Flamelet gives faster chemistry than ED-model
 

Hi,

I am simulating a turbulent spray in a hot coflow in an open area. The domain is a 2D axisymmetric domain. I use the realizable k-epsilon turbulence model with enhanced wall treatment for the flow near the nozzle. The fuel that I use is (liquid) ethanol and the atomizer is a pressure-swirl-atomizer.

I have done simulations with the ED-model (1 step reaction) and also with the Flamelet model (57 species).

The problem is that the lift off from the nozzle is shorter for the flamelet model than for the ED-model.

I expected the ED-model to be faster but this is not happening.

The spray is evaporating faster, the turbulence is higher and the combustion is faster. I have only changed the combustion model from the ED-model to the Flamelet model.

Has anybody an idea what can cause the faster combustion for the flamelet model?

Regards, Champshof