두 개의 와류분무 노즐로부터 분사되는 이중분무의 분무특성에 관한 실험적 연구

Abstract

Characteristics of twin spray ejected from two swirl spray nozzles were studied experimentally. By using a patternator for measuring volumetric flux of drop flow at various locations inside the spray, variation of th twin spray pattern along the axial direction was studied with changing the injection pressure and the distance between the nozzles. The general findings from the experiments are as follows: (i) as axial distance from the nozzles increases, the spray pattern in x-z plane which contains both nozzles changes significantly. On the other hand the spray pattern in y-z plane which passes the midpoint between two nozzles remains almost unchanged at outer region as axial distance and injection pressure vary ; (ii) at the downstream of the twin spray with spray interaction, the maximum volumetric flux in y-z plane (qmax)y, has tendency to become larger than that of x-z plane (qmax)x, due to a characteristic(hollow cone shape) of the constituting swirl sprays, and this trend is pronounced at higher injection pressure since the cross-section of each single spray remains hollw at the longer axial distance from each nozzle with higher injection pressure ; (iii) at a certain axial distance from the nozzles, the cross-sectional shape of the boundary of the twin spray tends to be circular similar to that of the single spray with twice the flow-rate, and that distance is not proportional to the distance between two nozzles ; (iv) though there are some collisions between droplets from each nozzles of twin spray, in present experimental range, the flow pattern of gas including the entrainment effect plays the key role in spray interaction.