Modeling Combustion
 

Goal: model deflagration and/or detonation wave of gaseous fuel in non-premixed duct using Eddy Break-Up Model.

Background: I have 3 years of experience with modeling internal and external airflow in Star-CCM+ and have ventured into modeling combustion. I have completed some of the Star tutorials for combustion, but something isn't carrying over into this project and it is not immediately obvious.

First off, I have a geometry and I believe my mesh is sufficient. This is a 3D analysis. I have set up my boundary conditions (regions). I am using Eddy Break-Up model in my physics. I have defined my reactions the best I could with products and reactants. My fuel is propane.

The setup: I have an inlet and an outlet to move the air. I am using an injector to bring in parcels of fuel, defined as a mass flow rate. I have the injector in a corner, far enough to not be negatively affected by the inlet. I then put a region of high temperature (a cylinder) to start the combustion as the parcels pass through it. I am doing this because I also failed at using the ignitors feature. Time step in 1.0e-4.

When I run the simulation, it crashes at 20 steps.
What I would like to know:

- Is the Eddy Break-Up model the correct model for this and am I employing it's use correctly? Is there something I am leaving out?

- Is my approach correct for thinking a hot spot could ignite my reactants and fuel? Should I just try to make the ignitors work?

- Do I need my initial conditions to include products for intermediary reactions to support combustion?


If any more information is needed, let me know. I appreciate any and all help.

Thank you.