Experimental investigation of the effects of passivated aluminum nanoparticles on butane flame structure

This paper investigates the effects of aluminum nanoparticles on a premixed butane-air flame using optical methods. The experiments are performed for a range of equivalence ratios in rich/lean environments (0.8 ≤ φ ≤ 1.2) and laminar steady flame conditions (50 ≤ Re ≤ 200). The aluminum nanoparticles are added up to 5 wt%. The Mach-Zehnder interferometry technique and Schlieren photography method are applied to obtain the flame temperature and its laminar burning velocity. Addition of nanoparticles caused a higher temperature flame in most cases. Also, the laminar flame speed was affected positively by the aluminum nanoparticles. A maximum augmentation of 237 K was observed in the flame maximum temperature. Also, the laminar flame speed was enhanced by 18.9% and 29.1% in the cases of adding aluminum nanoparticles by 2 wt% and 5 wt%, respectively.