# Calculating Exhaust Flow Rates

1. Jan 14, 2015

### Lavid2002

Hello everyone,

I have been trying to calculate some exhaust flow rates for a while, and I am having some issues here. I was wondering if anyone could provide any insight.

I am making a few assumptions for this calculation. I am assuming no fuel or air is lost through blow by gasses into the crank case or through valve leakage. I am also assuming perfect stoichiometry. In other words...

Mass in = Mass out
All the fuel is burned in a perfect ratio of reactants

I know the mass of the products entering the engine through fuel consumption measurements, and stoichiometry assumptions.

Since I know the mass of my exhaust gasses all I need to do is determine the density of my exhaust gasses to find the volume.

What I know -Temperature
-Chemical composition
-Pressure
-Mass

What I need to know
-Volume

Any tips? I want to use the ideal gas law, but I don't know if this would be an appropriate application of it.

Thanks!

-Dave

2. Jan 14, 2015

### Staff: Mentor

$\dot{m}=\rho \dot{V}$, where $\dot{V}$ is the volumetric flow rate, ρ is the gas density (from the ideal gas law), and $\dot{m}$ is the mass flow rate.

Chet