The Experimental Research Of The Bubble Plume's Flow Regime

Bubble plume is a complex two-phase flow. The author has designed a experiment platform having aeration tank and aeration air-blast model experiment on the basis of referring to a lot of home and abroad related documents about two-phase flow, flow field test visualization technology, digital image processing technology, etc. The purpose of this paper aims at through the use of gas-liquid two-phase experimental study and theoretical analysis methods to explore the movement rule of bubble plume in aeration tank.In this paper, the research methods, the main result and the conclusion are as follows:(1)Regarding test equipment research: Having developed the simulation installment of bubble plume aeration tank . Not only has this device could observe the bubble movement characteristic when changing air supplies and relative depth ratios .(2) Regarding mobility patterns of bubble plume research: Ascertaining rate of flow is the major factor of affecting bubble plume flow state. For the same depth, and the same aperture aerator generated by the same bubble plume , when the gas flow increases, the bubble volume increases, gas rate also increases markedly , bubble plume shows two states of flow . This paper descripts two specific types flow characteristics of the bubble plume.(3) Regarding the overall structure of the bubble plume research: Identifying three cross-section study, plume formation areas, formsation queen areas and surface flow areas. The formation of the plume contraction cross- section area is related to supplies, refueling capacity increases, the initial momentum of the bubble enhances, and entrainment flows around the body of water increases, compresses the interior plume water bodies, results in contraction cross-section areas. According to the experimental data didcusses the bubble plume velocity distribution of the cross-sectional and the axis speed existing obvious self-similarity. Through the conclusion of axis speed is the linear expansion , getting plume dispersion angle and determining the changing spread of bubble plume angle is between 10°to 12°.(4) On the study of bubble plume movement getting the following conclusions:The velocity distribution of bubble plume cross-section exists obvious self-similarity, and has nothing to do with the water depth and constant exports of Buddha Fort. The zero dimension spool thread axisspeed u_m/u_r in the plume main body area is reduced along the way. The processof bubble plume upward movement has the periodic change nature, the period of motion varies with the aeration quantity and the water depth. The bubble volume increases with increased distance, then the volume keeps invariable after reaching certain extent. In the same volume of water depth and different aeration conditions, the bubble volume in the plume-forming regions changes in the trend of small, then increases progressively until stably.