Force India VJM06 – glimpse of the rear end

Force India VJM06 – rear end and diffuser

     There is nothing radical on Force India VJM06 diffuser .The most striking points on the design are the perforated ( slotted) tab and the three in a row vertical fences separating the inner section from the our tunnels.

    Like several other teams in 2013, Force India does also share a carapace of carbon to enclose both the lower rear wishbone and the driveshaft.

Caterham CT3 – new diffuser at 1st Barcelona test

B spec, tested at Barcelona test on February

   Caterham tried a modified diffuser at first Barcelona test, featuring a new perforated tab fence demarcated between the rear wing’s endplates . The new design improves diffuser’s suction ability, thus improving downforce production . The perforated diffuser concept is not new in Formula 1 but present since few years ago.

Caterham CT01 – new diffuser at China

    Caterham shows a respective development rate for a small team . The fruits of hard labor delivered so far a new front wing , multiple cooling configurations and even a new diffuser .

Launch – the central fences were removed at China ( in yellow)

China- changes in yellow

    The new diffuser came alongside with the new double openings at sidepods tail . Firstly the side tabs are much wider , meeting the width of the horizontal tab to isolate better the outer diffuser chambers from turbulent air created by rear wheel spinning.

    The double openings at sidepods tail release hot air following an up-wash direction pattern with the help of the horizontal tab . That helps the central zone of the diffuser to extract more air from underneath the car. Additionally small portions of air bleed through the engine starter hole to reach the central diffuser chamber and energize the flow .

     The new diffuser philosophy dictated the removal of the two central vertical fences as there was no reason to keep apart the airflow coming from skid sides and the one coming from the centre because now the two types of airflow are closer in energy level .

Launch – flow pattern , in purple the disruption from rear tyres

China – flow pattern , in red the hot flow

    The big changes at rear end, both referring to diffuser and cooling openings, curved the path for the team to develop new Mc Larenish style exhausts that were tested during the Mugello test on May at Italy.

Related articles

• Caterham CT01 – cooling ( up to Bahrain) (formula1techandart.wordpress.com)

Ferrari F2012 – diffuser update before Melbourne stays in the shadow

Launch spec

Ferrari tried a modified diffuser before Melbourne but the new diffuser is not  yet raced so far ( up to Bahrain) . It features an arched roof above the two large vertical fences ( enclosed by a yellow circle in the illustration below), a design concept origins from Red Bull RB6 ( 2010 car) .

Barcelona test on March

The team exploits the vortexes spilled by the V shaped  areas of the roof  to prevent any mixing  between the flow coming out from the centre  zone with the flow coming out from the side  tunnels of the diffuser .Of course absolute prevention of mixing is not possible to happen but the lesser degree it takes place the more efficient the diffuser becomes .

Related articles

• Red Bull RB7 – arched diffuser roof at Germany (formula1techandart.wordpress.com)

Sauber C31 – Rear end improvements at Jerez test

mini plane on beam wing and floor supporters are shown in yellow

       To strengthen the stiffness of the diffuser and rear floor , Sauber  connected the later  to the rear crash structure via a pair of cable supporters . Their task is to eliminate possible vibrations that would potentially harm the aero behavior of the rear end . To even increase rear end stability an extra mini plane was added on the beam wing ( in yellow) .

 

Related articles

• Sauber C31 – Rear beam wing (formula1techandart.wordpress.com)

Sauber C31 – diffuser launch spec details

 

    C31 diffuser may  lack any eye-catching innovations but is nevertheless full of interesting details . The roof tab is slotted to allow portions of air bleed through hence reducing drag, a trend carried over last season and pioneered by Toro Rosso STR6 . There are three vertical fences , two of the same height and an outer shorter , at both diffuser sides symmetrically placed to allow not any  interaction between the air flows travelling through the  channels formed by the fences . The centre part ( magnified ,in the inset above ) looks very interesting and totally different than that of C30 -2011 car . It clearly exploits aerodynamically  the motor access hole to gain extra downforce . The flow travelling around sidepods bottoms reaches the slim rear end and penetrates through the starter hole to rich the diffuser zone to increase diffuser ability to pull air from under the floor. The contribution is enhanced by the warm air escaping from holes in the area of the gearbox and aided by a little flap . That flap apart from its aerodynamic role reduces the overall size of the engine starter entrance to comply with the  article 3.12.7  of the FIA technical regulations . Not far in the past that hole raised significant protests against Mc Laren which forced FIA to further clarifications about the size of the hole .

 

Red Bull RB7 – More diffuser revisions at Monza

 

The Belgium diffuser version was obviously a platform for further modifications which were seen at next race at Monza . The main tab fence gained  the same arched patern of the diffuser roof but with less deep cut . The side curved tabs were replaced with enlarged and slotted ones .Finally the rear brake winglets were shaped back to Silverstone configuration .

The too many diffuser versions is not a surprise because red Bull raced also many different front wings which from their part effect and direct rear end modifications .

Red Bull RB7 – one more diffuser update at Spa

 

      Two races ahead of Germany and Red Bull had one more new diffuser in Belgium . The new structure had a revised rear deformable structure with a full length winglet under the light to optimize the aero performance both above and below it . The inner vertical fences had regained their former height while the rear brake winglets were reshaped once again .

The new diffuser was tested first during free practice sessions on Friday with the aid of fluorescent paint to reveal flow details .

Red Bull RB7 – arched diffuser roof at Germany

  Interesting but promising updates took place on diffuser at Nurburgring . The new roof  is now arched where the vertical fences meet the roof rather flat as was before . Red Bull RB6 also featured a similar diffuser concept last season . Additionally the inner vertical fences ( in yellow ) are now shortened to let a stronger air interaction between the two flows passing through the centre zone .

Red Bull RB7 – Rear end revisions for Spain

pre-Spain

       In Spain Red Bull had a new upgrade package featuring several rear end modifications . In particular the diffuser inherited a winglet under the rear  deformable structure which blocks the hot air coming from the two outlets sitting on either gearbox bottom sides to enter the central diffuser section from above . So the only remaining access of those hot emissions to the diffuser is through the engine starter hole .

Spain

      Another change is that the rear wing’s endplates gained vented extensions similar to the ones seen on Mc laren and Sauber quite a long time now .Worth’s remembering that Toyota was first to exploit those extensions back in 2009 to help diffuser extract air from under the floor more efficiently, because they divert air flow outwards.

     Additionally the lower combo of the rear brake winglets were also new , being now angled upwards.

Red Bull RB7 –New diffuser with slotted tab fence in Melbourne

       Following the sister team Toro Rosso’s  steps, Red Bull presented a new diffuser at Melbourne with a slotted tab placed between the rear wing’s endplates . Furthermore the tab fence was also extended towards the diffuser’s side wall (all changes are highlighted in yellow color in the illustration above)  . The concept behind the slotted tab idea is to let portions of air flow through the slot favoring drag reduction . In Toro Rosso case (Toro Rosso diffuser link) the slot is deeper indicating a stronger airflow towards the diffuser roof due mainly to STR6  twin  floor configuration . A too large slot would of course effect diffuser functioning negatively  .

     As regards the rear brake winglets , the lower combo lost the endplate that kept the three fins joined together .

 

Red Bull RB7- diffuser updates before season kick start

          The first upgrades to diffuser came early at third Winter test at Barcelona . Actually Red Bull tested two different types of diffuser .

  Launch

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         The first one had a hole under the rear deformable structure to permit hot air coming from car’s internal components, such as engine radiators , to access the diffuser main section and energize it . The hot air exits through  two outlets that exist behind the diffuser roof and close to gearbox. Energizing the diffuser with radiator’s hot air is less efficient than exhaust gases both in heat energy that is transferred  and also in flow velocity.

Barcelona test on March – Type A

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Barcelona test on March – Type B

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         The second type had a revised fairing under the rear light which led to jack receptor changes as well (jack receptor help mechanics to lift the car up in a pit stop for tyre change )  .Moreover the gurney tab was chopped completely from the side walls close to wheels indicating a stronger flow through this zone . Another noticeable change is spotted on the rear brake winglets which are now increased in number and of different shape . (all changes in yellow , being pointed by red arrows)

 

 

 

Mercedes GP W02 – Further diffuser changes at Spain

       Further updates  on W02 pushed diffuser development into a new step to cope better with new aerodynamic needs of the chassis . The new diffuser not only has a new shape but is also built differently allowing the abomination of the metallic cables which increased rear floor-diffuser stiffness , offering a cleaner path and less obstacles to airflow .  

 

 pre Spain

  Spain , (all changes in yellow)

      The crucial central zone of the diffuser is modified to the former boxy launch version .Nevertheless it is not identical to launch spec as changes took place especially on the engine starter holes. Additionally the longer fences which separate the central zone from the side tunnels now have a leaning inwards attachment on the diffuser roof to restrict as possible mixing of the flow coming from the centre with the one coming from the sides tunnels leading to wicker vortexes formations and thus less drag .

  flow visualizing 

       The power of the diffuser to pull air from under the floor is also strengthened by the higher square tab fence under the rear crash structure which extends up to the light .

      As regards the exhaust pipes,they are placed since China a bit outwards combined also with new rear floor fences , both causing diffuser roof to regain back the side tabs but of a smaller width this time compared to launch spec . The side tabs prevent strong mixing of hot air from exhausts, which aim now closer to the wheels ,  with cool air coming from under the floor . Any interaction between the two flows will create  powerful vortexes which will be affected further by the wheel rotation leading to serious drag increase . Finally the endplates are supported on additional pillars onto the diffuser , not only to increase stiffness decreasing vibrations but also to isolate airflow coming under the beam wing from that coming close to the wheels .

Mercedes GP W02 -First major diffuser upgrade taking place before Melbourne

  Launch

 

    During early testing W02 showed poor performance , being unable to challenge top teams ,thus Mercedes launched major updates before season kick start in Melbourne including new bargeboards , exhaust layout , front and rear wing , nose vanes , sidepod panels and rear end major modifications among of which a new diffuser .

 

Barcelona test on  March , used in Melbourne

     Speaking for the new diffuser it features double small vertical fences now and a new less boxy central zone to extract air from under the floor more efficiently . The new central zone forced the team to put under change  the little hole which permit mechanics to enter the engine starter . Moreover the tab fence across the diffuser edge  was restricted in length being cut off thoroughly from the sides ,a change triggered by the new exhaust layout, the new nose vanes ,the revised sidepod panels and bargeboards which in total changed the way air flows around the car body and towards the diffuser . Finally the beam wing which had a raised lower section close to the endplates is now flat, a changed linked to the increase in number of the rear brake winglets (will be analyzed in another post)  and an additional winglet is placed over the rear structure to generate more downforce  (all changes in yellow color pointed with red arrows) .

      All changes paid off as the pace was improved but yet could not match the top teams both in qualify and race conditions .

 

Hispania Racing Team F111 – diffuser details

    The F111 follows also the trend of exhaust blown diffuser having the exhaust pipelines ending close to the rear crash structure . There is a pair of vertical fences (in yellow) twisted outwards  in either side section of the diffuser pattern and also a high tab fence across the diffuser roof extending even to its vertical sides to improve air sanction. Of course the tab partially blocks the hot exhaust emissions preventing a stronger blending of them with the air coming from under the floor, a situation by passed by some teams, like Red Bull, Lotus Renault and Toro Rosso for example, using a slotted tab fence .

Lotus Renault R31 – One more diffuser upgrade in Malaysia

   In Malaysia a metal joint was placed in the centre of the slotted tab to secure its stiffness  . Excessive vibrations of an element ruins its aerodynamic or mechanic effectiveness and  can even  cause it to crack in some occasions .

Lotus Renault R31 – More diffuser revisions in Australia

    Melbourne

  The diffuser was again revised in Australia despite the latest upgrade at Barcelona test ,  having now a new slotted tab under the crash structure to let air bleed through . The pioneer of the slotted tab feature is credited to Toro Rosso and Renault is another team ( along with Red Bull and  Mc Laren  ) to copy this idea .

https://formula1techandart.wordpress.com/2011/04/22/toro-rosso-str6-diffuser-update-before-melbourne/

  Barcelona test on March

Sauber C30 – Rear zone changes before Melbourne

Changes occurred also in rear car zone before Melbourne  . An extra winglet , which is considered to be part of the rear braking system and thus legal , was added inside the rear wheel surface to add downforce to the rear axle , rising the total number of winglets up to 6 . At diffuser area  a long slit can now be observed under the rear crash structure probably to reduce drag . The rear wing endplate vented extension to the bottom helps to increase diffuser sanction effectiveness .