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Would this work? Way to stop aero turbulence


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#1 rolf123

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Posted 23 November 2011 - 23:56

Now although I have a degree in mechanical engineering (including some fluid mechanics), I hated the subject and went into a totally different field after!

When I use a tap, the flow is often quite turbulent. The stream looks twisted and if you put your hand in it then water rebounds all over the place. But sometimes I will quickly flick where the water comes out of the tap and the flow will become less turbulent. Put my hand in it and it becomes smooth. The same effect as those grills over some tap outlets except the flow is not filtered as a grill would do. It looks fine.

Now, has the turbulent flow really been reduced? How does this work and, most importsantly, does this have any applications in F1 at all? e.g. maybe exhaust gases can be intentionally regulated to produce better flow over downstream components.

Edited by rolf123, 23 November 2011 - 23:58.


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#2 MatsNorway

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Posted 24 November 2011 - 06:42

You want to smooth out the pulses?

I believe it can not be done with the new rules. They spesify that it has to be a round pipe.

Im not sure if thats only the end of the pipe. if not a chamber to smooth out the pulses could be good. But i doubt it would help enough to give a measureable gain.

That chamber would also make packaging more difficult. Vanes and so on is probably not allowed under the new rules. i guess having a bigger exhaust pipe dia would help at least in teory.

Edited by MatsNorway, 24 November 2011 - 06:43.


#3 Bloggsworth

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Posted 25 November 2011 - 18:46

I think that there are some basic misunderstandings here.

#4 rolf123

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Posted 26 November 2011 - 18:30

I think that there are some basic misunderstandings here.


Spit them out please. It was a shot in the dark on my part anyway.

What I'm getting at is, is there some dynamic method of optimising air flow that somehow bestows an advantage?

#5 MatsNorway

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Posted 27 November 2011 - 10:53

"flows at Reynolds numbers larger than 5000 are typically (but not necessarily) turbulent, while those at low Reynolds numbers usually remain laminar. In pipe flow, for example, turbulence can first be sustained if the Reynolds number is larger than a critical value of about 2040[2]; moreover, the turbulence is generally interspersed with laminar flow until a larger Reynolds number of about 3000. In turbulent flow, unsteady vortices appear on many scales and interact with each other. Drag due to boundary layer skin friction increases. The structure and location of boundary layer separation often changes, sometimes resulting in a reduction of overall drag"


When I use a tap, the flow is often quite turbulent. The stream looks twisted and if you put your hand in it then water rebounds all over the place. But sometimes I will quickly flick where the water comes out of the tap and the flow will become less turbulent. Put my hand in it and it becomes smooth. The same effect as those grills over some tap outlets except the flow is not filtered as a grill would do. It looks fine.


The grill and the hand "effect" is two different things. the grill cuts the turbulence up. i think.

open up the valve so it flows very little. you will still hear the turbulence but its only in the valve.
when you slam the valve open you probably avoid the turbulence in the valve to go with you. avoiding it to escalade.

your tap is probably in the transient area between the reynolds number 2040 and 3000.



All you need to know is that you probably can`t do this on the exhaust of a F1 car. The air/gases involved gets turbulent too easy. Too high a Reynolds number probably.

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Slight OT:

"The structure and location of boundary layer separation often changes, sometimes resulting in a reduction of overall drag"

this can be used with benefit when porting engines, if i read what i think i read. Smooth polished ports are not neccesarily the best flowing. (that i have heard before)

Edited by MatsNorway, 27 November 2011 - 10:54.


#6 Tony Matthews

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Posted 27 November 2011 - 11:00

Smooth polished ports are not neccesarily the best flowing. (that i have heard before)

I think that is what Keith Duckworth always maintained.

#7 Catalina Park

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Posted 27 November 2011 - 11:09

I think that is what Keith Duckworth always maintained.

Waiting for VP to tell us that Duckworth was wrong.

#8 Tony Matthews

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Posted 27 November 2011 - 11:48

If he does, let me know!

#9 cheapracer

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Posted 27 November 2011 - 13:41

Rolf, you could look into articles of where and why motorcycle race bikes point their exhausts - F1 doesn't have sole ownership on the field.