# Pressure coefficient of a diesel engine

1. Oct 10, 2009

### Ry122

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?

2. Oct 10, 2009

### CFDFEAGURU

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

3. Oct 10, 2009

### xxChrisxx

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.

4. Oct 10, 2009

### CFDFEAGURU

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

5. Oct 10, 2009

### xxChrisxx

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

6. Oct 10, 2009

LOL, okay.

Thanks
Matt