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Old 03-08-2014, 01:19 PM   #10 (permalink)
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Quote:
Originally Posted by oil pan 4 View Post
I pitched this idea to my engineer, after a long awkwardly long peroid of laughter, a string of obscenities which cant be posted her his only responce I can repeat on here is "some one failed thermo".

The idea that heat is circumstantial to a turbochargers turbine is laughable to say the very least.
If it isnt why are all turbine calculations done with temperture differential?
heat is circumstantial to pressure. The temp differential calculation gives you an idea of how much pressure is generated using the temp diff across the face of the turbine.

Turbines are not heat engines, they are pressure differential engines. Your 'engineer' is mixing up principles.

If you don't believe me, put a vacuum cleaner nozzle on the exhaust out port of a turbo, or just blow compressed air through the turbine inlet.

BUT PRESSURE AND TEMP DIFFERENTIAL BLAH BLAH BLAH

No. Just no. If you wanna try it again, blow some compressed propane through it. You'll not only freeze the turbine blades from the complete lack of heat energy in the propane as it vaporizes, but it will spin and create discernible boost if piped into a closed environment.

Heat is not the determining factor in a turbocharger's performance. Pressure and flow are. The heat is circumstantial, but not necessary.

BTW - I've seen some very low compression competition engines feed compressed air to the turbine to spool it while starting up. Typically 2 stroke engines where the OE supercharger has been replaced with a large frame turbocharger.

Lets also keep in mind that not all turbines operate using heat as a source of energy, and thus, since all turbines operate on fundamentally the same principle, turbines, by default, can /not/ be necessarily heat-driven engines as a primary function.

So, I reiterate - pressure differential, not temperature differential, is the primary factor.
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