连续两弯水流特性的数值模拟研究

Experimental analysis and numerical simulation of continuous bend flow

连续两弯的过渡段及后弯水流特性明显受到前弯水流的影响.采用RNGκ-ε湍流模型和VOF方法处理自由水面的水、气两相流数学模型,对中心角为120°带过渡段的连续两弯水流进行计算,分析了连续两弯的断面环流和表面流态.分析结果表明,连续两弯的过渡段表面存在回流;回流与前弯剩余环流叠加,在后弯进口水面出现环流强度<0.14的特征区域;后弯的20°～40°断面为前、后弯环流叠加段,在40°断面前弯剩余环流已经消失.

The flow characteristics of the transitional stage and the second bend in the two con- secutive meanders are affected by the flow of the first bend. The RNG κ-ε model combined with VOF is used for doing the numerical simulation, which is used to calculate the flow of the two consecutive meanders with central angle of 120° and transitional stage. After contras- ting the difference in flow characteristics between the first and the second bends, it is found that the surface of transition section has recirculation. Because of the interaction between the circulation and recirculation, it is pointed out that the circulation strength of the region on the surface of the second curve is greater than 0.14, the circulation in- teraction is found in the section of the second bend from 20° to 40° and the circulation from the first bend disappears on the 40° section.