Combustion modes of the lean methane-air mixture in a U-shaped burner

Base on the model of a flowing reactor with an inert internal body, a numerical study of a lean methane-air mixture burning in a U-tube is carried out in the case of initiation of the combustion process by a preliminarily heated internal wall of the tube. The calculations were carried out for two values of a tube extent for revealing qualitative distinctions between established operating regimes. It is shown that, depending on the dimen-sionless parameter of heat exchange intensity in the reaction mixture on an external wall of the tube and dimensionless parameter of the mixture current, a high-temperature or low-temperature stationary regime, or an oscillatory operating mode can be implemented in the system. It is determined that the high-temperature stationary state is established at some distance from the input of the tube, and oscillatory modes are implemented in the top part of the tube; at the same time, the mixture in the bottom part of the tube has a decreasing temperature profile. It is shown that the parameter of heat exchange intensity of the mixture at the external wall of the tube determines the depth of establishing the high-temperature steady state.

Keywords

Authors

References