湍流模型对离心泵扬程预测准确性的影响

为研究涡黏性类湍流模型和雷诺应力类湍流模型在离心泵扬程预测中的准确性,采用CFX 14.0软件分别对10台不同比转数n_s的离心泵在3个不同流量(0.3Q,1.0Q,1.2Q)下的扬程进行预测,并将模拟值与试验值进行对比.研究结果表明:在0.3Q流量下,低比转数离心泵采用雷诺应力类中的BSL-EARSM模型可以获得更为准确的扬程值;在1.0Q,1.2Q流量下,采用雷诺应力类模型中的BSL-RS模型相对于常用的RNG k-ω和k-ω模型具有更好的准确性.当采用涡黏性类模型对1.0Q流量下的扬程进行预测时,预测值均小于试验值.对于文中研究的比转数大于103的扬程预测,在3个流量下,模拟值均小于试验值.研究结果为离心泵扬程预测的数值模拟方案选择提高提供了参考.

Influence of turbulence models on head prediction accuracy for centrifugal pumps

In order to study the applicability of eddy viscosity turbulence model and Reynolds stress turbulence model in head prediction accuracy for centrifugal pumps, the heads of 10 specific speed centrifugal pumps were predicted under three different discharges(0.3Q, 1.0Q, 1.2Q)by using CFX 14.0 version of eddy viscosity model and Reynolds stress model. The predicted values were compared with the test values. The results indicated that as for the low specific speed centrifugal pump we recommended Reynolds stress BSL-EARSM model for 0.3Q. For head prediction of the discharge(1.0Q), the BSL-RS model, compared with the commonly used RNG k-ε, k-ω model, has higher prediction accuracy. When using the eddy viscosity class model to forecast the head of 1.0Q, the predicted values are less than the test values. For the head forecast at n_s larger than 103, the simulation values are less than the test values. Researches provide reference for improving head prediction accuracy for centrifugal pumps.