Frenzy high speed bi-plane

[Smallworld]

Hi all, took a break from texturing stuff and re-vivited a model I started a few years ago. This started out as a sports bi-plane to my own design but I abandoned it because it wasn't working. Looking back with new eyes I have re-done just about everything and am really liking it now. Its amazing how your asthetic sensibilities develop over time.
Basically this is a high speed sports bi-plane, which could be used in single class racing or possibly as a record breaker with a big enough motor. The bi-plane world record is 323mph as far as I know and this might be able to break it. Its not much bigger than a Pitts and is a lot less draggy. It would take a big Lycoming flat six, or maybe a Porsche racing engine with 1000hp for the record breaker. I have since reduced the span a lot and done some detail work. Its a total flight of fancy but I would like to think it could fly!

[Mikala]

What a wild aircraft!

[Smallworld]

Thanks Mikala,
Here is an underside view with the reduced span wings and the exhaust system in place, plus the control surfaces cut and the wheels detailed.

[Taranis]

excellent design mate.. are you going to texture it

[Smallworld]

Thanks Ger,
Yes, going to paint her up in something gaudy, maybe a flame job down the sides or something.

[Mikala]

Yes she needs paint!!!!

[Taranis]

Sounds great .. looking forward to it

[BillS]

Wow.. where to begin :) Sorry I used to design R/C sport and Acrobatic planes so this one as a home design has peeked my interest. If your looking to make it flyable. then there are a couple tweeks that could be done, especially for a record breaker. First and for most is kill the nose wheel and go for a tail dragger. All your doing is adding a load of parasitic drag for no real gain. The wing area looks a tad on the low side but with a big enough power plant you can get anything to fly. The cord is way to thin unless you up the camber a bit. Something like an Eppler e186 would make a good airfoil for it. Or one from NACA like the 64-210. Anything with a low Reynolds # would make a good high speed airfoil. Similar on the tailplanes. If your planing on any acrobatics with it then I would kill off the sweeping inverted gull wing on top for a more angular one like on the corsair. Its easier to build stronger. Also the tail arm is to short for acrobatics. It would be fine for an all out straight line racer though. Balancing the ailerons would help the pilot a lot since I'd suggest making the area of them greater on all surfaces.

Without real numbers... Its hard to be more sepecific :D

[Smallworld]

Hi guys, got a bit tied up and havn't had a chance to get back to this. Thanks for all of the info and advice Bill, very illuminating. I hadn't really thought too much about the realities of it flying. It must be really something to see something you have designed actually take wing.
I'm a yacht and boat designer by trade (not been involved for about fifteen years though) so I have an inkling about aerodynamics, but no real idea about things like control surface area or foil sections in aircraft. If it looks like I have the c.g. roughly in the right place I'll be happy :)
I totally agree with the suggestion on making it a tail dragger. I have made the change and built a tailwheel. I have had a look at meshing her and have a problem around the cockpit opening, it seems determind to pull in with an odd kink either side which is vexing me.
I'll post progress as soon as I have any. Spent the evening working on something else to get away from the mesh headache.
Good night all :)

[BillS]

Hi guys, got a bit tied up and havn't had a chance to get back to this. Thanks for all of the info and advice Bill, very illuminating. I hadn't really thought too much about the realities of it flying. It must be really something to see something you have designed actually take wing.
I'm a yacht and boat designer by trade (not been involved for about fifteen years though) so I have an inkling about aerodynamics, but no real idea about things like control surface area or foil sections in aircraft. If it looks like I have the c.g. roughly in the right place I'll be happy :)
I totally agree with the suggestion on making it a tail dragger. I have made the change and built a tailwheel. I have had a look at meshing her and have a problem around the cockpit opening, it seems determind to pull in with an odd kink either side which is vexing me.
I'll post progress as soon as I have any. Spent the evening working on something else to get away from the mesh headache.
Good night all :)

Well it showed that you at the very least had a good understanding of fluid/aerodynamics. Its not only in the right spot is pretty damn close to optimal for what you said you wanted it for. Speed!

I imagine its the same pleasure that you get seeing a yacht or boat that you had a hand in out on the water... Just on a smaller scale for me :) The biggest think I designed only had a 60" wingspan. ;) I was always good at math and when I started flying R/C... well I was backwards to most. My thrill was taking a rough idea, drawing the plans, building it and seeing it fly. Where most would keep flying the same plane... I would be back building the "next" idea. The last one that I made was..... a little more radical in planform.. I should model it in 3D someday :) It was too much of a handful for me to fly at the time, but with the new radios and such I think it would have been an amazing plane....

I'm rambling.

Got an image of whats going on around the cockpit?

[Smallworld]

Here is the problem area. I'm thining that I will have to untrim the holes for the engine blisters and leave the fuselage in one piece. That should fix it but it is a bit wasteful and just not right, which bugs me :(

[BillS]

couldn't you put a fillet around the blister? Just to help it transition a bit.

[DELTA]

Looks fun to fly!