混流泵启动过程瞬态特性的数值计算

为研究混流泵启动过程的瞬态特性,以试验测试转速与流量作为求解边界条件,建立了混流泵瞬态流动求解模型与方法.通过准稳态、瞬态数值方法求解的计算扬程与试验扬程的对比,验证了数值方法的可靠性,进而分析了混流泵启动过程中瞬态流场的演化以及启动加速度对内部流场的影响规律.研究结果表明:所采用的数值计算方法可较准确地反映启动过程的...

Numerical simulation of transient characteristics of mixed-flow pump during start-up process

To study the transient characteristics of the start-up process of a mixed-flow pump,a model and method for solving the transient flow of a mixed-flow pump was developed by using the experimental test speed and flow rate as the solution boundary conditions.The comparison between the head obtained by quasi-steady state and transient numerical methods and the experimental head was used to verify the accuracy of the numerical methods.The evolution of the transient flow field during the start-up process of the mixed flow pump and the effect of the start-up acceleration on the internal flow field were analyzed.It is found that the used numerical calculation method is more accurate in reflecting the transient characteristics of the start-up process and the transient head presents significant transient effects.The quasi-steady state method has large errors,and the quasi-steady state method based on similarity law is not applicable in transient performance studies.Due to the effect of angular acceleration and fluid inertia,the inlet pressure gradient at the blade working surface is more pronounced during acceleration,and significant vortices are generated at the blade tip and the trailing edge of the blade outlet side.It leads to transient hydraulic characteristics different from that under quasi-steady state conditions.The start-up acceleration has a greater impact on the impact head,the acceleration magnitude determines the peak of the impact head,and the flow lag is also significantly different.