I do however see alot of fans angry that Pirelli may have gone too far with their compounds making them degrade too quickly. I think we have to consider that with the aforementioned weight distribution having stronger compounds will only give a linear result.


Driving Style


When a driver finds a setup sweet spot they are able to capitalize on this linearity and drive the tyres beyond their usual operating window much like Sergio and Lewis have done so far this season.
You will probably have noticed that some of the memorable drives from this seasons 5 races have come
from drivers out of position who have come back through the field by 'better managing their tyres' I however believe this has more to do with their lines during those laps. These drivers tend to spend less time caught up with drivers on the same strategy as them and with the aid of DRS overtake cars that have less pace. Ultimately it also means they spend a fair amount of time 'off line' which is essentially a colder surface and remember we are talking about 'Thermal' degradation, yes it may be dustier and have some marbles but it may remove some of the over heating effect from the surface temperature of the tyre. What do you do with your wet or intermediate tyres on a drying track (racing line)? That's right you get off the line and cool them off. Remember Lewis' pass on the 2 Toro Rosso cars? Yes it may of been instinctive as a racer for him to take the undercut style but it was not only more aerodynamically efficient (getting out of the turbulent air) but I think perhaps took much less life out of the tyre through a cooler contact patch.  The racing line is a build up of rubber created by reoccurring usage of the same line, as I'm not a tyre engineer I can't be sure but surely this creates a more abrasive surface and in turn heats the tyre more.


In Summary


Let's not be so hasty to jump on the Pirelli hate bandwagon and realize more factors are in play than simply Degradation due to excessive wear.  Pirelli were given a brief by the FIA to provide tyres with a bigger drop off to aid the show and make the racing much closer.  They have achieved this but I feel it's also important to realise that the effect the FIA made on the cars by removing EBD and also mandating weight distribution will also be contributing to the effect.  Many are questioning the tyres due to their degradation rate but we have to remember that all teams have equal footing in terms of rules/car design.  Those that spent more time analyzing and designing around the tyre effect are having a more productive season than most.  Lest we also forget that the teams that have been best utilising exhaust effects over the last few years in order to gain downforce have less data and indeed experience in gaining time from suspension setup at lower ratio aero efficiency than teams like Lotus, Williams and Force India.




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