Change in flame front area over time with premixed combustion across an obstacle

Abstract

This thesis is a joint project of USN, and CMR Gexcon to explore the changes in flame front area over time with premixed combustion across an obstacle. The objective of this thesis is to make a literature review on relevant topics, as well as perform experiments with flame tomography in the lab at USN. Through these experiments, this thesis will assess the change in flame front area over time across an obstacle and explore whether there is any relation between the different concentrations in H2-Air mixture. The method used to achieve this is performing experiments with flame tomography and recording it with a high-speed camera. The experiments are then evaluated through a MATLAB code developed during this thesis to track the flame front area, and through this code provide three different results. First being the area of the flame front, second being the change in area scaled to the cross-section area of the combustion chamber. The 3rd result being the change in area scaled to the cross section of the combustion area as well as the laminar burning velocity, and relative density between burnt, and unburnt mixture at the given H2-Air mixture. And all these are plotted dependent on the position of the flame front relative to the position of the flame front. Through these experiments it has been found that regardless of the concentration of the H2-Air mixture, the area of the flame front increases at a consistent rate dependent on the flame front position. The change to flame front area scaled to the cross-section area of the combustion chamber also stays consistent dependent on the flame front position regardless of H2-Air mixture. When additionally scaled to the laminar burning velocity, and relative density between burnt, and unburnt mixture, the results are no longer consistent, with there being a decreasing value in change per meter with an increase in consentration.