Abstract:A visual effervescent spray system and a gasliquid flow simulation model of atomizer interior and spray field were established to investigate spray characteristics of bubbly flow. The results showed that there was a gasphase expansion on spray surface, and the width of the gasphase expansion was increased with the increase of liquid mass flow rate and gasliquid mass ratio, distance between two expansions was decreased with the increase of gasliquid mass ratio. At the same gasliquid mass ratio, the spray cone angle was increased with the increase of liquid mass flow rate, and the influence of the liquid mass flow rate became weak at high liquid mass flow rate. The spray penetration distance was increased with the increase of liquid mass flow rate at low gasliquid mass ratio, while decreased at high gasliquid mass ratio. When the gasliquid mass ratio was low, the spray shape was apparently influenced by the gasliquid mass ratio, and the spray cone angle and penetration distance were increased with the increase of gasliquid mass ratio. As axial distance of the spray was increased, the droplet collision frequency was decreased and gradually became stable. The influence of gasliquid mass flow pulsation at atomizer outlet on the droplet axial velocity around the cross section of the atomizer outlet was limited to a very short distance. With the axial distance to the atomizer outlet increased, the distribution range of droplet size was widened, the number of peak droplets was decreased, and the peak size of droplet and droplet size distribution was moved to the direction of large size. With the increase of the axial distance to the atomizer outlet, droplet size in large scale droplet area was increased, the radial range of large scale droplet area was widened.