Challenge on Combustion

• Non-premixed Combustion: The air and fuel are injected into the combustion chamber at the time of combustion and they don\'t have any time for mixing.
• Premixed Combustion: The air-fuel mixture is introduced into the chamber both air and fuel are mixed well before entering into the chamber.
• Partially Mixed Combustion: The air and fuel are injected into the chamber before a small delay of combustion occur in this time period the mixing takes place it is called partially mixed combustion.

Phases:

• Fluid Phase (volumetric reactions)
• Wall (Surface Reactions)
• Particles (Surface reactions)
• Porous Regions.

Combustion simulation on the combustor model: In the combustion simulation we are using the 2-D model the cut section plane of the model as we are assuming that there is a uniform reaction taking place along the radial direction of the cylinder more over performing the combustion simulation over an entire cylinder is a time taking process.

Specifications of the project:

• The element size used: 5mm

1. Nodes:18911
2. elements: 18453

• The steady-state solver is used and the axisymmetry condition is given.
• k-epsilon turbulent model is used.
• Species transport combustion method is chosen with the eddy dissipation model.
• The NOx mode is turned on.
• A methane-air mixture is used.
• The inlet velocity of air-0.5m/s with 0.23 moles oxygen species.
• The inlet velocity of methane -80m/s with 1 mole of it.

The mesh model

The residual graph of the simulation

The velocity plot

The temperature plot

In total, I have used 5 line probes with an equidistance of 0.25m each and variables are collected and plotted in charts.

Mass fraction of carbon dioxide

The comparison of the mass fraction of carbon dioxide at different line probes

The mass fraction of water vapor

The comparison of the mass fraction of water vapor at different line probes

The mass fraction of methane

The comparison of the mass fraction of methane at different line probes

Mass fraction of Nitrogen

The comparison of the mass fraction of nitrogen at different line probes

Mass fraction of Oxygen

The comparison of the mass fraction of Oxygen at different line probes

Mass fraction of Nitrous oxide

The comparison of the mass fraction of Nitrous oxide at different line probes

These emissions are directly proportional to the temperature as the temperature increases NOx emissions are also increases. The NOx emissions are more at the high-temperature area this can be observed in seeing both temperature and mass fraction of NOx plots.

The mass fraction plot for oxygen shows that there is no oxygen beyond line 3 this tells that the total amount of oxygen is utilized that leads to efficient combustion.