摘要
为研究肘形进水流道的水力性能与泵装置运行工况的定量关系,采用CFD(Computational fluid dynamic)方法对轴流泵装置进行全流道的数值计算,在考虑了轴流泵与肘形进水流道内流相干条件下定量地分析了肘形进水流道水力特性各参数与泵装置运行工况的关系,并给出了相应的数学模型,对比了物理模型试验与数值预测结果的差异性。结果表明:在高效工况范围内,流道出口流场水流稳定性及均匀性均较好;在大流量工况时,流道出口流场水流稳定性及均匀性较差。流道出口流场的偏流角受泵装置运行工况的影响较小,极差为0.91°。肘形进水流道均化效率为99.215%,流道断面的均匀性主要受弯肘段几何边界条件的约束,在弯肘段时压能与动能的转换率较高,对于肘形进水流道结构尺寸设计及优化的关键在于弯肘段。
In order to investigate the hydraulic performance of elbow inlet conduit,the three-dimensional fluid flow inside an axial-flow pumping system was simulated based on the Reynolds time-averaged Navier-Stokes equations,the RNG k-ε turbulent flow model and the law of the wall. To verify the accuracy and reliability of the calculation results,a model test was conducted on the high-precision hydraulic machinery test bed. It was found that the calculated results agreed well with the measured results. The hydraulic performance parameters of elbow inlet conduit were analyzed quantitatively considering the hydraulic interaction of inlet conduit and impeller. The stability and uniformity of flow were analyzed by using static distortion index of outlet section in elbow inlet conduit. The mathematical model of static distortion index and flow rate coefficient was established with the method of regress analysis. The stability and uniformity of flow were good under the high efficiency conditions,while it was the worst under the large operating condition. The different operating conditions of pumping system had little effect on the velocity-weighted drift angle of outlet section. The maximum difference of velocityweighted drift angle was 0. 91°. The average static pressure ratio of linear contraction segment was0. 943,while the average static pressure ratio of elbow segment was 0. 826. The average hydraulic efficiency was 99. 215% for elbow inlet conduit. The uniformity of cross section was affected under the condition of boundary constraint. The conversion rate of pressure energy and kinetic energy was high in the elbow segment. The important technology of optimization design is elbow segment for elbow inlet conduit.
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2016年第2期15-21,共7页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家自然科学基金项目(51279173)
江苏省自然科学基金项目(BK20150457)
江苏省高校自然科学研究项目(14KJB570003)
扬州大学科技创新培育基金项目(2015CXJ033)
江苏高校优势学科建设工程项目
关键词
轴流泵
肘形进水流道
水力性能
数值模拟
axial-flow pump
elbow inlet conduit
hydraulic performance
numerical simulation
