University DRS project - TDH

[TDH]

I will introduce myself first. I'm an aeronautical engineering student in Belgium. I am currently in my final year before I will graduate. There is only one thing left to do and that is to make a project where I apply all the knowledge I gained over the past 2 years. I am always been fascinated by the best technologie and Formula one develops the best technologies in the world if you ask me. So for my project I chose to make a thesis and a practical example of a DRS because it's never done before in Belgium.

I am currently in the research phase of the project and I am trying to get into contact with a formula one team.

What does the project involve:
- A general explanation of the system used to activate and retract the DRS
- The rules which involve the DRS both technical as sportive
- A 2D CFD simulation and interpretation of the DRS
- The kind of materials used to produce the rear wing and the fabrication process
- The impact of DRS in the races (What do the riders/mechanics/fans think of the introduction of DRS)

The things that I really need are:
- Some oppinions
- The exact profile of a DRS/ rear wing
- A general explanation of the system used to activate and retract the DRS (Because I don't have a clue)
- Someone who works at a F1 team who can help me.

If someone helps me, you need to know that I will use the things you say in me thesis.
And if I find someone really helpfull I will put your name in the thesis as well.

I will thank you in advance and will keep you updated along the way

Tom

[mep]

Hi Tom,
In my opinion when you manage to do some CFD then you don’t need to talk about the used materials and manufacturing process anymore. That is just a totally different topic and has been done many times before. Just focus on 1 thing. On the other hand doing the CFD can be challenging if you have never done something like this before so be careful with that.
The rules you can get from the FIA homepage.
You don’t need to use exactly the same profile the F1 teams use. Have a look at some profile database available. Or check what Simon McBeath describes in his book “Racecar Aerodynamics”.

[TDH]

Thanks for the suggestions.

The main thing I need to do is the mechanism used and the CFD. All the other things I said are some extras to fill the thesis. I just want to show my professors that F1 is very similar to the aviation industry. I will definitly check out that book you suggested. I found the FIA regulations already and am working on them.

[mep]

Actually F1 is much more interesting that aviation industry from an aerodynamically point of view because the wings are operated in a very critical area close to a stall and there is a lot of micro flow management.

[TDH]

That is all true, but aviation isn't all about aerodynamics. If I look what I've learned over the past years. Weight is the most critical thing. The development of new materials and the push for beter technologies. Everything that I love about airplanes I find in formula one. Thats why I wanted to do a project about formula one. So my professors looked outside the box.

And I find the aerodynamics of a racing car far more interesting than the aerodynamics of a conventional plane.

[DaveW]

The main thing I need to do is the mechanism used...

I am not working in F1 &, although I have seen a "DRS" assembly, I have no idea how they are motivated. With that as a warning, this is how I would tackle the problem.

I would start with by considering the operation & the potential failure modes.

I assume that the device should always fail in the "closed" (high drag) condition. This means that the hinges should (ideally) be arranged so that the aero forces act to close the flap. You might want to think about helping this with a mechanical (spring) force to ensure that it is always closed at rest. It is probably worth considering the possibility that the hinge moments may change sign in the "open" condition. Also that the aero forces take time to develop when the flap is moved - a consequence of this would be that the device should change position quickly, to minimize the delay in the development of the aero forces.

It is probable that the device will be electrically triggered. This implies that the motivator has to translate a discrete electrical signal into one of two angular positions. The activation doesn't necessarily have to be controlled "proportionally" - something that can simplify the the design of the device.

Rotary actuators exist, but may not be desirable, unless it is possible to locate them "directly coupled". A requirement to gear them in any way would (I think) immediately raise the option of choosing a linear actuator.

Both electrical and hydraulic actuators exist & should be considered. The pros & cons of hydraulic actuators include:

- F1 cars already have a source of hydraulic power available.
- linear hydraulic actuators tend to have a higher power density.
- no power is required to maintain a position (other than "pilot" power, possibly).
- each device added to a common source of hydraulic power increases to probability of (terminal) failure.

Hydraulic actuators can be single or double acting. Double acting devices tend to be complicated (require a "four port" valve), unless a "differential" design is adopted. In that case a relatively simple "pilot operated" three port electro hydraulic valve can be used to control the actuator. See here for possible options.

I hope this helps.

[TDH]

Thanks, this is of great help. I was also thinking in the direction of hydraulics or electrics.

The thing you say about the wing, that it should be closed in a failed scenario is a new thing I didn't consider. Thanks for that input. The most basic thing I need is a certainty of the powersource. (electrical or hydraulical). My first guess would be hydraulically because you got a powersource already and the forces you can apply are pretty big for a relative weight contibution.

Does anyone know where the actuator is located? Could it be in the centre piece of the rear wing or is it located in the sides?

[mep]

I think you should start with an estimation/raw calculation of the forces. I would guess the actuator should be able to move something like 600kg. Probably more something for hydraulics. The actuator can be located in the middle of the wing. I am sure you can find some pictures when you search for them. Also keep in mind that you need to route the hydraulic pipes trough the tinny end plates of the wing.

[TDH]

Do you know how much pressure is generated in the hydraulic circuit? I will look for it on the forum but maybe you know it from the top of your head.

I just found that the differential can work with a hydraulic pressure of 200 bar.

[mep]

I don’t know the pressure from my head but 200 bar is not unusual for hydraulics. Maybe you can find the pressure used in planes. Btw. it is also important what kind of kinematics you use for the actuator. I could imagine something like an elbow lever.

[zonk]

Only mercedes have actuators in the endplates?

And only one failure in race ( stuck open) Canada 2012

http://www.yallaf1.com/2012/06/11/brawn ... s-failure/

Mark Weber European gp 2012 quali failure

http://en.espnf1.com/europe/motorsport/story/82298.html

[DaveW]

I think you should start with an estimation/raw calculation of the forces. I would guess the actuator should be able to move something like 600kg. Probably more something for hydraulics. The actuator can be located in the middle of the wing. I am sure you can find some pictures when you search for them. Also keep in mind that you need to route the hydraulic pipes trough the tinny end plates of the wing.

Without disagreeing with mep, I would guess (without doing the work) that it might be possible to keep the position of the flap where the aerodynamics dictate and the centre of rotation close but slightly in front of the centre of pressure in order to minimize actuation forces. That would minimize the size of the actuator and flow requirements, etc.

Personally, I do not like the idea of piping the hydraulic supply up the wing end plates, but there you go....

[mep]

I think the flap rotates around its trailing edge, which means not just downforce is acting against the rotation but also the drag with a certain lever arm. Obviously the worst position, but I strongly recommend you to check the rules regarding that issue. I think the rules define the gap between flap and wing. Having the centre of rotation located forward might not even work because the flap would crash into the trailing edge of the wing. You can also investigate where the rotation centre should be located and the shape of flap and wing in order to either maximise the DRS effect or to have maximum downforce in closed position. This thesis then starts to become very interesting.

[youtube]http://www.youtube.com/watch?v=oRcWrSFtWFY[/youtube]

[TDH]

Thanks for all the reactions and I will definetly keep you guys updated.

When I started this project I thought that it was a small subject but when I hear all these suggestions I realise that it's gonna be a hard nut to crack.

[DaveW]

Brilliant video! Looks as though it could do with a time delayed "fail closed" action, so that the flap remains open only whilst it is being updated by the controller. If the controller iterates every millisecond, then a 1.1 millisecond monostab should to the trick.