The Experiment Research Of Bubble Breakup And Its 3D-PIV Test

In the gas-liquid reactor, the interfacial area between gas-liquid phase could increase as a result of the bubbles'breakup, which is benefit for the chemical process that needs more contact area to accelerate reaction speed. In this research, the process of a single air bubble's breakup in the flow field induced by a horizontal water jet was studied with the method of high speed camera technology,2&3D-PIV (Particle image velocimetry) and numerical simulation.In the experiment of bubble macro behavior in breakup, the bubble's generation, rise, lateral movement and breakup were recorded by a high speed camera, and then were analyzed including the effect of jet Reynolds number, generation position, bubble size on the breakup form, probability and the daughter bubbles'distribution. The result showed that the bubble would move against to the direction of nozzle with apparent deformation in the ascent stage. Besides, in the shear-stretch stage, the form and probability of the bubble's breakup were determined by the strongly shear position. What's more, the form of the bubble's breakup can be classified as binary breakup, triple breakup and multiple breakup according to the number of daughter bubbles.In the PIV test part, the flow field of liquid phase was measured by the 2D-PIV method, in order to find the connection between the liquid flow field and the bubble's behavior. An important experiment of 3D-PIV was applied to synchronously measure the bubble behavior and the liquid flow field around it. The result indicated that the velocity of liquid flow with the existence of the bubble was higher than that without the bubble and the velocity of the bubble was also higher than that of the flow field around the bubble.In the numerical research of bubble breakup, the jet flow field and the bubble's behavior were studied by using the VOF model. The results of numerical simulation and that obtained by high speed camera show good agreement, including the bubble's deformation, breakup process. It also indicated that the velocity of the flow field around the bubble would change during the gas-liquid phase interaction.