Pressure fluctuation and cellularization characteristics of 2-ethylfuran spherical expanding flame

Abstract

The pressure fluctuation and cellularization characteristics of 2-ethylfuran (2-EF) liquid biofuel were investigated. The study was based on experiments in a constant volume combustion chamber (CVCC) under different initial temperatures (373, 403, and 433 K), initial pressures (1, 2, and 4 bar), and equivalence ratios (0.7–1.4). The spectrum analysis of the explosion pressure showed that the amplitude of pressure fluctuations was more intense with an increase in the equivalence ratio and initial pressure. Moreover, a three-dimensional reconstruction algorithm was constructed to analyze the evolution of cellular structures. It was found that both crack expansion and cell formation caused the irregular evolution of the flame front, which was more obvious at high equivalence ratios and initial pressures. Finally, the flame’s pressure fluctuation before reaching the quartz window was analyzed and combined with flame cellularization, which showed that the early pressure curve and cellularization parameters (cell number and crack length) had similar fluctuations, and the amplitude of the pressure fluctuation was influenced mainly by the initial pressure and the extent of flame cellularization.