Combustion Simulation

Challenge on Combustion

Lean premixed conventional micro-combustion and non-premixed flameless regime of methane/air are investigated in this project by solving three-dimensional governing equations. At moderate equivalence ratio standard k–ε and the eddy-dissipation concept are employed to simulate temperature distribution and combustion stability of these models.

Types of combustion simulations –

Based on mixing

• Non premixed combustion-In non-premixed combustion, fuel and oxidizer enter the reaction zone in distinct streams. Examples of non-premixed combustion include pulverized coal furnaces, diesel internal-combustion engines and pool fires.
• Pre- Mixed combustion- premixed systems, in which reactants are mixed at the molecular level before burning.
• Partially pre-mixed- partially premixed combustion model that is based on the non-premixed combustion model described in non premixed combustion and the premixed combustion model described in premixed combustion.

Based on phase-

• Fluid- when combustion is taking place in fluid phase (volumetric reactions)
• Wall-when combustion is taking place on wall (surface reactions)
• Particles-When reaction is taking place Lagrangian phase.

ANALYSIS SETUP-

3D Geometry-

2D Geometry-Axisymmetric geometry

MESHING –

Size Element-2.5mm

Elements-73611

CFD Tool-

• Turbulence model– k epsilon model
• Inlet velocity fuel- 80m/s at 300 K and mass fraction methane is 1.
• Inlet velocity air - 0.5 m/s at 300 K and oxygen mass fraction is 0.23.
• Mixture material selected methane and air.

For Converged of solution-Residuals

MASS FRACTION OF CH₄-

MASS FRACTION OF CO₂ –

MASS FRACTION OF H₂O-

MASS FRACTION OF N₂ –

MASS FRACTION OF O₂ –

TEMPERATURE PROFILE-

LINES

From inlet boundary we draw following lines at 0.3 m, 0.6 m, 0.9 m, 1.2m, 1.5m and 1.8m

We plot followings variation-

VARIATION OF MASS FRACTION OF CH₄-

VARIATION OF MASS FRACTION OF CO₂ –

VARIATION OF MASS FRACTION OF H₂O-

VARIATION OF MASS FRACTION OF O₂ –

VARIATION OF MASS FRACTION OF N₂ –

NO_X formation concentration is not formed in completed combustion as shown in below reaction.

OBSERVATION-

• Converged of solution take place around 220 iterations.
• Maximum temperature records as 2287.76 K