Wednesday, June 28, 2017

Formula Student Diffuser project:

Hello there!

I can't hide of been a little bored with being at home. So I have been filling my time with lots of maths and CAD work lately and trying to improve my abilities in both.

Below you can see a makeshift diffuser I've built in Solidworks. Iv applied a 16-degree angle of attack, which is not too far off what they have in LMP2 class at Le Mans.

As you can see, I've applied slats to the design, which is believed to control the low-pressure flow better, as it exits the car, thus reducing drag. So it will be good to see how this works.

Pic: Stefan Ruitenberg
My next step is to get some CFD on the design, then do a small paper on what I found out. I will make sure I publish my finding on here too.

Now, back to modelling.

Tuesday, June 27, 2017

My Analysis Of F1 2017's Unique Designs

Hello there!

It has to be said, that the 2017 Formula 1 season has been a season draped with action. So much so that, we have a new protagonist alongside Lewis Hamilton, which has to be said, the most dominant driver of this new hybrid era of single seater F1 racing.

This resurgence of Ferrari has given us a classic so far, Ferrari vs Mercedes, which even of the track has given us a lot to talk about. But people who know me will know my love for Engineering, and for the purpose of this article, I will be doing just that. Let's take a look at the unique technical designs of 2017, shall we?
Pic: Craig Scarborough
Red Bull Nose 

Ever since low noses were brought into the technical regulations, that year being 2014, teams have tried several ways to improve flow efficiency and blockage at the nose's tip. The main outcome here is to maximise as much flow to the underside of the car. There have been numerous attempts at achieving that net outcome: for example, back where the regulations were released, teams applied a finger-like tip to the first FIA regulatory box, which meant teams gained back some of the advantages the high-nose had. Thankfully this avenue was not brought forward in the next batch of regulations and thus gave us more aesthetically pleasing race cars.

One team to run a new concept in 2017, who's nose is quite a neat solution was Force India. Thier design incorporates two holes either side of the nose tip. But where this idea really shines is that from any viewing angle, you cannot see directly through them, making it a legal design. I did think this idea would catch on but seems it hasn't.

For the 2017 season, Red Bull Racing has gone down its own path in this area of regulations. The RB13 sports a small inlet on the nose tip, which after further investigation, it appeared to allow air to pass through, with eight small vanes to make the design legal to race.

This design is more interesting than meets the eye, as the duct allows air to pass straight through, but also it is able to move the flow up the underside of the nose. The car also uses an S-duct which helps reduce the high-pressure flow under the nose, by bleeding the boundary layer to the upper part of the chassis.

Beyond the nose concept, the  RB13 remains quite conservative with the aero surfaces. Speaking to a senior engineer on the matter, they believe that, that lies in the car's philosophy.
Pic: Craig Scarborough

Mercedes Chimney 

During pre-season testing in Spain, Mercedes caused quite a stir when the sheets on the W08 were pulled away to the public and media. As shown above, the WO8 appears to have a vented section which runs along the lip of the engine cover, thus giving the name 'the chimney'.  A common mistake is that people believe this is entirely new, but that would be false. As this style of the vent was seen in the early 2000's, where teams like Sauber or McLaen mounted ducts like this to the leading edges of the side pods. This was down to the tight nature of the regulations which did not permit many cooling vents.

The reason why they are a good idea is that they are much more efficient, an engineer's favourite word I find, and I agree. Back to the point, These vent's are mainly in areas of flow sensitive body work,  so my mounting one of these almost hidden vents, turbulent flow is somewhat reduced.

In Mercedes's case, the 2017 rear wing regulations, of which are lower, has meant Mercedes found this small window, in which can vent some of the temperatures given off my the mechanical side under the body. With the mainplane lower, this flow exiting the car shouldn't get in the way of the wing, thus not compromising downforce levels.

It is unclear to what Mercedes are venting here, but my best estimate would auxiliary cooler, which from research sits fairly high of Mercedes-powered performance cars. This would likely cool the MGU-H. It is believed Ferrari have something similar.
Pic: Craig Scarborough
T-wings And Fins

The rear mounted fins that hang of the back of the engine covers are not new to Formula 1 cars. However, the 2017 regulations brought a small loophole, what which Mercedes found, thus seeing the rest of the field follow.

This loophole is a 50mm wide strip along the car's centerline (25mm either side of the line) which has now been used to enhance the car's performance. As seen in the image above on the Sauber, the T-wing is made up of aerofoils, so produce downforce in their own right. This is done by inverting the ratio of 'drag to lift', something that is so crucial to making these F1 cars work. And as found out by Williams, who run three aerofoils, there is no limit to how many you can run unless the structural integrity is not met, then the FIA will step in.

As with all aero surfaces, dorsal fins also have a major impact on the overall performance of the race car. In one basket, they do indeed provide some effect in conditioning the flow to the rear wing. In other words, reducing the turbulent wake given off my the some of the aerodynamic elements placed at the front or side of the car.

But after speaking to a senior engineer in the aerodynamic field, there use lies deeper than that. In vehicle dynamics, yaw is the enemy of any engineer, so when the car is sliding on entry, team's will do anything they can to prevent this.

The fins play a vital role in pressure difference. Although dependant of where the wind is blowing, it will create a high-pressure region, thus pushing that part of the car down. But when the cars are mid-way through the corner, the fin becomes cambered, thus providing even more rearward downforce. But as I was told, this area can be a sensitive area to offset the overall balance of the car.

This is one of the very reasons we see this fin's on prototype race cars, as the high-pressure area prevents these cars from flipping under high-speed yaw. This can be noted in the 2016 Silverstone 6h WEC race as well as every NASCAR race with the flaps mounted on the outer bodywork. Let's just hope the FIA don't ban them, as I'm quite a fan of T-Wings and dorsal fins.

I hope you enjoyed the post!

Sunday, June 25, 2017

Under The Skin Of The Rebellion R-One

Pic: Stefan Ruitenberg
Hello there!

The Rebellion R-One was a very successful LMP1-L car, with an array of wins to its name. I was able to get closer at Silverstone last year and was able to get some pictures, so big thanks to the team for allowing this. 

It's was a car which beat its light rivals ByKolles Racing quite often, and It has to be said that the bigger team was just more professional than their rivals. Let's take a closer look. 

Pic: Stefan Ruitenberg
Starting off at the bulkhead, we can see the torsion bar, as well as the steering rack. The team has also labelled the brake and clutch reservoirs too. Also, note the sensor connector and pins that mount the nose to the tub too.
Pic: Stefan Ruitenberg
Compare to the Rebellion bulkhead, to the ByKolles one. It looks to be less complex, but this could be down to the tub design and the way they have packaged the internals. 
Pic: Stefan Ruitenberg
This small hatch is on top of the tub of the chassis and is for the mechanics. This image here shows where the driver's legs are placed also.
Pic: Stefan Ruitenberg
For the front suspension, the car has push rods, as shown above here. We can also see the aluminium and steel upright and wishbones too. For the brake duct, one pipe feeds the calliper, and one feeds the disc.
Pic: Stefan Ruitenberg
For the stopping power, the car has 6 pot callipers, and a vented carbon-carbon brake disc too. Note the temperature sensor being used here.
Pic: Stefan Ruitenberg
Likewise, to the CLM, the car uses a twin turbo AER V6, as you can see here. The car has twin charge air coolers in the side pod, one for engine cooling, and the other for the turbines. Also, note the small plenum and coil sprung suspension laid close to the transmission casing. For rear brake cooling, the team use a tube from the rear fender arches.
Pic: Stefan Ruitenberg
Here I was able to get a closer look at the turbocharger the engine has. The car has two of these and has over 600bhp. This thus has given the R-One a high top speed, often the fastest at WEC races I learned.
Pic: Stefan Ruitenberg
Here we can see the manifold, with has some coating to keep heat in, which then goes into the turbine. Note the intercooler piping and support bars going from the tub to the bell-housing.
Pic: Stefan Ruitenberg
Compare the installation to the ByKolles car, above. Which shows they have another cooler mounted in the side pods. Also, check the rearward intercooler mounted at the back of the car, just above the red spring units. 
Pic: Stefan Ruitenberg
At the very back end of the car, we can see the FIA regulated diffuser, and the gearbox oil cool, mounted at the very back of the casing. Note the plank of wood under the car too, which provides the FIA information on how low they run the race car. 
Pic: Stefan Ruitenberg
Although I took this out of focus, you can see this is one of the four coolers, as used by both ByKolles and Rebellion Racing. They are manufactured by US firm PWR.
Pic: Stefan Ruitenberg
For the floor, we can see 1/50th of it here, as the mechanic washes it. It's made from full Carbon.
 
Pic: Stefan Ruitenberg
A good look can be seen in the livery here, which I love. This is the front nose cone, note the blended brake cooling duct suggesting this is a low drag front. 
Pic: Stefan Ruitenberg
Compare the nose to the ByKolles high nose concept, which uses turning vanes to produce downforce, as well as using the high nose to apply more low-pressure flow under the chassis, thus improving the performance of the rearward diffuser. 
Pic: Stefan Ruitenberg
Above shows the rear bodywork assembly. Note the popular swan neck pylons and rear deck gurney flap.
Pic: Stefan Ruitenberg
For sure these are my favourite wheels from WEC paddock. They are made by O.Z Racing and made from full magnesium.

I hope you liked this little piece! 

My Analysis Of The SMP BR01 LMP2 Car

Pic: Stefan Ruitenberg

Hello there! 

It’s going to be a great shame that the BR Engineering SMP Racing BR01 LMP2 car won’t be able to race from 2017 onwards, due to new chassis regulations from the FIA and ACO, whereby SMP was not chosen. Having introduced the car in 2015, the year before really saw the project take off in the design and manufacturing side of things. Let’s take a closer look.

At the start of 2014, right the way to February in 2015 saw the car built, developed and even tested, albeit there was very minimal running time. Going back to when the car got the green light, SMP was able to draft in legendary designer Paolo Catone who penned one of the greatest LMP1 cars, the Peugeot 908.

One of the rules in LMP2 state that any chassis builder must be able to sell your products to a customer team. Even though Strakka and Dome dodged that bullet through a loophole with its S103, SMP wanted to stay true to the regulations, “We wanted to play things properly. We wanted a car that can suit all types of drivers in the spirit of the regulations.” says Catone when he was speaking to Lawrence Butcher in Race Engine Technology Magazine (RETM). Although Catone was able to find that loophole, he felt it was not right for the team to go down that direction, such as Strakka Racing did.

SMP wanted Catone to develop the car by himself, which for anyone is a big undertaking. “when I undertake projects such as the BR01, I have to use my network of supplies and people to do the design work. I have built up a reliable network of manufacturers who are very competent and reactive to my needs” says Catone in RETM. One of these companies was Fondtech, who was able to design and develop the aerodynamic package. Sub-contractors were key for SMP Racing in manufacturing and design of its new LMP2 car.
Pic: Stefan Ruitenberg

Chassis

Starting off with the chassis, the car uses carbon fibre composite tub and outer bodywork panels, of which have been made by Italian company ARS Technology. The key areas where BR Engineering looked at was the front bulkhead and driver cockpit, of which has been developed to work outside of the box, on which is explained later.

The SMP BR01 does share some similar areas to the other P2 cars in races with, such as the Strakka Dome and Ligier JS P2, of which all use a high level of detail to fine tune the overall balance of the car. Some of the key areas they have looked at are the front splitter, side turning vanes and rear deck.

“Our car is very tightly packaged, as we wanted it to be as small as possible, so that weight was down, as well as giving a suitable foundation for the aerodynamics.” Says Catone. He later hinted “that there are very little compromises” which he is very happy about as said in RETM.

Catone wanted his prototype car to be able to run at the front of the pack, and not just with professional drivers. This means that drives of all shapes and sizes must be able to race it. This, of course, needed some neat design features to be able to make Catone’s idea come true.

To achieve this, the car needs to be comfortable, and so BR Engineering had to modify the survival cell at best to improve the accessibility and visibility. This is something all drivers want but can give the car a compromise in the aerodynamic department. On the SMP car, the cockpit is bigger to the one used on the Ligier JS P2 and Oreca O5, but amazingly it's lower.

One key area the team improves was the windscreen surround, which is much thinner. While this gives the driver better viewpoints, the structural integratory was the same thanks to some neat ideas with the carbon fibre honeycomb structure.

Another area where SMP went to town was the doors, which is actually bigger than the regulations states. Cantone says “Driver change in key” so opted to use bigger doors to help the drives by getting into and out of the car. This approach means the teams can get quicker pit stops, which no compromises have been made with the aerodynamics of the bigger doors. Although the doors took longer to manufacture, and are more expensive, the car is not compromised in the area.
For the rear, steel composite tubes come from the back of the survival cell to the spacer in between the gearbox and engine, which makes it a type of hybrid chassis design.

Pic: Stefan Ruitenberg
Suspension systems

While the chassis stands out from current LMP2 cars, the suspension, in fact, does too. The design on the Strakka, Oreca and Ligier cars have torsion bars with a heave spring. The suspension up front on the BR01 is coil springs mounted horizontally in the bulkhead. There is a myth that this can compromise the tyre contact patch, but there is zero difference here.

The only place it will differ is the damper unit would become a damper spring unit, so it’s a bit bigger in diameter to the ones used within a torsion bar set up. I can confirm that this concept is harder to package in the bulkhead, with the steering rack, column, universal joint and a large array of sensors here too.
While a torsion sprung front end is more expensive, the SMP Racing boys opted to use coil springs as it's much cheaper. And due to the car being sold to customer outfits, the team had to keep costs down as low as possible. The LMP2 cost cap is around the £380,000 mark. And to build, design and optimise a car under this is by no means an easy task.

“I like to keep things simple, so teams are able to fix things. What’s the point of a racecar which is hard to repair and work on?” Catone asks. He later adds “coil springs are much quicker to set up too but weight more in the process,” he said in RETM.

For the back end of the car, the car uses coil springs too but laid on top of the innovative transmission casing, on which more later. The back end shows a relativity flat design, with push rods coming from the machined uprights to the bell cranks, which turn the forces 90° into the heave spring. The team has also applied the third element to help with other chassis movements. Catone never stated them, so could be for pitch, warp or even aero load. This set up is the same to what’s used on the other LMP2 cars, except the system is mounted lower due to the chassis and floor design. So, the biggest gain here on the BR01 is lower CofG.
Pic: Stefan Ruitenberg
Drivetrain changes

When the BR01 project began way back in 2014, there was a large array of possible engines to use as the powertrain. As the technical regulations state, your chassis must be able to carry two engines. And for BR Engineering they went for the very popular Nissan VK45DE unit, and the Judd HK 48. Starting off with the Nissan VK engine, which is the one SMP recommend, and the one which all of its customers use. The engine is a V8 with a bank angle of 90°. It has a placement of 4494CC. The engine weighs 145kg with a bore and stroke of 93mm x 82.7mm.

With a 40mm air restrictor, the engine can produce 450bhp at the top of the rev range. While some teams have the turbocharged HPD unit, the Nissan unit is naturally aspirated, giving it a lot of low down grunt. But to meet the regulations, the chassis must accommodate two units. So BR Engineering just went with the two most used units. The chassis only needs minor changes to house the Judd HK 48 engine. With the engines, you can have sourced information and parts from either Gibson or Oreca. For the Nissan engines, they have parts sourced by Gibson Engineering, thus providing one of the most reliable engines in the LMP2 field.

Change of fundamentals

With lots of supplies helping out with the car, such as Fondtech doing the aerodynamic package, both high and low downforce options, BR Engineering got Paolo Catone to design the transmission casing, and to improve on the existing off the shelf units.

While all the other teams use off the shelf Hewland or Xtrac transmissions. Who use off the shelf internals and casing. Both of these gearbox manufacturers are well proven and have bullet proof reliability. SMP felt they could do better with the case design.

When you look at the case designed by Mr. Catone, you can see how it completely eliminates the bell housing, which is a big weight saving element to the design. It also saved quite a bit of cost cut too. The design only has a small spacer in-between the gearbox and engine.

As Catone says “The height of the 6-speed casing is down to me, as we wanted to run the rear deck lower for better performance in the aerodynamic department.” He later adds “The height of the casing is pretty much the thickness of the back end” both of which were stated in RETM.

With the small case, the pick-up points for the wishbones are closer together, with the push rod arm going through the pair of them. The material used for the casing is magnesium, where most are aluminium. The use of magnesium was down to lightness but does offer a small compromise in the structural integrity of the case. The loss here is only very small. 
For the uprights, the team has also designed them too and are CNC’d from Aluminum. The design also sees a simple approach being taken, which has also helped to cut costs. The brake set up sees 6 piston callipers all round with vented discs and carbon brake ducts.
Pic: Stefan Ruitenberg
Aerodynamics

To design the aerodynamic package, Italian firm Fondtech was drafted in by Catone for the job. He says “I knew the wind tunnel was very reliable, and the same goes for the CFD development Fondtech did for us. You have a lot of companies offering CFD but I felt it was pointless to have one person or company looking at the wind tunnel and other at the CFD. If there were any problems, one company would simply tell the other that their part was no good and vice versa, so Fondtech did both the CFD and wind tunnel work” said in RETM.

He later adds “I am old-fashioned, and for me, the wind tunnel is the best way to go. The split between CFD and wind tunnel development was about 25-75 per cent” He said in RETM.

From looking at the car, the car does look quite stable through the fast corners of Daytona banking to the magnets and beckets at Silverstone. The aerodynamic performance looks to be safe, and a great all round package.

If we look at the front bodywork, Fondtech opted for a low nose design, which is similar to the Dome S103 and Oreca 05, but differs to the high nose on the Liger JS P2.

Unlike LMP1, LMP2 chassis builders must have a homologated aerodynamic package, with one low drag package being used at Le Mans only. These kits are capped at £10,000, so in theory, the LMP2 aerodynamic package is a compromise for all the class runners.

Most of the design work was focused on the front nose structure, where the team had nine different options, with almost twenty types of the splitter in use.

In the end, the nose has a stepped motion, with carbon turning vanes filling in the space either side of the nose to the wheel arches.  Like a normal prototype car, this bleeds air via the side turning vanes, which on the BR01, are very JS P2 influenced.On the high downforce package, four twisted vanes are used in the side pod. But for low drag, these are taken away, providing less downforce, but drag in the process. A must at Le Mans.

At the rear, the setup shares some conventional ideas with normal prototypes. For the rear wing set up, the design sees a twin main plan set up in a set of end plates, with a sawn neck pylon from the dorsal fin. One area where all LMP cars benefit is from side force through cornering. Through cornering, the fin becomes a cambered wing which produces downforce. But as the load comes from the side, it’s side force which can dramatically produce more grip through cornering.

But the area where it does differ is the rear deck, which explained earlier is much lower thanks to the small transmission casing. The flow patterns here are somewhat better to the rear wing, due to less obstruction from the rear engine cover.

Different approach

When contractors were used to helping in the design or manufacturing process, it was difficult times due them not receiving payment from SMP Racing, which saw team boss Boris Rotenberg’s bank frozen. As Catone recalls, “We could not pay for things, and we even had a case of having a payment going back to the supplier as the bank sent it back. We asked the supplier why they had not started work and they said they have not been paid. It was then we discovered that the bank was just sending payments back, but not telling anyone they had done so. These problems meant we had some delays in the delivery of parts, so while the idea was to finish by November, as that is when the supplies are less busy, in reality, it overran and then supplies were overloaded with Formula One business. With those problems, it meant that it was not until February 2015 that we finished the first car. It was really complicated” he states in RETM.

If you want to build a quality race car in a year from scratch, you want the operation to run as smoothly as possible. And payment delays really did affect the SMP Racing boys. Due to this hurdle, SMP never really got the track time to test its new product, and to iron out any gremlins.

The debut race for the BR01 was at Le Mans in 2015, where the top car finished 14th place overall, that’s 6th place in class, which for a new car, hardly tested, was a fantastic result.

With the different approach of individual companies helping make the project happen, it almost stabbed them in the back with several delays occurring. But where credit is due to BR Engineering, the team pulled out all the stops to make a customer car which turns out to be quite quick in the WEC and ELMS championships. The team is always learning, so expect good things to come off the car.

Conclusion

With the help of outsourcing parts from well-proven supplies, the BR Engineering team was able to get the car made in time for 2015 WEC and ELMS seasons. With a shadow of a doubt, without the key supplies, Catone used, the car would not have been ready in time. While selling the car to teams, the company doesn’t make as much money as it would have liked. But as Catone says “It’s all about learning, and getting cars out there” which he has done.

The early days of the project meant that Paolo had to do a lot of research to get his head back to where it was with the 908 days. He had to look at a lot of current cars to see where the trend was going so that the BR01 car would be a success. He mostly checked the open top Oreca 03 chassis, which SMP was running in 2014.

But the biggest gain from the project is knowledge. The team has already hinted at a possible LMP1 car in the near future, but Catone was tight-lipped on that. We will have to wait and see if the next car from BR Engineering is as quick and beautiful as the BR01 is. BR02 anyone?

Acknowledgments
I would personally like to thank Race Engine Technology editor Lawrence Butcher for allowing me to reference his SMP Racing BR01 article in 24 Hour Race Technology Magazine 2016 issue. To read a more in-depth feature on the car, head over to www.highpowermedia.com.

Thursday, June 15, 2017

My Views On The WEC GTE Pro Cars

Hello There!

With the 24h of Le Mans right around the corner, most of the attention is focused on the top hybrid class of LMP1-H. While the cars are amazing, as shown in Racecar Engineering Magazine, I wanted to delve deeper into the stuff of the GTE Pro class. With the likes of Ford, Ferrari and Porsche in one class, it makes for one of the most competitive classes of racing, while having a big blend of technology and engineering being used, which I love!

A quick run down of the car in the class thus follows: Ford, Corvette, Ferrari, Porsche and Aston Martin. Albeit, I have less information on the C7.R Corvette, as they only race at Le Mans. In 2017, so leaving that one out. I was at Silverstone WEC this year, so I was able to chat to some of the guys and gals in the teams about their race cars.

Pic: Stefan Ruitenberg
Ford

Starting off with Ford, who were the overall class winners at Le Mans in 2016, which marked the first year of the GT race programme, albeit it a controversy race car. The GT is a very interesting car in my eyes both aerodynamically and mechanically. It's fundamentally known that a tear-drop shape is best aerodynamically, and this is what Ford have applied to the upper surface of the bodywork.

To package the engine, suspension and cooling at the back of the car, Ford has had to apply structures which taper of the tear-drop and onto the rear wheel wells, which house mini intercoolers. I like this idea, as Ford are able to to get the best overall aero profile, while still packaging everything else.

At the front end, shown above, I was able to get a good look at the cooling the front suspension. The slanted positioning of the radiators means Ford can get the best profile to suit the aerodynamics. The suspension remains fairly standard to this GT car, with double wishbones all-round which are actuated by pushrods.

Pic: Stefan Ruitenberg
Porsche 

The new 2017 911 RSR is a completely new development with all-new: suspension, body, aerodynamics, engine and transmission to name a few, have all been designed from the ground up for its new racer. With the engine, the company has improved downforce by the bigger and higher diffuser. On the previous RSR, the rear mounted engine was mounted lower for better C of G, this thus gave the car a small diffuser, and a compromise in the aerodynamics. This has now all be addressed with the engine being mounted in the middle of the car, as seen in the Ferrari 488 and Ford GT.

I really like this neat overhaul, It not only makes the 911 more dynamic and stable, it helps with the flow structure underneath the car, with a higher angle of attack of the diffuser. The car also uses pushrod suspension all round with four-way adjustable damper with dual coil-over springs.

Pic: Stefan Ruitenberg
Aston Martin 

I feel as though the Aston Martin is underestimated in GTE class. But for 2017, the team has updated the car further, as well as remaining quite interesting in my eyes. For instance, the rear plenum that lies in the boot, shown above, is a way of passing flow to a radiator. 

Aston Martin even confirmed to me that this improves the aerodynamics here. Above the diffuser, the car has a large radiator, which is fed flow via the plenum and the ducts mounted at the back of the car. Aston Martin is able to pass air through the diffuser, thus seeking a performance gain by the diffuser.

I also spotted the front suspension and brakes on show at Silverstone. With pushrod being used with double upper and lower wishbones. Of which are made from steel. 

Pic: Stefan Ruitenberg
Ferrari 

The 488 GTE contested the WEC for the first team last year, after a very successful life in the 458. The car very almost won Le Mans in 2016, coming in 2nd place in GTE Pro, thus spoiling Ford's Le Mans return.

The 488 is a simple yet effective race car, which much emphasis occurring at the back of the car. The car has a mid-mounted 4.5L V8 with twin coolers mounted above it. I got a good image of the packaging this year at Silverstone, which is shown above.

The positioning of the coolers means the side pods can be slimmed to increase flow efficiency. This space has been replaced by ducts that feed gearbox and oil coolers mounted at the rear.

Conclusion 

Once the finally BoP (Balance of Performance) has been issued by the ACO/FIA, we will for sure have a clearer picture of where the cars stand among the GTE Pro field. This BoP is going of 2016 race pace, but this was later changed, where the FIA and ACO will collect data from the Le Mans test day and qualifying ahead of the big race. Let me know what you think.

I hope you enjoy the race!

Sunday, June 11, 2017

Customizable Toy Car Project:

Hello there!

Here is a past project I wanted to show you. It started in A Levels when looking on the internet. I saw those toy cars, that are customizable, are very dangerous for the 3 years. I looked into detail at this issue, which I think is quite important at the lower end of this proclaimed age.

Pic: Stefan Ruitenberg
After carrying out 80 pages of research, I designed a McLaren style car. By using a Monocell, the chassis in which McLaren use for its road cars, I could build a car which has big enough parts, that they do not come across as a hazard. They would simply slot into place, with the holes in the chassis arms.

Pic: Stefan Ruitenberg
Above: Here you can see the back end of the structure. The spaceframe style rear was inspired from single seater race cars, which was implemented on a cost constraint, as well as the rigidity remaining high and ideal for my specification.

Pic: Stefan Ruitenberg

Above: Here you can see the first prototype bodywork, albeit, in its utmost simplest form. The ridges you see on the bonnet is for the supports to be laid on top off so that the final finish on the bonnet is as smooth as possible.

Pic: Stefan Ruitenberg
Above: The image above shows the underside of the 3D model. Note that the wheels were only extended so that the design had perfect alignment. While a prototype model has now been manufactured, issue's were addressed, and a new one is coming soon, along with a small 10V motor and bevel gear arrangement to turn the power 90 degrees and propel the car forward.

I am also in process of designing new bodywork. The key idea here is that the base Monocell can be used to make several types of cars. And this is what I'm working on currently. With a 4X4 and a cabriolet all in the works. More soon.

Rebellion R-one and SMP BR01 Video Analysis

My Review Of Formula Student 2016

Hello there! 

When the verdict had been settled at Formula Student Germany, the University of Karlsruhe from Germany took the overall crown, and with an ICE from Stuttgart winning the British Formula Student event, it goes to show how advanced, and efficient this engineering event is. With the Germans taking the big two. And while we see new technical approaches each year, this year had to be the biggest step in terms of different technology on display. 

Pic: Stefan Ruitenberg

Up and down the field, with all sorts of budgets, there are many concepts used by the teams, who are always very talkative that they have the best car, while the team next door thinks they do. The competition is great, the teams are all so friendly, and willing each other on, as did Oxford Brooks to Bath in the endurance test on social media.

The purpose of this feature is to look at the technical advancements of 2016, with many great ideas on display. Even some of the outfits with smaller budgets managed to be innovative with their cars. Let’s take a look at what’s what.

The Aachen RWTH was a car that took my eye due to the neat approaches the team had taken. The first being the front suspension, which reminded me of Formula 1. The design uses push rods to the uprights, where the team has mounted hub motors, which are from AMK. The team has mounted its heave springs on top of the chassis, where a small vanity panel covers them. Bell cranks join the pull rod to the heave elements and dampers, making it coil over dampers. They also use an anti-roll too.

Where the Aachen car differs is that most teams mount the suspension system on top of the bodywork, but the Aachen car has mounted it lower and have a bespoke panel to cover it, thus giving better aero, something that Aachen mechanical engineering student and a close friend, Andreas Kociok very happy.
But when you look at their FS car, quality really shines through, with some other neat ideas. The rear wing sees long, swooping end plates which are bolted directly onto the rear tub. Where they are bolted, it is a hollow section, as the team has a neat set up for its battery. The car has a big slot where the battery is placed in, which is right at the back of the car. The team has also incorporated the diffuser and cooling fans into the design, of which saw fellow teams bowing down too.

"Aerodynamics are a great way to pull out performance, the aero race has become even hotter this year" Andreas Kociok (Aachen mechanical engineering student)

Pic: Stefan Ruitenberg

Another team that stood out was Australian Monash team, who by far showed up with the most advanced suspension system in FS. The design in question was a front to the rear interconnected system, which saw hydraulic links going to a pair of actuators under the space frame chassis, as you can see. This design was used in Formula 1 up until 2014 German Grand Prix, where it was outlawed.

The design was first developed in 2015 by students, but for full optimisation, the team opted not to use it on its 2015 car. The design was adopted, and modified to work even better, and worked to full effect on its 2016 FS car.

The idea behind it is that it can isolate each type of chassis movement, that’s: roll, pitch, heave, warp and hump motions. The system has a much greater control on these and is able to keep the wheels, and chassis more level for optimum tyre grip and aerodynamic downforce. By using the space frame chassis, the team is able to keep bits simple, and bits advanced, i.e. the suspension system.

Some other teams that excelled in the suspension sector are both the cars from Stuttgart University. Its Rennteam, and Greenteam who both had a system that the FS paddock was amazed by. The interesting thing here is that the ICE powered car from Rennteam won the UK FS event, while Greenteam played quite well overall too. So with two cars from the University, they had to be in with a chance of doing well in the contesting events.

Pic: Stefan Ruitenberg

Starting off at Rennteam, the rear suspension concept consisted of three elements, two for pure wheel and chassis movements, and one element, the top mounted one, was used for the aerodynamic load. The design proved quite effective and was able to propel them to the top place on the podium in FS UK.

For Greenteam, the front suspension is where that car really shined through. The car has a coil over damper with two extra elements to absorb yet more motion. I also liked the design on Hamburg’s car, which had two heave springs going down to push rods. Where the designs differ, is that they have novel anti-roll bars, which are able to be adjusted to present understeer or oversteer, thus being able to be adapted to the driver's driving style. Both teams were able to control both heave, pitch and roll to create cars which have astounding front tyre grip.

But for the rear suspension, it remained quite still in 2016, apart from the top University’s from Germany, who really pushed the boat out. For the Dutch-based Delft team, the defending champions ran pushrod with vertically slanted springs and dampers. But the way this was joined to the back of the chassis was in a neat manner.

Pic: Stefan Ruitenberg

Another Team that had neat rear suspension was the University of Paderborn, who ran an ICE at the rear. And like Rennteam Stuttgart they showed rear suspension on ICE cars is still just as good as a car with hub motors, even with bigger engines. The design is push rod but has horizontally laid out springs and dampers. Even with an ICE powertrain, the University was still able to package its suspension system in the way they wanted it to.

While hub motors are the way forward for a lot of teams, one team went one step forward and made a design which reduces unsprung mass, as well as improve the centre of gravity. The team in question was Germany FS winners, Karlsruhe, who was able to engineer a powertrain installation concept completely new to FS.

While the team may have used motors, they were self-developed by the University and mounted the motors under the chassis. This design means you have less unsprung weight on the front and rear suspension, in each corner, thus making the car more agile and dynamic.

This design had many rival teams applauding their effort, as the car not only drove well in Germany but the UK too, where they came in at 2nd place. The students and University showed that they are very capable of pushing the boundaries of design, and a design which automotive manufacturers will be looking closely out.

Pic: Stefan Ruitenberg

 "Teams are now spending more than ever, going quicker than ever, the engineering is better than ever. It's a tasty visit!" Andrea Quintarelli (Ford suspension engineer)

Another top performing team in Formula Student is 2010 winners TU Munich from Germany, the team showed up with the most advanced aerodynamic package in FS history the paddock says. The team worked many hours in CFD to create a very advanced package, that not only produced a huge amount of downforce, it was not compromising any of the cooling system the car uses - an unfriendly challenge to any Motorsport design engineer.

The design really differs in all areas of the car, that’s the front wing, side wings and rear wings. With the front wing, you can see these elements that stick above the normal flaps of the wing. The design sits in between the tub, and the two front wheels, and is a section where teams have the freedom to explore.

Pic: Stefan Ruitenberg

The reason TU Munich was able to apply wings here, is that they moved the cooling system right to the very back of the car, behind the ICE engine. Most teams have side pod cooling, with a small intercooler mounted there, but as this was not here on the Munich car, they had free space to develop. So the team was able to apply big wings to produce even more downforce.

This approach has not been done before, and with some clever thinking, and a move to the cooling system, the team was able to gain even more downforce. With the front wing, they were able to draw more downforce, as the wing they designed would block air to the coolers, but that would be the case if the car had a conventional cooling layout.

For the rear wing, the car saw an array of Formula 1 style louvres to help reduce the drag of the wing, a design also new to FS. So for me, the TU Munich team gains the award for the best aerodynamic package, and a design which was mostly covered by the team members of the University. I can see why they didn’t want people to latch onto its designs, but Formula Student has no place for this, that’s more Formula style.

This brings me onto front wings, which are getting quite advanced in the number of elements teams are applying. There was one neat trick used by both Delft and Monash though. They had a pair of arms which went from the suspension to the front wing, with a pair of bell cranks on the way.

This system was a way to maintain front wing ride height, so when the car corners, there is suspension compression under braking, and the arms would stop the front wing from being too closer to the ground, if not scrapping it. Watch out for this design in the future I say.

Pic: Stefan Ruitenberg

Looking at the teams with smaller budgets, innovation was still able to shine through, and this was evident at the Imperial College from the UK. The London-based University had in fact designed and manufactured its own battery pack from scratch. But the more interesting feature is that the team had self-developed its own electronic control box, deemed the ‘E-Box’, as you can see in my image above.

This quite innovative electrical engineering was from the world of which craft and was a big shame the car never ran to its full potential. The car had minimal running which was down to the  E-Box. But where credit was due, this was some astonishing engineering in use here.

The same could be said for Liverpool, who designed some neat bodywork, in which made it look like a mini Formula 1 racer to me. The elegant body had the front wing, nose cone and side pods all blended into each other, which portrayed a very elegant and classy style, one which also worked aerodynamically they told me. If there was an award for the best looking car, Liverpool would have been up there.

Pic: Stefan Ruitenberg

I also applaud the efforts from Modena University, shown above, from Italy too, as the team have a longitudinally mounted 4-cylinder engine, the concept promotes easy access to both sides of the engine vs the traditional transverse layout, yet amazingly it was no longer than a transverse car due to the very neat final drive packaging the team acquired.

So, the question is how good are Formula Student cars? Very is the answer. This engineering design and racing competition are really motoring forward and gather momentum on the way. No wonder it’s the place where Formula 1 and WEC teams come to hand pick its engineers, they're just too good these days. I erg you to attend the soonest event.

My Analysis of the Aachen Eace05 Formula Student Car

Hello there!

So, when walking around the paddock at Formula Student (FS) 2016, a number of cars court my eye, mainly due to the quality and professionalism they had. While most people look around Delft or Munich, the RWTH Aachen team showed up with a very professional car, that was somewhat overlooked.

The 2016 car, deemed the eace05 is a clear evolution from the eace04 model. Team manager Marcel Eckert says “It is the first time that the team built a four wheel driven electric formula student racecar. So we are proud that we managed the challenge to build up a new car from scratch with this drive concept.” He also confirmed the 2017 car from RWTH Aachen will be an ‘evolution’ from the current model.
When I was around the car at Silverstone Formula Student event, the team’s members all had their own individual tasks and got on with them. The car was well looked after, and never really ran into problems. The tasks where Aachen looked at most on the eace05 was to “save weight by optimisation of all parts, and guarantee a production without any faults” says Eckert. Although the team had the odd glitch at Hockenheim, the eace05 is one of the quickest and reliable overall racecars. 

Chassis

Pic: Stefan Ruitenberg

The age old question in Formula Student is space frame or monocoque. While the latter is much more expensive, the performance gain is somewhat advantageous. If your team does use a space frame, a good solution is to use bonded panels to increase the overall structural integrity. For the RWTH Aachen team, they opted for a monocoque, as they were able to find the sponsorship to do so. This is something that teams don’t try hard enough in currently, I find.

For the chassis, the team has used two materials to make the monocoque. The inner honeycomb structure is aluminium, with outer carbon bodywork. This concept has slashed the manufacturing time, while not losing out on the structural integrity of the chassis. The design is Prepeg sandwich structure, which is used by all other monocoque users in Formula Student.

The design has been made in-house at the team's base in Aachen. The design is a blend of neat approaches undertaken by the team: such as the battery position, spacious peddle box and unique side pods. Due to these innovative ideas, the team has created an all-around solid package.

The biggest compromise with the chassis is the battery housing. Chassis engineer Christopher Schob says “the way we designed it, it has only a minor impact on overall stiffness of the monocoque. For us, it was a fair tradeoff in terms of maintenance and stiffness.”

One area where the car really stands out is the one-piece alloys. Like TU Graz, RWTH Aachen had produced its own lightweight carbon alloys for its eace05 car. This is an idea quite new to Formula Student, and one which will sure catch on.

Powertrain

Pic: Stefan Ruitenberg

For the power train, the car uses hub motors, which are from German based company AMK. These are placed in specially designed uprights for the car. While they never went for the inboard motors as seen on the Karlsruhe Institute of Technology (KIT) car, which saw them mounted horizontally under the carbon monocoque chassis.

Speaking at the team's base Janek Jurasch said “In our opinion, the ‘AMK - Racing Kit’ is the best buyable system of motors and inverters for Formula Student cars. We did research right at the beginning of the development of the eace05 and found the supporter AMK with their motors and inverters as the lightest components with a very high performance compared to other manufacturers. Only a self-developed motor or inverter could increase the performance on the one hand, but on the other hand, there is a high risk in the reliability of the car if we would develop these complex components by our own. So we decided to buy the AMK system” who is head of powertrain solutions at Ecurie Aix.

Another neat feature, a simple one, is the battery pack, which has a special housing fight at the back of the chassis. This easy to use concept, has the battery, diffuser and twin cooling fans as one object. This creates a quick process if the battery has to be changed quickly. Some teams in Formula Student have battery packs that drop out under the chassis, so this is a neat feature on the Eace05 racer.
Janek Jurasch adds “the position of our battery container - right behind the driver - as low as possible inside the car has been chosen because of the centre of gravity and for packaging reasons. To get the maximum performance out of the battery pack, it is necessary to cool the cells. We realised that with an air stream, which starts at intakes below the driver’s seat and ends its way through our battery container in the fans installed at the rear of the car.”

Suspension system

Pic: Stefan Ruitenberg

As highlighted in my previous article looking at the technical trends in Formula Student, suspension systems are one area which saw big gains from the previous year.  The gains with a system which can isolate each chassis movements are key. That’s roll, pitch, heave, warp and hump motions is much bigger than it once was.

The front suspension on eace05 is pushrod arms which are mounted on top of the uprights. This set up is used all round, with twin wishbones from the tub to the uprights. The rear also sees it laid horizontally on top of the tub.

Speaking on the concept “the suspension design all in all is quite good. Due to the small rim, we had some issues with A-Arms that collide with the rim at some setups, so we were not able to run all setups we want. Furthermore, the tie rod of the rear axle has too much compliance which has to be fixed for next year” exclaims Marcel Eckert.

One other area the suspension is optimised up front is the addition of an anti-roll bar, which is integrated within the two front heave springs mounted on top of the tub. As the team has a special place for its front set up, which is deeper in the chassis, the team has created a neat little cover for them. “The front cover is a huge step forward from the old layout with uncovered suspension. It reduces the positive lift of the monocoque and gives an overall benefit of 5% in downforce. I’d like to highlight the cover at the rear end of the car because it has an especially positive influence on the overall performance. The intentional idea was reducing drag by improving the airflow around the rear. But during development, it turned out that the cover had a much more positive effect on rear wing and diffuser than actually reducing overall drag. Lift on these parts were increased by about 30% without any overall drag penalty” says Marius Reiter, head of aerodynamics.
Due to the sensible changes, the suspension packaging has been able to reduce drag levels, while not interfering with the tyre set up and contact patch.

Aerodynamics

Pic: Stefan Ruitenberg

The overall aerodynamic packages in Formula Student are of big interest. The overhaul at Munich saw an all new layout which gave them huge side wings. For Aachen at least, it was a subtle evolution from the car before.

Starting with the front wing, it’s a two element design, with an inboard fence, and curved end plates. “We use an aerofoil configuration based on last year’s development, which is optimised for using the small available space of up to 250mm above ground level (defined by the rules) most effectively. It was relatively easy to create the required amount of downforce based on this already good configuration, so the development focused on optimising the airflow to other parts of the car. We were able to gain 40% more Downforce on side wings and underbody by optimising the end plates and the step-shaped main wing element” says Marius.

Talking on side wings, RWTH Aachen was able to create a small side pod intercooler, as well as apply quite sizeable side wings on the car. This concept proved to be quite popular for 2016, as It was used by a number of top teams, such as Eindhoven University of technology and Delft.

The design sees lots of carbon used in the two element side wings which are mounted on the floor of the car. An end plate has been added to counter out the vortex produced on the wing tips. Speaking on the design, Marius Reiter says “One main design goal of the side covers beside creating the required airflow through the radiator was having no negative effect on the side wings. The strategy to leave a slot between these parts turned out to work really well. In fact, if you left out the side cover, it would result in an overall loss of downforce of nearly 10%, so it has even a positive effect on overall performance.”

Pic: Stefan Ruitenberg

He adds “We know from our lap time simulation that downforce is much more important than low drag, so we’ll focus on creating as much downforce as possible in the development for 2017.”
One area where the RWTH Aachen does stand out is the rear wing set up. A pair of curved end plates is bolted on the back of the tub, with triple main planes places between them, all with trailing edge gurney flaps. These differ to conventional end places which are normally swan neck pylons.

Team aerodynamicist Marius says “The biggest disadvantage of mounting the wing on the elements themselves, be it from the bottom via posts or rods, or better from the top via swan neck, is, that the flow close to the wing and in the boundary layer is disturbed by these devices, which causes flow separation. So consequently, we decided to mount the wing only on the end plates.”

He later adds “The characteristic curved S-shape is caused by the fact that the frame, where the end plates are mounted, is much smaller than the maximum width of the wing. In Addition, we were able to save weight compared to swan neck pylons, because the system of rear wing with structural end plates is lighter than a rear wing with swan neck and non-structural end plates.”

With weight being saved, and good downforce figures coming from the CFD process, the team has built a car which produces a lot of downforce. Marius adds “The influence of the side wings on the rear wing has always been a challenge. A part of the upwash of the side wings is hitting the rear wing, which has a negative effect on its lift. The challenge is to find a solution which creates the most overall lift, and this is the point where we have a great opportunity to improve in the next year”.

While the radiators are packaged in their housing, the team has applied turning vanes behind the intercooler to help combat the turbulent air. As Marius states, the interaction of the air from the radiators to the rear wing set up is difficult, not only for Aachen but any other team who has a similar philosophy here.

Conclusion

Pic: Stefan Ruitenberg

To conclude this feature, the eace05 car is the first to run hub motors all round, and what a first attempt. The car came in at 16th place out of 111 FS entries at Silverstone, as well as winning the best engineering award by Schaeffler at Hockenheim shows the team has many bright heads, and while they don’t have the biggest budget in the world, they are certainly a team to watch out for in 2017 beyond.