Science How i belive a flying car could be built

Moach said:
my thoughts exactly! :thumbup: - i imagine there were also plenty of nay-sayers back then when someone suggested "hey, what if we remove the horse?"




that's a pretty clever way of discribing it :tiphat:

NOTE: this DOES NOT imply that the system will try to somehow "convince" drivers that they're not really airborne - special training would still be required for even for the most "casual" types of permits (as it is for regular cars) - a flying car IS still an aircraft - an accessible, road-legal one, but an aircraft, nonetheless - and should be treated with all the respect an aircraft demands :hmm:


now... about ducted fans being less efficient, that can't be right :shifty: -
look here - there is some foundation to that "fairy tale" after all:rolleyes:


still, i reckon, turbo-electrical drives must go... and wings must come :yes:
even small wings, which would conventionally imply high stall speeds and poor handling at low velocities, in this case could prove sufficient - since at low speeds, the fans would take charge....


i have devised a new type of engine that could prove more fitting - i call it the "RAPTOR" (Recoil-Action, Pulse Turbine with Overpass Rotor)

it's not a jet turbine, since it works with a discrete compression-expansion cycle, like a good 'ole piston engine - but it removes the major reciprocating mass and most of the excess moving parts in that type of engine :idea:

not a jet, not a piston... it's uhm... something in between :lol:

picture.php




this very crude animation explains better than i possibly can....

this, i hope, should make for a "best-of-both-worlds" solution.... like a piston engine, the fuel/air mix is compressed in an isolated form - then, the shape of the recoil-valve forces the injector opening to close while the exhaust opens:

hence, a "two-stroke turbine" :P


this could be mechanically connected to the fans - but still centrally positioned, allowing the engines to work in tandem, so that if one fails, it doesn't matter which, since the other two can seamlessly pick up it's slack....

the wheels would still be electric... but only one engine needs to be running for that.... reducing noise and consumption
Click to expand...
Congratulations, you've "invented" the turbocharger...or tried to, anyway. Looks like you stuck a giant turbocharger on a ...one-cylinder two-stroke engine? Have fun with that.

Problem with your design (one of many) is, if the exhaust is powerful enough to drive both the compressor and the propeller, you might as well just be throwing the exhaust overboard and calling it a piston-powered jet...

The exhaust of a piston engine isn't particularly powerful--most of the work is actually done by the "bang" part. Your design is completely wasting that...
 
Hielor said:
The exhaust of a piston engine isn't particularly powerful--most of the work is actually done by the "bang" part. Your design is completely wasting that...
Click to expand...


After it's had it's energy sucked dry by the piston, sure.

A pulse jet works kinda like this - opening and closing a valve and exploding the mixture. It's inefficient because of the low compression ratios, but it's enough to drive an RC plane, and fast:




I think the engine "design by Moach" could work with some tweaking (I'd worry about the valve), but I have my doubts that it's an original idea...
Although the animation is awesome! :tiphat:


On a side note, I think the engine design would less fuel efficient then piston engines. In general you want to avoid pistons... constantly accelerating a mass up and down requires energy. A more energy efficient approach is a rotary element and engineers *know* that. So many have tried designing an engine that would eliminate pistons, but although the engines produce much power, they're short on fuel economy...
 
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RisingFury said:
After it's had it's energy sucked dry by the piston, sure.

A pulse jet works kinda like this - opening and closing a valve and exploding the mixture. It's inefficient because of the low compression ratios, but it's enough to drive an RC plane, and fast:
Click to expand...
Except that a pulse jet is using the exhaust itself for thrust, rather than trying to drive a compressor and a propeller from the exhaust. It's like he's aiming for a turboprop (which are fairly efficient themselves), but introduced several inefficiencies along the way.

I think the engine "design by Moach" could work with some tweaking (I'd worry about the valve), but I have my doubts that it's an original idea...
Although the animation is awesome! :tiphat:
Click to expand...
I highly doubt that his engine design would be any more powerful than a piston design of comparable fuel consumption...
 
a "piston powered jet" is probably not the best way to put it...

i think my animation fails to portray the intended nature of the overpass rotor... unlike a jet turbine, where the ehxuast can force it's way through the blades whether they are spinning or not, this rotor is supposed to the expanding gas, trapping it in a way that ensures that the better part of the energy being released is converted into shaft rotation...

once the gas makes it into the exhaust, most of it's force will have been transfered onto the rotor - so there's ideally not as much waste as it would seem - the idea is to exploit the "bang" not ignore it :thumbup:


so yes, this is more "piston" than it is "turbine"


another thing to worth mentioning, is that the combustion chamber cycles are completely independent from the rotating parts (which is how we eliminate the reciprocating mass from the drive chain) - instead of mechanical linkages and valves, the ignition and pressure are computer-controlled for optimal power output


as for powering "both" the compressor and the drive - how is that an additional cumberance in comparison to a piston engine?


i guess it would be possible to remove the valve core from the middle of the blast chamber... but possibly uneeded - it does not appear to be under any larger stress than a car piston bears, so it is possible that a complex outer frame would only increase the amount of moving parts?


now, as for the fans, those are not simple blowers in there, you know... they are more like little helicopter rotors, plus, the duct allows for tandem, counter-rotating sets of blades to work as a two-stage airflow acceleration....

and i'm still reading over various sites and articles that ducted fans are supposably more efficient than open-stream propellers... how come is that? perhaps at high RPM?

now i'm confused? :shifty:


more on the engines, i have come to realize that if there was a second alternating combustion chamber, the compressor and drive would have a solid thrust thoughput... as one side is "charging" the other one is "blowing", which in turn, drives the compressor for the first one

and no, i would not dare say this is an "original" idea... (and never have i claimed it was) - the pulse-jet is the most obvious comparison :rolleyes: - this is more an adaptation than an "invention" per se


thanks for the feedback - keep it coming :salute:
 
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Moach said:
a "piston powered jet" is probably not the best way to put it...

i think my animation fails to portray the intended nature of the overpass rotor... unlike a jet turbine, where the ehxuast can force it's way through the blades whether they are spinning or not, this rotor is supposed to the expanding gas, trapping it in a way that ensures that the better part of the energy being released is converted into shaft rotation...

once the gas makes it into the exhaust, most of it's force will have been transfered onto the rotor - so there's ideally not as much waste as it would seem - the idea is to exploit the "bang" not ignore it :thumbup:


so yes, this is more "piston" than it is "turbine"


another thing to worth mentioning, is that the combustion chamber cycles are completely independent from the rotating parts (which is how we eliminate the reciprocating mass from the drive chain) - instead of mechanical linkages and valves, the ignition and pressure are computer-controlled for optimal power output


as for powering "both" the compressor and the drive - how is that an additional cumberance in comparison to a piston engine?


i guess it would be possible to remove the valve core from the middle of the blast chamber... but possibly uneeded - it does not appear to be under any larger stress than a car piston bears, so it is possible that a complex outer frame would only increase the amount of moving parts?


now, as for the fans, those are not simple blowers in there, you know... they are more like little helicopter rotors, plus, the duct allows for tandem, counter-rotating sets of blades to work as a two-stage airflow acceleration....

and i'm still reading over various sites and articles that ducted fans are supposably more efficient than open-stream propellers... how come is that? perhaps at high RPM?

now i'm confused? :shifty:


more on the engines, i have come to realize that if there was a second alternating combustion chamber, the compressor and drive would have a solid thrust thoughput... as one side is "charging" the other one is "blowing", which in turn, drives the compressor for the first one

and no, i would not dare say this is an "original" idea... (and never have i claimed it was) - the pulse-jet is the most obvious comparison :rolleyes: - this is more an adaptation than an "invention" per se


thanks for the feedback - keep it coming :salute:
Click to expand...
I think you should build a prototype.
 
Hielor said:
I think you should build a prototype.
Click to expand...

i think that too... :cheers:
but i have no idea how to go about such a thing - where does one even begin?

doing such things usually involve time and money... both of which, i terribly lack :facepalm::lol:
 
I'd suggest starting with the above, then start constructing a proof of concept scale version , which, if it proves efficient, could be used to build a small scale proof of concept of the whole "car" for further testing.

As to how to proceed once you have the blueprints... You'll need to manufacture the parts. A toolmaker or related craftsman can do that, and if you don't have the money to pay him for his work you got to find someone that is willing to join up with you on this. However, it STILL won't be cheap, since most of the bucks per hour you pay a toolmaker you actually pay for the machines he uses, and I doubt that you'll be fortunate enough to find someone that will readily use his 2 - 500'000 bucks CNC center for nothing (and a CNC center you'll need: In serial production, many of the larger parts are cast, but for a prototype it's "hand"-manufacturing all the way).

That said, I have one serious concern for this machine: Fossil Fuel! If you're already revolutionizing traffic and a whole industry, which would lead to a serious overhaul of infrastructure, you might as well spend some effort to see if you can't do so on a fuel that isn't going to run out in a hundred years or so...
 
That said, I have one serious concern for this machine: Fossil Fuel! If you're already revolutionizing traffic and a whole industry, which would lead to a serious overhaul of infrastructure, you might as well spend some effort to see if you can't do so on a fuel that isn't going to run out in a hundred years or so...
Click to expand...

Well, you better be looking into some form of hydrocarbon, because it needs that energy density...

I calculated that if such a flying vehicle was battery powered, with a perfectly efficient motor, it would need over a ton of lithium ion batteries...
 
jedidia said:
(...)
That said, I have one serious concern for this machine: Fossil Fuel! If you're already revolutionizing traffic and a whole industry, which would lead to a serious overhaul of infrastructure, you might as well spend some effort to see if you can't do so on a fuel that isn't going to run out in a hundred years or so...
Click to expand...

i think this is one of the scarce amount of things that make me proud to live in Brazil - we've got that covered since the 70's -- we drive on ALCOHOL! :thumbup::lol:

no need to wait a hundred years, if i go down to the gas station across the street right now, i can readily fill up my tanks with ethanol fuel (of course that would be conter-productive for me, since MY car still runs on gas :facepalm: - gotta get me one of those "flex" models)


i spent some time last night trying to conceive how this rotor could stop the expanding gas from flooding over to the "wrong" side of the rotor... which would make for a quite a waste of energy (think: two ppl on a canoe paddling opposite ways)

i slept on it, and this morning i figured it out - how to force the gas to push the rotor one way while blocking the other - WITHOUT constantly alternating moving parts....


this calls for another animation... hold on :hmm:
 
I calculated that if such a flying vehicle was battery powered, with a perfectly efficient motor, it would need over a ton of lithium ion batteries...
Click to expand...

yeah, electricity is kind of out of the question... The standard flying car in SF usually came complete with its own pocket sized fusion reactor, but I'm afraid we don't have such luck.
 
yeah, electricity is kind of out of the question... The standard flying car in SF usually came complete with its own pocket sized fusion reactor, but I'm afraid we don't have such luck.
Click to expand...

Yeah... the ton-massive battery was only for 20 minutes of flight time, too...
 
Whoa, whoa, whoa! What's this defeatist attitude? When exactly did a massive battery become a reason for disheartening rather than for rejoicing? And why should we need one battery? Think in stages, folks: let's use many batteries and drop them when they go flat. Piece of cake.

And anyway, we're Orbinauts, or Orbiteers, or Orbiwhatevers: when we want something to move up, we put a rocket under it. If it doesn't work, we go to step 2 and put either more rockets, bigger rockets, more powerful rockets or a combination of those under it. Repeat step 2 until liftoff, explosion, or both. And then go back to the drawing board to design a something that won't blow up when we put rockets under it.

Any human problem can be solved through the correct and massive application of rocket thrust. This is an absolute truth.
Need to deliver stuff far away? Rocket.
Hail falls on your car? Rocket.
Fax too slow? Rocket.
Car doesn't budge? Rocket.
Noisy neighbors? Rocket.
Can't sleep? Rocket.
Headache? Rocket.
Erectile dysfunction? Rocket.
You favourite TV show cancelled? Rocket.
Too many rockets? Rocket.

And flying cars would be a problem? Great Scott, put more rockets on them! Works all the time, I tell ya!
 
T.Neo said:
I calculated that if such a flying vehicle was battery powered, with a perfectly efficient motor, it would need over a ton of lithium ion batteries...
Click to expand...
I'm confused about this, as there are several existing [ame="http://en.wikipedia.org/wiki/Electric_airplane"]electric aircraft[/ame] that can run for rather more than 20min on rather less than a ton of batteries...
 
Ghostrider said:
Whoa, whoa, whoa! What's this defeatist attitude? When exactly did a massive battery become a reason for disheartening rather than for rejoicing? And why should we need one battery? Think in stages, folks: let's use many batteries and drop them when they go flat. Piece of cake.

And anyway, we're Orbinauts, or Orbiteers, or Orbiwhatevers: when we want something to move up, we put a rocket under it. If it doesn't work, we go to step 2 and put either more rockets, bigger rockets, more powerful rockets or a combination of those under it. Repeat step 2 until liftoff, explosion, or both. And then go back to the drawing board to design a something that won't blow up when we put rockets under it.

Any human problem can be solved through the correct and massive application of rocket thrust. This is an absolute truth.
Need to deliver stuff far away? Rocket.
Hail falls on your car? Rocket.
Fax too slow? Rocket.
Car doesn't budge? Rocket.
Noisy neighbors? Rocket.
Can't sleep? Rocket.
Headache? Rocket.
Erectile dysfunction? Rocket.
You favourite TV show cancelled? Rocket.
Too many rockets? Rocket.

And flying cars would be a problem? Great Scott, put more rockets on them! Works all the time, I tell ya!
Click to expand...

Excellent speech! :thumbup:
 
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