Investigation of the combustion properties of C 3 H 8 /H 2 mixtures in O 2 -enriched environments

This research focuses on examining the effect of H2 content and O2 concentration on the laminar combustion characteristics of C3H8. The laminar burning velocity (S L ) is determined using a constant-volume combustion bomb and is evaluated across four reaction mechanisms. These findings indicate that adding H2 slightly raises the S L of C3H8, primarily because of the enhanced reactions driven by the increased presence of H radicals. A rise in the O2 concentration significantly boosts the S L of the mixture. When the O2 concentration increased from 21% to 40%, the S L at Φ = 1.0 increased by 216.2%. As the H2 content increases, the NO mole fraction slightly decreases. Conversely, increasing O2 concentration accelerates the thermal NO formation rate, causing a sharp rise in its mole fraction.