Quantitative Visualization of Three-Dimensional Turbulent Bubbly Flow Induced by Plunging Water Jet
K.C. Kim(1), J. Oh(1,2)
1: Eco-friendly Smart Ship Parts Technology Innovation Center, Pusan National University, Republic of Korea
2: School of Mechanical Engineering, Pusan National University, Republic of Korea
DOI:
Air bubbles entrained at the ambient is known to increase the turbulence when turbulent water jet plunges onto the free surface. However, the flow field measurements have rarely been studied compared to bubble property analysis due to limitations of experimental techniques. In this study, the bubbly flow field was measured using time-resolved three-dimensional Lagrangian particle tracking technique and the acquired flow field was used for turbulent structure visualization and statistics calculations. We dropped water in the water tank, and the generated bubbly flow was captured using four high-speed cameras and illumination systems. The obtained liquid tracer particle images were processed using Shake-The-Box algorithm and Vortex-In-Cell sharp method. The bubble images were converted to binarized images to calculate their properties. We observed strong vortex pairs at both jet shear layer and jet core. Also, we confirmed the existence of bubbles can increase the jet turbulence by comparing turbulent intensity to the single-phase jet.
