蜗壳式离心泵外特性仿真与实验研究

为探索不同仿真方法的适用性,对ns=157的单级蜗壳离心泵不同工况的扬程和效率进行定常和非定常计算,并分别分析了定常计算时不同叶片夹角及非定常计算时不同时间步长的影响,通过与实验对比,得到的主要结论有:定常计算仅适用于额定工况外特性仿真,其扬程和效率计算误差分别为4.9%和2.9%,而定常多相位的计算误差分别为7.1%和3.2%;非定常仿真计算时,以4°为时间步长,并间隔20°保存一次计算数据,较好地预测出扬程曲线走势,额定工况扬程和效率计算误差约1.1%和1.8%,但小流量和大流量区间扬程计算误差达到10%左右。因此在水力优化设计时,若只关注高效点位置及其扬程和效率,可采用定常计算,若还关注扬程曲线走势,则应采用非定常计算。

Simulation and Experimental Study on External Performance of the Volute Centrifugal Pumps

Both steady and unsteady numerical simulations of the volute centrifugal pump,with ns=157 of one impeller,are calculated to study the applicability.In the steady simulations,the effects of different phase angles are analyzed,simultaneously different time steps are studied in the unsteady calculations.The steady calculation is only applicable for the external performance simulation at the design condition,with the head and efficiency calculation errors of 4.9%and 2.9%respectively.The calculations of the different phase angles are just effective for the external performance simulation near the design condition,of which the head and efficiency calculation errors are almost 7.1%and 3.2%respectively.And in the unsteady calculation,4°is selected as the time step and 20°is the saved time interval.The predicted head curve is better than the steady one,and the calculation error of the head and efficiency at the design condition is about 1.1%and 1.8%.However,the head calculation errors of the small flow condition and the large flow condition are about 10%.The main conclusions are as follows:in the hydraulic design processes,if only the external performance of the high-efficiency point is concerned,the steady calculation can be chosen.When the head curve is completely concerned,the unsteady calculation should be used.