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• Dihedral : You draw a horizontal line along the base of the wings in a commercial airliner, dihedral here means the upward angle by which the wings are tilted from this horizontal line.
• Anhedral: Its also called negative dihedral, or when you look closely a fighter jet plane, the wings will be positioned downward from the horizontal base wing line.
• Polyhedral: In 2008 season the front wing of Mclaren MP4 23 was designed at custom angles and saw usage of bridges and complex endplates. This is to further improve the airflow.

Pre Season Testing
The world of Formula One is different. Each team follows its own unique way in interpreting the regulations, and the resulting idea defines their grid places. Mclaren started off with the interim car for 2009 season fitted with a 2008 specification rear wing in answering the downforce related issues. Mclaren does aero evaluations of MP4-24 back in the Mclaren Technology Center at Woking, England. Engineers use Wind Tunnel and advanced technologies like Computational Fluid Dynamics.

Modern Formula One cars are sensitive to the minute change in airflow. Engineers test the airflow around the car and even they get to know how the airflow influences the cooling of various components which are open to high temperatures in an actual racing scenario. Using the measurements from Wind Tunnel and actual results from race tracks, they can really influence in evolving a better car for future races. They use dyes and sensors to do better airflow visualizations.

Mclaren carried out intense test programs in Portugal and Spain from November 08’ to March 09’. They tested various components in preparation for the new season reflecting numerous changes in rules and regulations from 2008 predecessor. “We are definitely not where we want to be. We will continue our test programme next week at Jerez for another four days. But it will take time to improve.” -  The comment from Mclaren management during preseason testing clearly showed they were standing on a thin red line of not being able to set competitive lap times.

Chassis and Mechanics
Mclaren has three race chassis for this season. The MP4-24 chassis acts as a central component which connects all the other components and make the whole car. This includes the various aerodynamic components, engine, transmission, suspension. Every component is carefully mounted onto respective points in the MP4-24 chassis. The full carbon-fibre composite monocoque forms the survival cell of the drivers. Mclaren developed a zero-keel chassis design for MP4-24 where the suspension is mounted directly into the chassis.

The suspension has thick upper wishbones and thin lower wishbones which is positioned a little backward. Brake ducts contain special inlets for efficient cooling. An upside V cut down the trailing edge infront of the main frame directs smooth airflow to the central chassis frame. MP4-24 houses reduced water and oil radiators in its sidepod and the reduced engine rev’s this season meant  a reduced sidepod inlet so that they could actually use the space beneath the inlet to better guide the airflow to the rear and underfloor.

MP4-24 has a special small inlet to cool the electronics on the right sidepod. The bodywork to the rear is retouched almost in every race with changing characteristics of the circuits. Different positioning of components especially the exhausts reflected the need to follow asymmetric bodywork templates. The wing mirrors are positioned much closer to the driver, inherited from the MP4-23. The additional vertical element around sidepod positioned above the car’s floor improves the airflow efficiency in and around the floor. MP4-24 is powered by Mercedes Benz FO 108W.

The 2.4 litre V8 engine revs at 18,000 max. The engine has a bank angle of 90°. Engineers at Mercedes Benz factory have taken the approach to design the engine at this wide angle. This is also due to the increase in overall width of the machine. The design also helps in housing the engine as low as possible.  K.E.R.S, the Kinetic Energy Recovery System is also positioned carefully. The whole device is triggered by a button on the steering wheel, which recover the energy under braking. The energy recovered is stored for a lap and is released when the system is triggered.  Hamilton and Kovalainen can gain a whopping 80BHP for 6.7seconds per lap. It can account to an overall gain of 0.3 to 0.5 seconds per lap. The device is very important since a small error in positional judgement will affect the whole balance of the car and will shift the center of gravity. K.E.R.S is instrumental in every race starts as Lewis and Heikki pulls away from opposition using the extra boost.

It’s also a good weapon to be used in defense as it helps you move faster from the vacuum being generated in the rear and prevents others from  slip streaming you. The exhaust outlets are placed far into the rear. Aerodynamic package around the exhausts were constantly revised in every grand prix. The design was to aid the quick exit of hot air.  Most of the races, MP4-24 raced with asymmetrical exhaust outlet designs allowing more hot air to exit quickly. Symmetric exhaust outlet design were used in Monaco due to the nature of the circuit, since the whole car needs a unique symmetrical balance to aid the handling in the high downforce circuit. Malaysia and Bahrain saw higher and wider design around exhaust outlets to answer the hot temperature scenario of these circuits. Additional elements were integrated around exhaust outlets in some races for hot air not to spill and stuck around. It was revised again in an asymmetrical manner in Hungary which is generally known as the ‘Hottest Grand Prix’.

The whole design package has been reliable enough to make sure the Mercedes Benz engine breathe fresh air and exhale the hot air in a clear manner. Another component which influences the entire design package is the engine cover. Mclaren has been renowned in using the strange Shark Fin engine covers in 2008 season. However, MP4-24 were more designed with a traditional approach. Many changes were reflected in engine cover as the season progressed. In Hungary, the design was a direct slope towards the crash structure. It reduced the overall surface area. There are winglets attached to the airbox zone which improves the aerodynamic efficiency.

Front Wing and Nose Cone Assembly
Mclaren have been very cautious about the front wing, they used many variants of front wings in test sessions and races. MP4-24 had different configurations of front wings with respect to the track downforce requirements. The front wing which is attached beneath the nose, accounts for one-fourth of overall downforce generated. Curved moveable flaps are introduced which would direct better airflow to the inside of front wheels. Lewis Hamilton and Heikki Kovalainen can operate an adjustable upper element of the wing at 6° from the steering wheel, which is activated by an adjuster positioned in the end plate.

Mclaren already had updates coming to the very first race at Australia from the configurations of pre-season testing, and influenced the flow of air into the inside of front wheels. They introduced a double flap on the upper deck in China to improve the aerodynamics. The team updated from single profiled front wings to double profiled front wings as the season progressed. In Hungary, MP4-24 used a simple approach of stacked front wing. The front wing endplates also plays a serious role in aiding for a much better airflow around the overall car. Endplates of MP4-24 were also designed to minimize the pitch sensitivity of the car. In simple terms, when Lewis Hamilton and Heikki Kovalainen attacks the corners of various circuits at high speeds, the car might pitch up and down. Drivers approach a corner quickly and come out of that corner quickly; the sudden acceleration and deceleration can shift the center of gravity. Endplates are designed to answers these issues. Also, it drives the airflow around the outside of the front wheels and directs it to the rear of the car.

New endplates were introduced in China in a measure to improve the airflow around front tyres. At Germany, MP4-24 saw using new vented front wing end plates which attracts the outside airflow inside.

The Nose of the MP4-24 is unique. Nose cone hole was re introduced in Australia after being tested without nosecones in many occasions. It helps in improving the airflow. Nosecone winglets aid the airflow to the sidepods. Nosecone winglets were positioned closer to the tip of the nose on many races, but they were positioned higher in races where they introduced new Front Wings, again to improve the airflow to the sidepods with change of design in front wings.

Bargeboards were also revised in races especially at Australia from testing configurations. It seriously influence the handling of the car since the bargeboards cleans up the airflow over the front wing and directs it better to the rear. The vertical extension channel under the nose floor directs airflow into sidepod inlets and radiator outlets. Mclaren has gone for a radical design for their sidepods. Special Rim Shield was developed to be used in front wheels to channel the air from front wing to the brake ducts and direct it to the rear. The new shield also helps the hot air exit from brakes not to spill around. However, during the Hungarian Grand Prix the special shield was taken off both the cars and the front wheels were restricted to a more traditional approach with a simple rim shield. Also to be mentioned is the use of fences beneath front wing and splitters under the nose cone in MP4-24 which doesn’t give any chance for generating a high pressure zone under the car.

The Floor and the Diffuser
Another very important aerodynamic component in MP4-24 is the Floor. This component plays a significant role in governing the downforce. The floor is so low to the ground. When the MP4-24 is racing at high speed a venturi is created by the ground and underside of the car. Air is restricted through this region, and airflow gets much faster in this region when the MP4-24 races forwards. A low pressure area is generated quickly and the MP4-24 is sucked down to the track. The floor in MP4-24 had a cut-out section infront of rear tyres.

The cut-out which features a delta shaped leading edge, accelerates the airflow into the diffuser. The new floor in MP4-24 forms the throat of a venturi just ahead of the rear tyres. Simply put, the airflow from the front will lead to the cut out area where the floor reduces to a smaller cross section, it forms a throat or neck, the airflow is accelerated in this area which gets directed to the immediate opening into the diffuser. The pressure drop generated is massive. The whole rear bodywork in MP4-24 thus aids in generating the optimum downforce level that helps Lewis Hamilton and Heikki Kovalainen draw the perfect racing line in all circuits. However, coming to Hungary, they have massively revised the floor. The cut-out was removed and the suspension area along with wishbones were redesigned.

The diffuser in MP4-24 is designed to control the accelerated airflow from the cut-out floor. Diffuser is one important aerodynamic component that drew a lot of controversies in 2009 Formula One season. To the start of the 2009 season, teams like Brawn GP was able to interpret the regulations in a unique way that would drive their cars much quicker than a Mclaren when it attacks a corner. The unique Double Diffuser design gained the cars of Brawn GP, Williams F1 and Toyota immense cornering speed than other teams in early races. Now teams have caught up, especially the Mclaren MP4-24. The diffuser in MP4-24 actually slows down the accelerated airflow from the throat of venturi formed at the leading edge of cut-out floor and stabilizes the faster velocity of airflow back to normal velocity. This helps in for a smoother airflow exit from the rear creating less drag and reduced turbulence. The central section of the diffuser was revised in Bahrain with the addition of a flap that would improve the aero-efficiency.

Coming to Spain, the diffuser featured a twin central section to control the airflow here and allows a cleaner air exit at the rear. During the German Grand Prix, both Hamilton and Kovalainen were using different diffusers. For the race in Hungary, both drivers reflected a similar design to what Hamilton was using in Germany.

Rear Wing and Rear Suspension Assembly
The rear wing of MP4-24 create more than one-fourth of the downforce generated by the whole car. Due to regulations, MP4-24 doesn’t contain multi-elements in rear wing. The main plane should create the downforce without compromising on drag. The gurney flap in the trailing edge of the rear wing forms the flickup that can help generate extra downforce. MP4-24 uses a unique double pillar to support the rear wing to the crash structure. The main plane as seen in the picture is heavily revised. The main plane now runs a horizontal leading edge, the design leading to the leading edge will aid in catching more air and generate good downforce. They introduced a central slot in the main plane by the race in Monaco to cope with the high downforce measures of the circuit and have implemented the same in the rest of the circuits.

Initial races, the main plane was a little curved in the central part without the central slot. The endplates joins the flap and horizontal shark grills. These shark grills are designed with an idea to reduce turbulence. The unique design of the endplates also aid the airflow for a tidy exit from the rear.

One crucial component architecture in MP4-24 is of the rear suspension. The layout was changed in almost every grandprix in respect to changing demands and loads of the various circuits. When Lewis Hamilton and Heikki Kovalainen attack a corner, the MP4-24 is susceptible to various lateral cornering loads. The sudden deceleration when coming to a corner, and the sudden acceleration when exiting quickly out of a corner absorbs and transfers a lot of energy loads. The tyres need optimum grip and must be able to hold onto the circuits at high speeds. A small error in setting up the ratios can lead to poor handling of the car or leads to the drivers losing rear end easily. MP4-24 changed the design and setting of lower wishbone joints in almost every grand prix. They added extra winglet and fin around this region to improve the airflow and reduce the drag generated by rear tyres. From Australia to Hungary, the change in design around suspension arms is visibly different.

One quick flying lap through the first half of 2009 Formula One Season
Let’s look at the images from test session at Portimao and races at Australia and Hungary, we can evaluate how the race winning machine has evolved aerodynamically. The front wheel rim shield which was used in test sessions were recalled at the last races. MP4-24 featured shark fins along the sidepods and a small aero-element at tests. The sidepod was heavily revised to the first race in Australia and was much different in the last race at Hungary.

Test bargeboards were huge and the architecture was modified to a simple and small bargeboard to the races at Australia through Hungary. The underfloor was also modified, the unique cut-out floor in MP4-24 was carried over from testing to initial races, but called off and featured a  much closer design in the Hungarian Grand Prix. From testing through all races, bodycover was redesigned both in a symmetrical and asymmetrical manner. The sidepod houses different electronics and other components, the section had to be revised due to changing characterestics of circuits.

Even the exhaust outlets were changed in many grand prix due to increased temperature in certain circuits. Engine  Cover also saw changes from testing to races at Australia and Hungary. The rear suspension geometry was also updated in every grandprix. Diffuser probably saw the biggest challenge having had to use flow visualization dyes and sensors in testing and german grand prix. Diffuser also got huge updates till the race in Hungary. Mclaren was not using any rear wheel rim shields in initial races but has seen a unique rear wheel rim shield at the rear wheels at Hungary. Nosecone winglets and winglet near airbox vent were constantly repositioned.

The Verdict
MP4-24 has seen numerous changes in the evolution of a race winner at Hungary from a car that was struggling to beat the lap times of current front runners. The whole team studied the early flaws and tested every part in minute detail to gain that fraction of a second to mount a serious challenge. Hamilton and Kovalainen were using different configurations in many races to test the updates direct from the factory. Most of the updates were initially tested in Hamilton’s car and Kovalainen retained to original configuration. The updates were reflected in Kovalainen’s car once the team was convinced the new update had paid off. Hungary saw equal machines to both drivers where they were able to run much quicker than early MP4-24 configurations. Having scored the first victory at Hungary, the whole team is now confident they can retain and reflect the same performance in remaining races.