Mercedes Power Unit Hardware & Software

[saviour stivala]

Thanks for the picture/photo appreciate your find and posting on here. Will appreciate a link to were you found it as apart from the picture I was talking about, I have spend a lot of time trying to also trace this one, because Yes. I have also seen that picture/photo before but it is not the one I was talking about. This photo also shows the vanes fully closed from an Angle of the right side, it clearly shows the pivoting the vanes rotates on. The one I was talking about, and I am sure it was on this here forum and fairly recently, the photo was taken head-on and although the vanes pivoting is not shown, the vanes looks much neater and as I said they were hand numbered one to five with something like a jam marker.

[PlatinumZealot]

Out of the four different power unites used the only one I actually seen was the Mercedes. I do not remember the time but it was recently and on this forum, there was a Mercedes power unit photo showing the turbo compressor intake throttling system with all five vanes closed and marked one to five.

The thing is, looking at the actuation mechanism, the colar, it isn't possible for them to be closed, the maximum movement they seem to present is around 45 degrees.

Even if they do manage to close, it doesn't seem the vane design covers all the frontal area.

They can close 100% as evidence by photographs of the Mercedes and Honda engines.

[PlatinumZealot]

After reading about it, Garret doesn't make a secret out of it, you're absolutely right.
They close "fully", increasing the turbo spin speed and help keeping it spinning.
I did find a picture witch I believe might be from an older Mercedes engine.

https://postimages.org/

Keep it spinning? Only the MGUH can keep the turbo spinning if you close off all the air to the engine. And then what? Aren't you going to load it after that anyway? Why waste battery power when you can spin it with the air pumping of the engine itself under engine braking and still have faster boost rise after that?

Too many questions come up.

[saviour stivala]

When compressor throttling blades are closed the compressor load is no more, so compressor spins faster (try block nozzle of a vacuum cleaner with your hand). Because at the same time that driver lifts and compressor intake throttle blades are closed ICE intake throttles are also closed, the pressurized air volume caught inside the ICE intake system is still trapped in there. On the other hand when driver lifts and ICE intake throttles are closed, the ICE cylinders are pumping no air to keep the turbine spinning, and no, that is a situation where the ‘H’ is doing no work on the turbo shaft.

[Clubman1d]

Thanks for the picture/photo appreciate your find and posting on here. Will appreciate a link to were you found it as apart from the picture I was talking about, I have spend a lot of time trying to also trace this one, because Yes. I have also seen that picture/photo before but it is not the one I was talking about. This photo also shows the vanes fully closed from an Angle of the right side, it clearly shows the pivoting the vanes rotates on. The one I was talking about, and I am sure it was on this here forum and fairly recently, the photo was taken head-on and although the vanes pivoting is not shown, the vanes looks much neater and as I said they were hand numbered one to five with something like a jam marker.

I did a quick search on google and found a FB post about it. It does have more info.

I also found a Garret PDF describing the turbo cutaway you can see in one of the pictures where they describe the same use for the vanes.

[Clubman1d]

After reading about it, Garret doesn't make a secret out of it, you're absolutely right.
They close "fully", increasing the turbo spin speed and help keeping it spinning.
I did find a picture witch I believe might be from an older Mercedes engine.

https://postimages.org/

Keep it spinning? Only the MGUH can keep the turbo spinning if you close off all the air to the engine. And then what? Aren't you going to load it after that anyway? Why waste battery power when you can spin it with the air pumping of the engine itself under engine braking and still have faster boost rise after that?

Too many questions come up.

Like someone already wrote on here, this "tech" has been available since WW2, and it's been used with the same principle.

If you still have doubts about it, just think about this: Why would Mercedes design it so it can be fully closed like in the picture, if they have, like you say, no use for it in the closed configuration? If, again like you say, have no use for it in the closed configuration, why would they risk a malfunction and have it close on itself mid race? Why not design it so it can never close?

As it is described, it serves multiple purposes, it swirls air into the compressor blades, in it's various open positions. And in the closed position it serves as a "no drag" device for the compressor blades during off throttle situations.
I believe I've read somewhere it can also be used has a temperature control device.

[saviour stivala]

Once again thanks.

[PlatinumZealot]

After reading about it, Garret doesn't make a secret out of it, you're absolutely right.
They close "fully", increasing the turbo spin speed and help keeping it spinning.
I did find a picture witch I believe might be from an older Mercedes engine.

https://postimages.org/

Keep it spinning? Only the MGUH can keep the turbo spinning if you close off all the air to the engine. And then what? Aren't you going to load it after that anyway? Why waste battery power when you can spin it with the air pumping of the engine itself under engine braking and still have faster boost rise after that?

Too many questions come up.

Like someone already wrote on here, this "tech" has been available since WW2, and it's been used with the same principle.

If you still have doubts about it, just think about this: Why would Mercedes design it so it can be fully closed like in the picture, if they have, like you say, no use for it in the closed configuration? If, again like you say, have no use for it in the closed configuration, why would they risk a malfunction and have it close on itself mid race? Why not design it so it can never close?

As it is described, it serves multiple purposes, it swirls air into the compressor blades, in it's various open positions. And in the closed position it serves as a "no drag" device for the compressor blades during off throttle situations.
I believe I've read somewhere it can also be used has a temperature control device.

To swirl from he centre all the tips have to come very close at the centre. And to obtain shallow swirl angles the tips need to be close to the centre too. Doesn't mean it driven closed.

This is not even new in motorsport. Here is one that doesnt even close.

https://motoiq.com/sneak-peak-unidentif ... rts-turbo/

Compressor inlet guide vanes are commonly used in industrial centrifugal compressors. It is to increase efficiency at different speeds.

Remember F1 compressors are huge for a 1.5 liter engine.

[saviour stivala]

The wedge-shaped blades system meant for THROTTLING a compressor intake is a huge improvement from the THROTTLING systems (butterfly and slide throttles) used before it. Like the THROTTLING systems used before it, the wedge-shaped blades system modulates from fully open to fully closed. Providing an infinitely variable degree of THROTTLING and pre-rotation when fully closed. There are opportunities for energy saving when compressor inlet is THROTTLED. The difference between this wedge-blade THROTTLING system when used on an industrial centrifugal compressor and on the present formula one turbocharger compressor is, as used on the present formula one turbocharger compressor, when the THROTTLING wedges are fully closed they are totally blanking/closing off the compressor intake. While the one used on the industrial centrifuge compressor, when fully closed is not totally blanking off/closing off the compressor intake, meaning this type of compressor is still pumping some air when the THROTTLING system is fully closed.

[noname]

Out of the four different power unites used the only one I actually seen was the Mercedes. I do not remember the time but it was recently and on this forum, there was a Mercedes power unit photo showing the turbo compressor intake throttling system with all five vanes closed and marked one to five.

The thing is, looking at the actuation mechanism, the colar, it isn't possible for them to be closed, the maximum movement they seem to present is around 45 degrees.

Even if they do manage to close, it doesn't seem the vane design covers all the frontal area.

They can close 100% as evidence by photographs of the Mercedes and Honda engines.

Ferrari's VIGV also could closed 100%.
Although at the beginning they used radial VIGV, nor axial like Mercedes.

[saviour stivala]

Any links/pictures/photos as to the VIGV systems FERRARI were and are now using will be greatly appreciated.

[Clubman1d]

Keep it spinning? Only the MGUH can keep the turbo spinning if you close off all the air to the engine. And then what? Aren't you going to load it after that anyway? Why waste battery power when you can spin it with the air pumping of the engine itself under engine braking and still have faster boost rise after that?

Too many questions come up.

Like someone already wrote on here, this "tech" has been available since WW2, and it's been used with the same principle.

If you still have doubts about it, just think about this: Why would Mercedes design it so it can be fully closed like in the picture, if they have, like you say, no use for it in the closed configuration? If, again like you say, have no use for it in the closed configuration, why would they risk a malfunction and have it close on itself mid race? Why not design it so it can never close?

As it is described, it serves multiple purposes, it swirls air into the compressor blades, in it's various open positions. And in the closed position it serves as a "no drag" device for the compressor blades during off throttle situations.
I believe I've read somewhere it can also be used has a temperature control device.

To swirl from he centre all the tips have to come very close at the centre. And to obtain shallow swirl angles the tips need to be close to the centre too. Doesn't mean it driven closed.

This is not even new in motorsport. Here is one that doesnt even close.

https://motoiq.com/sneak-peak-unidentif ... rts-turbo/

Compressor inlet guide vanes are commonly used in industrial centrifugal compressors. It is to increase efficiency at different speeds.

Remember F1 compressors are huge for a 1.5 liter engine.

I remember reading a paper from japonese authors in 1999, that tested inlet guides in multiple configurations, and one of the conclusions was that a center swirl had very little impact in compressor performance.

You can see it in the Garrett cutaway turbo. They ignore the center part, using it to have a center shaft.

[PlatinumZealot]

That's depending on the compressor design of course. If your compressor has a big bullet in tge middle of course the centre swirl won't have much effect.


It is all about efficiency. Gonna use some volectity diagram here.
Some of my colleagues are forgetting this is an efficiency formula. The compressors are massive and boost pressure is very high so every percent savings in compressor work goes to faster battery charge or more self sustaining power to the MGUK.

Just some not so random images to give an idea how the F1 emgineers would alter the vane angle to get more efficiency.

[johnny comelately]

That's depending on the compressor design of course. If your compressor has a big bullet in tge middle of course the centre swirl won't have much effect.


It is all about efficiency. Gonna use some volectity diagram here.
Some of my colleagues are forgetting this is an efficiency formula. The compressors are massive and boost pressure is very high so every percent savings in compressor work goes to faster battery charge or more self sustaining power to the MGUK.

Just some not so random images to give an idea how the F1 emgineers would alter the vane angle to get more efficiency.

https://ars.els-cdn.com/content/image/3 ... 854337.jpg

https://ars.els-cdn.com/content/image/3 ... 098950.jpg

https://ars.els-cdn.com/content/image/3 ... 000335.jpg

In this circular discussion...
is the second image from a water pump? as its y axis is head
doesnt matter as the same principles apply... the comment is that the "guide vanes with preswirl counter to the impeller rotation" explains my original assertion as it feeds(with reduced turbulence) into the inlet of the vanes much better than if it was with the impeller rotation.

Second point to remember, (guessing) these engines idle at 3K to 4 K ?? without cylinder cut, so upstream throttling right off as shown somewhere is maybe not possible.

[gruntguru]

... the comment is that the "guide vanes with preswirl counter to the impeller rotation" explains my original assertion as it feeds(with reduced turbulance) into the inlet of the vanes much better than if it was with the impeller rotation.

The object is for the air to hit the leading edge of the impeller with approximately zero angle of attack. For a given impeller speed and pure axial airflow:
1. If the flowrate is just right, the AOA will be zero and pre-rotation of the air will be detrimental.
2. If the flowrate is lower, the AOA will be high and pre-rotation of the air in the same direction as the impellor would be beneficial.
3. If the flowrate is higher, the AOA will be low and pre-rotation of the air in the opposite direction to the impellor would be beneficial.