Bugatti 100T

I have failed to find the thread that mentioned the Bugatti airplane that is being prepared for flight. I had a little chat with one of my ex associates in PD who is the aero guy now. When I mentioned that the people who were building the replica were getting close to first flight , he said, " They're not going to try to fly that thing??" I commented that the tail was too small to be so short coupled and he agreed and then said that the worst thing about the tail ( horizontal stabilizers ) was the leading edge radiator air intakes destroying flow over the surfaces that were too small to begin with. Also with the swept forward wing leading edge could produce some confusion in the spanwise flow. So, every knowledgable engineer with whom I have talked about this airplane has negative comments about it.

 

Bob,

Their website is here: The Bugatti 100p Project - An ambitious project created to build and fly a replica of a magnificent aeroplane

But it isn't up to date with their progress, they do that every other day or so on their Facebook page here: https://www.facebook.com/TheBugatti100pProject?fref=ts

I don't know for a fact that the 100p has them, but could Bugatti's patented split-ailerons be used to help the tail with yaw control?
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I am not an expert on this type of thing but it looks like the split ailerons could aid in directional control as in the Northrop flying wing and the current flying wing B-2. I sense a loss of pitch control as much as directional control. We all could be fooled if it flies but it still doesn't look right to people who are much more qualified than I am. Take a look at successful configurations; the ME109, Spitfire, Hurricane, P-51, and F8. Then take a look at the Curtiss SB2C, short coupled and a miserable airplane. The PB4Y and the B-32 required huge vertical fins to make up for the lack of tail arm. The Bugatti displays the wrong way to do it.

 

oh wow I don't think I've ever seen a SB2C, sure isn't a very elegant looking plane :/

I just posted a question on their facebook page asking what they expected the handling to be like, and if they or someone else did windtunnel or computer simulations. Let's hope so!
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Check the last page (at this time) of "Warbirds over the beach" thread.

 

I have never heard anything good about this airplane. A high school buddy who joined the Navy during the war was a tail gunner on one of these and he said that it could very well kill him before he saw action. It did.

 

I understand all of the short coupling problems, but to me, it does not seem to have a conventional flyable weight and balance. With two large engines and carrying coolant, it's going to be exceptionally heavy, high wing loading and seemingly exceptionally tail heavy. And I guess we can rule out a flying tail. Delmar Benjamin's GeeBee looks safer than this airplane, but I do hope it somehow works.

 

This thread needs more photos.
Maybe it's intended to be closer to a flying wing than a conventional aircraft, with the tail acting more as a counter balance than an active aerodynamic device?
I know it's not the same but I've got several RC models of wings that don't look like they should fly as well as they do (without canards or vertical stabs).
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It looks like the wings don't have as much forward sweep as I thought.

The leading edge looks like only a few degrees, the trailing edge is very tapered.


Where are the radiators?

 

Leading edges of the tail & ventral fin are the intake to a single (split) internal radiator mounted in the aft fuselage behind the rear engine.


"Also unorthodox was the racer's cooling system, designed specifically to reduce cooling drag to the minimum. Air was scooped into ducts in the leading edges of the butterfly tail and the ventral fin. The air collected at these high pressure points was rammed into a plenum chamber in the aft fuselage and passed forward through an increasing area duct to the radiator, which was located behind the rear engine. The air thus was slowed down to an efficient cooling speed by the time it reached the radiator. After absorbing heat, the cooling air was then exhausted out into a low pressure area behind the wing trailing edge. The pressure differential at the intake and outlet created a natural air circulation so that no fans or blowers were required. The radiator was in two parts, one for each engine."

 

From their Facebook page:

"Where the "rubber meets the road" or - more accurately - where "CAD and CNC meet 80-grit sandpaper and epoxy".

We reached a milestone today with the final installation of the gearbox, a 30-month collaborative project between the US and the UK. We've said this before, but it bears repeating; it might be easy for Boeing to build components in different parts of the world and assemble them together to make an airplane, but has been a challenge for us. Fortunately, everything fit perfectly!"
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Beautiful, but scary to me somehow. All of that torque, heat and thrust transmitted there. I assume the gearbox is oil cooled.

 

Subscribed.

Pete

 

Thanks.

Sounds like almost no cooling airflow while slow taxiing... weird.

 

What exactly was the purpose of this recreation (and actually making it fly)?

Airshows?

 

One way suicide mission for the unlucky person commissioned to test it.

 

With no ejection seat, too...

 

The intakes placed in the leading edge of the small horizontal tail will seriously diminish the aerodynamic quality of a surface that is already too small. I wonder about cooling when that contraption is sitting on the ground with both engines running.

 

Just a casual question - has this contraption ever done any serious computer analysis or wind tunnel time?

Or, did they just make it the same shape as the ancient Bugatti and hope for the best?

Second question - I heard somewhere that the original plane was found after WW2 in the Bugatti works in France...do we know what happened to it?

 

I'm obviously no aeronotic engineer but it seems to me that if the gear box grenades, you only have a inch of wood protecting the pilot. And if it goes bad enough, what about the two driveshafts? if it fails there, I'd hate to have one of those driveshafts flailing around within inches of me.
I know most regular prop planes have the gearbox in front (I can't remember which one has the engine and gearbox behind the pilot) but they also have a large engine behind the gear box for protection and if a piston engine goes, it's usually a thrown rod which I'd much rather have than have the gearbox grenade and have an inch of wood protecting me and no driveshafts going through the cockpit.

How did they make the props counter rotating, does one engine rotate opposite the other or does the nut and shaft that is only on the left side how it achieves counter rotation with an idler gear?
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With the very high wing loading that this aircraft surely must have, if the gearbox and / or associated drivetrain goes haywire at any time other than while it's on the ground, the pilot is probably toast anyway.

 

Most large piston planes (and small piston planes) that actually worked did not have a gearbox between the engine and the prop.

I too would be afraid of that co-axial gearbox, but it may well be the least of the problems on this mess.

 

What is on the front (or rear?) of the Rolls Royce Merlin engine then?, in the Spitfire.
Pete

 

The constant speed prop regulator and the propeller.

The propeller (with a prop blade pitch regulator) is actually the transmission itself - the blades to high RPM for greater pull at low speeds (low gear) and higher pitch for greater speed when the plane is moving fast (high gear).

These big engines did not turn very fast to make their power - less than 3000 or maybe a little more at the most. Prop speed, in other words.

EDIT - you bring up another limitation of the Bugatti 100T - there is nothing there to regulate the prop blade pitch...almost universal among working high speed aircraft.

 

Its propellers don't have variable pitch??

There's no doubt that Bugatti was a genius at designing cars, the problem though is like an MD, they think since they can fix bodies, they can do anything, years ago I was wrenching on an MD's car and he was telling me the problem, I was like no, this is the problem, it was pretty obvious. He insisted he was correct so I sent him down the road. No doubt if I had fixed what he thought was wrong, when the problem wasn't fixed, he probably would have blamed me. I think my final words were, why don't you fix it yourself?
I don't tell a Doctor what I think is wrong with me unless I break a toe or something which was a recent problem. The worst part is there is nothing they can do but put a specail shoe that protects the toe. Grrr.