Troubles with heat release rate

Xavier Ponticq

Hi all,

I'm modelling an heptane pool fire in a tunnel by an inlet with a fixed mass flow rate of heptane. This mass flow rate is fitted to reproduce a 750 kW burner in complete combustion conditions.

When I post-treat my runs, I compute the heat release rate using the O2 consumption method widely used in experiments. I obtain heat release rate way above the imposed value (around 970 kW). I'm using the Eddy Dissipation Model with a custom single-step reaction for heptane, with a SST turbulence model in steady state.

I cannot understand why the calculated heat release rate is above the theoretical heat release rate imposed at the inlet. So if you, folks, have any idea about that, I'll be interested.

Regards