Моделювання якісного складу паливно-повітряної суміші у факельному запальнику камер згоряння ГТД

The qualitative composition of the fuel-air mixture, which is formed in the torch igniter of the combustion chamber of the gas turbine engine (GTE), determines the efficiency and reliability of their work. The main task of the study is to determine the qualitative composition of the fuel-air mixture near the electric spark plug of the GTE torch igniter depending on its geometric features and engine operation condition. The composition of the mixture was evaluated using analytical, experimental, and numerical methods. According to the analytical model, a significant over-enrichment of the fuel-air mixture in the igniter housing was established and confirmed experimentally. A numerical model was used to determine the fields of mass concentration of fuel particles in the fuel-air mixture in the torch igniter housing, considering the peculiarities of airflow and fuel supply for different combinations of GTE design features and operating conditions. The influence of geometric parameters of the housing and external factors was investigated using the numerical model of stationary combustion of fuel-air mixture, which was prepared in the torch igniter housing of GTE combustion chamber by evaporation and spraying of aviation kerosene particles in the air stream. The implementation of a small-factor experiment allowed to establish the degree of influence of each factor under study and their interaction on the excess air coefficient. The correlation coefficient between the coefficient of excess air near the spark plug and the average flame temperature is set. Given the absence of serial designs of controller torch ignites, it is proposed to use a pulsed fuel supply to control the quality of the fuel-air mixture. Further ways of research to increase the reliability of ignition of both the torch igniter from the electric spark plug and the combustion chamber of GTE from the flame is outlined.

Optimization of Length of Mixing Zone in GH2-GO2 Based Torch Igniter, Applying Numerical Techniques

Initiation of chemical reactions liberating thermal energy in non hypergolic propellants require ignition systems which are reliable as well as robust in nature. This necessitates the igniter and its subsystems be on par or exceed every quality criteria required for the main stage. The ignition systems which provide pilot action and flame holding in supersonic environment adds new challenges in its structural and thermal stability. The paper aims to conduct a numerical analysis of the Augmented Spark Torch igniter required for an air breathing rocket (SCRAMJET) engine with the emphasis on the optimization of the mixing length ratio required to achieve a uniform mixture ratio distribution in the zone of the igniter combustion chamber. Nomenclature