Definition of the "venturi" system

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the joint
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Definition of the "venturi" system




by the joint » 15/03/07, 22:12

Hello, I'm going more and more through this forum and my faith is great! and I take great pleasure in it. : Cheesy:

However there is a notion that escapes me and that prevents me from understanding certain positions, that of the venturi. :?: :?: :?: So here are some questions that will help me and other novices I think

What is a venturi actually used for?

What the hell is that?

On which assembly is this one used? (100% pantone, water doping, or both)

At what level is it in the assembly?

I think I haven't forgotten anything, thank you.
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by I Citro » 15/03/07, 23:28

The venturi is a system used in fluid dynamics.
Here is the definition wikipedia

There are many applications in various fields.
In automobiles, carburetors used the venturi effect to draw fuel into the air stream and mix it with the latter.
For the pantone we use it to create the depression which will suck the pantone gases or the doping with water ...

In a piston engine, this vacuum in the intake manifold generates pumping losses. They are more important in petrol engines because of the throttle valve which shuts off the air supply and slows down the pistons' descent at the intake. Manufacturers are currently developing butterfly-less systems (BMW's variable Vanos distribution for example) to overcome this drawback.
These systems are necessarily associated with an injection.
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by PITMIX » 15/03/07, 23:35

Hello
So, to understand correctly, I took my illustrated dictionary and I looked at what little Larousse said about it.
Then I discussed with the others who use it either to spray the water at the inlet of the reactor or to force the suction in the reactor in doping with water and even sometimes both at the same time.
You should be able to find in my post on my R5 diagrams and discussion on this subject (carburetor with water venturi and also on the post of Rezut (venturi of admission) and many other posts still.
montages injection water / renault-super-5 al-doped water-t1110-60.html
For the 100% pantone the intake venturi is not used since the reactor is directly connected to the intake pipe, but it can be used to spray water at the inlet, if it is well designed.

Besides on this subject I have questions:
Have all those who have a working water doping reactor noticed that the intake venturi is essential?
If so, are there suction values ​​to be observed.
Zac and André agree that it takes 700mm of water column, is this essential for the operation of the reactor?
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by I Citro » 16/03/07, 13:50

I am not an expert, but I have read that among the phenomena likely to occur (ionization, plasma ...), the pressure / vacuum conditions greatly influence the production of these phenomena.
Plasmas normally occur under very high temperature OR under very low pressure, one speaks then of "cold plasmas".
This would also be the reason why we cannot store these ionized gases which quickly lose their specificity. :|
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by the joint » 16/03/07, 14:21

Ok so if I understood correctly the venturi serves to accelerate the speed of the water vapor in order to optimize the efficiency of the engine.

It would therefore be placed at the inlet of the reactor on the side where the water vapor arrives (on a water doping assembly). However I have read on different posts that reducing the intake causes a loss of power. Is it all a question of the size of the venturi then?

Pitmix when you talk about 700 mm water column, what does that mean? How do you measure that?
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by Other » 16/03/07, 20:10

Hello

The venturi is simply used to siphon into the receiver
for the rest i can't comment
a venturi slightly brakes the gas stream but in general one exploits its depression at the neck which can be 3 times greater than that in the intake manifold and it is interesting for walking at mid-speed.

Andre
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by PITMIX » 16/03/07, 20:47

To make it simple in the explanation the venturi effectively serves to accelerate the air.
The venturi effect is also what inflates the hoods of cabriolet cars on the highway.

In the case where it is at the entrance of the reactor, like the first assemblies on my R5 and like on André's cars, we use the local acceleration of the air to suck and spray the water. Like what happens with gasoline in a carburetor (in simplified of course).
It is also used to accelerate the air when it is placed in the intake tube, therefore at the outlet of the reactor but this time just to suck in the reactor.
The venturi is a constriction but which is supposed not to make too much pressure drop. This is why it has a very specific form.
On my Golf the venturi is not smaller than the original venturi which is in the air filter.

Look at the little drawing on the link I gave above.
When I say 700mm of water column it means that the venturi sucks water through the small tube.

Imagine a tube 1m high and 10mm in diameter with the venturi at the end at the top.
THE speed of the air passing through the venturi will cause the water in the tube to rise to a height of 700mm.
Watch the little video here
Remastered video THX : Cheesy:

fixtures-injection water /-calculate its venturi-t1859.html
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by sam17 » 17/03/07, 19:01

Super your little pit videos !!
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by zac » 17/03/07, 20:11

the join wrote:Pitmix when you talk about 700 mm water column, what does that mean? How do you measure that?


Hello

I answer you instead of pitmix
you prick the inlet and you reread to a transparent pipe taped on a straight thing of a meter, you plant the end of the pipe in a basin of water, you put your engine at 75/100 of its maximum speed and the depression must make you raise the water to 70cm, 700mm or 0.7m :P

You see it's stupid

if you have a problem to make your venturia; see the photos that I put on the forum or contact me

@+
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by the joint » 17/03/07, 21:29

Ok thank you Zac it's clear now, with these measures we can actually judge the efficiency of the venturi.
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