A Theoretical Analysis for Modeling and Prediction of the Jet Engine Emissions

This paper is to formulate a mathematical model to predict the amounts of the emissions produced from the combustion process of the gas turbine unit of the jet engine. These emissions have bad impacts on the environment if they are out of standards, which cause real threats to all type of life on the earth. The amounts of the emissions from the gas turbine engine are functions to many operational and design factors. In landing-takeoff (LTO) these amounts are not the same as in taxi or cruise of the plane using jet engines, because of the difference in the activity period during these operating modes. These emissions can be affected by several physical and chemical variables, such as fuel type, fuel to air ratio or equivalence ratio, flame temperature, combustion pressure, in addition to some inlet conditions such as ambient temperature and air humidity. To study the influence of these variables on the amounts of these emissions during the combustion process in the gas turbine unit, a computer program has been developed by using the visual basic 6 software. Here, the analysis of the combustion process is carried out by considering it as a chemical reaction with shifting equilibrium to find the products of the combustion of the octane fuel, at different equivalence ratios, compressor pressure ratios (CPR) and combustion temperatures. The results obtained have shown that there is noticeable influence of the equivalence ratio, CPR, and the combustion temperature on the amounts of the main emissions which are considered pollutants, such as CO, CO₂ and NO.

• Jamal S. Yassin

• Mathematical model
• gas turbine unit
• equivalence ratio
• emissions
• shifting equilibrium.

[1] Borgnakke, Claus, and Sonntag, R.E., Fundamentals of Thermodynamics, John Wiley & Sons, USA, 2013.
[2] Moran, M.J., and Shapiro, H.N., Fundamentals of Engineering Thermodynamics, John Wiley & Sons., England, 2006.
[3] Perry, R.H., and Green D.W., Perry's Chemical Engineers' Handbook, McGraw-Hill Companies, USA, 2008.
[4] Cheremisinoff, N.P., Handbook of Air Pollution Prevention and Control, Elsevier Science, USA, 2002.
[5] Seinfeld, J.H., Atmospheric Chemistry and Physics of Air Pollution, John Wiley & Sons, New York, 1986.
[6] Irwin, J. G., and Williams, M. L., "Acid Rain: Chemistry and Transport", Environmental pollution , 1988, 50:29-59
[7] Whelpdale, D. M., Summers, P. W., and Sanhueza, E., "Global Overview of Atmospheric Acid Deposition Fluxes", Environmental Monitoring and Assessment, 1977, 48:217-247.
[8] Rua, A., Gimeno, L., and Hernandez, E., "Relationships between Air Pollutants Emission Patterns and Rainwater Acidity", Toxicological and Environmental Chemistry, 1997, 59: 199-207.
[9] Turns, S. R., An Introduction to Combustion: Concepts and Applications, McGraw-Hill Companies, Inc., 2000, Singapore.
[10] Bathie, William, Fundamentals of Gas Turbines, John Wiley and Sons, New York, 1996.
[11] Bowman, C. T., "Control of Combustion-Generated Nitrogen Oxide Emission: Technology Driven by Regulations", Twenty-Fourth Symposium (International) on Combustion, The Combustion Institute, Pittsburgh, PA, 1992, pp. 859-878.
[12] Thomson, D. J., "Dependence of global temperature on atmospheric CO2 and solar irradiance", Carbon Dioxide and Climate Change, vol.94, National Academy of Sciences, CA, 1995, pp 8370-8377.