분무 노즐에서 분사되는 액체막의 분산현상에 관한 실험적 연구 -주위 기체의 응축에 따른 효과-

Abstract

The effect of condensation of ambient gas(steam) on the breakup of liquid(water) sheet were studied through experiments. in case of condensation of ambient steam on the water sheets from spray nozzles, the perforation(formation of holes)breakup mode occurred dominantly except for laminar water sheets ejecting from fan spray nozzles. This implies that the perforation mode is more easily affected by the condensation of ambient steam than the aerodynamic wave mode is. The effect of flow conditions inside the nozzle is shown to be responsible for the initial local point disturbances which are the origins of the holes in the water sheets. Thus the perforation depends on the internal shape(or type) of nozzles as well as the flow motions of ambient steam by condensation effect. Generally the breakup length of water sheet decreases in case of condensation of ambient steam due to the perforation near the nozzle orifice, and for the low sheet velocity, the breakup length decreases as the sheet temperature decreases(subcooling temperature increases). However, at the high sheet velocity, the effect of subcooling temperature on the breakup length turned out to be insignificant due to the flow instability of water sheet itself.