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Ducati patents variable jet exhaust
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Whoever wrote that article should have done at least a little bit of research on variable geometry jet engine exhaust and understood something about the after burner section. This has zero to do with that. The individual who made the comment with regard to a variable geometry petal design modulating exhaust gas dynamics was accurate. A different "flapper" if you will. That being said if the design does incorporate fuel nozzles and an igniter in that section then yes theoretically you could obtain a vectored thrust of some mathematical value. This however would (depending on frequency amplitude and duration of deployment) exhaust your fuel supply in short order. It's not free folks.
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i think it was rather targeted towards the directional abilities rather than creating additional thrust like a turbine would do.
i admire the extent of thinking at ducati, to even consider the impact of this in regards to aerodynamics (or turbulences for the rider in draft
)
i admire the extent of thinking at ducati, to even consider the impact of this in regards to aerodynamics (or turbulences for the rider in draft
)
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There is a lot of energy in exhaust, we have seen it in cfd and wind tunnel modeling for land speed cars. Exiting exhaust in the turbulent pocket behind the vehicle is good for big mph gains by reducing drag. And yes there is a measurable thrust factor.
Anyone that remembers the blown diffuser in F1 a few years back, also remembers how effective it was in creating down force with something that was just being wasted. Ducati has a BIG budget and incredible resources at their disposal.
We now have full blown aero wars going on in MGP, an engineer's wet dream.
Anyone that remembers the blown diffuser in F1 a few years back, also remembers how effective it was in creating down force with something that was just being wasted. Ducati has a BIG budget and incredible resources at their disposal.
We now have full blown aero wars going on in MGP, an engineer's wet dream.
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Never mind the article or the journalist not being well versed in aerospace engineering. The fact is Ducati have put this patent in and I can guarantee you that everything you just said and more is being discussed and analysed by a team full of engineers. Not like us lot throwing around assumptions and if's, but or maybe's. There must be something in it for them to remotely bother with the patent. And as for the fuel consumption, I'm pretty sure they'll be all over it and whether the trade off makes it viable.
I guess if there's nothing to be gained then it will end up on the shelf like other ideas. Nothing ventured, nothing gained as they say.......
So the data of the actual patent does not seem to be available and a patent search did not turn up anything so we have a few drawings. Its not a bad idea and not really a new one. It is a thrust augmentor but the word "thrust" is a bit ambiguous. There is a thrust component as you have spent combustion under pressure exiting the pipe but I would highly doubt that it has the ability to effect geometry but It could be more significant than I assume.Who knows. The arrows on the drawing are just that and do not detail anything. Now the idea from a dynamically controlled, ECU synchronized exhaust pressure regulator makes much more sense. A constantly modulated exhaust pressure ratio to intake ratio is very plausible and a great idea. They have been doing that on turbojet/turbofan engines for 60 years. It would be a fairly simple mathematical calculation to determine what the exhaust pressure would be starting with a fixed pipe diameter. You could then further mathematically calculate the change with varying degrees of attenuation.
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Cars have had variable intake runners for some time now. Porsche has been doing this with variable vane set ups on their turbo chargers as well. The tech has been there just not too common in the bike scene. What I believe they are trying to replicate/attain is what Ferrari is doing with their 488. Variable torque, fuel, power ect. per each gear. I doubt they are achieving altering levels of "thrust" but the ability to control the exact amount of torque/hp through a turn based on lean, tire wear and all other factors would be amazing. Especially when its comes to Lorenzo's smooth style of riding. Maybe like somebody else mentioned, it could generate dirty air for following riders as a byproduct as well.
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I am nowhere near the engineer that you, half the people on this forum, or the gal making coffee at my local Ducati dealership are. But after drinking a bulletproof coffee and staring at the picture, I think your theory makes more sense than the propulsion one.
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I'm inclined to agree on that one too.
Well ........... I thought I had the possibility of getting me a f*cking jet bike
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Well comparing the number of exhaust driven turbocharged engines on the roads of the world including racing applications compared to the proliferation of recovered exhaust power augmentation applications (in a thrust model to boot), I would have to say that engine pioneer Harry Ricardo needed a few mote math and physics courses. Additionally your comparing a power producing application to a thrust producing application. That Cycleworld used a power producing (turbocharger producing a pressurized induction system to in turn make more "power") application to a air pressure or "thrust" application just violates a whole bunch WTF and you cant very well shove spent exhaust gasses down an induction system so don't get any crazy ideas. This is just goofy unless it is just augmented, optimized pressure balancing then I like it better than a butterfly type valve arrangement but you any tuning gains would obviously have to outweigh the complexity of the system. Looks like a lot of stuff to go wrong
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