The Technical World of Formula 1 Explained

Lotus Malaysia 2013 Upgrades

2013-03-28T10:07:00.002-07:00

In Malaysia Lotus brought forth a couple of upgrades that included a new front wing endplate, a new tunnel under the exhaust and a new diffuser gurney flap.

After introducing their brand new front wing in the last preseason test in Barcelona which featured new upper elements, new cascade winglets and new endplates, Lotus have introduced a slight modification to the front wing endplates in Malaysia. The upper part of the endplate is now split into two elements. The change can be seen in the illustration below. This is done to improve flow around the front wheels, as the split endplate will now induce a stronger vortex and aid the flow of air around the front wheels and incidentally reducing their wake and improving flow towards the rear of the car.

New Front Wing Endplate

Old Front Wing Endplate

The team also introduced a new tunnel under the Red Bull inspired exhaust ramp, which much like the upgrade Red Bull introduced in late 2012, the tunnel is now smaller. The tunnel is there to improve flow at the rear of the car as the so called coke bottle is now lost. By reducing the size of the tunnel, they are achieving cleaner flow towards the rear of the car as well as reducing the drag induced by the larger tunnel.

New Sidepod Tunnels

Old Sidepod Tunnels

The third upgrade introduced by Lotus is a new diffuser gurney flap, which is actually no longer a gurney flap. Red Bull started a trend in 2011 of replacing the gurney flap with a small airfoil on top of the diffuser’s trailing edge. Since then most teams have followed. Lotus had already replaced the gurney flap in the central section of the diffuser with the airfoil, and have replaced the gurney flap on the edges of the diffuser last weekend in Malaysia as can be seen in the illustrations below.

New airfoils on top of the edges diffuser

Old gureny flaps on the edges if the diffuser

The last upgrade lotus introduced is a slightly revised barge board which had already been previously upgraded featuring slots to strengthen the vortex induced and keep the airflow attached behind the barge boards.

Red Bull Winter Testing Upgrades Report

2013-03-14T12:57:00.003-07:00

Red Bull ran their version of the DRD (Drag Reduction Device) during the second day of the second and last Barcelona test.

Last year, from Singapore onwards Red Bull raced with their own version of the Double DRS (Red Bull 2012 DDRS). As such devices have been outlawed for this year. Teams have tested passive drag reduction devices, similar to the one Lotus introduced in the summer of 2012. Red Bull’s DRD however is neater than Lotus’.

Near top speed, air will bleed through the vertical duct, breaking up the flow, reducing downforce and subsequently drag. The system is made up of three main parts. The first is the intake which is not apparent, but it is hidden inside the roll hoop. The second is the outlet through which air will flow through at all times which is either below the beam wing are behind the rear crash structure above the diffuser and the vertical duct which blows on the rear wing.

During the third day, the team introduced their major upgrade package which included a new front wing, new nose, and a slightly revised tunnel underneath the coanda ramp.

New Front Wing

Old Front Wing

Red Bull has changed their cascade wing philosophy, as it now curls down to meet the footplate vertically together with the endplate, similar to the way the main profile of the front wing is shaped. Additionally, there are now slots in the endplate to keep the airflow attached. This will improve the way the air flows around the front wheels.

The new nose is now slightly lower, and there is a new vanity panel which is no longer chamfered. The new nose still sports the holes at the bottom and at the top which form the S-Duct (S-Duct Explanation).

New Nose

Old Nose

Ferrari Winter Testing Upgrades Report

2013-03-14T11:58:00.003-07:00

Ferrari was one of the first teams to introduce their major upgrade. On the second day of the second test in Barcelona, once the rain had stopped we saw part of the upgrade package, as some more parts were tested in the last day of the test and the rest of the parts will be tested tomorrow Friday 15/03/2013 during free practise of the Australian GP.

While the concept did not change, the new sidepods now bend down more. As a result the coanda ramp is now lower to better aim the exhaust plume towards the diffuser’s edge.

New Sidepods

Old Sidepods

As well as a changed coanda ramp, the cooling outlets have changed. In the following drawings I have moved the suspension and rear wing so that you can see what has changed more easily.

New Cooling Outlets

Old Cooling Outlets

The new version sports wider cooling outlets just behind the exhaust and coanda ramp while in the older version they were slimmer. However, in the original version which is very similar to the one present on the F2012, there was a second cooling outlet further back which also featured two cut-outs on each side. The second cooling outlet has now been removed, thus the need for the wider outlets behind the exhaust.

New

Old

The new front wing was briefly seen on the second day of testing and brought back for the last day.

This new front wing adds yet another element on its outer tips, together with new cascade wings, endplates and the adjustable upper element.

New Front Wing

Old Front Wing

The new element on the outer tips, allows the wing to curve outwards at a larger angle to create more downforce and direct a larger portion of the airflow around the wheels.

The new endplate is covering up a portion of the open area that allowed airflow flowing over the top of the wing to flow to the outside. This will create more downforce. As well as the new endplate, the footplate now features a slot which is an innovation by Ferrari it is the first time seen on a car, ever.

New Front Wing Endpate

Old Front Wing Endpate

The new cascade element is no longer divided into two different parts, instead it is one winglet only much wider than before. The fence that divided the two cascade elements on the older version has now become a vertical fence which will induce a stronger vortex in the attempt two direct the airflow around the front wheels as efficiently as possible.

At the top of the endplate a smaller winglet has been added, similar to the one used by Red Bull.

The inner adjustable element of the wing has been revised, with its inner extremities now taller than before.

Moving slightly upwards, we will find the new strake running along the sides of the nose that was first introduced in the last day of the first Barcelona test but was slightly revised in the second one. The strakes are there for legality purposes, so they were tested before Melbourne.

On the last day of testing, the team tested more new parts. On of which was the new rear wing. The wing now features smaller v-cutouts on the top of the upper element. In addition, the endplate has been revised and the gills are now slightly smaller than before. Those gills bleed the high pressure air from the inside of the wing to the outside, reducing drag by weakening the strength of the vortex shed at the wing tips.

The last new part tested was a new diffuser which still features the airfoil shaped gurney flap on top of the diffuser’s trailing edge, but it now curves downwards instead of stopping at the edges. Also, the diffuser no longer dips down where the two main vertical strakes are located.

The new era is ever closer - 2014 Turbocharged Engines

2013-02-25T13:09:00.000-08:00

Renault Sport F1:

WHAT WILL CHANGE

The gauntlet the FIA has thrown down to F1’s engine makers for 2014 is to reduce the quantity of fuel needed for a Grand Prix by almost 40 percent, yet still maintain the same level of performance and power outputs (i.e. around 750 horsepower) as today. This change to the ground rules is poised to spark a major technological metamorphosis and a whole new challenge for the sport’s engine experts.

The discussions that took place to prepare the new regulations led to the choice of a new engine technical definition.

The countdown to 2014 is already well under way as the engineers turn their attention to the development of what is termed a ’power unit’ that combines a downsized turbocharged engine with two electric motors to recover braking and exhaust heat energy.

Downsized internal combustion engine
Switch from a V8 to a V6 architecture
Cubic capacity reduced by one-third from 2.4 to 1.6 litres
Turbocharging (single-stage compressor), plus engine torque capped at 15,000rpm for a power output of approximately 550 horsepower

New ‘Energy Recovery System’ (ERS): kinetic energy (ERS-K) and exhaust heat energy (ERS-H) is recovered by two electric motor-generator units named MGU-H and MGU-K.

THE NEW RESTRICTIONS SPECIFIED BY THE 2014 FIA REGULATIONS

A double-restriction concerning fuel
The amount of fuel that can be used during races has been reduced : the maximum quantity of fuel that may be carried by the car during a race will be reduced to 140 litres. Energy management will become a major factor of race strategies.
Fuel flow reduced : the maximum fuel flow rate will be reduced to 140 litres/hour, making optimisation of every gram of fuel vital for cars to go as fast as possible on a given quantity of fuel.

A double restriction concerning the flow of electrical energy
The amount of energy that can be recovered during each lap has been reduced
The amount of energy that can be restored has also been reduced

Development costs have been limited and the number of engines each driver can use in the course of the season has been further capped: five per driver in 2014, then four per driver from 2015 (compared to eight per driver at the moment). The technologies and materials employed must be similar to those used for production engines.

Energy efficiency, the new aim in F1

This step from a competition that has traditionally placed the emphasis on power with little consideration for fuel consumption to a new era focused on energy efficiency and reduced fuel consumption (for the same level of performance) is a real revolution for the world of F1.

As a pioneer of engine downsizing as long ago as the 1980s, Renault benefits from an extensive understanding of the turbocharged V6 architecture. Meanwhile, thanks to the electric vehicle programme it instigated in 2009, Renault also enjoys an edge in the field of electric motor technology. These are two indisputable trump cards as it prepares for the switch from normally-aspirated V8s to electrified V6 turbocharged power units.

Red Bull and Sauber S-Duct

2013-02-17T11:46:00.002-08:00

In the past two years Red Bull have been utilising holes around the nose of the monocoque. In 2011, said hole was placed at the bottom of the nose to cool the electronics and reduce the boundary layer development. Something which they also did last year while also adding the so called letter-box hole at the top of the nose. Its purpose, largely, was to overcome the issues of the stepped nose and cool the driver. This year however they have copied an innovation seen on last year’s Sauber. The, so called, S-Duct.

This year both Sauber and Red Bull have adopted this solution. Both teams decided to not to completely cover the stepped noses with a modesty panel and instead use a smaller modesty fairing. A decision which, according to Adrian Newey, saves weight. Keeping the stepped nose though, means that the problem of keeping the airflow on top of the monocoque attached remains. In addition there is high pressure generated at the bottom of the nose because of its height. Red Bull has kept the hole under the nose and by ducting airflow using an s-shaped duct, it exits facing rearwards on top of the nose.

The lower slot relieves some of the high pressure and the boundary layer build-up at the bottom of the nose, bleeding some of the high pressure on top of the nose which in turn keeps the airflow attached behind the step of the nose and prevents the build up of a thick boundary layer on top of the monocoque.

Below the flow trajectories on the top and the bottom of th enose without the s-duct are illustrated. Note the 3rd and last picture where you can see the formation of the thick boundary layer.

DRD (Drag Reduction Device) CFD Test

2013-02-15T08:35:00.001-08:00

F138 nose hole

2013-02-14T07:48:00.001-08:00

The hole is located exactly at the point where the pressure decreases.

Ferrari F138 as seen in Jerez

2013-02-08T07:52:00.002-08:00

When Ferrari revealed its new car, we saw a lot of differences to its predecessor, the F2012, although the sidepods and cooling layout are almost exactly the same. There are many differences, front and rear wings, slightly different front pull-rod suspension and a significantly different, slimmer rear end with a new gearbox and new suspension layout. One of the most apparent differences though is the nose of Ferrari’s 2013 challenger. Ferrari is one of many teams that opted use a modesty panel to cover the step despite the very small disadvantage of the weight of the carbon fiber up high which would have a negative effect on the CoG (Center of Gravity) of the car, as Red Bull, Sauber and Lotus argue. The step on the nose was created as a result of last year's regulation changes which did not allow the nose of the cars to extend above 550mm above the horizontal reference plane (the bottom of the wooden plank under the car) and 150mm forward from the front bulkhead. This rule was enforced to protect the driver's head in case of a t-bone crash as the crash structure protecting the driver is also 550mm above the reference plane. Compared to the F2012 the F138 has a slightly taller nose tip which allows more air under it and then under the floor to channel more air to the diffuser and produce more downforce. Below I have highlighted in yellow the area in which the nose is not allowed to enter which also gives an idea of where the modesty panel is.

Ferrari also kept the smaller radiator above the gearbox used to cool the oil. The smaller radiator is fed with air from a second intake behind the airbox (highlighted below):

This year though, the second intake is removable, or rather, changeable. It was rumoured that Ferrari would be testing a DRD (Drag Reduction Device), and this supports the rumours as they can increase the size of the intake to feed air to the DRD which acts as a fluidic switch to stall the rear wing at high speed and improve top speed. The system was innovated by Lotus in 2012 and extensively tested by them as well as Mercedes. More teams tested similar devices at last year’s Abu Dhabi young drivers test but has not yet been used successfully. It remains to see if Ferrari will use such a device.

An innovation on the F138, are the vertical rear wing endplate slats. These vertical slats are there to improve extraction of air from the rear wing to improve its efficiency. In addition, the slats extend down and become part of the vertical strakes below under the rear wing end plate which work to turn the airflow behind the rear tires and reduce the turbulence behind the tire.

In the following photos you can see vortices shed behind the rear wing of the F138. Vortices are usually visible when there is a lot of humidity or when it is damp, for example after it rains. To see vortices shed there though is very strange as it was neither damp nor too humid. Moreover, the vortices are shed at a very peculiar angle.

Those vortices are usually a sign of drag, but I suspect they might have something to do with the vertical slats on the rear wing.

The front wing is largely the same as the wing Ferrari ended 2012 with. The difference is that the upper flap is split into two more flaps about halfway from its attachment point. This is down to help keep the airflow attached below the wing and improve flow around the tires and towards the back of the car.

2012 Front Wing

2013 Front Wing

The most interesting feature of the F138 is its very slim rear end. Compared to last year the gearbox is longer for this exact reason, to improve packaging and slim down the rear end. It is definitely the slimmest car at the rear of all the 2013 cars we have seen (Williams’ FW35 remains to be revealed). This is partly because of the slimmer, longer gearbox and partly because of the vertical configuration of the radiators which make the sidepods bulkier at the front but tighter towards the rear. Below you can see the car’s rear end colour-coded.

The vertical strakes are there to manage the airflow on top of the diffuser to help extract more air out of it. The shroud housing part of the lower wishbone, the half-shaft and the track rod is also visible (Half Shaft Shroud) The brake ducts sport some new features, but are simpler than the ones used at the end of last season, so they are expected to be upgraded along with other parts of the car in the big upgrade package Ferrari will introduce in the last pre-season test in Barcelona.

In the following drawing, the space freed up below the gearbox is visible. This will improve the airflow over the diffuser and out of the SMH (Starter Motor Hole) which helps in preventing the diffuser from stalling. The floor is now so far away from the gearbox they had to use two rods, one on each side (highlighted with red colour) and an inverse U shaped flow conditioner on top of the diffuser to improve its rigidity with the rest of the car (again highlighted with red color).

by Andreas Mouzouris

Half Shaft Shroud

2013-02-04T11:15:00.000-08:00

Since 2009 Red Bull has used a fairing in different formats to cover the half shaft, the track rod (for adjusting toe angle) and half of the lower rear wishbone. The reason for this is that the rotation of the half shaft produces downforce because of the Magnus Effect, which is good. The problem is that when you introduce the exhaust plume into the equation, this effect becomes more unstable as exhaust flow is given out by the engine only on every exhaust stroke.

In addition, covering them will provide a clearer path for the airflow at the rear of the car allowing the diffuser to produce more downforce.

This year Ferrari, McLaren, Force India, Sauber, Lotus and Mercedes (up to the day of posting this) have followed Red Bull's path of using the half shaft shroud as it is more aerodynamic than having them separate.

Effect of Vortex Generators on Exhaust Plume Trajectory

2013-01-29T08:45:00.003-08:00

I carried out this CFD test to help me understand better the effect of vortex generators (VGs) on the trajectory of the exhaust plume.

This first test was carried out without any VGs:

The second test was carried out with one VG. You can see how the exhaust plume was deflected towards the tire.

The third test was carried out with 2 VGs. The deflection this time was minor, but was made apparent because it was pushed towards the tire and the 'dirty' air behind it which messes up the flow of the exhaust plume.

Grooved Surfaces CFD Test

2013-01-26T08:17:00.005-08:00

A new thread was created in the F1 Technical Forum concerning grooved surfaces. A user asked whether grooved surfaces would be beneficial for channelling air around the car. But soon the question became whether grooved surfaces would reduce drag. The question concerns both longitudinal grooves and lateral grooves. So I decided to carry out a CFD test to answer the question. I tested a body with lateral grooves, longitudinal grooves and no grooves at all.

The body has a teardrop shape, it is 320 mm long and 100 mm thick on its thickest part. I tested it at 42 m/s and found the drag produced by each body.

Ungrooved body:

Drag: 0.27 N

Longitutinal Grooves:

Drag: 0.95 N

The longitudinal grooves reduce the thickening of the boundary layer. Also because of the increased surface area the body produces much more drag.

Lateral Grooves:

Drag: 3.68 N

The drag increased too much here partly because of the grooved shape of the front of the body.

Lateral Grooves V2:

Drag: 2.57 N

I smoothed out the front of the body that created a lot of drag, but still the drag figure for the body with lateral grooves is too high.

Exhaust Comparison Using CFD

2013-01-19T13:45:00.003-08:00

I carried out a CFD (Computational Fluid Dynamics) test to compare the two exhaust solutions that were used in the 2012 season, the McLaren style exhaust (1st Picture) and the Red Bull-Sauber Style exhaust (2nd Picture). There has been a lot of discussion about which one of the two solutions is the best and which solution teams will follow in 2013.

I removed the drive shafts, suspension wishbones and pullrod, to keep the test as simple as possible. I did not include a rear wing to reduce the time needed for the test to be carried out. In general, I tried to keep things as simple as possible.

I used a road speed of 55 m/s (200 km/h, 124 mph) and the exhaust speed out of the pipe is at 350 m/s and 850 degrees Celsius.

These are my results:

I obviously didn’t manage to get the exhaust plume to bend down to the diffuser in my first iteration of the McLaren style sidepods (1st Picture), but it is definitely possible. This indicates that using this solution it is harder to get the exhaust plume flowing exactly where you want it as opposed to the Red Bull – Sauber style sidepods which I got almost right on the first try (2nd Picture).

It is believed that using the Red Bull ramp it is easier to get the plume where you want as it is continuously following bodywork to reach the diffuser. My results support this belief, and show a more consistent and predictable flow, which will in turn produce more consistent downforce.

I believe that more teams will follow the trend set by Red Bull and Sauber in 2012 as it is, as I believe, the better solution.

Here are some more shots of the CFD test:

Cardboard F2012 Front Wing & Nosecone

2012-11-27T08:30:00.001-08:00

Ferrari India & Abu Dhabi Updates

2012-11-09T08:35:00.004-08:00

Renault 2014 V6 Turbo Engine Revealed

2012-10-23T10:41:00.002-07:00

Renault has revealed its 2014 V6 1.6 liter Turbo Engine. You can read more about it here with a free preview of four pages with Renault Sports' Rob White giving a lot of details about the new engine.

Some of the outlines are that despite the regulations allowing the engines to run up to 15000 rpm, he predicts that manufacturers will choose to run them at only 12000 rpm to avoid the higher frictional loses at higher rpm. The new ERS (Energy Recovery System) will consist of MGU-H and MGU-K (Motor Generator Unit Heat and Kinetic). The MGU-H will be placed on the turbine, and the compressor shaft will rotate at about 100,000 rpm.

The new type of turbos to be used can be seen here. www.auto123.com posted this article about 2014 F1 turbos from Magneti Marelli. The MGU-H is placed in the middle of the turbine and the compressor, hence the elongated turbos.

F1 Tires...Part 2

2012-10-22T12:02:00.001-07:00

If you missed Part1 of my series about Formula 1 tires, click on the link to read it.

Slip Angle

The slip angle of a pneumatic tire can be defined as the angular displacement between the plane of rotation of the wheel (the direction in which the rim is pointing) and the path that the rolling tire will follow on the track surface. Isolating the effects of slip angle, for the vehicle to change direction, regardless of road speed, each of the 4 tires of the vehicle must have some slip angle.

The pneumatic tire is elastic in twist and because of this property exists the slip angle phenomenon. When the tire is turning, the segment of the tire that is in contact with the track surface will resist the turning moment and will not turn as much as the rim does since it is elastic. The rolling path on the road surface will always lag behind the plane of rotation of the rim by some value of angular displacement which is the value of slip angle.

Visualize a single particle of rubber on the tread. Most of the time, it is not in contact with the track surface. However, when the particle in question does roll into contact with the track, progressing form the leading edge of the contact patch to the contact patch itself and then to the trailing edge of the contact patch, that is when the elastic deformation takes place. Although the actual deformation takes place during the time that the particle is actually in contact with the track, all of the particles are interconnected so displacement begins before the particle is in contact with the track surface. Due to the properties of rubber, the leading tread deformation is gradual while the trailing edge deformation is much more sudden.

In order to proceed with the relationship between slip angle, coefficient of friction and the cornering force, it has to be noted that grip from a racing tire is developed by a combination of mechanical gripping on the road surface irregularities and by molecular adhesion between the tread surface and the track surface. The molecular adhesion itself comes into play at very high loads and coefficients and it is the reason behind being able to leave black marks on the track when the car is neither spinning or locking its wheels or sliding.

Slip Angle, Coefficient of Friction and Cornering Force

Coefficient of friction varies with slip angle; subsequently the cornering force will vary with slip angle as well. The coefficient of friction will increase as slip angle increases until a given point where any further increase in slip angle will result in a decrease of Coefficient of friction resulting to the tire “breaking lose” or losing traction.

An ideal tire will give an almost linear, high gradient curve at the beginning so that the coefficient increases rapidly (so that the driver can build up cornering force quickly) with increasing slip angle and then levels off gradually with a reasonably flat curve for the widest range of slip angles possible (for the driver to be able to get as close as possible to the limits of adhesion). The segment of the curve at the top where an increasing slip angle does not change considerably the coefficient of friction is called the threshold range. The expected downward slope of the curve has to start off gently so that the driver can feel it and react accordingly. If the curve would plunge down suddenly then the driver would spin off the track. For example if the curve of the tire would look like the hypothetical tire curve, even the most daring, experienced and talented drivers would not be able to exploit the maximum potential of the tires. A tire with this graph would be a very, very inefficient one. In reality what happens at the point the curve starts sloping down, the tire is running out of elastic capability and is starting to slide, a further increase in slip angle will get the car into a bigger slide while the elasticity of the tire would continue to decrease. A high slip angle will generate more heat than a low slip angle. If heat is generated beyond what is needed to get the tire into its optimum operating temperature, the tire deteriorates and there is no contribution to performance.

Vertical Load VS Coefficient of Friction

A tire’s coefficient of friction decreases as load increases. However, this does not mean that traction decreases. Traction will increase with an increasing vertical load.

This effect is illustrated in the graph below:

To explain this in simple arithmetic, let’s assume each rear wheel had to support a load of 200 kg, using the formula described in Part1 (Load Developed (kg)=μ CoefficientOfFriction x Vetical Load), 1.35 x 200 Kg = 270 Kg, times 2 for both rear wheels gives us a load of 540 Kg. However if we add 50 kg per wheel because of load transfer, then (1.33 x 250) x 2 = 665 Kg and if we add the effect of the rear wing, which for example gives 200 Kg of vertical load to each rear wheel, then (1.26*450) x 2 = 1134 Kg. So despite the decreasing Coefficient of Friction, the force developed increases as vertical load increases. The truth is it is not that simple, but the point is that increasing vertical load decreases the Coefficient of Friction and increases the traction capability of the tire.

The illustrations in this post are similar to (and inspired from) the ones in Caroll Smith's book "Tuned to win"

Scuderia Ferrari News n.18 (ENG)

2012-10-20T00:20:00.004-07:00

In the latest Scuderia Ferrari Racing News Ferrari has given us some very nice shots of wind tunnel testing:

Article in totalf1.gr

2012-10-19T13:41:00.004-07:00

For the Greek speaking audience of my blog, I have written an article (Click here to read it) in totalf1.gr for Lotus' and Ferrari's Korean upgrades! It is an excellent site to stay informed about motor racing!

Throttle Maping

2012-10-19T11:03:00.004-07:00

A GREAT article from F1technical.net about throttle mapping! It is a must read! Click Here to read it!

Red Bull DDRS System

2012-10-17T11:47:00.001-07:00

With a photo of the Double DRS outlet surfacing today, revealing a hole below the beam wing on the rear wing endplate (highlighted on the above drawing), it is believed that we have discovered how Red Bull's DDRS system works!
As we all know, with htis system Red Bull manages to shed off even more drag when the DRS is activated which is giving them a small top speed advantage.
Last weekend the holes feeding the system were revealed by Sutton Images, with a photo showing the holes clearly. Below you can see those holes:

It is believed that there are actually two holes on each side of the beam wing. Air is fed from the top through the holes in the above drawing and then channeled down to the beam wing via pipes inside the endplates to the two holes in each side of the beam wing. These holes manage to stall the airflow thus reducing downforce and breaking up the wing tip vortices induced.

Red Bull has four more races left to use this system and take advantage of it, because as of next year these systems will be banned.

Ferrari Exhaust Rumors

2012-10-16T10:05:00.000-07:00

With all the rumors that reached the surface today about Ferrari's upgrades for the Indian GP about a new front and rear wing and a new exhaust, I decided to make a drawing of the F2012 with Red Bull's exhaust layout!

Red Bull DDRS Plausible Functionality

2012-10-14T11:53:00.001-07:00

Red Bull had introduced their own version of the Double DRS system (DDRS) system in Singapore, tested it and used it for the race although at the time no one outside the F1 teams realised it. In Japan though thanks to Sutton Images, we had seen photos of the RB8 with the DRS open revealing two holes in the endplates, one in each side. At that point we knew that Red Bull were using a DDRS system but we didn’t know what they were blowing. We were sure though that unlike Mercedes Red Bull weren’t blowing the front wing as photos of the front bulkhead showed that it was unchanged.
The aim of this article is to reveal a possibly or definitely what Red Bull is blowing with their version of the DDRS. The first thing discovered this weekend in Korea, again thanks to Sutton Images, is that each hole is actually divided into two smaller ones, however not of equal size.
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Then the idea rose that they were actually blowing at two different places. The first one is possibly below the rear wing main plane in order to stall flow in the corner between the rear wing main plane and the endplate to reduce downforce and increase top speed.

Furthermore the size of the hole below the rear wing main plane is consistent with the size of the smaller hole in the endplate.

Here we come to the most intriguing part, it is believed by other Formula 1 technical journalists, Giorgio Piola and Mark Hughes, that Red Bull is blowing the central 15 cm of the beam, where there are less restriction as to what teams can do, in order to reduce its downforce and achieve the drag reduction effect.

However, the central 15 cm of the beam wing is situated behind the gear box, the engine and Red Bull’s cannon like hot air outlet, so it doesn’t get clean flow and is producing relatively less downforce already. So the drag reduction effect would be that high. At first I though that it couldn’t be right, they must be blowing something else. But then it dawned on me. To understand why they are blowing the central 15 cm of the beam wing we have to look at Red Bull’s ramp coanda exhaust with the tunnel underneath. Red Bull unlike other teams is using a ramp to guide the exhaust to the diffuser instead of a McLaren style bulge. By doing this they can more accurately aim the exhaust plume to the diffuser (red colored flow). The ramp though takes up space from the tight coke bottle shaped sidepods that Andrian Newey’s cars have been featuring since 2009. The effect of the tight coke bottle shape was cleaner flow on top of the diffuser allowing it to produce more downforce. In order to retain this advantage Newey has created two holes underneath the coanda ramp.

The first and bigger tunnel (blue colored flow) is directing air flow inside the sidepods and together with the sidepods internal flow, the air exits above the diffuser again to gain the advantage described above. The second and smaller tunnel (yellow colored flow) is redirecting flow to the starter motor hole, something that Red Bull was doing last year with the RB7 as well. The two tunnels however add a lot of surface area to the bodywork and create additional drag and the RB8 had one of the lowest top speeds.

The reason for blowing the starter motor hole is because it is the steepest part of the diffuser and the one most difficult to keep the flow attached to. The started motor hole behaves like an extra slot in a wing. Blowing inside that slot accentuates this effect keeping the flow attached.

So what does all this have to do with the DDRS system?

The low pressure below the beam wing helps with the extraction of air from the bigger tunnel and from the diffuser. Stalling the central section of the beam wing, removes that effect and airflow from inside the tunnel is now slower and flow underneath the central 15 cm of the diffuser is more likely to stall. When the air entering the two tunnels underneath the coanda ramp can not flow easily on the other side it will spill out and follow the rest of the airflow to the rear of the car.

This sheds some of the drag induced by the two tunnels. So Red Bull are getting a triple effect by blowing the central 15 cm of the beam wing by removing drag from the beam wing itself, stalling the central 15 cm of the diffuser and shedding some drag from the two tunnels underneath the coanda ramp. Add to that the drag reduction from blowing some air below the rear wing main plane and they have achieved a quadruple effect.

If this is indeed what Red Bull are doing, it’s ones again hats off to Andrian Newey and Peter Prodromou.

Ferrari Korean Updates

2012-10-13T09:32:00.001-07:00

Ferrari brought a couple of small updates in Korea all targeting rear downforce. They also tested an older rear wing, used in Belgium, which features only two gills on the endplates. The certain rear wing was also tested in Japan. The reason, is simply because of the nature of the Korean track which has 3 long straights at the beginning and then fast flowing corners for the rest of the lap, so Ferrari tested both a high and a lower downforce setup but at the end they opted for the higher downforce one.

The first small update is a new fin on the front brake ducts (highlighted), aiming to produce a vortex and improve flow towards the rear of the car. This shows the complexity in design of today’s F1 cars, as s small part on the front of the car actually affects the rear.

The other two updates are actually parts raced in previous races which had been replaced with ‘upgrades’. Reverting to the older parts though suggest that they weren’t really upgrades but maybe downgrades. The first of the two are the vortex generators below the wing mirrors introduced earlier this season (1^st drawing) but were later modified by attaching the mirror to the one away from the driver in order to reduce the strength of the vortex it produced (2^nd drawing). This weekend though they reverted back to the older design (1^st drawing). These two vortex generators induce vortices to help direct the exhaust plume down towards the diffuser.

The other update is to the diffuser’s footplate. Again this small tunnel on the footplate (1^st drawing) was introduced earlier this season to push the exhaust plume down inside the diffuser to energize the flow, but was then removed as an ‘upgrade’ as Ferrari’s CFD and wind tunnel test deemed it unnecessary (2^nd drawing). This weekend again though, they reverted back to using it.

Both of the later two updates are just another confirmation Ferrari has been experiencing wind tunnel problems.

F2012 New Cascade Wing

2012-10-13T02:52:00.002-07:00

Ferrari introduced a new revised cascade wing in Japan and used it only on Alonso's car. Along with the new cascade a new upper flap was introduced in Japan as well that was used on both cars. In Korea however the new cascade wing was used on both cars.

Above you can see the new cascade wing on the main drawing and the old one on the inset. The new cascade wing aims to improve management of flow around the front tires.

Lotus Introduces Coanda Exhausts

2012-10-13T01:52:00.003-07:00

Lotus had announced earlier this week that they would be finally introducing their own version of the Coanda Exhaust as pioneered pre-season by McLaren Sauber, Red Bull and Ferrari. The new exhaust system uses the Coanda Effect to aim the exhaust plume next to the rear brake ducts where the plume meets a series of vortex generators that aerodynamically seal the diffuser by reducing the air leakage from the gap between the diffuser and the track, as well as energizing the flow inside the diffuser to produce more downforce.

The exhaust layout is very similar to Sauber’s 2nd iteration of the coanda exhaust as the bulge is not very big. It is a very tidy solution from Lotus. The area around the exhaust unlike other teams is not carbon fibre coated with a heat resistant material but it is a metal, most likely inconel, the same material the exhaust itself is made from.

Lotus have added a new winglet (highlighted) on the brake ducts to help direct the exhaust plume towards the diffuser and extract more downforce from it.

Lotus only used the new exhaust on Raikkonen’s car after testing it on Friday. Below is a direct comparison between the two exhaust solutions.

NEW

OLD

The coanda exhaust seems to have paid off as Raikkonen was faster than Grosjean by 3 tenths of a second while he was on average one tenth of a second slower when both drivers managed to get in Q3. That is a difference of 0.4 s and maybe an indication as to how much performance the coanda exhaust can bring, much lower than last year’s blown diffuser which was said they brought about 1.2 s or more of performance.
Lotus haven’t yet managed to set up the car to suit the new exhaust as Raikkonen was complaining about understeer which is logical as the new exhaust shifts the CoP (Center of Pressure) backwards. As soon as they go out in Q1 the car’s are under Parc Ferme rules which allow them to change the front wing angle so the increased the AoA (Angle of Attack) to balance the aerodynamic grip.
Lotus is expected to improve further in the next few races as it took Mercedes 2 races to learn how to setup the car correctly and had a big improvement this weekend in Korea on the 3rd race after they introduced their coanda exhausts.
We can expect Lotus to bring a slightly modified version of their front wing in India to increase the front downforce as well in order to balance the car.

Finally Lotus’ technical director James Alison said “We are at the beginning of a relatively long road with them, [coanda exhausts] it's not straightforward to make them work from the start, but the numbers we got are good so we are quite pleased.”