Pressure coefficient of a diesel engine

AI Thread Summary
Calculating the pressure coefficient of a diesel engine using heat exchanger and exhaust calorimeter data is not feasible, as the pressure coefficient (Cp) pertains to fluid flow rather than the engine itself. While pressure ratios can be calculated, the concept of a pressure coefficient is not applicable to the entire engine due to the varying pressures throughout the combustion cycle. The discussion highlights confusion between pressure coefficient and specific heat at constant pressure, which share the same abbreviation. Understanding pressure coefficients in specific flow points may provide insights, but not for the engine as a whole. Overall, the concept of a pressure coefficient in this context is clarified as inappropriate.
Ry122
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With Heat exchanger, Exhaust Calorimeter (water and gas) temperatures along with dynometer readings for each temperature reading, is it possible to calculate the pressure coefficient of the engine?
If so, what formula would be required?
 
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I have calculated pressure ratio's in diesel engines before but I have never heard of a pressure coefficient. What is that? By knowing that value what can one learn from it?

Thanks
Matt
 
You can't have a Cp for an engine, as Cp conerns the relative pressures in flow of fluids.

So you could have Cp for points of flow in the engine. But not the engine itsself.
 
Ohh, you mean the specific heat of costant pressure? Yes, you cannot have this since as the combustion cycle, cycles, the pressure is changing.

Thanks
Matt
 
CFDFEAGURU said:
Ohh, you mean the specific heat of costant pressure? Yes, you cannot have this since as the combustion cycle, cycles, the pressure is changing.

Thanks
Matt

Nah I was just using Cp for pressure coefficient. I forgot that specific heat has the same abbreviation/symbol.
 
LOL, okay.

Thanks
Matt
 
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