摘要
采用多块网格技术,利用六面体结构化网格和四面体非结构化网格相结合的混合网格离散计算域,采用稳态多参考系方法求解RANS方程,对余热排出泵内部的三维湍流流动进行数值模拟.为了增强数值模型的可靠性,对4种湍流模型的适用性进行了评估,其中剪切应力输运(SST)湍流模型计算值与试验值最接近.通过分析余热排出泵叶轮子午面和叶片通道间的流动,发现由于局部结构设计不合理使叶片进口边靠近前盖板侧有回流且叶片通道内有较大的旋涡和流动分离现象,流动损失较大.在保证导叶与蜗壳结构不变的前提下,通过调整叶轮盖板的曲率形状和修改叶片进口安放角和叶片型线对叶轮进行了优化设计,使叶轮内流场分布得到了有效改善.结果表明:优化后泵的流量和扬程都满足设计要求,且设计工况点的效率提高了约7%.
The flow field of a residual heat removal pump,which was meshed by hexahedron-constructional and tetrahedron-non-constructional grids based on a multi-block approach,was calculated numerically with the quasi-steady Multiple-Frame-Reference method by solving Reynolds-Averaged Navier-Stokes equations.In order to enhance reliability of numerical results,applicability of four turbulence models for predicting the overall-parameters such as head and efficiency was evaluated,and the results of SST turbulence model showed the best agreement with experimental data.The flow field in the impeller meridional channel and blade-to-blade surface were investigated,some distortion flow phenomenon caused by unsuitable local structure were detected such as reverse flow and secondary flow around the blade leading edge and between adjacent blades which badly added flow losses.According to the results,on the precondition of keeping guide vane and volute unchanged,improvements were executed by adjusting the impeller meridional curvature,the blade inlet angle and the blade profile.The results show that the interior flow field of the optimized impeller are improved evidently,it can satisfy the design target of both flow rate and head,and foremost,efficiency of the design point is raised about 7%.
出处
《排灌机械工程学报》
EI
2011年第5期397-400,共4页
Journal of Drainage and Irrigation Machinery Engineering
基金
国家自然科学基金资助项目(51009142)
关键词
余热排出泵
叶轮
流场
数值模拟
优化设计
residual heat removal pump
impeller
flow field
numerical simulation
optimal design
