V-22 Osprey

Stargazer · December 12, 2009, 01:23:48 PM

Quote from: GTX on December 12, 2009, 11:36:12 AM
"its my fecking model"!!!

You didn't have to write tons... the last five words would have been enough. If I took the time to go over the designation bit, it's because I cared enough for your work, otherwise I would not have bothered.

Quote from: GTX on December 12, 2009, 11:36:12 AM
you seem to portray yourself as a bit of a JDN

Sorry, I don't know what a JDN is, but in your words it sure sounds like something rather unpleasant. I have the weakness to believe that "whif" doesn't mean improbable, and that the more truth you put in an imaginary project to make it resemble reality, the more enjoyable it is. It is YOUR f-ing model, but that's my bloody outlook on things, so you could also respect it.

This being said, you can be sure I will not make the mistake of commenting on your work again.

Jeffry Fontaine · December 12, 2009, 03:13:47 PM

More SketchUp goodness in the form of the V-22 Osprey with six-blade rotors instead of the original three-blade units. Easy enough to accomplish when you can manipulate the 3D model components modify them easily enough.

As for as the designation issue, I don't really care. Should I feel the need to designate it CV or VC or MCV or MVC or whatever, that is my choice to make not yours.

kitnut617 · December 13, 2009, 07:48:56 AM

I started to do a QTR a couple of years ago like in the pic below, I'm using a Transall instead as my base kit. Problem is I cut plastic to how I envisioned it from the picture and I think I've got it too short. What ever happens though I'll need a minimum of 6" or 152mm between the rotor centers when they're in lift mode but like a number of my other projects I had underway before my house move, it's packed away still --- somewhere.

Jeffry Fontaine · December 18, 2009, 04:20:54 PM

Howsabout a XMCJV-22J Osprey with ducted fan units instead of rotors? The 3D model of the large fan jet engine I was playing with earlier appears to be well suited for scaling up to replace the rotors on the Osprey. Of course there will be nay-sayers amongst us that say this is impossible to do in real life but who cares, it looks wicked-cool.

I can not take credit for this idea as it was actually portrayed in a cheesy video game called Recoil where it was used to transport you to the next level of the game. I just took the idea and made it look a little better thanks to the major contributors on the 3D Warehouse at SketchUp

Stargazer · December 18, 2009, 07:57:46 PM

Nice! But what's the purpose of the ducts being dented in their rear end?

Shasper · December 19, 2009, 08:05:53 AM

Noise reduction I think, the engines on the 787 & 747-8s sport the same saw-tooth pattern.

Ok this has been sitting in the back of my mind for awhile now, but if the number of blades were increased could the protor blade length be reduced?

Switching gears, just picked up G. I. Joe on dvd & I'm totally digging the jet powered V-22 thingy, if something like this were to be done in real life would it use 4 engines or only 2 & have some sort of thrust-diverting from the wing to the tail mounted "lift pods"?

Caveman · December 19, 2009, 10:29:36 AM

The saw tooth edge is to improve mixing between the intermediate speed fan exhaust and the free stream. The shear layer between the two is one of the origins of exhaust noise. Improved mixing therefore reduces this. You can find pictures on the interweb of all sorts of interesting shapes which have been tried over the years.

Joe C-P · December 19, 2009, 03:47:07 PM

Remember when considering a jet version of the V-22 that the prop engines are cross-linked, so that if one engine dies, the other can turn the rotor and keep the plane up in the air. If a jet engine blows, the plane spins around one of its axes until the other engine can be killed, and then you have a very heavy glider with a very dizzy crew.

Jeffry Fontaine · December 19, 2009, 04:29:45 PM

Quote from: JoeP on December 19, 2009, 03:47:07 PMRemember when considering a jet version of the V-22 that the prop engines are cross-linked, so that if one engine dies, the other can turn the rotor and keep the plane up in the air. If a jet engine blows, the plane spins around one of its axes until the other engine can be killed, and then you have a very heavy glider with a very dizzy crew.

For the less observant.

The engines remain the same. All that was done to modify the original 3D model was to remove the rotors and replace them with the ducted fan portion of a fan jet engine so the engines are the same as before.

Shasper · December 19, 2009, 08:41:28 PM

Quote from: JoeP on December 19, 2009, 03:47:07 PM
Remember when considering a jet version of the V-22 that the prop engines are cross-linked, so that if one engine dies, the other can turn the rotor and keep the plane up in the air. If a jet engine blows, the plane spins around one of its axes until the other engine can be killed, and then you have a very heavy glider with a very dizzy crew.

Thats why I was thinking of a similar arrangement to the Curtiss X-19 ie engines mounted somewhere on the fuselage (preferably ontop) & ducting the thrust to the wingtips & tail.

jcf · December 19, 2009, 10:49:58 PM

Love the JDN classifier Greg, the JMNs were getting a bit lonely.

Mr. Joyless Designation Numpty meet your roommate the Joyless Modelling Numpty.
Play nice boys.

GTX · December 20, 2009, 10:07:21 AM

Re the ducted fan XMCJV-22J, it's not that far fetched - remember the X-22 (nice name coincidence):

Re the saw-tooth pattern, it would be a definite aid to noise reduction - a possible reason for the duct addition in the first place.
How about a variation with slightly smaller ducts but also with a single one in the tail to help balance the load?

Regards,

Greg

GTX · December 20, 2009, 11:06:03 AM

Couldn't help myself:

And whilst the brain was switched off:

Regards,

Greg

Talos · December 20, 2009, 01:23:05 PM

How about a more streamlined cockpit, Greg?

elmayerle · December 20, 2009, 04:49:34 PM

Quote from: Shasper on December 19, 2009, 08:41:28 PM
Quote from: JoeP on December 19, 2009, 03:47:07 PM
Remember when considering a jet version of the V-22 that the prop engines are cross-linked, so that if one engine dies, the other can turn the rotor and keep the plane up in the air. If a jet engine blows, the plane spins around one of its axes until the other engine can be killed, and then you have a very heavy glider with a very dizzy crew.

Thats why I was thinking of a similar arrangement to the Curtiss X-19 ie engines mounted somewhere on the fuselage (preferably ontop) & ducting the thrust to the wingtips & tail.

But ducting the thrust like that tends to lead to so much duct loss (XFV-12A being an extreme case, but I don't believe anyone's found explanding on the XV-5A's exhaust driven fans to be worth investigating - ISTR that the failure of the exhaust-driven fan concept was one reason Mcdonnell-Douglas'' JSF entry had problems). For this, i prefer mechanical interlinking and drives.