The main aim of this paper is the investigations of aircraft gas turbine engine emissions. In semi-empirical emission correlation methods to predict the sum of nitric oxide and nitrogen dioxide (NOx), carbon monoxide

The main aim of this paper is the investigations of aircraft gas turbine engine emissions. In semi-empirical emission correlation methods to predict the sum of nitric oxide and nitrogen dioxide (NOx), carbon monoxide (CO), hydrocarbons (HC) etc. To calculate the amount of emissions for flight operating conditions, the actual parameters involved like the fuel/air flow (for the NOx correlation method), the reciprocal value of the combustor loading parameter (for the CO and HC correlation methods) and the combustor inlet temperature and pressure, the flame temperature and the equivalence ratio (for the soot correlation method) are set with reference to the respective reference ground values. The combustion process in the gas turbine engine can be classified by two ways: 1. Diffusion flame combustion 2. Lean premix staged combustion In the diffusion flame combustion, the fuel/air mixing and combustion take place simultaneously in the primary combustion zone. This generates regions of near-stoichiometric fuel/air mixtures where the temperatures are very high. It means more emission and engine has to consume high Specific fuel consumption (SFC), so we switch to lean premix staged combustion. For lean-premix combustion, fuel and air are thoroughly mixed in an initial stage resulting in a uniform, lean, unburned fuel/air mixture which is delivered to a secondary stage where the combustion reaction takes place. Manufacturers use different types of fuel/air staging, including fuel staging, air staging, or both. The lean-premix principle is applied. Gas turbines using staged combustion are also referred to as Dry Low NOX combustors. The engine thermodynamic state is mainly determined by the thrust demand of the aircraft, the ambient conditions and different flight missions have to be considered. Therefore a flight performance module is presented by using the technique of lean-premix combustion to control the emission and to improve the performance of engine SFC.