(RC)Tanker

Ok, I'm sorry if im posting this in the wrong section, but I was thinking of trying a scratchbuild eventually and though of a VTOL or STOL flying wing, the only problem is balance. It works based on the osprey design.

Check file please( this is just a basic sketch up, cant find all my serious plans right now, got lost in my schoolwork, post them when I find them)

As you problably noticed the propellers being forard isnt a problem for the conventional part of this design, but causes inherent stability issues when attempting a VTOL.

I was wondering if any of these solutions would correct this without compromising the conventional functions of the aircraft.

Make the propeller higher than the pivot it rotates around.
Slightly tilt the small push propeller down.
Should I add a turbine and use thrust vectoring to give the rear upward thrust on takeoff?

Could I just put the landing gear closer to the back and just accept that that it wont take off perfectly straight or will it not be able to work without constantly adjusting the propeller angle?

Im still on the drawing board phase, so please realize that the design is mainly focused on a list of essential parts, what space they need to fall in, the basic rib structure and the basic external form, so im still a few months atleast from getting the final plan print and purchasing parts. (I also need to read up on my glues and radio equipment)

And, on a nonrelated note, would this ever be feasable for landing and takeoff in water(with obvious modifications, such as floats and the repositioning of propellers as not to soak)

Lnewqban

Your schematic is hard to see, because it shows sideways.

At least I couldn't understand the idea[]

(RC)Tanker

It is a flying wing design. The middle of the wing is split in 2 with a hole in the middle which allows air to flow through will using VTOL. The propellers are 4 shaft each, with the front ones being 15.5 inch(diameter) and the inner ones being 9.5 inch(diameter)
Here is the basic design that I found in the weirdest place in the house(jammed underneath our piano)

Is this clear for you Lnewqban?

Bundubasher

You get a lot of styrofoam model plane toy designs that actually fly in toy shops. The only reason that they can fly on very small scale (<30cm) is that they are made out of light foam and use strong, small motors and batteries. When you scale this up, you would need larger props - getting alsmost in rotor size teritory. Another problem is flying surface generated turbulence. Try building a small scale designfrom foam and see how it goes, then scale it up.

Cheers

(RC)Tanker

Thanks.

If it gets into raising rotor size would i be able to just lower the RPM and get the same thrust as a smaller rotor in standard flight.

Ram-bro

My Feedback: (101)

your idea kinda puts me in mind of the Flying Pancake. Designed for the nayas a vtol

(RC)Tanker

Thats actually one of the planes I looked at when I was thinking of this idea.

Ram-bro

My Feedback: (101)

me personnally, I think making it a 4 engine setup the way you have it would make it overly complicated. On a foamy maybe not so much. If I understand your design, are you making it a tilt rotor design? I also think not havig a verticle stbilizer for a vstol type aircraft will add to the unstability but that is part of the fun and the challenge. Iam not trying to discourage but to let the challenges be known and lets get to wor solving them.

Lnewqban

It is clear now, thanks.

The lack of wing for horizontal level flight is the main problem that I see.

The wing will be useless for lift where the propellers-motor are, close to the edges of those openings, and by the sharp wing tip.

The thrust line for hovering should cross the CG, which should be at 25% of the MAC for horizontal flight on the wing.

(RC)Tanker

It might be because I am a complete nicompoop, but why would having the flight surfaces split have any effect, assuming the second propeller keeps the front wings drag from interfering with the second one? Would somehow isolating these flight surfaces from the rest reduce airflow loss??

Lnewqban

There is a pressure differential between the top and bottom of the wing during horizontal flight.

There is always a leak of air around the ends of the wing, which affects efficiency and generates vortexes.

The whole idea behind long and slender wings for sailplanes is to keep those leaks small respect to all the mass of air that the wing moves for useful purposes (lift).

By splitting the wings, you will create four additional ends and paths to air leaks and generators of vortexes.

Nothing impossible to overcome, it is only that you will need more wing area than the area of the equivalent solid wing, in order to obtain the same lift.

An additional difficulty is the structure of the bridges joining the wing sections.

For a normal wing, the spars take that bending stress.

Spars should keep certain separation between them; thing difficult to achieve by the LE and TE of the wing.

Note that the V-22's design places the rotors by the tips of the wing, avoiding all those difficulties (although they sacrifice around 10% of the rotor's lift when they hover and the downwash hits the top of the wing).

ARUP

Try it out! Nothing ventured, nothing gained!

CanDo

A fellow designed a VTOL plane called the "Vertigo" that was published in Model Airplane News magazine. You might get some ideas from his design:
http://www.airagestore.com/plans/rc-...t/vertigo.html

Props4ever

Very interesting design i must admit at minimum....why do you want to have puller and pusher configuration on your engine set up, would one or other do the job if enough thrust can be produced to overcome using both configuration. Plus don't forget with both engine almost back to back with each other and running at different rpm while producing different levels of thrust can cause a lot problems with thrust flow and will cause turbulence when thrust produced from puller propellers will contact thrust from pusher propellers, right there will be airflow differential problem due to different rpms and level of thrust....Single engine type would be a lot better being it puller or pusher due to such a short gap between the two.