Thundercat Rear Wing

[Roflhat]

Looking for ideas for what to use as a rear wing on my thundercat, thinking something like a yacht rudder or something similar, needs to be as lightweight as possible but strong. Was thinking yacht rudder as the profile is about right for a foil, but need something bigger really

[fel2]

[simonl]

That's outrageous - who in their right mind would paint the spolier red when the car is such a lovely pink?

Never seen a thundercat with a wing. What's the goal? Aerofoil or water foil?

[Roflhat]

Originally Posted by fel2

Attachment 121330

haha, pretty much!

Originally Posted by simonl

That's outrageous - who in their right mind would paint the spolier red when the car is such a lovely pink?

Never seen a thundercat with a wing. What's the goal? Aerofoil or water foil?

No neither have I, but in my mind it should work. As long as it doesn't create too much drag and it's not too heavy. Thinking an aerofoil

The problem with going faster in a thundercat is that it becomes very unstable, as less and less hull is in contact with the water. The entire hull acts as a wing, with the lifting surface ahead of the centre of gravity, which is right at the back where the engine is. So as the boat starts to lift (going to flip) there is no moment counteracting that. Adding a large rear wing with 0 angle of attack whilst travelling at normal speed and angle would then act as a counter moment, which could stop the boat flipping over backwards.

My idea is to put a large rear wing far behind the transom, so as the boat starts to lift the air hitting the wing would then push the bow back down.

[fel2]

Keep in mind it would need to be adjustable because of wind condition

Well, it's not like you enjoy going out with 100 mph front wind. After all

A-frame with a wing just under the top wouldn't look too strange.

[simonl]

I think it'll be a struggle. Some thoughts - As the front lifts there's a large hull wing as you say. Once this lifts it increases in frontal area hugely.
Upward force = say 1 sq.m 3m from c.o.g. 1 x 3 = 3

To counteract this at a point 1m from the c.o.g
3 x 1 = 3
you'd need 3m2 to equal the upward lift, plus it would have to be at least at the same angle as the front, plus it would be shadowed by the front so you might need to double it! We're now at the size of a good windsurfer sail!
If it's not about winning races, maybe work out a way to stuff a 'water brake' at the back as the nose rises. that'd pull the bow down sharpish. It could be done automatically, but it's a harsh environment. Another way would be to use a small wing at the front. This could use radio control technology to keep a perfect trim. Not too difficult... except for the environment again.


edit: pessimistic post by me. Anything you do will be interesting & something to learn. Keep us posted

[fel2]

Then

[fel2]

If you need
More great idea let me know ! [emoji112]

[simonl]

Originally Posted by fel2

Then Attachment 121331

Comes with free keyring

[Roflhat]

thanks Felix, good inspiration [emoji112]

I had thought about how large the wing would have to be, I was thinking of a long wide wing, wider than the hull so it would be running in clean air. Was also thinking it could be mounted a couple meters back, using lightweight tubing as framing to mount it.

Had also considered an active front wing, but that would require some sort of automatic actuation which is going to be difficult and require electrical power

[simonl]

Originally Posted by Roflhat

Had also considered an active front wing, but that would require some sort of automatic actuation which is going to be difficult and require electrical power

Front wing, well out front if that's viable: Needs power, absolutely. But it's not that difficult to do - the radio control guys are doing stuff like that all the time and all the components are readily available. The control circuit woulds be tens of pounds, nut hundreds. It wouldn't require much power (small battery pack) and could act significantly, way before the front gets any significant lift. It would need plenty of trial & error tuning I suspect . It's the waterproofing I can't visualize though

I think anything at the back would be so big that its weight would be taking your cog back further, compounding the problem.

[Roflhat]

I was thinking two seperate wing sections, one on each side of the front nose cone like they use in jet boat racing. Out in front is going to be too exposed I think, I take the boat out in pretty big waves and surf so I think they would likely snap off.
This is the sort of arrangement I'm thinking of -
Mounting it would be another issue, as the whole side of the boat is obviously rubber

[Stevie Bill]

Might be easier to mount anti flip vanes out the back? Think drag bikes which are fitted with rear stabiliser to prevent over wheelie... Something like a long oar mounted on each sponson. Normally clear of the water, so no drag, but as bow lifts, the vanes contact the water... Would be very much smaller than aero equivalent, and look much less intrusive...?