[Dimman]

Originally Posted by serialk11r

That's not true, jet engines aren't velocity (impulse) turbines, they're more pressure turbines. The ducts in a jet engine serve to efficiently slow down the air and pressurize it, and the compressors increase the pressure. The air under pressure is then combusted and allowed to expand through the turbine, which only needs a small portion of the pressure to provide enough power for the compressor. The gas is then finally allowed to expand fully in the nozzle, and exits with high velocity to provide an impulse. sidenote: The reason afterburning is not efficient is because it attempts to raise the pressure by heating when the gas is not at its peak pressure, and at the typical speeds aircraft see, using mechanical power to compress gas is more effective than using just heat to do it, but the advantage is that afterburning is like turbocharging, it only increases the pressure behind the exhaust and not direct mechanical stress.

Axial or radial, you can optimize either more for velocity or pressure. I think at higher flow volumes a radial turbine is not so efficient anymore because the gas needs to make all these turns but I'm not sure. I'd actually think an axial might be worse for a piston engine compound turbine since you can't really separate exhaust gas pulses into 2 groups or more like in a twin scroll turbo. In F1 I'd imagine 2 or more turbine stages since they have money to do that, with a compressor to improve specific power output.

Turbine design is inherently very complex, but there are lots of people who work on this stuff, and F1 can cough up the cash to make it happen the way they want it to.

Anyways back to intake tuning, I saw a picture of someone who put some kind of resonator cavity into their intake and was talking about tangential waves, and said on whatever car they were using it increased power by a few hp, but significantly improved at relatively low rpm. I don't really understand what he was doing though.

That velocity/axial part was paraphrasing what it said in the article.

My understanding is high velocity going in a straight line becomes pressure once it runs into something like a turbine blade.

Maybe what I didn't make clear was that there is also a turbo in front of this second generator turbine. So pulsing is not an issue.