Gadeirus' flying things

[Gadeirus]

No real updates on airplanes. My son and I were visiting my brother out of town and within an hour of being home on Sunday from that I ended up having to take my wife to the hospital, and as of noon yesterday I have a new child. They had to get her out early (~4 weeks) and she's in the NICU for now, but so far everything seems to be going pretty ok.

I have been working a bit on yet another "fast airplane" design, though it doesn't really look much different than the last few.

It's designed around a 2320-2180kv motor that is advertised with pitch speeds of up to 185mph on 5 cells without pushing it. Upwards of 190mph pitch speeds possible for short bursts. Obviously I'm not expecting it to fly that fast, but I'd like to see 150mph.

My current focus is on trying to optimize the wingroots to reduce interference drag as much as possible, the rest of the airframe is pretty clean, wing is MH30 and tailfeathers NACA 0008.

 

[AIRFORGE]

No real updates on airplanes. My son and I were visiting my brother out of town and within an hour of being home on Sunday from that I ended up having to take my wife to the hospital, and as of noon yesterday I have a new child. They had to get her out early (~4 weeks) and she's in the NICU for now, but so far everything seems to be going pretty ok.

I have been working a bit on yet another "fast airplane" design, though it doesn't really look much different than the last few.

View attachment 259553

View attachment 259554

View attachment 259555

It's designed around a 2320-2180kv motor that is advertised with pitch speeds of up to 185mph on 5 cells without pushing it. Upwards of 190mph pitch speeds possible for short bursts. Obviously I'm not expecting it to fly that fast, but I'd like to see 150mph.

My current focus is on trying to optimize the wingroots to reduce interference drag as much as possible, the rest of the airframe is pretty clean, wing is MH30 and tailfeathers NACA 0008.

Congrats on the new Gadeirus! 👶

 

[telnar1236]

Congratulations to you and your wife!

 

[telnar1236]

Looks like a good design. MH30 is a good choice for a speed plane. My experience from CFD on midwing designs is that at our scales and speeds, a wing root fillet adds more drag in frontal area than it saves in reduction in turbulence - my twin fuselage racer concept had them for aesthetics but based on CFD they objectively made it worse. They do also add strength though, which might make them worth it - I used them on the tail surfaces of the super duper sabre partially for that reason

 

[telnar1236]

What's the wing root chord length?

 

[Houndpup Rc]

No real updates on airplanes. My son and I were visiting my brother out of town and within an hour of being home on Sunday from that I ended up having to take my wife to the hospital, and as of noon yesterday I have a new child. They had to get her out early (~4 weeks) and she's in the NICU for now, but so far everything seems to be going pretty ok.

Congrats to you and your wife!!😁👍 I will pray for her safety👍

 

[Gadeirus]

Thanks everyone for the well-wishes!

What's the wing root chord length?

 

[telnar1236]

Thanks everyone for the well-wishes!



View attachment 259576

Weirdly enough, you might want to look at a lower lift airfoil for your design - the MH30 is a pylon racing airfoil and really built to perform well in hard turns at high speed but if you're going for straight line top speed a NACA 0008 airfoil is probably a bit better. At 100 mph, if your plane weighs in at 1 kg, you'll be flying at a coefficient of lift of 0.05 so the cambered airfoil hurts instead of helps.

Also you want it, here's the laminar flow airfoil I designed for my entry - it's not as well suited to your wing since it really is intended for slightly higher Reynolds numbers, but it's thicker which makes structure easier and above Re = 1E6 it does perform better for straight lines and by 3E6 it's better for most of the flight envelope. You really need a lower aspect ratio wing to get the most out of it though and at your wingtip chord it's worse across the board.

The NACA0008 is probably better for straight line speed unless you're building quite big though

 

[Gadeirus]

Hm, interesting, I thank you.

Because of how I intend to segment the model for assembly, swapping wings out would be quite simple, perhaps I just build more than one wing and see how they compare.

 

[telnar1236]

Hm, interesting, I thank you.

Because of how I intend to segment the model for assembly, swapping wings out would be quite simple, perhaps I just build more than one wing and see how they compare.

Multiple wings isn't a bad idea - 3D printing does very well with modularity

 

[Gadeirus]

Been a very busy week, taking care of the kids, shuttling the wife back and forth to the hospital, going to work for a few hours here and there, but I've still managed to make a little bit of progress on Mercury V4. Faired out the wing roots to a somewhat acceptable level as well as the horizontal and vertical stabilizers. Worked on cooling air inlets and outlets, and started segmenting the model a little bit.

And since I don't have enough going on, I started two more new aircraft designs.

One is another DTFB "speed" plane. 750mm span constant chord wing using a KFm4 type airfoil. Thought about just stacking parts and laminating them to build up the fuselage, but I'm having second thoughts....I think it'll be too much work considering I have to cut all of that out by hand, and also, it looks kind of stupid.

The other design is for yet another "hybrid construction" DLG glider, so DTFB flying surfaces, carbon boom, and printed fuselage pod. Rudder/Elevator only, using rather small battery and receiver. Typically one does not use V-Tails on DLG's since they need a lot of stability during launch which is why you usually see large vertical stabilizers. I don't want to use ailerons on this one since it can complicate the wing build, servo linkages, blah blah. Problem is, generally what I would do would end up requiring me to create a slot in the top of the CF boom to allow a pushrod to come through. I've done this numerous times, but I'm trying to make this easy to build so if anyone (heaven help them) would like to build one of their own but isn't equipped to slot a CF tube they don't get stuck. The solution was V-Tail as I can run both pushrods out of the end of the tube, and then to increase vertical surface I added the stabilizer section below the boom.

HOWEVER...this introduces more parts, a more complicated tail feather mounting arrangement, more complicated linkages at the tail, and it looks kinda weird anyways. So I may just go back to a traditional layout after all. 1200mm span, for what it's worth.