不足膨張噴流の干渉に関する研究 : 第1報,2個の平行な噴流の干渉特性

From the standpoint of engineering, and industry or space engineering, it is important to clarify the basic interference characteristics of underexpanded jets issuing from several pipes towards the atmosphere. In this paper, the interference characteristics of three parallel underexpanded jets, with intervals between each jet axis four times the pipe inner diameters, were studied. In particular, the flow visualizations of both mean and instantaneous flows with time were conducted by the schlieren and shadowgraph methods. Moreover, the length of pseudo-shock waves, the mean pressure and velocity distributions along the vertical axes, and the equivelocity diagrams within a vertical section to the jet aces were investigated in detail. As result, it was found that three parallel jet flows could be classified into 4 patterns for mean Mach numbers, ranging from 1 to 2, at the pipe exit.