F1 in Schools - mrjustsid's project

[mrjustsid]

Hi...i am a member of the team 5 4 0 YEAH! and i have a few questions regarding the aerodynamics and a few other related issues.
Just to give you a brief introduction about this challenge:
F1 in Schools is a multi-disciplinary challenge in which teams of students aged 9 to 19 deploy CAD/CAM software to collaborate, design, analyze, manufacture, test, and then race miniature gas powered balsa wood F1 cars.
The cars are powered by CO2 canisters, which are punctured to release the car at speeds of up to 60kmph. The objective of the race is to tear down 20 meters in under a second.

1)questions regarding the aerofoil:
-what should the angle of the aerofoil be.....how much of a difference will it make?
-should we have side fins attached to the spoiler?
-for the front aerofoil would curves make sense?
2)should we have deflectors in front of the rear wheels?...if yes what purpose does it serve and how high should it be?

3)wheels:
-how big should it be in terms of the diameter?
-should the wheels be thick or thin?
-what are ideal materials that could be used for the wheels?

4)axles---we were thinking of aluminium or carbon fiber axles....we just wanted to know how thick should it be...so that it does not shatter!

5)ball bearings.....we just wanted to know if they were actually required...or if was just enough for the axles to rotate?

6)one of our cars is based on the design of a bullet...is the aerodynamically viable?...if yes...how agressive should it be?


as you can see, we have a lot of questions!
any help would be extremely appriciated!
if you wish to know more about the competition visit-www.f1inschools.com
thank you!

[Jersey Tom]

You don't need any downforce or tire traction. Should answer a lot of questions.

[flynfrog]

there are some good threads on this site about this already. I suggest you read through them first. that should answer most of your questions.

Dont be afraid to ask more but do a little homework first.

[mrjustsid]

hi!
thanks for ur replies....i just wanted to know why downforce isnt required?
and in reply to the second post....i already went through all the other posts but there were a lot of contradicting views on these matters...so thats why i posted this!

[Jersey Tom]

There is no grip required from the 'tires.' All your propulsion is coming directly from that CO2 canister... and you're not taking and corners.

In this case, downforce (or at least its associated drag) will only slow you down.

[tok-tokkie]

6)one of our cars is based on the design of a bullet...is the aerodynamically viable?...if yes...how agressive should it be?

I understand that the rules have been changed recently. If you look at Basizland's design it has an open channel down the middle so that it does not have to displace that air. That is no longer allowed I believe.

Basically you are required to design a rocket powered trolley. I would think a bullet shape is an excellent shape. Look at the CFD analysis (computer flow dynamics?) red is high pressure; blue is low pressure. You really want all the high pressure behind the car to push it along & all the low pressure in front to suck it along. That is the reverse of what you will see on the CFD models but anything you can do to approach the optimum will be to your advantage. Bear that in mind when designing your car.

[mrjustsid]

These are the initial car designs that we came up with:



The second one:



Please let me know what you guys think, and suggest possible changes.
Thanks so much!

[tok-tokkie]

I know a standard CO2 cartridge is used. What I don't understand is when is it put into the car? How is it activated (I know the seal has to be punctured but exactly how do they do that)? How is the car let loose?

[flynfrog]

why are you making that cutout in the center of the car?

Leave the points off of the car. They are for supersonic flow. You are no where near that.

Have a look at some land speed cars. http://images.google.com/images?oe=utf- ... CCwQsAQwBQ

they have a similar goal in mind aero wise.

Also read through

green power dude reloaded thread on here as well as the other f1 in schools thread all are full of good info.

some quick thoughts on you car

1: loose the center ressesion its not doing anything.
2: less is more. the less you have to change the airs direction the less drag you will cause the faster the car goes.
3: Keep is smoother if you do have to make a transition do it over as long of an area as possible.

If you post a 3 view of your cars it helps to be able to draw suggestions on them

[mrjustsid]

I know a standard CO2 cartridge is used. What I don't understand is when is it put into the car? How is it activated (I know the seal has to be punctured but exactly how do they do that)? How is the car let loose?

the co2 canister is placed in the canister holder at the back of the car.....which is then punctured to propel the car down the 20 m track!

[mrjustsid]

why are you making that cutout in the center of the car?

Leave the points off of the car. They are for supersonic flow. You are no where near that.

Have a look at some land speed cars. http://images.google.com/images?oe=utf- ... CCwQsAQwBQ

they have a similar goal in mind aero wise.

Also read through

green power dude reloaded thread on here as well as the other f1 in schools thread all are full of good info.

some quick thoughts on you car

1: loose the center ressesion its not doing anything.
2: less is more. the less you have to change the airs direction the less drag you will cause the faster the car goes.
3: Keep is smoother if you do have to make a transition do it over as long of an area as possible.

If you post a 3 view of your cars it helps to be able to draw suggestions on them

we actually thought that those depressions in the center would help us take some mass off the car...that was our main aim!and then we tried to do it as aerodynaically as possible!
can you suggest some better ways to do that?

thank you!

[mrjustsid]

why are you making that cutout in the center of the car?

Leave the points off of the car. They are for supersonic flow. You are no where near that.

Have a look at some land speed cars. http://images.google.com/images?oe=utf- ... CCwQsAQwBQ

they have a similar goal in mind aero wise.

Also read through

green power dude reloaded thread on here as well as the other f1 in schools thread all are full of good info.

some quick thoughts on you car

1: loose the center ressesion its not doing anything.
2: less is more. the less you have to change the airs direction the less drag you will cause the faster the car goes.
3: Keep is smoother if you do have to make a transition do it over as long of an area as possible.

If you post a 3 view of your cars it helps to be able to draw suggestions on them

what exactly did you mean by supersonic flow?...is that what happens at supersonic speeds?

[tok-tokkie]

I know a standard CO2 cartridge is used. What I don't understand is when is it put into the car? How is it activated (I know the seal has to be punctured but exactly how do they do that)? How is the car let loose?

the co2 canister is placed in the canister holder at the back of the car.....which is then punctured to propel the car down the 20 m track!

How do they puncture it (what sort of tool)?
What if the cannister holder was not at the back of the car but deep in the car surrounded by a shield - can they puncture it then?
When they puncture it, how do they hold the car or cannister?
How do they release the car once the cannister has been punctured?

[TheMinister]

Main piece of advice is forget the word F1- it is a MASSIVE red herring. What you are building is the opposite of an F1 car. I just wish the organisers would tell everybody that when they start their projects, it gets tiresome reading the same old misconceptions over and over...

I liked this idea so much I want to convince someone to give it a go; how about a car that produces a little bit of ground-effect lift? Sorta like an ekranoplan or something, to eliminate any friction with the ground.

One other thing, A=F/M. Get M as low as possible; where you are using a solid piece of balsa wood, think if it would be possible to use just a shell. Maybe even lighter materials (drinking straw frame with paper skin or something? whatever you are allowed to do that will save mass).

[Jersey Tom]

Main piece of advice is forget the word F1- it is a MASSIVE red herring. What you are building is the opposite of an F1 car. I just wish the organisers would tell everybody that when they start their projects, it gets tiresome reading the same old misconceptions over and over...

This.