Tastverhältnis - VTG offen/zu - Verständnisfrage | Posts 16+

Hello everyone.
Is the image stolen if it's from the forum? It's from the technical articles. I only added red/blue markings to it (but it's not the image that's currently visible, but that doesn't matter).

Subject:
From this, it's clear that I engaged with the article, but it's still not entirely clear how to proceed, as the discussion shows. So, it was definitely worthwhile to ask that question directly.

Thank you for the links; I need some time to think about it.

Sure, here is the translation of the text from German to English:

"PS: It is an ALH."

Okay, as mentioned above, the animations are a bit lacking (e.g., the missing acceleration of the turbine shaft, etc.).

But I think I've got it.

The example with the garden hose is quite good. When the variable geometry turbine (VTG) is closed, the exhaust from both turbines has to force its way through, which increases the speed and, consequently, the pressure on the fresh air side. But isn't it also (a matter of) the interaction between the reduction in turbine size (=closing the VTG) and the improved airflow to it?
When the variable geometry turbine (VGT) is open, the exhaust gas hits the turbine blades at a relatively shallow angle. When the VGT is closed, the turbine blades are optimally (i.e., steeply) impacted by the exhaust gas flow.

Just for understanding and for posterity.