What is Digg?42 Comments
- borez, on 12/27/2008, -0/+19Well that's kinda what the Osprey does.
- XPpro, on 12/27/2008, -2/+16http://en.wikipedia.org/wiki/Airwolf_(helicopter)
- Peko, on 12/27/2008, -0/+12I thought the main constraint was that rotor speed versus airspeed thing - something along the lines of - if the forwards moving rotor tip + heli airspeed is higher than the speed of sound = problems.
Or was it with the backwards moving rotor + airspeed = too low; creating instability?
Ok, I'm confuzzled. - Terasiel, on 12/27/2008, -2/+13Next: The Quest for the 300-m.p.h. Segway.
- borez, on 12/27/2008, -0/+9You've gotta love the: "Mach 2 max speed ( citation needed )" bit of that Wikipedia entry.
- Peko, on 12/27/2008, -1/+10Ok, I'm right on both accounts! Two intrawebs for me!
http://en.wikipedia.org/wiki/Dissymmetry_of_lift
But uh - so unless you solve the whole dissymmetry thing - it doesn't matter how much thrust you stick on the back of a heli - if you go over Vne you're screwed. - Jeepinator, on 12/27/2008, -0/+7The framerate of the camera happens to match the frequency of the blades perfectly. It's like a scientific strobe.
- wreckosaurus, on 12/27/2008, -0/+6http://www.sikorsky.com/sik/about_sikorsky/news/20 ...
sikorsky x2, can fly at 285 mph
http://en.wikipedia.org/wiki/Sikorsky_X2 - Disgod, on 12/27/2008, -0/+5Neat, I thought the theoretical limit for a helicopter was around 250mph, but I guess they're getting around it by not using the main rotor to supply the extra speed.
This is why pure helicopters' can't go past 250mph, with our current technology.
http://en.wikipedia.org/wiki/Dissymmetry_of_lift - lamejoketeller, on 12/27/2008, -0/+4Congratulations, you have been awarded two internets.
- Dipsomaniac, on 12/27/2008, -0/+4Autogyros lack at some of the most desirable features of a helicopter, especially for the military - sustained hover and maneuverability in any direction, to name only two.
- kingdee40, on 12/27/2008, -15/+19Q: How do you make a 300mph helicopter?
A: Turn it into an airplane. - nullcodes, on 12/27/2008, -0/+3Carter copter's autogyro gets around the issue by slowing the rotor down.. forward thrust is via a propeller and the wings sustain flight. It can get up to 500mph.
http://www.cartercopters.com/ - neutronphaser, on 12/27/2008, -0/+3Already done:
http://timstvshowcase.com/airwolf0.jpg - Jeepinator, on 12/27/2008, -1/+4The Osprey is still not to be considered a helicopter.
- hulahula, on 12/27/2008, -0/+3The advancing blade will lose efficiency as the tips go transonic but will still produce lift. Even if the tips are supersonic the advancing blade will produce lift. It is the retreating blade that is typically the limiting factor since, at speed, lift will approach zero. Installation of the wing on the retreating side compensates for this loss of lift and solves the dissymmetry of lift. Vne of 300 mph shouldn't be a problem if correctly engineered. The Westland Lynx, a conventionally configured helicopter, reached 249 mph in 1986. The real limiting factor has been a lack of need for high speed helicopters.
- lamejoketeller, on 12/27/2008, -0/+3speechless.
- Clbull, on 12/27/2008, -0/+3then its not a helicopter
- dmm219, on 12/27/2008, -0/+3Airwolf has been around for 20 years...buried...
- DJBONEZ, on 12/27/2008, -0/+3I think the picture alone says it all.
- RudolfDiesel, on 12/27/2008, -0/+2I forget the name, but there's that helicopter that can rotate the rotors 90deg once at speed. Can't those do 300MPH?
- Peko, on 12/27/2008, -0/+2I've ran into articles about the carter copter before (probably on digg). Always thought it seemed like a spiffy design - I'm curious why it hasn't gone caught on more/faster.
- koldmilk, on 12/27/2008, -1/+3http://www.youtube.com/watch?v=_Isi2cwJsp4&fea ...
- giloron, on 12/28/2008, -0/+2"it doesn't matter how much thrust you stick on the back of a heli - if you go over Vne you're screwed."
Unless you add a wing to the side losing lift as was mentioned in the article. - Fletchnuts, on 12/27/2008, -0/+2Yep, receding blade stalls are a bitch.
- lamejoketeller, on 12/27/2008, -0/+2why are you being thumbed down? This is essentially what both of the mentioned designs are doing...
Vectored thrust and fixed wings are traits that until now exclusive in fixed wing aircraft... - AgentOrn, on 12/28/2008, -0/+2The limit on a normal rotary wing aircraft is held up by retreating blade stall.
The blade that is moving backwards though the air has is moving so slow in relation to the air it is cutting though because of the forward movement of the aircraft, that is in effect stalls the blade by creating no or almost no lift. This at its worst can cause the aircraft to role over because all the lift is loaded on to one side of the rotor system. - astyguy, on 12/28/2008, -0/+2I heard the government had a project like this called "airwolf" but someone stole the prototype ... someone called hawke
- drewgibs, on 12/27/2008, -0/+1Wow says here the Airwolf helicopter crashed back in 02, killing 3
http://airwolf.tv-series.com/default.asp?ModuleID= ... - Disgod, on 12/27/2008, -0/+1Read further down:
"However, as entry of the rotor tip into the supersonic aerodynamic realm is one of the unstable conditions that affects forward flight, even helicopters with two rotor discs rotating in opposite senses will be subject to a never-exceed speed"
Even two rotor helicopters will have issues. - inactive, on 12/27/2008, -1/+2I actually think the helicopter that turned into an jet from the cartoon M.A.S.K. was a good design.
http://en.wikipedia.org/wiki/M.A.S.K. - RusskiGuy, on 12/27/2008, -0/+1"It is a phenomenon that affects single-rotor helicopters"
Seems like adding a second rotor should help. But that's already been done, so there must be something else to it... - inactive, on 12/27/2008, -1/+2I've always thought a Chinook would make a perfect motor home, or even a nice primary residence.
- aceslick911, on 12/27/2008, -0/+1are you ***** retarded or somethin
- ncmason, on 12/28/2008, -0/+1Hopefully it has seatbelts.
- Truth3, on 12/28/2008, -0/+1That's what she said.
- dgeet, on 12/28/2008, -0/+1The "Carter Copter" has already beat the rotor speed vs. airspeed dilemma ("mu of 1"), with a goal of ultimately exceeding 500mph. Technically its a gyrocopter, but still a cool idea. Their web page has a good explanation of the "mu" obstacle facing high speed helicopters.
http://www.cartercopters.com/mu-1.html - Parch33zi, on 12/27/2008, -1/+2your uh phuching mormon!
- Parch33zi, on 12/28/2008, -0/+1your deduction ability is amazing
- RAGEdemon, on 12/27/2008, -4/+2Quite so. We already have aircraft with the advantages of both helicopter and a fast aeroplane: the Harrier militery Aircraft.
No need to re-invent the wheel. - Parch33zi, on 12/27/2008, -7/+1that be so stupid, how do it works? you gotta bee one of them stupid folks for posting this. go make me a ham sandwich!
- glutamate, on 12/27/2008, -16/+6***** FAIL
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