MS Thesis-Simulation of Gas Compressibility in Mining Scenario

This project is the essence of my MS Thesis at West Virginia University. We did an extensive study in the simulation of large-scale combustion problem.

Project Background

Due to mining fire accident in 2011, a computational study on Mining fires was initiated West Virginia University, funded by Alpha Foundation.

Project Idea

A numerical analysis reg. the effect of compressibility on mining fires was studied using Matlab & Simulink software. Here, geometry is of the order of magnitude 2M. For, this large-scale Combustion problem finger-flame acceleration mechanism along with DL-instability was considered for research. The flame started as a spherical flame. Being constrained along the walls, it becomes oval in shape and resulting in an increase in surface area of corrugations. Resulting, in increased flame speed.

Fig.: Consecutive stages of the mining fire scenario: (a) ignition of an expanding flame; (b) formation of a cellular flame structure; (c) finger-flame acceleration; (d) flame propagation driven by wall-friction; and (e) flame spreading through obstacles.

Effect of Compressibility

Analytical modeling of flame was done to simulate the flame propagation. To increase, the accuracy of the results the effect of compressibility was incorporated into the study. A self-made solver using Matlab & Simulink was used to analyze the simulate the flame in incompressible scenario. Mining environment with Air-Methane & Air-Propane was considered. The effect of both combustible & in-combustible dust was taken into account. Parameters like flame-tip position, flame-tip speed and the effect of combustible & inert dust were studied for rich-lean mixtures.

Results

The effect of compressibility was observed to be the maximal for the stoichiometric air-fuel ratio. A 20-30% reduction in flame speed & flame tip position was observed in this scenario.

Similarly, the Ztip (wall) & Utip(wall) also achieved their maximal at stoichiometric ratios.

Detonation scenario was observed in the presence of combustible dust particles. However, the fire was mitigated in the presence of inert dust.

Related Publications

The axis symmetric version of my research was published in the Taylor & Francis Journal.

DOI-https://doi.org/10.1080/13647830.2017.1403654

My research also yielded a conference publication at Princeton Combustion Summer School

Conference Proceedings-http://toc.proceedings.com/30228webtoc.pdf