| loads on the rotating group for sake of not getting too far away from the main point. The answer to your question is no - there is not a corresponding counter axial force created at the turbine. This is because of the geometry of the turbine wheel - it does not have a full face at the rotor base. There is a small face at the hub of the turbine but it is considerably smaller in area than the compressor wheel's area. There is even more to it though. On the "working" side of the compressor wheel there is a rearward force created by the rise in pressure of the air as it progresses towards the wheel's periphery, but it is only a fraction of the force created on the backside of the wheel. Also, the inducer of the compressor wheel creates a forward thrust as it "grabs" the air and accelerates it further into the compressor wheel. Radial turbine wheels are a mixed-mode device - they are both an impulse turbine as well as a reaction turbine. The turbine's inducer blade tips are impulse driven by the radial inflow of exhaust gases but as the gases expand and move further through the turbine wheel, the wheel geometry transitions to a reaction turbine. The impulse section transitions to the reaction section which also changes the direction of the gasflow - this transition produces a forward axial force. The reaction section of the turbine wheel produces a rearward thrust force on the rotating group but this is also only a small fraction of what is created behind the comp wheel and is mostly negated by the forward thrust created at the inducer-exducer transition. A mathematical approach to figure out these loads isn't simple. It isn't a static condition - it is dynamic and depends on several variables. Regardless, without going all in on the maths I will tell you that the forward thrust created at the back of the comp wheel far exceeds the other thrust forces created at the other 5 stations. As for finding more info, that is a tough recommendation. I've been studying these systems for almost a decade now since building the first gas turbine engine from a stock turbocharger. A lot of the knowledge I have has come from so many various sources that I dont have a single suggestion for you. I've read countless nasa documents.
Countless patents.
Several textbooks on gas turbines.
Countless documents on turbomachinery, turbobearing systems.
Thermodynamics textbook.
..... and a decade of tinkering, fabricating, testing, etc etc on turbochargers, turbine engines.. A lot of this type of info is a bit difficult to find with it being so specialized. It is out there though....
Enthusiasts soon understand each other. --W. Irving.
Are you an enthusiast? If you are out to describe the truth, leave elegance to the
tailor.
Albert Einstein
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