테이퍼 노즐을 통한 스월분무의 강성 향상

Abstract

The spray characteristics of swirl spray at different taper angles are investigated and then a taper angle, generating an opened hollow cone spray, is chosen to create the robust swirl spray at various surrounding conditions. The tapered nozzle altered the symmetrical distribution of fuel and velocity to asymmetrical state. The larger portion of fuel was positioned in some area with higher injection velocity, and the smaller portion of fuel was located in another area with lower injection velocity. When the taper angle was decreased, the fuel velocity to a certain direction was getting increased and spray images showed more asymmetrical shape. By cutting the nozzle to have a tapered nozzle with an angle less than the flow angle, opened hollow cone spray was formed because some part of fuel impinges to the cut area. This shape assists in equalizing the pressure difference between the centerline and outer part of spray envelop. The results showed that there is a potential from a tapered nozzle spray to be independent of the various surrounding conditions without much sacrifice of the atomization quality when the taper angle is less than the flow angle.