WilliamsF1 wrote:Wazari
From your personal experience with Turbocharged engines what is the line of thinking in the various projects you have worked with regard to the sizing of turbine and compressor.
What are essential for the turbine to generate maximum shaft power?
What are the pros and cons of small and large compressor in using shaft power?
Would MGU-H been always on generator mode of a VGT was allowed?
Let's see, where to start. First off, when I was working with turbochargers for F1, things were much simpler. We didn't have this thing called a MGU-H attached to the turbo to act as a generator and motor. The overall theory seems simple enough on paper but when I start thinking about the actual application in a race engine with fuel flow restrictions, well it gives me a headache.
Turbocharging efficiency has many, many variables. In the very simplest of terms, not factoring cost and the MGU-H unit, it's a balancing act. How much exhaust gas are we working with, how much forced induction do we want to push into the combustion chamber, how much are we going to lose due to plumbing, etc. All these factors are weighed into the actual design of the turbo desired for that application.
When you mention the turbine generating maximum shaft power, are you talking about torque to the compressor or the compressor speed? Again in simple terms, you need to look at how much exhaust volume and velocity you're working with. People mention size of the turbine or compressor but there is much more than that. I think people are associating the radius of the actual turbine as being bigger. Vane design is everything in a turbocharger. The radius is one factor, but you need to take into considerations the width of each vane, how many vanes, the total surface area of the vane and curvature of the vane. This is the most important consideration when trying to factor maximum torque and speed to the compressor side.