曲がり噴流における渦の合体と遠心力不安定による渦塊のはく離

抄録

An experimental study was carried out on a turbulent jet with streamline curvature to study vortex coalescence and its behavior downstream in both the centrifugally stable and unstable flow. The experiments were conducted in a hydraulic tank using Laser Doppler Velocimetry (LDV) for velocity measurements and computeraided image processing technique for enhanced visualization of flow. In particular, a conditional sampling technique of autocorrelation calculation from the velocity signal was developed in this study to detect vortices which irregularly appear in the flow. From this study, repetition of vortex coalescence in the inner region and vortex separation due to centrifugally unstable flow in the outer region became clear.