Experimental study on aerosol explosion characteristics and flame propagation behavior of aluminum/ethanol nanofluid fuel

Aluminum/ethanol nanofluid fuel, which exhibits superior emission and combustion properties as well as broad application prospects, is a novel clean fuel produced by dispersing aluminum nanoparticles into liquid ethanol. However, the aerosol explosion characteristics of the fuel are not clear at present. In this study, a visible closed aerosol explosion device was set up to perform the explosion experiment, aiming to investigate the explosion characteristics and flame propagation behavior of the fuel under different blending ratios (0 wt%-10 wt%) and aerosol concentrations (97.53 g/m3-214.81 g/m3). The results showed that, as the blending ratio increased, the maximum explosion pressure Pex, the maximum rate of pressure rise (dP/dt)ex, the explosion index Ka, the maximum flame propagation velocity Vmax, and the average flame propagation velocity V over bar all increased first, reaching their peak values at the critical blending ratio (4 wt%), and subsequently decreased. Similarly, for nanofluid fuel of different blending ratios, the explosion time te was first shortened and then extended, with the minimum value also occurring at 4 wt%. Moreover, an analysis of fuels' evaporation properties was performed using TGA analysis. The morphologies and compositions of the explosion products were analyzed by SEM, EDS, and FTIR analysis. Based on the above analyses, a reaction mechanism model for the nanofluid fuel was established. This model reveals the influence mechanism of the blending ratio on aerosol explosions, explains the corresponding explosion behavior, and provides a reference for the research and development of nanofluid fuel.