Gas Turbine Combustion Chamber CFD Simulation

Description

Gas turbine introduction

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 in 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.

Project description

In this project, methane-air fuel mixture combustion inside a gas turbine combustion chamber is simulated. Methane and oxygen are injected inside the combustion chamber with the velocity of 128.9304m/s and 12.0396m/s and the temperature of 286K and 109K, respectively. The fuel mixture is then ignited and energy and heat are generated. Energy model is activated. Also, the species transport model is used to analyze the combustion process.

Eddy-Dissipation method has been used to investigate the chemical-turbulent interaction of combustion reactants and the standard k-ε viscosity model with the use of standard wall functions is exploited to solve the fluid flow. The ideal gas equation has also been used to determine the water vapor’s density changes due to changes in temperature

Gas Turbine Geometry and Mesh

The geometry required for this analysis, which includes only the gas turbine injector part, is designed in ANSYS Design Modeler® and mesh inside ANSYS Meshing®. The mesh type used for this geometry is structured and the element number is 197006.

CFD Simulation Settings

The key assumptions considered in this project are:

• Simulation is done using pressure-based solver.
• The present simulation and its results are considered to be steady and do not change as a function time.
• The effect of gravity has not been taken into account.

The applied settings are summarized in the following table.

Results

Contours of density, pressure, temperature, velocity and species mass fractions are presented.

All files, including Geometry, Mesh, Case & Data, are available in Simulation File. By the way, Training File presents how to solve the problem and extract all desired results.

This ANSYS Fluent project includes CFD simulation files and a training movie.