Top Secret Plane Project

[woodyapex]

ok Mooey

sorry for the delay been mad busy building the plane !!

 

right this it top secret ( seriously )

 

ok

 

we have a 8 m wide plane we need to launch off a 6 m high platform !

to get the lift and speed we need to achieve at least 20 mph ! But faster means further !

any less we go down hill

we are aiming to have the craft and pilot weighing no more then 150 kg although ideally less . weight is downward force but speed is a squared measurement so speed is better then less weight but both is really good though ( leave the weight to us )

 

So back to speed . ok so bearing in mind plane and pilot aprox 150 kg we the pullers 300 kg ish ( macdonalds every day ) i say pullers as we are going to pull it off the pier .

so lets say we can get to ( and we are about to do tests ) 15 mph then jump off ! For a split second we will add nothing to the speed of the craft as we are free falling and can not unfortunatly jump down hill then we will eventaully hit 15 mph heading down hill and that will give us extra speed , now obviously thats why i'd like to know the answer to the oririnal question how fast would we be travelling after falling 6 m ??

 

i realize drag will have effect and friction on rope ect but at the min im thinking ideal situation !

 

i hope your all still with me !??

 

right now we have a little potential trick up our sleeve to use a 1:2 pull ratio so 300 kg pulling 150 kg but as it turns out that will make us be pulling the same as we weigh !

Now the amount we can pull is undefined at the min ! as we don't know how strong we are and of cause you dont ! but what should be simpler is the calculation after we jump off still pulling 1:2 but obvioulsey the speed we were travelling at leaving ramp would have to be taken into account ! ie 10 mph take off speed ( tos ) on jumping should pull 14 mph on landing and 12 mph tos should pul 16 mph on landing !!

Friction is going to play a big part on our efficency but again leave that to us ! so lets ignore that if we can !

 

Yes i know what you are thinking! it is the r e d b u l l F l u g t a g we are in but please don't retype that as i really don't want it to show in google searches

Thanks a lot guys and girls and i'm sure you mooey will put this problem / puzzle in the right place in this forum and you have my total perrmision to cut and paste into a new topic if needed ( will you just let me know where so i can find it )

 

Hope you can help thanks woody

[J.C.MacSwell]

ok Mooey

sorry for the delay been mad busy building the plane !!

 

right this it top secret ( seriously )

 

ok

 

we have a 8 m wide plane we need to launch off a 6 m high platform !

to get the lift and speed we need to achieve at least 20 mph ! But faster means further !

any less we go down hill

we are aiming to have the craft and pilot weighing no more then 150 kg although ideally less . weight is downward force but speed is a squared measurement so speed is better then less weight but both is really good though ( leave the weight to us )

 

So back to speed . ok so bearing in mind plane and pilot aprox 150 kg we the pullers 300 kg ish ( macdonalds every day ) i say pullers as we are going to pull it off the pier .

so lets say we can get to ( and we are about to do tests ) 15 mph then jump off ! For a split second we will add nothing to the speed of the craft as we are free falling and can not unfortunatly jump down hill then we will eventaully hit 15 mph heading down hill and that will give us extra speed , now obviously thats why i'd like to know the answer to the oririnal question how fast would we be travelling after falling 6 m ??

 

i realize drag will have effect and friction on rope ect but at the min im thinking ideal situation !

 

i hope your all still with me !??

 

right now we have a little potential trick up our sleeve to use a 1:2 pull ratio so 300 kg pulling 150 kg but as it turns out that will make us be pulling the same as we weigh !

Now the amount we can pull is undefined at the min ! as we don't know how strong we are and of cause you dont ! but what should be simpler is the calculation after we jump off still pulling 1:2 but obvioulsey the speed we were travelling at leaving ramp would have to be taken into account ! ie 10 mph take off speed ( tos ) on jumping should pull 14 mph on landing and 12 mph tos should pul 16 mph on landing !!

Friction is going to play a big part on our efficency but again leave that to us ! so lets ignore that if we can !

 

Yes i know what you are thinking! it is the r e d b u l l F l u g t a g we are in but please don't retype that as i really don't want it to show in google searches

Thanks a lot guys and girls and i'm sure you mooey will put this problem / puzzle in the right place in this forum and you have my total perrmision to cut and paste into a new topic if needed ( will you just let me know where so i can find it )

 

Hope you can help thanks woody

 

Hopefully we will offer googleresistant comments, questions and answers. Green Cow flax, or something similar, can easily be googled as can any specific competition rules or references to the event (I copied your r e d b ... etc... pasted in Google and it comes up, so if you are serious you may want to delete that)

 

I looked at some youtubes of past events.

 

Is the 6m the total starting height of the object above the surface of the water? It looked higher, plus additional height seemed to be gained by a moving platform on the most successful entry which then seemed to trip, sending the object ahead and downward before release. As maximum kinetic energy was gained approaching the water surface it then pulled out of the dive aerodynamically getting lift from the wings. It should have stayed parallel to the water but over corrected or it would have gone further than the 200 meters it flew. Getting low fast and staying there would help as you get additional lift from a ground effect closer to the ground or in this case water.

 

Is your goal to beat the 200 + 7 meters? Or just want a decent showing?

 

You want to convert that potential energy to kinetic energy as efficiently as possible and can add further kinetic energy by pushing or pulling. Any other sources of energy available or allowed? (elastic bungy etc)

 

Since the driver (is he a lightweight athletic and skilled pilot or hang glider?) is a good portion of the weight of the object, can he run or perhaps bike to top speed and not just be pushed or pulled by others? Can he drive a propellor? (that would be tricky and not nearly as efficient on the platform vs biking against the platform but may or may not be effective in the air)

 

How long is the platform/runway/pier?

 

Can you use a slingshot effect? pulleys?

Edited June 13, 2011 by J.C.MacSwell

[woodyapex]

Hopefully we will offer googleresistant comments, questions and answers. Green Cow flax, or something similar, can easily be googled as can any specific competition rules or references to the event (I copied your r e d b ... etc... pasted in Google and it comes up, so if you are serious you may want to delete that)

 

I looked at some youtubes of past events.

 

Is the 6m the total starting height of the object above the surface of the water? It looked higher, plus additional height seemed to be gained by a moving platform on the most successful entry which then seemed to trip, sending the object ahead and downward before release. As maximum kinetic energy was gained approaching the water surface it then pulled out of the dive aerodynamically getting lift from the wings. It should have stayed parallel to the water but over corrected or it would have gone further than the 200 meters it flew. Getting low fast and staying there would help as you get additional lift from a ground effect closer to the ground or in this case water.

 

Is your goal to beat the 200 + 7 meters? Or just want a decent showing?

 

You want to convert that potential energy to kinetic energy as efficiently as possible and can add further kinetic energy by pushing or pulling. Any other sources of energy available or allowed? (elastic bungy etc)

 

Since the driver (is he a lightweight athletic and skilled pilot or hang glider?) is a good portion of the weight of the object, can he run or perhaps bike to top speed and not just be pushed or pulled by others? Can he drive a propellor? (that would be tricky and not nearly as efficient on the platform vs biking against the platform but may or may not be effective in the air)

 

How long is the platform/runway/pier?

 

Can you use a slingshot effect? pulleys?

 

Hi ya

Great questions mp i'm going to try to answer them all .

Firstly all the questions you asked have already been approached and thought about !

there is a 3 m capping on craft hieght not , maybe after a few teams starting from 8 m above the 6 m high platform as yes its def 6 m .

So we have constructed a nice friction free as we can get trolley . so 8 m in total .

I've watched nearly every flight i can and know the one you are on about with the " trip " we are not having any " trip " . just straight off .

Our goal is to get as far as possible and not just land in the drink 8 m from the platform ( thats the main thing )

But we've gone in to try and win and even though there are lots of points available for aesthetics and a pre flight show we are not under any disillusions that the team that flies the futest has a better chance of winning

 

Right Pilot

Our pilot is on a strict diet at the min shedding pounds per the day ! He has never flown but today we have constructed a 40 meter runway . with a exit ramp at the end for test runs !

to test fly this plane / craft so we will learn to fly it for two weeks before the big day !

there has been some calculations put into this craft so far and we are using a wing shape designed by the guy whom designed the airbus A 380 so a trusted wing foil.

 

as for ground effect i am very familiar with it but would rather make this as fail proof as possible , as the plane that over compensated was a slightly differently engineered craft ( maybe stronger ) ours has to look like a kestrel lol and in a ideal way not a plane . hard i know but we will get great points if it looks like our initial design.

YouTube - red bull flugtag locarno switzerland winner team 2006 balu

The above link altough looking like a plane is what we'd love to achive on the day in style and distance .

 

take not how the plane only benefits on the last metre 2 metre of there plunge hence why we'd like to up the anti .

 

Let me know what you think ! thanks woody

 

[J.C.MacSwell]

Hi ya

Great questions mp i'm going to try to answer them all .

Firstly all the questions you asked have already been approached and thought about !

there is a 3 m capping on craft hieght not , maybe after a few teams starting from 8 m above the 6 m high platform as yes its def 6 m .

So we have constructed a nice friction free as we can get trolley . so 8 m in total .

I've watched nearly every flight i can and know the one you are on about with the " trip " we are not having any " trip " . just straight off .

Our goal is to get as far as possible and not just land in the drink 8 m from the platform ( thats the main thing )

But we've gone in to try and win and even though there are lots of points available for aesthetics and a pre flight show we are not under any disillusions that the team that flies the futest has a better chance of winning

 

Right Pilot

Our pilot is on a strict diet at the min shedding pounds per the day ! He has never flown but today we have constructed a 40 meter runway . with a exit ramp at the end for test runs !

to test fly this plane / craft so we will learn to fly it for two weeks before the big day !

there has been some calculations put into this craft so far and we are using a wing shape designed by the guy whom designed the airbus A 380 so a trusted wing foil.

 

as for ground effect i am very familiar with it but would rather make this as fail proof as possible , as the plane that over compensated was a slightly differently engineered craft ( maybe stronger ) ours has to look like a kestrel lol and in a ideal way not a plane . hard i know but we will get great points if it looks like our initial design.

YouTube - red bull flugtag locarno switzerland winner team 2006 balu

The above link altough looking like a plane is what we'd love to achive on the day in style and distance .

 

take not how the plane only benefits on the last metre 2 metre of there plunge hence why we'd like to up the anti .

 

Let me know what you think ! thanks woody

 

Big plane compared to most.

 

Brave bunch of pullers to leap in ahead of the plane and trolley!

 

Is there some way to use some of their potential energy from the vertical fall to further increase the horizontal plane speed? (you don't want them swinging back toward the pier though)

 

It would seem that the most critical thing is that the "take off" speed is above stall speed of the wings, or you would get less lift and high drag. Easier in a headwind than tailwind, though significant headwinds would have higher drag.

 

The advantage of the diving down initially is that you increase velocity while initially requiring less lift. The pullout stage would be critical as most lift would be required at that point, so it should not be too abrupt. As long as you are not close to stall but in efficient gliding range of speed a flatter initial flight as you suggest might be good. This is where pilot skill would make a big difference in getting the glide right.

 

Turbulence would be a factor in trying to achieve an efficient glide and any crosswind would require lots of control for the pilot

 

Maximizing velocity is probably the biggest factor along with efficient aerodynamics.

 

Can the trolley be lengthened and the pilot accelerate forward with respect to the trolley? Run or bike or something that could be jettisoned? maximise the trolley speed and maximse the plane speed wrt the trolley type of idea.

Edited June 14, 2011 by J.C.MacSwell

[woodyapex]

Big plane compared to most.

 

Brave bunch of pullers to leap in ahead of the plane and trolley!

 

Is there some way to use some of their potential energy from the vertical fall to further increase the horizontal plane speed? (you don't want them swinging back toward the pier though)

 

It would seem that the most critical thing is that the "take off" speed is above stall speed of the wings, or you would get less lift and high drag. Easier in a headwind than tailwind, though significant headwinds would have higher drag.

 

The advantage of the diving down initially is that you increase velocity while initially requiring less lift. The pullout stage would be critical as most lift would be required at that point, so it should not be too abrupt. As long as you are not close to stall but in efficient gliding range of speed a flatter initial flight as you suggest might be good. This is where pilot skill would make a big difference in getting the glide right.

 

Turbulence would be a factor in trying to achieve an efficient glide and any crosswind would require lots of control for the pilot

 

Maximizing velocity is probably the biggest factor along with efficient aerodynamics.

 

Can the trolley be lengthened and the pilot accelerate forward with respect to the trolley? Run or bike or something that could be jettisoned? maximise the trolley speed and maximse the plane speed wrt the trolley type of idea.

 

Hi mac swell

Firstly we are not brave just daft

2ndly your observations re tubalence wind direction and speed are all out of our hands so no use worrying too much about them so please ignore them . at the end of the day we all should have the same conditions so bad for us bad for them !

We are well aware speed is of the eccence , and my initial first questioin was " if 300 kg is dropped off a 6 m high platform how fast will it be travelling when it hits the ground ?

 

could anyone please give me the answer ?

If i get that? then i can get a base from there ! like i say i can put a 1:2 ratio on this i reckon and get a rough idea of how fast they were flying on the vid ?

 

woody

[Spyman]

if 300 kg is dropped off a 6 m high platform how fast will it be travelling when it hits the ground ?

In free fall without air resistance:

 

Fall Time: [math] \sqrt{\frac{6*2}{9.8}} = 1.1 s [/math] Velocity: [math] 9.8*1.1 = 10.8 m/s [/math]

 

http://en.wikipedia.org/wiki/Acceleration#Uniform_acceleration

[woodyapex]

In free fall without air resistance:

 

Fall Time: [math] \sqrt{\frac{6*2}{9.8}} = 1.1 s [/math] Velocity: [math] 9.8*1.1 = 10.8 m/s [/math]

 

http://en.wikipedia....rm_acceleration

 

 

 

Nice one spyman !

thanks

right! next question

 

if i was going to pull something horizontally on a flat surface on a low friction trolly weighing 150 kg with 300kg of vertical downward gravity propelled force ?

for now from stand still . ie a brick is tied to another brick and one is chucked of the ledge ! how fast will it pull the other off ?

 

 

 

[J.C.MacSwell]

Assuming no friction the acceleration would be 2/3. Essentially, using a pulley to redirect part of the force, you are accelerating the whole 450kg with the force of gravity of that on the 300kg.

 

Fall Time: [math] \sqrt{\frac{6*2}{6.53}} = 1.36 s [/math] Velocity: [math] 6.53*1.36 = 8.88 m/s [/math]

Edited June 14, 2011 by J.C.MacSwell