[andon6141]

Hallo,

i am currently working on a decomposition in a pressure vessel but i have a problem with the pressure calculation in my model.

Case:

- Fluent 17.2
- pressure based solver
- transient
- k-e turb model
- 2D an 3D
- volumetric reaction
- decomposition in a pressure vessel
- Implemented simple combustion kinetik (16 reactions UDF)
- Calculation of density, viscosity, thermal conductivity, heat capacity (UDF)
- Ignition of the combustion with a hot filament

The problem is the calculation of the pressure in the vessel. If i use an UDF to calculate the density it is not possible to initialize with a certain pressure. After the first iteration the pressure falls back to zero. Only when i use the ideal-gas setting in the mixture density instead of my own UDF the pressure dose not fall back to zero.

My aim is to simulate a full decomposition in the pressure vessel. I want to
examine the flamefront und the increase of the pressure during the decomposition process.

Further questions:

What ist the right solver (pressure or density based) und what should i consider?

Best Regards!