Gas Turbine Combustion Chamber 2-D CFD Simulation

Gas Turbine Combustion Chamber (2-D), ANSYS Fluent CFD Simulation Tutorial

This simulation is about a Gas Turbine combustion chamber via ANSYS Fluent software. We perform this CFD project and investigate it by CFD analysis.

A gas turbine is a rotating machine that operates on the energy of combustion gases. Each gas turbine includes a compressor to compress the air, a combustion chamber to mix the air with the fuel and ignite this mixture, and a turbine to convert the energy of hot and compressed gases into mechanical energy.

Part of the mechanical energy produced in the turbine is spent on turning the compressor itself, and the rest of the energy, depending on the application of the gas turbine, may spin the generator (turbo-generator), accelerate the air (turbojet and turbofan) or be used in other applications.

The fuel system in gas turbines is constantly changing, and engineers and designers in the field of mechanical engineering have tried to improve this important part of gas turbines.

The use of gas turbine injectors in the fueling section of gas turbines is one of the most important and, at the same time, efficient methods in this field. In this project, methane-air fuel mixture combustion inside a gas turbine combustion chamber is modeled.

Methane and oxygen are injected inside the combustion chamber with a velocity of 128.9304m/s and 12.0396m/s and temperatures of 286K and 109K, respectively.

The fuel mixture is then ignited, and energy and heat are generated. The geometry of the present model is drawn by Design Modeler software. The model is then meshed by ANSYS Meshing software. The model mesh is structured, and 197006 cells have been created.

Method

In this simulation, air and fuel enter the combustion chamber. So you have to define the species in the model. Therefore, the species transport model has been used. This model solves the transport equations of each defined species.

Also, the volumetric reaction should be used to define the combustion reaction. The Eddy-Dissipation method has been used to investigate the chemical-turbulent interaction of combustion reactants.

The real gas equation has also been used to determine the vapor’s density changes due to temperature changes.

Conclusion

After simulation, the contours of each defined species’ temperature, velocity, pressure, and mass fraction are obtained. The results show that the combustion reaction occurred properly inside the combustion chamber.

The oxidizer and fuel are high at the inlet of the combustion chamber and then begin to fade because these are considered combustion reactants. On the other hand, H₂O and CO are initially zero and then start to grow along the combustion chamber because these are considered combustion products.

Also, since the combustion reaction is exothermic, significant heat is generated inside the chamber, which helps to increase the temperature of the combustion chamber.