流固耦合作用对离心泵关死点内流的影响

Effect of FSI on Inner Flow Field in a Centrifugal Pump at Shut Off Condition

为了揭示流固耦合作用对离心泵关死点工况下的内流影响,对一比转数为46的离心泵关死点工况下的结构场和内流场进行了流固耦合数值计算,并对离心泵关死工况下内流计算的边界条件作了详细说明.基于流固耦合计算结果,对比了流固耦合前后关死点扬程预测精度、泵内流场分布和压力脉动的差异,并给出了叶片位移变形.研究结果表明:考虑流固耦合作用对关死点扬程的预测精度影响较小;考虑流固耦合作用后叶轮各流道内的"射流-尾迹"更为明显,蜗壳扩散段的漩涡强度增加,叶轮内压力脉动也呈现出更为明显的周期性;流固耦合作用对于压力脉动幅值频率有较大影响;叶片位移变形从进口到出口逐渐增加,靠近隔舌的叶片位移变形最大.

The fluid structure interaction （FSI）has an important effect on simulation of flow field in a centrifugal pump at shut off condition（SOC） .A centrifugal pump with specific speed of 46 was selected as research model, and a combined calculation for turbulent flow and structure response of impeller was established by using two-way coupling method. The detailed description of the boundary conditions for the simulation at SOC was presented.The difference of the average head prediction accuracy, velocity distribution and pressure pulsation were compared and the deformation of blade was presented according to the FSI calculation results. The comparison results show that FSI calculation has little effect on the average head prediction value at SOC.In the FSI simulation, the＂ jet-wake＂ phenomena in the impeller passage is more obvious, and the impeller pressure pulsation shows a more obvious periodicity, and the intensity of vortex at diffuser of volute gets bigger.The FSI calculation has great impact on the pressure fluctuation amplitude and frequency.The deformation of blade increases gradually from inlet to outlet, and gets bigger when the blade is close to cut-water of volute.