Unsteady flamelet modeling of pollutant emission in diffusion flame

摘要

The emission of nitrogen oxides NO and NO_2, collectively known as NO_x, is an important source of atmospheric pollution. The stringent NO_x emission reduction regulations made the NO_x emission control a significant criterion in the design of combustion systems. Formation of NO_x in turbulent flames is a complex process due to its dependence on flow mixing, chemical reactions and the interactions between them. To reduce the NO_x emission from combustion systems, combustion modification and post-combustion reduction are two techniques commonly adopted. In combustion systems where the fuel does not contains nitrogen, the dominant source of NO_x is the thermal mechanism which has a high dependence on temperature and O_2 concentration.