导叶式混流泵内部非定常流动特性数值模拟

发布时间：2018-01-07 17:41

本文关键词：导叶式混流泵内部非定常流动特性数值模拟　出处：《农业机械学报》2016年S1期 　论文类型：期刊论文

【摘要】：为了研究不同流量工况对导叶式混流泵内部非定常流动特性的影响,基于ANSYS CFX软件并采用标准k-ε两方程模型对混流泵的外特性进行了数值预测,分析了流量工况对混流泵内压力分布、流线分布和湍动能的影响,探讨了不同流量工况下不同监测点的压力脉动时域和频域响应。研究结果表明,数值计算的外特性结果与试验测量结果趋势基本一致,最优工况点数值预测与试验测量的扬程和效率误差分别为3.29%和0.27%,数值计算的准确度较高。小流量工况下,叶片工作面与背面之间存在着较大的压力梯度,形成的轮缘泄漏流对主流产生较大干扰,同时受到动静干涉的影响,在叶轮出口和导叶流道内造成较大的能量损失和湍动能耗散;随着流量增加,轮缘泄漏流逐渐减少,动静干涉效应相对减弱,流场流动趋于平稳。不同流量工况下,各监测点压力脉动呈明显的周期性变化,一个旋转周期内压力脉动曲线有4个波峰和4个波谷,叶片通过频率始终占主导作用;流量对叶轮进口处和导叶中间处的压力脉动影响最明显,小流量工况下压力脉动系数的幅值变化最大;随着流量的增大,压力脉动频域幅值随之减小。本研究可为扩大混流泵的运行范围以及混流泵叶轮和导叶的优化设计提供参考依据。
[Abstract]:In order to study the influence of different flow conditions on the unsteady flow characteristics of the guide vane mixed flow pump. Based on the ANSYS CFX software and the standard k- 蔚 two-equation model, the external characteristics of the mixed flow pump are predicted numerically, and the pressure distribution in the mixed flow pump under the flow condition is analyzed. The time-domain and frequency-domain responses of pressure pulsation at different monitoring points under different flow conditions are investigated by the influence of streamline distribution and turbulent kinetic energy. The external characteristic results of numerical calculation are basically consistent with the experimental results. The errors of lift and efficiency between the numerical prediction of the optimal operating point and the experimental measurement are 3.29% and 0.27% respectively. The accuracy of numerical calculation is high. Under the condition of small flow rate, there is a large pressure gradient between the blade face and the back of the blade, and the resulting flange leakage flow has great interference to the mainstream and is affected by the static and static interference at the same time. Large energy loss and turbulent kinetic energy dissipation are caused in the impeller outlet and the guide vane passage. With the increase of the flow rate, the leakage flow of the flange decreases gradually, the static and static interference effect is relatively weakened, and the flow field flow tends to be stable. Under different flow conditions, the pressure pulsation of each monitoring point shows obvious periodic change. The pressure fluctuation curve has four peaks and four troughs in a rotation cycle, and the blade passing frequency always plays a dominant role. The flow rate has the most obvious influence on the pressure fluctuation at the inlet of the impeller and the center of the guide vane, and the amplitude of the pressure fluctuation coefficient changes the most under the condition of small flow rate. With the increase of flow rate, the amplitude of pressure pulsation in frequency domain decreases. This study can provide a reference for expanding the operating range of the mixed flow pump and optimizing the design of the impeller and guide vane of the mixed flow pump.
【作者单位】：江苏大学流体机械工程技术研究中心;
【基金】：国家自然科学基金项目(51409127;51579118;51679111) 江苏省重点研发计划项目(BE2015119;BE2015001-4;BE2016319) 江苏省六大人才高峰项目(HYZB-002) 镇江市农业支撑项目(NY2013031) 江苏高校优势学科建设工程项目江苏大学高级专业人才科研启动基金项目(13JDG105) 常州市科技支撑计划(农业)项目(CE20162004) 江苏省自然科学基金项目(BK20161472)
【分类号】：TH313
【正文快照】： vanes.With the increase of flow rate,the tip leakage flow was decreased gradually,the rotor-statorinteraction became weaker and the flow field in the impeller tended to be steady.Under different flow rateconditions,the pressure fluctuations at different

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