F1 Engine Noise?

All that has to do with the power train, gearbox, clutch, fuels and lubricants, etc. Generally the mechanical side of Formula One.
RH1300S
RH1300S
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Joined: 06 Jun 2005, 15:29

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Nice reply - while we are on cool stuff - like Ferrari's playing Bach.

Your avatar? Is that a Fibonacci spiral? 1+1=2 2+1=3 2+3=5 3+5=8 etc. etc.

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Ciro Pabón
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RH1300S wrote:Nice reply - while we are on cool stuff - like Ferrari's playing Bach.

Your avatar? Is that a Fibonacci spiral? 1+1=2 2+1=3 2+3=5 3+5=8 etc. etc.
Well, almost. It is what you could call a Golden Spiral, based on the gold number, not on Fibonacci's series. At the "center" they coincide.

Or you could say it is a really good aproximation to a car trajectory. Actually, spiral curves for roads are logarithmic and for railroads are cubic, but this is a tradition and a convenience, differences are imperceptible to a driver.

Here is a site that explains the difference and that "clearly" shows how a golden spiral is much more beautiful. Nahhh, it doesn't, but I think so. It is linked to natural forms, as you can see in this image I've already posted. :)

Image

Sorry for the negative, but this is the only way I found for the AutoCad image to be (barely) visible.

Now that you mention it, the relative length of organ pipes and the notes of the "natural scale" can be derived from it. Or (misteriously) the relative length of your fingers, for example.
Ciro

pyry
pyry
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Joined: 04 Jul 2004, 16:45
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thats cool, now you never need to argue about girls, which one is better looking, all you have to do is measure their faces and come up with a "relative beautyfulity" :) we could even compare each others girlfriends without pictures, thus no arguements, just pure arythmetics. im temporarily between relationships(about 18 months :)) and i dont think that my ex would appreciate me measuring her face, so why dont you ciro start? :)

RH1300S
RH1300S
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I like to use Phi in my interiors - I don't suppose people notice, but it's fun to know it's there.

I know it's not exactly the same, but I thought that building the spiral with increasing sizes of squares (using Fibonacci) actually creates a proportion very close of the Golden ratio. I.e. develop the spiral and a rectangle with a side of 8 will have another of 5 (ratio 1.6) or another side of 13 (ratio 1.625). Stays very close to 1.618.

Cool stuff 8)

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Ciro Pabón
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pyry wrote:thats cool, now you never need to argue about girls, which one is better looking, all you have to do is measure their faces and come up with a "relative beautyfulity" :) ... i dont think that my ex would appreciate me measuring her face, so why dont you ciro start? :)
Did you really rip all her pictures? Now I see why you don't see the diamonds as a good alternative... c'mon, cheer up. :D

You are exactly on the mark: most of renaissance painting is based on golden proportions. Here you can find a page on the proportions of a human face to check suitable girls (warning! it has George Clooney's pictures! :? beware! it takes you to Golden Ratio Dentistry!). I am sure you can find golden ratios in other parts of the body... suit yourself. Palladio's arquitecture, heck, even the Parthenon is based on the golden ratio, or they say so.

Leonardo's famous "circumscribed man" shows it clearly :wink: . A pentagon is composed of golden ratio triangles... I wonder if they shows this in the movie on Da Vinci's code.

Not that I buy it (specially the Clooney part). After all, renaissance was a long time ago and you have impressionists to show you that perfection is inhumane, surrealists to show that reality is an illusion and, what the heck, I'm totally out of thread, deconstructivism to show you that your illusions are illusions.
Ciro

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flynfrog
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Joined: 23 Mar 2006, 22:31

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Ciro Pabón wrote:Sorry to lengthen this even more, but I found this interesting. I downloaded the software from IWT. I tried small port sizes (2 mm). I found that the smallest chamber length the software gives you is around 650 mm, which is well over half a meter.

Image

To my surprise, the chamber length the software delivers doesn't vary with different port sizes, only with changes in the time the exhaust port opens and the rpm. As this length is probably a function of the properties of the column of air, I would conclude there is no way to use expansion chambers in such small engine as yours, because your model car would seem ridiculous with a pipe bigger than the vehicle. On the other hand, this could be a software limitation, because it is clearly designed for bikes.

I wonder if someone with more experience in small engines can gives us a clue. BTW, every link I found refers you to G.P. Blair book on two stroke engines, that you can buy (with software included) at the SAE site.

To give this some resemblance of a thread, I found that MITRE has developed software to simulate engine noise (another link for me! :wink: ) based on engine characteristics. Here you have an explanation that makes a beautiful comparison between exhaust pipes and organ pipes.

You could try to tune your model car engine to, let's say, G major, with a little "pizzicato". Then you could say: hey, this engine rocks! From now on I will think I hear some Bach music every time a Ferrari F1 passes... :wink:
im not sure how small his car is but pipes do work

Image

these engines are around .12 in^2 i have a few putting out over 1.5 hp

Tp
Tp
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Joined: 02 Mar 2006, 15:52
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Cool, I also have a petrol R/C car (well two petrol R/C cars infact), but one of mine puts out 2.3hp 8)

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flynfrog
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Joined: 23 Mar 2006, 22:31

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out of a .12 or a .21

i have some nova rossi .21 engines over 2 but no .12s

pyry
pyry
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ciro, my point was that i dont have a girlfriend, and the ex doesnt matter. btw, we are still good friends

Tp
Tp
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Joined: 02 Mar 2006, 15:52
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flynfrog wrote:out of a .12 or a .21

i have some nova rossi .21 engines over 2 but no .12s
I have a .21 sized engine and a .15. As they are both monster trucks, they need the torque rather than rpm

By the way I've got a HPI Savage 21 and a HPI MT.

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mep
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Joined: 11 Oct 2003, 15:48
Location: Germany

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The car is larger than you suggest.
It'll be in scale 1:4,5 and I'll use a MVVS 23,5 Twin Boxer engine.
The maximum power is produced at 8500 turns.
Unfortunately the engine is not produced anymore so I can't simple
buy two reso pipes.
I have a bit of space in the car but not to much so it's better if
the pipes are smal.
I'm also thinking about one special pipe for both cylinders.

I have some more constructal issues to think about so I'll post more.
For example about the weight
viewtopic.php?t=2477
I know more now but maybe one has a new idear.

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mep
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Ciro Pabón wrote:
I have read your PC is far from having the power needed for designing an optimal chamber.
:!: :!: Where have you read this :?: :?:
(Bigh Brother is watching me - aaaaaah)

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flynfrog
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Joined: 23 Mar 2006, 22:31

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http://homepage.mac.com/rg500delta/deltaphasetwo/

check out how a freind of mine made pipes for his bike

also try to find macdizzy two stroke page there are a few port calculators on there and post pics

pompelmo
pompelmo
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Location: Lucija, Slovenia

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manchild wrote:Noise level = difference between pressure in cylinder when ehxhaust valves open vs athmospheric pressure. That includes speed of opening of valves and diameter and lenght of exhaust as well as frequency/rpm.
come onn :shock: if that's true make me a (math & physics) proof!!!
I do not believe that's true...where have you heard that???

pyry
pyry
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Joined: 04 Jul 2004, 16:45
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i tihnk that sounds pretty logical