They can close 100% as evidence by photographs of the Mercedes and Honda engines.Clubman1d wrote: ↑22 Sep 2022, 19:46The 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.saviour stivala wrote: ↑21 Sep 2022, 21:42Out 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.
Even if they do manage to close, it doesn't seem the vane design covers all the frontal area.
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?Clubman1d wrote: ↑23 Sep 2022, 00:41
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/
I did a quick search on google and found a FB post about it. It does have more info.saviour stivala wrote: ↑23 Sep 2022, 03:37Thanks 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.
Like someone already wrote on here, this "tech" has been available since WW2, and it's been used with the same principle.PlatinumZealot wrote: ↑23 Sep 2022, 04:07Keep 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?Clubman1d wrote: ↑23 Sep 2022, 00:41
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/
Too many questions come up.
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.Clubman1d wrote: ↑23 Sep 2022, 12:25Like someone already wrote on here, this "tech" has been available since WW2, and it's been used with the same principle.PlatinumZealot wrote: ↑23 Sep 2022, 04:07Keep 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?Clubman1d wrote: ↑23 Sep 2022, 00:41
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/
Too many questions come up.
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.
Ferrari's VIGV also could closed 100%.PlatinumZealot wrote: ↑23 Sep 2022, 03:59They can close 100% as evidence by photographs of the Mercedes and Honda engines.Clubman1d wrote: ↑22 Sep 2022, 19:46The 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.saviour stivala wrote: ↑21 Sep 2022, 21:42Out 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.
Even if they do manage to close, it doesn't seem the vane design covers all the frontal area.
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.PlatinumZealot wrote: ↑24 Sep 2022, 03:41To 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.Clubman1d wrote: ↑23 Sep 2022, 12:25Like someone already wrote on here, this "tech" has been available since WW2, and it's been used with the same principle.PlatinumZealot wrote: ↑23 Sep 2022, 04:07
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.
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.
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.
In this circular discussion...PlatinumZealot wrote: ↑26 Sep 2022, 00:26That'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
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:johnny comelately wrote: ↑26 Sep 2022, 02:30... 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.