후래시 미립화 기구에 대한 실험적 연구

Abstract

Flash atomization mechanism has been studied experimentally. Two-phase flow behavior inside a transparent nozzle with the rectangular cross section has been observed carefully with the flow visualization method. Bubbly, slug and annular flows appeared depending on the degree of superheat and the injection pressure. Drop size has been measured by using the light scattering method. The measured results show that the drop size decreases with the increase of the degree of superheat. However, increase of the injection pressure reduces the effective degree of super. heat, and the drop size appear to be larger. The spray angle increases with the degree of superheat up to a certain maximum but start to decrease with further superheat. Through the present experiments, it was confirmed that the internal flow behavior determines the external flow (spray) behavior.