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29 June 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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28 June 2012
25 June 2012
Red Bull - Valencia GP - Technical Analysis

After each GP i provide a Technical Roundup for www.finalsector.co.uk however I felt that the latest updates from Red Bull required a more expansive analysis of it's own.  I looked at the main element of their upgrade at the previous article http://somersf1.blogspot.co.uk/2012/06/red-bulls-tunnel-vision.html
This article however moves to further explain both the reason for the Tunnel and the other components that go to exploit it's potential.



Starting at the front of the sidepod Red Bull have simply converged on the idea of airflow strakes above the sidepod in order to create vortices that energise the flow over the sidepod toward the exhaust plume


Above: RB8 during Australia at the start of the season
 
The original Sidepod Tunnel concept had a cutout in the sidepod ramp with a linear height of 50mm from the floor which utilizes the minimum radius rule. This concept had the Tunnels airflow exit just aft of sidepod ramp in order try and assist the airflow toward the coke bottle region.  Red Bull have experimented with other iterations exiting inside the engine cover in the same way their new tunnel/duct system works but have always had a problem with airflow attachment.
 
Above: RB8 configuration used in Valencia

The new version (above) continues to use the 50mm radius rule at the rear portion of the tunnel but is separated from the the frontal section of the Tunnel by a vertical section of bodywork. Forward of this seperation the height increases and reminds me of the Ferrari Acer Duct in the way the bodywork hangs over the floor. These two tunnels combine and merge atop of thefloor in ducting which exits at the rear of the car (See Below).

Above: These pictures shows the floor of the car, the silver ducts are the tunnels that lead from the Sidepod entry to either the outlets in the the engine cover at the rear of the car (Coke Bottle Region) or to the starter hole.

 Above: Tunnel & Duct Close up

Two theories are emerging in regard to the nature of the 2 ducts and whether the larger tunnel entrance combines with smaller entrance to form a larger airflow pattern as described below:

The image above shows that Tunnel 1 has a step as it enters the duct, this allows the airflow to merge with Tunnel 2's airflow and rotate the stream. This creates a spiraling vortex inside the ductingspeeding up the airflow and removing an element of the boundary layeras the air speeds through the tunnel. The tunnel acts like a Venturi tube with the entrances being the inlet, the duct speeds up the airflow as the duct creates the 'throat' and the lower engine cover exit or starter hole isthe outlet. (See Image Below)

Above: Flow Diagram of a Venturi Tube

The other alternative is that the first tunnel entrance simply merges with the airflow from the engine cover and exits out of the lower cooling hole.  Leaving the later tunnel entrance to flow airflow through the duct and out of the starter hole.

This Tunnel section adds a new dimension to the airflow pattern giving the airflow from the exhaust plume a further means of interacting with the diffuser. Without the means of a better way of describing it, this concept adds another deck. Although not in the same direct way as the original DDD's (Double Deck Diffusers) as it's not part of the diffuser itself, it will increase the effectiveness of the diffuser. 

Due to the way the 3 flows interact (Diffuser, Tunnel & Over bodywork) the diffuser is sealed much further outbound than has been possible so far this season. Being able to seal the diffuser is imperative to the way in which the tyre squirt interacts laterally with the diffuser flow, providing more balance for the driver. Red Bull are further managing this effect with diffuser strakes that turn outward, this allows the flow emitted from the tyre to be straightened and minimize the tyre squirt into the diffusers main airflow channel. If you have a look at my crude representation above I have marked the diffuser area (strakes) in green, the tunnel(s) are shown in Blue and the exhaust channels are marked in Red.

As we can see below from the Australian spec RB8 the original intention was that the airflow from the exhaust and tunnel would converge above the floor and exit through the centralised starter hole.

Above: Melbourne configuration with the starter hole exposed 

As we can see below with the current iteration of the engine cover and internal ducting the air is still directed through the starter hole but no external airflow has interaction with this airflow

 Above: Shows the rear end of the RB8 covering the starter hole

Driveshaft Fairing / Cowl

Above: Sebastian Vettel's stricken RB8 in the pitlane having been removed from the circuit

The other aspect we must look at for Red Bull is their usage of a cowl for their driveshafts, they have covered their driveshafts in the same way all the teams do with the suspension components.  This is not a new feature for Valencia but the effectiveness of the new Tunnel/Duct system is utilised with the combination of this component. This has a many effects on the airflow:
  1. Creates another element in which to turn airflow and manage the airflow coming over the bodywork towards the rear of the car.
  2. Encloses the driveshaft, this removes the Magnus Effect on the exterior airflow. The Magnus effect can create lift something you want to reduce in this area as it will have an impact on the air you are trying to generate downforce with. More importantly though due a massive boundary layer build up it can create a huge chunk of drag too. Not being able to divert the exhaust gases in a precise manner means you would like to control the airflow aft of the exhausts as much as possible. Reducing the effects of this spinning element from the equations especially in such a critical area may be a shrewd move by Red Bull.

I believe that all of these factors in combination are the reason for Red Bull's leap in performance.  They also tie in to the decrease in tyre wear that Sebastian and Mark had at Valencia.  More rear downforce = a more stable rear end and will help reduce tyre degradation.  This current configuration has only been developed due to Adrian Newey and Red Bull's determination to make the original concept work, meanwhile they have inadvertently come across a much stronger version of the original concept.  If we see the strakes, floor and driveshaft cowls as one unit they give the appearance similar to that of the diffuser below which should enhance the diffusers airflow profile.   I hope for the sake of the close championship battle we are currently seeing that the other teams already have similar concepts in development.  As this in my eyes is not simply a one off for Valencia and will continue to provide Red Bull with a large gain over the other teams.

All Images Copyright their original owners: Sutton Images / AMuS / @Khan_F1 etc
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23 June 2012
Red Bull's Tunnel Vision



Valencia see's yet another iteration of Adrian Newey's / Red Bull's vision of this years ultimate concept. This version of the Sidepod / Exhaust / Tunnel concept is the most expansive version to date, encompassing much more bodywork and floor area in order to create a airflow caption area above the diffuser. It's no secret that the Milton Keynes based outfit have been confused that their original iteration of this concept didn't work as planned. Red Bull have attempted numerous versions now in order to attain the effect they first desired at the start of the season, whilst the rest of the field are seemingly converging on the McLaren style exhaust outlet in order to achieve more rear end downforce.  The idea of having this 'false' floor is to further create additional rear end downforce and help toward create a sealing effect.


We can see from the picture above that the exit slope of the sidepod has been increased in length this is to not only accommodate the extended tunnel section but also allow for the McLaren-esque exhuast channel that’s carved into the bodywork. This whole section is a multi faceted airflow conundrum with airflow interacting in many differing ways. In the picture below I have marked out how this flow is destined to work.


Please be aware this is an approximation to further help understand how the flows work and interact

The blue airflow shown coming around the side of the sidepod is destined for the first portion of the Tunnel (As the strake inside the tunnel separates the flow patterns) The strake is there to provide a boundary which creates a higher pressure region, this in effect speeds up the flow either side of the strake and encourages the first element of flow and in turn helps with the second channel of flow which is highlighted in a bolder blue colour.
Lastly as the Tunnel finishes there is a small gap between the sidepod's edge and the vertical floor strake. This area will act like a funnel and converge with the the downwash flow (orange) & exhaust flow (Red)
The green area depicts the last area of airflow for the floor and one that becomes more neutral due to the airflow being robbed by the Tunnel ahead of it.
The McLaren style exhaust channel (Airflow shown in red) helps to guide the airflow from the downwash (Airflow shown in orange) whilst speeding up the airflow of the Tunnel beneath


Moving inbound the flow converges with the airflow coming through the engine cover and exits just below the beam wing and above the diffuser. As we can see from @Khan_F1 's pictures above the exit here has changed from the Montreal spec in order to utilise the additional airflow at exit.


As we can see from the image above Red Bull were utilising a hole in the floor above the starter hole to expell air passing across the floor. This hole is now encompassed by the larger engine cover outlet in order to further funnel the tunnel flow through this area of the floor.


As I write this I'm still unable to find a rearward shot of the RB8 depicting the Diffuser area clear enough to see if there is a difference in design ethos without the tyre squirt ducts. The current diffuser however can be seen to be much more like the Lotus design with outer portion of the diffuser pointing outwards. This helps manage the outer portion of the diffuser flow which in turn manages the effects of tyre squirt towards the central channel of flow. 

Images Copyright Sutton Images / AMuS / @Khan_F1
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21 June 2012
Disparity between Front Runners & Lower Tier Teams


I'd imagine it is difficult for the causual or none technical fan to understand why there is such a disparity in performance between the front runners and lower tier teams. If we were to take Red Bull Racing and Caterham as examples for this article we will see differentiators in performance. I have decided to use these teams as an example as the 2010/11 Champions Red Bull are a team at the top end of their game. Meanwhile Caterham joined the sport in 2010 (under the guise of Lotus Racing and ran 2011 as Team Lotus before finally settling on the Caterham marque). Caterham initially entered the sport using the Cosworth engine and although they weren't quite upto the speed of the established teams they did make their mark as the best of the 3 new teams.
The main reason I have decided to use these two teams as the reference points is due to their common use of the Renault engine but also because Caterham purchase their gearbox and parts of the rear suspension from the Red Bull Racing team (albeit the Caterham uses the previous seasons setup, so for this year the RB7's setup)

So why is there a performance difference between the two I hear you ask. Well that may not be as an easy answer as you would think. Firstly using last years suspension setup means that you are using a geometry/layout that was designed to cater for EBD (Exhaust Blown Diffusers) without the use of this, this year the teams lack rear end downforce. Red Bull utlised the quantity of air flow that could be generated through EBD to run much more rake. Something that the teams this year would need to start with much less of and as the season progresses and additional airflow is scavenged through upgrades they can increase the rake.
Rake for those that are unfamiliar is the pitch angle of the car over its longitudinal distance (ie higher at the rear than at the front, pointing downward) The reason for more rake is as you find a way to add downforce on top the car you need to balance this with creating more airflow under the car. Adding Rake or raising the rear end can give the diffuser a larger cavity to flow more air.
This obviously gives the Caterham designers something to work around and results in a compromise that will ultimately narrow the window in which the suspension can be adjusted. With EBD now banned next year should see Caterham take advantage of the RB8's design philosophy of which the RB9 will simply be an evolution.

Infrastructure

Aerodynamically the Red Bull team over recent years has had the jump on most of the field, lead by Adrian Newey the Red Bull aero team are at the forefront of F1 design. Red Bull embraced the transition from on track testing to a less restrictive ability to design their cars in the Wind Tunnel and CFD. They have also adopted the use of 3D printing in order to rapid prototype parts and test them in the Wind Tunnel environment, this speeds up a process that in the past may have taken much longer to produce parts for testing. Red Bull have many test rigs in order to analyse stress and performance of the car either in it's entirety or individually. By designing the car at this level it allows for a higher level of freedom in terms of design, allowing you to test many components in a short amount of time. As Caterham are a much younger team their level of infrastructure is much less than Red Bull and so it will take time in order for them to purchase and use the equipment and get the skilled staff required to operate them. Red Bull also had a head start by purchasing the pre existing Jaguar team and simply building on that pre existing setup. Caterham however have started from nothing and are working hard to replicate the infrastructure of teams like Red Bull.

The video below is a great watch as it goes around the Red Bull factory circa 08/09 to look at the ways in which the team approach the design of their F1 car. As an emerging team i'm sure they continue to push the envelope and add additional features to those shown but it gives a great idea of the processes involved:


Engine / KERS Performance

Red Bull Racing began using the Renault engine back in 2006 and has such has a fantastic understanding of how to extract the best from the powerplant. Adrian Newey's designs always centre around shrink wrapping the car and making the bodywork as tight as possible. This is part of a match made in heaven as the Renault engine is incredibly efficient and requires less cooling than it's counterparts. Number's touted around the paddock suggest that the Renault engine is down on overall power in comparison compared to the Mercedes & Ferrari engines by around 15bhp. This however is not a problem as the drive ability and much better fuel consumption the engine produces can outweigh this. It is said that the Renault uses around 15 Litres less of fuel over a race distance, this equates to around 10KG's which in a race car is essential weight that can be placed elsewhere.
Red Bull Racing's ongoing technical partnership with Renault has also allowed them to perhaps better understand the mapping requirements of the engine in comparison to Caterham who are only in their second year of supply from Renault.

KERS is something that both teams purchase from Renault Sport and can also affect the balance of the car whilst in both the harvesting and dispensing stages.  Red Bull have more experience using the KERS system and although they struggled initially with system failures they now seem to be on top of the system.  This being the first year that Caterham have used the system they not only had to find a way to package the system but also find a balance in order to gain additional lap time.  KERS also has an aerodynamic effect as additional cooling is required in order to keep the batteries cool.  (Imagine using a piece of electrical equipment for a while and then fetching the battery out, you will notice how warm it is.  As electricity is dispensed the chemical reaction taking place inside the battery heats up the chemicals and in turn the casing.  To give you an idea of the difference in a battery you use to the type installed in a KERS system: A small AA battery has a discharge rate of just less than 10,000 Joules or 1Kj, a KERS battery can store 400KJ's so that's 400 times the storage capacity.  Heatsoak can be a massive factor in the performance of both the batteries life and performance.  The more heat the battery is exposed to the faster the cells degrade and the less effective the cells produce optimum power.
Energy Harvesting is when the electrical motor connected to the crankshaft on the front of the engine withdraws power under braking (engine braking) which has an effect on the balance of the car.  This is why you see drivers adjusting their brake balance during the lap.  The team that can best manage the transition between harvesting, energy storage, battery cooling and energy release will attain the best system.  This I believe is why Red Bull now have Super Capacitors located at the rear of the floor.  These Super Capacitors help to store and release energy more quickly than the larger batteries housed under the drivers seat.  Cooling them will require a more intense level of airflow and that's why they have been situated near the starter hole as it almost sucks airflow into that region.


Mechanical & Aerodynamic Platform

If we take a look at the RB8 and CT-01's main features it's clear to see the disparity in both mechanical & aerodynamic performance between the two. This comes mainly from Red Bull's desire to win and clear determination to provide an effective aerodynamic platform.


Looking quickly at the 2 images above will leave you with very little to tell the differences between the two packages. However on closer inspection there are many details that differ here (Please bear in mind that the photo has been taken at different zoom levels and at different angles and so the 2 photos aren't a true 100% representation of the same thing. We also have to remember that we don't know what fuel loads are onboard either car which could also affect the way in which the cars look/operate):

Mechanical

Firstly the ride height, the Red Bull car is running closer to the tarmac as we can see by the distance the front wing and skid block are from the tarmac. This not only has an effect on the suspension but the aerodynamic platform, you'll note that all of the suspension elements are much more upright on the Caterham this invariably leads to less motion available and in turn less adjustability.  The CT-01 would also seem more softly sprung as you can see by the weight transference. The weight of the car is leaning over on the right of the car as the weight shifts under cornering load. Due to the softer suspension approach we can see the additional angle of attack that the Caterham driver is having to take in order to get around the same corner. Both the wheel angle and drivers hand position show the Caterhams deficiency to the Red Bull.

In order to attain more grip we can see that the CT-01 is also running with less air pressure in the tyres. This is shown as the tyre bulges off the rim. Lower tyre pressures help to squat the tyre on the rim giving a larger contact patch which in turn gives up more grip. The problem with less tyre pressure is it also dissolves some of the suspensions work. Due to the tyre having less inflation the weight of the car acts on the sidewalls creating squish. This squish acts as a form of suspension and counteracts some of the suspensions actions. I'm not saying running with massive tyre pressures is good either as that can create deflection and have the opposite also non desirable effect on the suspension. Finding a happy medium between the two will result in a much more responsive suspension.
One of the larger problems with more body roll is that you spend more time cornering than your opposition and as such will also have to run compromised gear ratio's in order to corner in the right rev range.

Aerodynamically

The front of the nose cone on the RB8 has a much more bulbous frontal area which is in stark contrast to the CT-01's almost pointed nose. The RB8's nose design is all about continued flow management in order to feed/push the airflow into the path of the next component. The CT-01's nose is a much more blunt design with perhaps the highest possible nose configuration available. This is done to try and drive more air under the car towards the floor and speed up the airflow to the diffuser beyond.



The step nose that features on most of the cars this season is a direct response to the teams wanting to get as much air under the nose to the floor as possible.  When EBD (Exhaust Blow Diffusers) were in use this wasn't such a huge requirement as the exhausts fed the diffuser with more than enough airflow.  This meant the air from the front of the car could be directed at both the underside and top side of the floor. 

Red Bull's nose slot in the step area helps to stop flow detachment that usually occurs when airflow meets with a sheer surface. The step or ramp of the nose design although minimally will create some drag. This disadvantage has been deemed acceptable by the teams to gain the air underneath.


The Front wing planes used by the two teams are very similar in design even with the top element sporting similar pointed ends at the inner edge of the element. The RB8's front wing however has additional pylons/vanes just infront of this area that combine with the top element in order to generate flow vortices. These vortices travel at a higher speed than a normal laminar flow. In the case of the RB8 these vortices are then targeted at the turning vanes behind (mounted below the nosecone) in order to direct the flow further down the car. As Caterham don't have these pylons/vanes the vortice(s) generated from the wing tip is much smaller and so the turning vanes are also designed more neutrally.


The picture above is a very crude explanation (in 2D) to explain what I mean by a votice or vortex, the two wing tips create airflow that act on one another sending the airflow into a spin and create a higher speed airflow we call a vortice.


The frontal entry point of the Sidepods of both cars are very similar dimensionally however where the top of the Sidepod on the RB8 slopes inward toward the cockpit the CT-01's lean away. The reason Red Bull follow that ethos is this helps to funnel the airflow towards the rear of the car creating a downwash towards the rear of the floor.  Caterham's version will allow the airflow to tumble off the sides towards the floor and so less flow is contained and sent towards the rear floor. Although both cars run the same engine due to mapping requirements their cooling methods may differ and so radiator size and layout will differ between the two cars. This leads to the difference in sidepod size and shape (packaging).

Due to the requirement to vent the exhaust in a specified way this year design and integration of the exhaust remains a key element of this years car designs. The exhaust gases can be used to manipulate airflow and generate additional downforce when used in the correct way. Red Bulls approach to this is to create a ramp at the rear end of the sidepod with a channel to direct the exhaust/exhaust plume. Positioning/Angling the ramp and channel is vital in helping to draw the airflow coming across the top of the sidepod and from around the sidepod toward the exhaust plume which in turn directs the flow toward the rear of the floor. Doing this helps to generate downforce. 

 
The CT-01's exhaust solution is higher on the body and deals more directly with the airflow from the top of the sidepod than the air travelling around the side. The Shark Gills that cover the exhaust are there to try and keep the airflow attached from the top and side of the sidepod and also reduce the boudary layer speeding up the flow heading toward the exhaust plume. (The Shark Gills are ejecting air that comes through the sidepod entry) The exhaust plume at this higher point on the car does not provide as much airflow toward the rear of the floor as it's Red Bull counterpart and so generates downforce on other area's including the beam wing.


The rear wing has become an area in which much more performance can be extracted than simply by adjusting the wings angle of attack. The beam or beam wing as most call it creates a level of downforce aswell as providing the wings attachment to the car. This area is now designed in order to achieve additional downforce shaped like a wing plane. Some designs are much more complex than others but it's design/usage is very much determined by the airflow presented to it by the components in front of it. 
Rear wing design has altered since the inception of DRS as teams try to balance the effects of using or not using the DRS system. Designing the heights of the two wing planes will effect not only the angle of attack that can be implemented in the closed position but also the effect of the effectiveness of DRS when active. This is a tuning decision made based upon the circuits characteristics.
The louvres that you see at the front edge of the wing endplates are used to reduce drag at the rear wing tips. Robbing airflow from one side of the endplate and sending it to the other thus affecting the airflow and reducing the drag.
To add additional downforce the rules permit a Gurney Flap on the trailing edge of the rear wing plane. If used it helps to stunt the flow and forces the air backwards causing the air to spiral against itself creating more downforce.
In the case of the two rear wing designs from Red Bull and Caterham there is nothing major in design philosophy between the two with very similar endplates except at the rear where the RB8 has trailing strakes that will manipulate the airflow and help guide any airflow exiting the rear of the car.


The diffuser is obviously a key area in extracting rear downforce from an F1 car. Over the last few years the teams have exposed loopholes within the regulations in order to better extract more downforce. Each year the FIA has to re clarify areas within the technical regulations to try and reduce the amount of downforce the teams can generate. The latest of these has been the removal of EBD (Exhaust Blow Diffusers) unlike the top exiting exhausts of this season the exhausts used to channel their airflow in a cavity in the floor of the car in order to speed up the diffuser process and seal the diffuser edges. (When we talk about sealing the diffuser this is achieved by creating a channel of airflow, the stronger & wider the airflow the better the effect. The term sealing is like creating a wall of airflow to which outside airflow doesn't affect the performance with the diffuser channel.) Without EBD this has become a much more difficult task and means the teams had to start with a much narrower sealed area. This is all intrinsically linked to Rake as we discussed earlier and depends heavily on how much air can be driven underneath and over the rear of the floor/diffuser.
Unlike when EBD blocked it's passage into the diffuser airflow, tyre squirt has become a factor for the teams to manage this season. Tyre Squirt is the air that is pushed laterally off the sides of the tyre as it rotates. This air, if not managed will push latterally into the diffuser flow and upset the balance of the car. 
We have to remember that although most of us can only visualise airflow in a uniform way (front to back over the car) as the car turns and travels on it's suspension the airflow is also moving. This means that managing an element like tyre squirt can greatly affect the level of downforce and in turn the balance of the car.


Just like the gurney flap I mentioned in the Rear Wing section the diffuser is also allowed a gurney flap in order to generate downforce.  As we can see from the pictures above both teams again have very different 
Philosophies in this area to attain better performance.  Red Bull's Gurney flap is slightly detached from the diffusers edge, this allows the flap to work as a wing in unison with the diffusers top edge. This bleeds airflow through the gap allowing an element of flex and allows more downforce to be applied to the gurney flap as the low pressure air goes beneath the flap.  Meanwhile the Gurney flap on the Caterham is a much more blunt approach with a sheer 90 degree surface at the maximum 20mm permissible surface area.

In Season Updates

This is perhaps one of the more important aspects of racing within a series like F1, as the season progresses and the team are able to find additional performance gains they are bought to each circuit to be evaluated.  Updates come in either Mechanical or Aerodynamic forms and sometimes utilise both in order to gain either additional balance for the driver and/or extra downforce.  For example this season has shown the depths and pure rate of development that Red Bull can achieve having produced at least 4 major different exhaust configurations in quick succession.  To say that the teams always get things right would be wrong though, Red Bull chased their Sidepod/Tunnel/Exhaust solution for a number of races only to abandon it in favour of a more neutral solution.  Sometimes the over complexity of a design can lead it impacting how it feels for the driver.  In terms of the Tunnel solution Caterham also briefly tested a version of the same type of idea at Mugello.  This is something that I intend to write an article on in the future but will briefly touch on it now: Aero Convergence is when a seemingly leading team has a key area of aerodynamic gain, other teams see this a way of extracting more performance from their own package and so develop their own iteration.  McLaren's exhaust system this season highlights this brilliantly, with the clear advantage at Melbourne the teams invested their development time chasing similar solutions to the McLaren style exhaust.

Red Bull's Exhaust / Sidepod / Tunnel solution featured a section that was missing from the bottom edge of the sidepod and in its first iteration exited at the rear of the sidepod.  The idea was that the airflow from around the side of sidepod would go through the tunnel and help produce an extremity of airflow above the diffuser to help seal itSeemingly this worked in both the Wind Tunnel and CFD but when placed on the car didn't have the desired effect.  Red Bull latterly exited the airflow inside the engine cover and presumably but abandoned this method too.  I'm still not sure this is the last we will see of this design as the team refine how the airflow pattern works.

Caterham CT-01 - Mugello: As we can see from this picture Caterham did test an alternative exhaust solution at MugelloThe design centres around the same ethos as the Red Bull Tunnel with the exhaust placed in the lower position in an attempt to draw airflow into the tunnel below.  The Caterham version exited the airflow into the engine cover and presumably out of the starter hole at the rear.

In Summary

Red Bull are no stranger to the world of FIA rule changes / clarifications as they push the boundaries and interpret the rules in a different way. Having perhaps without the DDD (Double Deck Diffuser) the best car of 09 and then using their facilities to rapidly catch and overtake the initially superior Brawn GP car of that year. This was a year I believe Red Bull learnt many lessons both on and off track in terms of strategy, car design and how to handle the FIA's ever changing rule book. In 2010 & 2011 they produced cars that leant on the side of illegality and prospered using 09 as a yard stick for future processes.  More recently they have fell to the wroth of the FIA's ever changing rule book and have had both their Floor and Front Brake housings banned under rule clarifications.  This won't stop the teams pushing ever closer to their interpretations of what is legal and illegal.

As we can see from the disparity between these two teams, having the same/similar engine/gearbox and ancillaries is not the only thing required to produce a winning car. It's a multi faceted design process that requires decisions on everything from engine mapping, exhaust tuning, gear ratio selection, suspension geometry, tyre pressures, aerodynamics to name a few. These processes are also reviewed and changed based on the particular circuit F1 are visiting at the time.

In terms of running an F1 team the costs are large, having invested a large sum of money in their team Red Bull have reaped the rewards with the constructor wins in 2010 & 2011 giving them a return on their investment through the prize money received at the end of the season. In stark contrast Caterham having been placed 10th since its inception will receive a much smaller prize fund. As the Caterham team continues to expand I expect their expectations will be met with much better race placings giving them the opportunity to shadow Red Bull Racing's success.
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17 June 2012
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You will find that perhaps some of this article is not as #TechF1 filled as most of my articles but at it's root lies a debate about restricting the very innovation I talk about. Ferrari have, through their president Luca di Montezemolo thrown their hat into the Budget/Resource Restriction ring. This is a subject that will now be voted on by the teams prior to 30th June. Before this date it only requires a majority to be in favour for a new ruling to be installed, afterwards it would need a unanimous vote. This to me is a multi faceted debate and just like an onion as you peel away one layer another debate arises.

I understand in a time where the world is suffering financially that F1 should also lead the way in making Motorsport sustainable this I feel however should be the choice of the teams their selves to police. In any business you simply have to take as much money as you can spend to survive and F1 should be no different. Placing a restriction on the amount of money each team can spend is firstly impractical but secondly self defeating. If we take Ferrari and HRT as the polar opposites, Ferrari like HRT use the sponsorship they receive in order to fund their racing. Ferrari's costs far outweigh that of HRT and so to sponsor Ferrari you would have to pay more than you would for the same amount of space on the HRT. It's exposure vs cost something that advertising anywhere and on any platform is the same. The problem is however that if Ferrari suddenly become cheaper to advertise with teams like HRT also have to lower their costs to keep their sponsors (Why advertise with HRT when you can get more exposure for the same money with Ferrari)

So if we can't control costs because it affects Income, can we control Spending?

Component Control: We have seen over recent years that controlling the life span of components ultimately results in a lower cost with only 8 engines allowed during a season (without incurring a penalty for additional gearboxes) and gearboxes needing to complete 5 races (without a grid penalty)
I've also heard people talk about unifying supply of other components such as Brake Calipers / Discs / Clutches and having one sole supplier. That’s all well and good if you want to control the cost the team pays for these items, however if we are being conscious of the global economy the current plethora of suppliers would end up with no business whilst one is left with the Monopoly. This in itself is a self defeating/narrow minded way of dealing with the facts of the world economy.

Staff Restrictions: Although FOTA would lead you to believe that there is currently a restriction on team personnel this only extends to it's own members of which Ferrari, Red Bull Racing, Sauber, Toro Rosso and HRT are not members. As FOTA holds no authority the decisions made by it's members are localised in use to those teams, putting it's members at a disadvantage. Any decisions made by the FIA on limiting staff numbers would need to be added to the Regulations and would then affect every team in the Paddock. This could be done by restricting personnel available at both the factory and/or at the circuit for races, the former placing the biggest restriction on the teams. Once again this is a fine balancing act as the more successful teams always employ many more personnel than the smaller teams can afford. Making people redundant from Top Tier teams in order to lower the costs associated with running that team doesn’t bold well for the world economy, as the lower teams already have as many team members as they can afford, meaning more people looking for employment.

Research Restrictions: With limited on track testing the strides made by F1 teams have been through the use of the Wind Tunnel & CFD over recent years. Placing similar limits on the time available to use the Wind Tunnel &/or CFD could act as another means of saving money. However with additional track time available this season for In season testing the teams have called for more. It would appear they want to have their cake and eat it but more testing will only incur more cost.

In Summary

The teams need to adapt to an ever changing economic and social environment, this is not the first or the last time the world economy has faltered. Placing a restriction on the teams spending will inevitably lead to a decline in the quality of the 'show' something that F1 can ill afford. Losing it's market share of viewers would also mean losing sponsors and so the whole scenario is systematic. F1 needs to continue to make strides into emerging markets and should look to embrace social media in order to further increase it's fan base.

Montezemolo's recent outburst about cost control is more about creating a rival control, with Ferrari trying to stem the development rate of teams like Red Bull.  Ferrari for many years were really only ever competing with McLaren but over recent years Ferrari's slow adoption of Wind Tunnel and CFD usage has allowed other younger teams to capitalize.  Top tier motorsport has always been about how fast can you afford to go and in my opinion should stay that way. The only way costs should be controlled is by the teams themselves if a team like Red Bull Racing have the backing of a drinks manufacturer that is willing to spend more money than the prancing horse so be it. 
We also have to remember that whilst the FIA make the following statement ' The intention is to help all teams participate in the Championship in a fair and equal manner' CVC continue to provide a protracted view supplying the teams money at the end of the season based on their position and heritage within the sport. This perhaps needs to be the largest change within the sports economic ethos providing an equal fund for all competitors except perhaps the championship winners.

Limiting the capability of the teams will only result in a lesser Formula and so the teams should think long and hard before voting on measures to restrict not only their rivals but own capabilities.

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14 June 2012
08 June 2012
03 June 2012
Sunday Musings - Wing Mirror Design


This weeks Sunday Musings are about Wing Mirror design, as always with the musing articles this is a thought that I have had and simply wish to get down on paper. I don't have the benefit of millions of pounds worth of CFD and Wind Tunnel equipment and so the benefits to be gained or indeed even lost may either be negligible or at worst flawed. These articles are at best here to stimulate thoughts on potential area's of aerodynamic gain whether it be directly or indirectly.

As you can see from the excerpts of the FIA's technical regulations below the mirrors are an area that teams have yet to exploit and have favoured a more neutral approach for this season. In previous years the teams chose to utilise the mirrors and corresponding elements in order to gain aerodynamic advantage. So lets have a little look at what could be done should the teams decide to re design their mirrors in order to gain an advantage.

14.3 Rear view mirrors :
14.3.1 All cars must have two mirrors mounted so that the driver has visibility to the rear and both sides of the car.
14.3.2 The reflective surface of each mirror must be at least 150mm wide, this being maintained over a height of at least 50mm. Additionally, each corner may have a radius no greater than 10mm.
14.3.3 All parts of the rear view mirrors, including their housings and mountings, must be situated between 250mm and 500mm from the car centre line and between 550mm and 750mm from the rear edge of the cockpit entry template.
14.3.4 The FIA technical delegate must be satisfied by a practical demonstration that the driver, when seated normally, can clearly define following vehicles.
For this purpose, the driver shall be required to identify any letter or number, 150mm high and 100mm wide, placed anywhere on boards behind the car, the positions of which are detailed below :
Height : From 400mm to 1000mm from the ground.
Width : 4000mm either side of the car centre line.
Position : 10m behind the rear wheel centre line.

3.8 Bodywork in front of the rear wheels :
3.8.1 Other than the rear view mirrors (including their mountings), each with a maximum area of 12000mm² and 14000 mm2 when viewed from directly above or directly from the side respectively, no bodywork situated more than 330mm behind the front wheel centre line and more than 330mm forward of the rear wheel centre line, which is more than 600mm above the reference plane, may be more than 300mm from the car centre line.

Effort is currently being made by teams to use aero elements to energise and direct the flow that goes over the sidepods and downwashes toward their exhaust solutions. I see no reason why the shaping of the mirrors cannot be altered to either direct/funnel the air and/or generate vortexes that would speed up the flow.

Firstly lets look at the dimensions available and the distinctions between the mirror and the mirror casing.

The reflective element of the mirror needs to be at least 150mm wide but could be a maximum of 250mm. This width needs to be at a height of at least 50mm. This obviously doesnt rule out the option of shaping the mirror rather than having a oblong (as we see currently), in order to utilise the additional 100mm of space.
Moving onto the Mirror housing and we can see that no shapes are defined and only dimensional limitation, meaning that edges could be created to turn airflow.
Combining the two elements and you could have the reflective surface (mirror) one size embeded in a mirror housing of a different design. We can also see that there are no definitions is regards to holes/slots etc and so air could be bled from the front surface to the rear, in order to reduce drag and point flow into a singular area in order to generate stronger vortices.

I have 3 pictures for you to look at, please ignore the mirror stalk as this is not an element I'm taling about:

The first is a standard looking mirror which would need to have the casing slightly enlarged in order to leave a gap around the edge of the reflective surface on the rear. The collector hole in the front face of the mirror casing is there to attract air in and can then be redistributed to the other side of the mirror sending the flow to a desired area (ie the extremities) in order to reduce / stop flow detachment / drag




In picture 2 we can see I have added two flow conditioners/vortex generators on the outer edge of the mirror which positioned/angled correctly should angle flow toward the sidepod and into the downwash toward the exhaust plume.



Picture 3 is a combination of both of the above and could generate energised vortices that tumble off the end of the mirror and spiral over the sidepod toward the exhuast plume.



Due to the size limitations imposed (12000mm2) the mirror will more than likely be shaped very diffferently to my interpretation but none the less should give you a good Idea of what I'm talking about.

Once again i'll say that this is something that may or may not be viable and other regulations may in fact prohibit (Although as the mirrors have their own heading I'd see that any stipulations in regard to radius/geometry/shape should be defined in this section also)

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02 June 2012
Red Bull 'Tyre Squirt Duct' Part 2 - Now deemed Illegal

The FIA have now moved to define the floor used by Red Bull since China as illegal having previously stated that the hole in the rear of the floor was indeed deemed as a slot.  Please see my previous post on the subject http://somersf1.blogspot.co.uk/2012/05/red-bull-tyre-squirt-duct.html

Red Bull's previous results whilst using the floor will remain in place (Much to the concern of many F1 fans)  Had Ferrari or McLaren formally protested the floor post race (within the 2 hour limitation) both Mark Webber's and Sebastien Vettel's results could have been revoked.

So what does this mean for Red Bull?

In order to conform with the regulation Red Bull have 3 options, they can remove the design altogether and abandon the tyre squirt path (highly unlikely).  They could redesign the area entirely and follow a similar path to Sauber or Ferrari making their slots run closer to outer floor edge.  Or lastly they could simply cut out a finite amount of the floor to make their current solution legal (The most likely scenario)

I've adjusted my picture/diagram below to show how Red Bull could achieve the latter.  They could either add a slot in a similar position to the Sauber version (shown in green) towards the edge of the floor.  Or they could detach the floor from the aero strake (shown in orange).  To make it a slot doesn't even mean being able to see the gap in the floor, it could be as fine as a hair.


The reasons behind Red Bull's initial design are/were 2 fold, with the duct being so far across the floor the airflow will have a much bigger impact on the tyre squirt.  Secondly without the slot the area of floor remains much more rigid so isn't affected by additional force as speed increases which in turn affects the performance on tyre squirt reduction.

Whilst explaining Tyre Squirt to a fellow tweeter yesterday I drew the following caveman style pictures on my iphone however it may help you to visualize what tyre squirt is:


In Picture 1 above we look at the wheel/floor from above, the blue lines I drew depict the airflow passing toward the diffuser under the car.  The green area denotes the airflow coming across the top of the floor toward the tyre and tumbles / rotates off the tyre and 'squirts' laterally into the diffuser flow.



In the second picture above we can see how the 'Tyre Squirt Duct' will help guide the flow and reduce the tyre squirt effect.
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