Experimental study on initial temperature influence on flame spread characteristics of diesel and gasoline–diesel blends

A set of experiments were conducted to investigate the initial temperature effect on the flame spread characteristics of diesel and gasoline–diesel blend (dieseline), including the flame shapes, main flame spread velocity, subsurface flow velocity, surface temperature, flash flame velocity, pulsation frequency and pulsation amplitude. The flame spread process was recorded visually while the fuel temperatures were measured during the experiments. The results showed that the mean spread velocity of main flame of both fuels increased with initial fuel temperature while the dieseline main flame spreads almost twice that of diesel. During flame spread, the front temperature and velocity of subsurface flow increased with initial fuel temperature and the velocity of dieseline increased faster due to longer subsurface flow. Furthermore, it was found that the pulsation amplitude of diesel flash flame increased with initial fuel temperature while the one of dieseline decreased initially and then increased with increasing initial fuel temperature. The pulsation frequency and velocity of flash flame were found to be independent to the initial fuel temperature.