Numerical Analysis of Micro-Scale Diffusion Flame Structure Using Methane Gas as Fuel

Abstract

Number of numerical analyses are done and we have made a comparison on the microscale flame shape for different methane fuel exit velocity, height, and structure by varying the flow velocities along the domain. These calculated numerical models and analysis results thus created by taking the mathematical model is used to figure out the height of the flame and its shape accordingly. We have shown the relationship between exit flow rate of fuel (methane) and the height of the flame. The non-dimensional flame height varies linearly with increasing methane flow rate. Flame structures on center, radial, and axial directions and different species concentrations along them can be found. Also, heat conduction along different directions from the flame can be simulated. For different fuel flow rate, we have measured total heat conducted radially and axially and also have done comparison of various chemical compositions in flow velocity of 1 m/s and 2.5 m/s. As the buoyancy-driven velocity is a function of gravitational constant and flow residing time inside the channel, so buoyancy effect is little on flow field when methane exit flow rate is either high or low. As thermal expansion predominates at higher methane flow rate so mass, energy transport due to axial diffusion minimizes.