why sweat the coatings if ya want more zoot huge injectors and big wind! thats more zoot. but not nearly as fun to debate

 

You keep refering to a turbo as a "heat recovery device". This makes no sense to me. I could hook up a heating coil on my turbine housing and cook it to 5000* and it won't do a thing for my air supply!
I do, however get the connection between heat and pressure, if that is what you are getting at.
As stated above, I'm no expert. I said my piece above, I'll leave it at that.

RJ

 

I call it a heat recovery device because thats what it is.

It makes no sense to you because you never studied turbines, thats all.... It is in fact hard to grasp.

It is a gas turbine. It operates off of the energy in the exhaust stream which is FLOWING out of the engine. Increase either one of the quantitites (flow, or temperature) and you increase the energy available for the turbine to produce work.

Here is where I think you are missing the theory..... You are correct, if you hook up your heating device to the turbine housing and cook it to 5,000°F you wont spool the turbine, because that is a static condition.. But hook up your heating device to a stream of pressurized gas moving at roughly 2,000 Lb/Hr and heat that gas from ambient to 5,000°F then put that into your turbine and viola, rotation (actually at 5,000°F you would grenade it, but point made).

Its all about mass flow and enthalpy change. Massflow is a function of engine RPM and fuel burn, and enthalpy is a function of temperature and pressure.


To put a formula to it: Turbine HP = massflow* (enthalpy in - enthalpy out ) * turbine efficiency / 2544

where: massflow is in Lbs/Hr
enthalpy is in Btu/Lb
turbine efficiency is expressed as a percentage with n=1 corresonding to 100%

If you want to learn the beautiful science of turbine theory, do some internet searches. Its quite interesting and you will come off understanding a whole lot more about our turbochargers and their true function...


Kevin