Combustion in Flownex can be considered as the ability to determine the amount of heat added to a system due to a calculated air/fuel ratio in the working fluid within Flownex. Flownex can then also be used for the prediction of the flow and temperature distribution and pressure losses across the combustion chamber.
Flownex provides two methods to calculate combustion; combustion chart and an adiabatic flame component. Combustion charts are used to determine the combustion temperatures. When combustion is specified for a component, the combustion temperature will be calculated from the fuel fraction (air to fuel ratio) in the chamber.
The Adiabatic Flame element calculates the off-gas composition and maximum temperature for a chemical reaction of a chemical mixture.
If we consider a combustion chamber with multiple airlines and a fuel injection line, Flownex will calculate the fuel fraction throughout the combustion chamber and intern the temperature distribution over the chamber. This gives the user the ability to ensure accurate simulation of temperature distribution throughout the combustion chamber and intern see the effect the combustion has on the air flow. It is also possible to calculate conduction, convection and radiation heat transfer from the combustion chamber to external components or atmosphere.
In Flownex, the combustion modelling functionality can typically be used to model:
- Air flow and temperature distribution in aircraft combustion chambers.
- Simulation of multiple air and fuel lines in a combustion chamber
- Continuous mixing of the air fuel mixture with fresh air or a second stream of fuel with different combustion characteristics.
- Heat transfer from a combustion chamber to external components or atmosphere.