雾化气流脉动下乙醇喷雾旋流火焰特性

The unsteady combustion behaviors of an ethanol spray flame perturbed by pulsations of different atomizing gaseous flows were investigated experimentally.By varying the atomizing gas flow rate, the responses of flame length and lift⁃off height to different pulsation frequencies and durations, as well as the flame structure and temperature distribution under flow pulsations, were examined.The results showed that the spray flame changed from attachment to lift⁃off as the atomizing flow⁃rate increased.The atomizing process of liquid ethanol was significantly affected by the flow pulsation, resulting in oscillations of flame length and lift⁃off height at the same frequency.Under the same atomizing flow rate, the average flame length of attached flame and lifting height of lift⁃off flame increased.The droplet velocity, size and spatial distribution dominating the mixing of ethanol spray and oxidant were directly affected by flow pulsation, resulting in an enhancement of heat⁃release, while the effect of pulsating frequency was less significant.