[Weiqiang Liu]

Hi all,

I met a very interesting situation when I did a methane combustion simulation with fluent. I used species transport model to do the simulation. I tried to ignite the mixture by patching a 2000K to the whole computation domain as initial condition. For the chemistry solver, I have two options . one is the default non explicit source . The other is the stiff chemistry solver.

I first used the non explicit source solver. After iteration starts, the maximum decreases to room temperature very soon. In other words, the mixture can not be ignited. However, if I exchange to stiff chemistry solver, the mixture can be ignited although it can not be fully converged.

Can anybody who has experiences on combustion simulation give me some suggestions on why would this happen?

why would this two solvers cause ignited and non-ignited results?

Best regards

Weiqiang

[vinerm]

Until and unless the flow is laminar or the time-scales of turbulence and chemistry are really disparate, don't use Explicit Source. User Stiff Solver or CHEMKIN Solver.

[Weiqiang Liu]

Originally Posted by vinerm

Until and unless the flow is laminar or the time-scales of turbulence and chemistry are really disparate, don't use Explicit Source. User Stiff Solver or CHEMKIN Solver.

got it. thanks very much!