深井离心泵的回归分析与数值模拟

Regression analysis and numerical simulation of deep-well centrifugal pumps

选择了叶轮叶片出口安放角、叶片进口冲角、叶轮出口宽度及导叶进口宽度这4个几何因素,按中心组合试验方法,设计了30组方案.通过FLUENT软件,对冲压井泵的全流场进行数值模拟,获得了额定工况下30组方案的效率.采用四元二次回归方程拟合四因素与效率值之间的函数关系,通过求解回归方程以寻求最优几何参数组合.利用Design Expert 6.0.5软件对回归模型进行分析,得到二次回归响应面图.由图中发现:在给定的范围内,叶轮出口宽度对效率的影响最为显著,表现为等值线最密;导叶进口宽度与叶轮叶片出口安放角次之;叶轮叶片进口冲角对效率的影响最小,表现不显著.通过样机试制及试验,发现在设计工况下采用两级全流场的数值模拟值与试验值相当接近,误差在2%以内,验证了数值模计算的可行性.

The test with four factors, including impeller blade inlet placed angle, impeller blade outlet placed angle, and impeller blade outlet width and inlet width of guide vane, was designed. According to CCD central composite design method, 30 programs were designed. The well pump in the whole flow at rated point was simulated by FLUENT and 30 groups of efficiency at rated point were obtained. Through quadratic regression equation, the function relationship between efficiency values and each factor was fit. Also, the optimal combination of geometric parameters can be found by solving the regression equation. Through analyzing the regression mode by Design Expert 6.0.5 software, the quadratic regression repines surface figure could be got. According to the figure, impeller blade outlet width exert the most significant influence on pump efficiency showing the densest contour; inlet width of guide vane and impeller blade outlet placed angle take second place; impeller blade inlet placed angle takes the minimal impact on efficiency which shows as a non-significant factor. Through the experiment of the mode pump, the numerical simulation values under the whole flow field are much closed to the experimental values and the error is less than 2 X, which verify the feasibility of numerical simulation.