掺气水流不同粒径气泡运动特性研究

Study on movement characteristics of air-bubbles with different sizes in aerated flow

采用三维数值模拟方法和离散相模型(DPM模型)模拟了不同比尺高水头直槽式泄洪洞和带反弧泄洪洞掺气水流中不同粒径气泡的运动特性,分析了不同粒径气泡对近壁掺气浓度的影响范围,研究成果可为掺气浓度的缩尺效应提供依据。分析表明,气泡的影响范围与流速成正比,与气泡的粒径成反比;泄洪洞底坡越小,气泡的影响范围越大;泄洪洞反弧段半径越大,气泡的影响范围越大。

With the relevant 3-D numerical simulation method and the discrete phase model（ DPM）,the movement characteristics of the air-bubbles with different sizes in the aerated flows in the high head vertical chute spillway tunnels and the spillway tunnels with ogee sections of various scales are simulated,and then the areas of the impacts from the air-bubbles with different sizes on the near wall aeration concentrations are analyzed,from which the study result can lay a basis for the scale effect of the aeration concentration. The analysis shows that the impacting length of the air-bubble is proportional to the flow velocity and is inversely proportional to the size of the air-bubble,while the smaller the bottom slope of the spillway tunnel is,the larger the impacting length of the air-bubble is to be,furthermore,the larger the radius of the ogee section of the spillway tunnel is,the larger the impacting length of the air-bubble is to be.