Exhaust gas input to charge air ratio.

[Psychoreo]

Not sure exactly how to word this but, what i'm trying to find out is if there is more air coming out of the charge side of the turbo (between the turbo and throttle body) than there is exhaust flowing through the other side?

example: Is it possible for a 10cf/m flow of exhaust to flow through a turbo and yeild a 15cf/m flow of charge air? all numbers are just for demonstration.

I've tried to read flow charts and graphs but i just don't get it.

I'll explain the why behind this question depending on the answer.

Thanks!

[91White-T]

example: Is it possible for a 10cf/m flow of exhaust to flow through a turbo and yeild a 15cf/m flow of charge air? all numbers are just for demonstration.

Need more parameters. Volumetric flow rate is not enough to define a flow, you need temperatures, pressures, and fluid properties for both fluids. You have to find the mass flow rates for both. Then you can apply the first law of thermodynamics and see if it is possible.

[Psychoreo]

refresh my memory, my physics is very rusty. but lets see if this can be solved without crunching numbers. what i'm asking is if the exhaust turbine is efficent enough to suck more air into the turbo than the ammount passing through the exhaust side. but you're probably right. didn't think of the 1st law. duh. energy cannot be created nor destroyed.

[91White-T]

Ok, look at it this way: The mass flow rate through the compressor outlet has to equal the mass flow rate through the turbine inlet because an engine is a closed system. So, the volume flow rates can(and probably will) be different, because of the differences in temperature, pressure etc. The mass flow MUST be constant however, what goes in's gotta come out. So, the answer to your question is no, you can't suck more mass throgh the compressor than is going through the turbine, that would violate the 1st law.

[Psychoreo]

good point and kind of a dumb question on my part. thanks

[Legacy777]

Actually the mass flow rate will be slightly more on the turbine side then the compressor side. Reason being is your are inputting mass from the fuel, and then combusting it.