Non-premixed microjet flame combustion mixes and ignites fuel and oxidizer streams fed separately into a combustion chamber. This method is employed in gas turbines, rocket engines, and industrial burners. The combustion chamber receives fuel and oxidizer from independent microjets or nozzles. Chemical reactions between fuel and oxidizer produce combustion products and heat when mixed.

What makes the present simulation unique is not just about non-premixed microjet combustion but also using the CHEMKIN mechanism. CHEMKIN provides precise chemical processes to model reaction kinetics, species concentrations, temperature distributions, and other combustion characteristics. Besides, we are going to simulate based on a numerical paper entitled “Combustion characteristics of non-premixed methane micro-jet flame in coflow air and thermal interaction between flame and micro tube” published in Applied Thermal Engineering journal.

Simulation Process

The combustion chamber is a 2D rectangle that can be easily drawn in Design Modeler software. A structured grid is then generated. The model schematic is shown in the following:

Based on the microjet combustion assumptions, a non-premixed model is activated, along with a Volumetric reaction. ANSYS Fluent provides an option to import CHEMKIN mechanism and it is very important in this simulation. Also, Eddy dissipation turbulent-chemistry sub-model is used.

Post-Processing

During post-processing, numerous important findings regarding the CHEMCHINK mechanism’s simulation of methane combustion were discovered. From the start of the phase, where methane combines with oxygen to generate carbon dioxide and water, the combustion process shows typical characteristics. Notably, the kinetics of methane oxidation were clarified by determining the ignition delay time and flame speed. Moreover, the examination of temperature profiles and species concentrations demonstrated complex interactions between chemical and thermal influences, which impacted the overall behavior of combustion. All things considered, this work clarifies the basic principles of methane combustion, which has effects on improving combustion procedures and cutting emissions in a range of engineering applications.