Talk-Polywell.org

Euro Skunks, Inside Secrets of Project Zero

Very nice! I take it this is a tilt rotor? This is a two person general aviation aircraft? Would be hard to qualify in a single seater. . .

Hmm. . .disappointing reading at the link. It's more about the company who built it for just $8M comparing itself to Skunkworks than it is about the plane. Not much like Skunkworks. . .that kind of budget. Too, it's electric, which means it can fly from one end of the airfield to the other then sit and recharge for 8 hours.

Nothing like Skunkworks.

GIThruster wrote:Very nice! I take it this is a tilt rotor?

Tiltrotors in a blended wing body. Cool. Looks like a precise cross between Gerry Anderson and anime

GIThruster wrote:This is a two person general aviation aircraft? Would be hard to qualify in a single seater. . .

Drone.

GIThruster wrote:Hmm. . .disappointing reading at the link. It's more about the company who built it for just $8M comparing itself to Skunkworks than it is about the plane. Not much like Skunkworks. . .that kind of budget.

Perhaps they mean an agile and fairly autonomous group within an organization insulated from that organization's bureaucracy and tasked with working on advanced/secret projects?

... you know, something like the dictionary definition of a skunk works?

GIThruster wrote:Too, it's electric, which means it can fly from one end of the airfield to the other then sit and recharge for 8 hours.

Can't even get that far hovering on batteries but that was not the goal.

Next stage is where it gets interesting: adding a hybrid module.

... at which point very sharp looks will be rained down upon the V-22 program.

And of course even current electric vehicle battery packs can be recharged within minutes. The "8 hours" meme is due to antiquated domestic power infrastructure.

GIThruster wrote:Nothing like Skunkworks.

... until they walk off with Boeing's lunch.

If they can.

zapkitty wrote:

GIThruster wrote:Very nice! I take it this is a tilt rotor?

Tiltrotors in a blended wing body. Cool. Looks like a precise cross between Gerry Anderson and anime :)

Thunderbirds producer?

So that's where Skylon comes from (just knock off most of the Y tail):

DeltaV wrote:Thunderbirds producer?

So that's where Skylon comes from (just knock off most of the Y tail):

Yep, and such series as UFO as well. The Anderson miniatures and effects team headed by Derek Meddings are some of the unsung heroes of modern aerospace design

... but what I like about the Project Zero layout, aside from shedding the weight and clunkiness of V-22 style mechanical transmission gear, is that it's designed to use the tiltrotor ducts as additional lift surfaces when the rotors are tilted forward.

This recovers a portion of the lift surface lost due to the rotors being set into the wing in the first place and makes it a.... what do you call that?... not a triplane, right?

A combination/variation of the joined-wing and rotor-in-wing concepts, perhaps.






Now, with more, smaller fans (say at least 8) there would be less of an empty-area penalty (in the sense that the holes are distributed, though the total hole area would be similar), and you could think about quasi-spherical propulsors arrayed along a duct, pivoting ball-valve style to near-vertical for VTOL, then back into duct-axis alignment to seal the blended-wing-body surfaces for forward flight --

viewtopic.php?f=4&t=2317&p=60161&sid=23 ... 7d1#p60161

(BTW, I've protected this idea in perpetuity by placing it into the public domain.)

<Edit - fixed dead link.>

I wonder how well it does with rolling take-off or landing? Or the loss of a rotor?

I also wonder about fan efficiency in forward flight with the airfoil across the center of the fan rotor?

Just because you can do something does not mean you should do it.: "someones" corollary of aircraft design

ladajo wrote:I wonder how well it does with rolling take-off or landing? Or the loss of a rotor?

I also wonder about fan efficiency in forward flight with the airfoil across the center of the fan rotor?

Rolling takeoff looks like it would be severely limited by rotor tilt before liftoff. A liftoff then acceleration in ground effect before climbing looks more likely.
Loss of a single rotor looks fatal in hovering flight, nearly so in horizontal flight.
I don't see the wing as a problem for the fan in full forward flight, but could give pitch difficulties in transition.

hanelyp wrote:Rolling takeoff looks like it would be severely limited by rotor tilt before liftoff. A liftoff then acceleration in ground effect before climbing looks more likely.

Agreed. Rotor tilt angle/limit for takeoffs/landings would best be automated, driven by several redundant, voted radar & laser altimeters. The small wing surface area also means that rotor thrust (rpm) should have an automatic lower limit near the ground.

hanelyp wrote:Loss of a single rotor looks fatal in hovering flight, nearly so in horizontal flight.

Agreed.

hanelyp wrote:I don't see the wing as a problem for the fan in full forward flight, but could give pitch difficulties in transition.

Also agreed. Burble coming off of the front airfoil at high AoA could cut fan lift roughly in half. Automatic limits, again.


A lot of these issues would be reduced with more, smaller fans, at least up to the point where the total mass flow/watt starts to drop off with decreasing intake areas. Wish I knew enough CFD to find the optimum fan number and diameters. Considering only redundancy, I'd like at least 8.

DeltaV wrote: A lot of these issues would be reduced with more, smaller fans...

Well, this particular item is just a one-off testbed for some concepts at this stage

Further iterations will undoubtedly get deeper into the hypothetical weeds.

I'd go with 4-6 fans as a balance between redundancy and weight+complexity+drag.