Scratch Building, Aircraft Design, 3D/CAD If you are starting/building a project from scratch or want to discuss design, CAD or even share 3D design images this is the place. Q&A's.

Would this idea work at all?

Reply

Old 11-27-2011, 07:01 PM
  #1  
(RC)Tanker
Member
Thread Starter
 
Join Date: Jun 2011
Location: Willoughby, OH
Posts: 66
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Would this idea work at all?

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)

Attached Thumbnails Click image for larger version

Name:	Nl28265.jpg
Views:	8
Size:	50.4 KB
ID:	1692273  
(RC)Tanker is offline  
Reply With Quote
Old 11-28-2011, 10:15 AM
  #2  
Lnewqban
 
Lnewqban's Avatar
 
Join Date: Apr 2007
Location: South Florida
Posts: 4,042
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Would this idea work at all?

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

At least I couldn't understand the idea[]
Lnewqban is offline  
Reply With Quote
Old 11-28-2011, 12:23 PM
  #3  
(RC)Tanker
Member
Thread Starter
 
Join Date: Jun 2011
Location: Willoughby, OH
Posts: 66
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Would this idea work at all?

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?
Attached Thumbnails Click image for larger version

Name:	Ca81849.jpg
Views:	7
Size:	140.5 KB
ID:	1692576  
(RC)Tanker is offline  
Reply With Quote
Old 11-28-2011, 12:29 PM
  #4  
Bundubasher
Senior Member
 
Bundubasher's Avatar
 
Join Date: Dec 2008
Location: Cape L\'\'\'\'\'\'\'\'Agulhas, SOUTH AFRICA
Posts: 687
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Would this idea work at all?

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
Bundubasher is offline  
Reply With Quote
Old 11-28-2011, 01:25 PM
  #5  
(RC)Tanker
Member
Thread Starter
 
Join Date: Jun 2011
Location: Willoughby, OH
Posts: 66
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Would this idea work at all?

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.
(RC)Tanker is offline  
Reply With Quote
Old 11-28-2011, 01:30 PM
  #6  
Ram-bro
My Feedback: (100)
 
Join Date: Jan 2002
Location: Bennington, NE
Posts: 5,731
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Would this idea work at all?

your idea kinda puts me in mind of the Flying Pancake. Designed for the nayas a vtol
Attached Thumbnails Click image for larger version

Name:	Da83282.jpg
Views:	4
Size:	28.8 KB
ID:	1692601   Click image for larger version

Name:	Cx74685.jpg
Views:	3
Size:	35.1 KB
ID:	1692602   Click image for larger version

Name:	Ej13380.jpg
Views:	4
Size:	74.7 KB
ID:	1692603   Click image for larger version

Name:	Jc86101.jpg
Views:	7
Size:	18.5 KB
ID:	1692604   Click image for larger version

Name:	Yj65697.jpg
Views:	5
Size:	13.5 KB
ID:	1692605   Click image for larger version

Name:	Lc48748.jpg
Views:	4
Size:	26.0 KB
ID:	1692606   Click image for larger version

Name:	Rt32976.jpg
Views:	4
Size:	81.5 KB
ID:	1692607   Click image for larger version

Name:	Ih25713.jpg
Views:	5
Size:	46.9 KB
ID:	1692608  

Click image for larger version

Name:	Xv35068.jpg
Views:	3
Size:	99.3 KB
ID:	1692609   Click image for larger version

Name:	Fr80270.jpg
Views:	6
Size:	14.8 KB
ID:	1692610   Click image for larger version

Name:	Fl54395.jpg
Views:	22
Size:	13.6 KB
ID:	1692611  
Ram-bro is offline  
Reply With Quote
Old 11-28-2011, 01:34 PM
  #7  
(RC)Tanker
Member
Thread Starter
 
Join Date: Jun 2011
Location: Willoughby, OH
Posts: 66
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Would this idea work at all?

Thats actually one of the planes I looked at when I was thinking of this idea.
(RC)Tanker is offline  
Reply With Quote
Old 11-28-2011, 02:28 PM
  #8  
Ram-bro
My Feedback: (100)
 
Join Date: Jan 2002
Location: Bennington, NE
Posts: 5,731
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Would this idea work at all?

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.
Ram-bro is offline  
Reply With Quote
Old 11-28-2011, 05:56 PM
  #9  
Lnewqban
 
Lnewqban's Avatar
 
Join Date: Apr 2007
Location: South Florida
Posts: 4,042
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Would this idea work at all?

ORIGINAL: (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.
........

Is this clear for you 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.
Lnewqban is offline  
Reply With Quote
Old 11-28-2011, 06:26 PM
  #10  
(RC)Tanker
Member
Thread Starter
 
Join Date: Jun 2011
Location: Willoughby, OH
Posts: 66
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Would this idea work at all?

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??
(RC)Tanker is offline  
Reply With Quote
Old 11-29-2011, 10:07 AM
  #11  
Lnewqban
 
Lnewqban's Avatar
 
Join Date: Apr 2007
Location: South Florida
Posts: 4,042
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Would this idea work at all?

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).
Lnewqban is offline  
Reply With Quote
Old 11-29-2011, 11:18 AM
  #12  
ARUP
Senior Member
 
Join Date: Jan 2007
Posts: 2,343
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Would this idea work at all?

Try it out! Nothing ventured, nothing gained!
ARUP is offline  
Reply With Quote
Old 11-30-2011, 11:28 AM
  #13  
CanDo
Senior Member
 
Join Date: Feb 2006
Location: SoCal, CA
Posts: 505
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Would this idea work at all?

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
CanDo is offline  
Reply With Quote
Old 11-30-2011, 11:53 AM
  #14  
Props4ever
 
Join Date: Aug 2005
Location: Mississauga, ON, CANADA
Posts: 4,196
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default RE: Would this idea work at all?

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.
Props4ever is offline  
Reply With Quote

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service