Combustion Chamber (Transient) Description

In this project, we simulate a combustion chamber by ANSYS Fluent software applying a Transient and Pressure-based solver, considering the gravity effect. Inside the combustion chamber are three main parts: the air inlet pipe, the burner section, and the outlet pipe.

Inside the chamber is a thin wall with several cavities of varying dimensions. The small primary holes for cooling the chamber wall by layering flow, and the next big ones are to keep the flame in the middle of the chamber. The geometry of the present model is 3-D, and Design Modeler software designs it.

ANSYS Meshing software performs the meshing of the current model. The mesh type is unstructured. We use a triangular grid, and the element number is 694928.

Methodology

We simulate the combustion chamber by applying a Transient and Pressure-based solver, considering the gravity effect. We use the Standard Wall Function and K-epsilon RNG model for the turbulence equation since the flow inside the chamber combustion is relatively complex.

We apply the Species Transport Model to model the combustion. Mass flow rates of the air and the fuel (CH4) equal 0.02 kg.s-1 and 0.0006 m.s-1, respectively, with a temperature of 300k. Also, the chamber’s outer wall is adiabatic. in this case, there are two steps of methane-air combustion, with six species involved in the reaction: methane, Oxygen, nitrogen, water vapor, carbon dioxide, and carbon monoxide.

Mass fractions are .23 and .77 for Oxygen and nitrogen, respectively.

Combustion Chamber (Transient) Conclusion

For the current simulation, we present both Volume rendering(3D Contour) and streamlines of velocity, pressure, temperature, density, and mass fraction of components to give much insight into the problem. Briefly, the air and Methane-air enter the domain from the around and bottom surfaces of the geometry, respectively, and make a combustion region.

Temperature and pressure increase and the flow then goes to the outlet at a higher speed, as depicted in the Figures, which is the main challenge of this simulation.