Experimental and modeling study of carbon suboxide decomposition behind reflected shock waves

Abstract

At temperatures between 1150 and 2000 K and pressures between 0.1 and 0.2 MPa, the thermal decomposition of carbon suboxide (C₃O₂) behind reflected shock waves was investigated with a high-repetition-rate time-of-flight mass spectrometer (HRR-TOF-MS) connected to the end flange of a shock tube enabling rapid repetitive (100 kHz) measurements of the gas-phase composition. Concentration–time profiles for C₃O₂ and CO were measured and compared to simulations based on an improved mechanism for C₃O₂ decomposition and carbon cluster growth. In addition, relative concentrations of C atoms and C₂ molecules were detected and related to model predictions. For temperatures up to 1800 K, satisfactory agreement between experimental data and calculations was obtained. At higher temperatures, measurements and simulations differed noticeably. The importance of C₂ for the growth of carbon clusters was confirmed.