2011年福建高考数学试题(理科).docVIP

河南科技大学毕业设计（论文） PAGE PAGE 1 液压集成块局部液阻的流动特性分析 摘要 液压传动与控制领域正越来越多地采用液压集成块配置，可以显著减少管路联接和接头，降低系统的复杂性，增加现场添加和更改回路的柔性，具有结构紧凑、安装维护方便、泄漏少、振动小、利于实现典型液压系统的集成化和标准化等优点。 液压集成块是集成式液压系统的核心零部件，其内部流动特性直接影响液压系统的能耗和工作性能。从工程实用的角度，液压集成块不仅应具有良好的结构形态，还要具有与其所属液压系统的既定设计要求相匹配的通流品质。本文应用计算流体动力学方法对液压集成块内部典型流道流场进行了模拟研究，提出结合液流流动特性来优化集成块典型流道结构设计的方法。通过数值模拟得到了压力云图、速度矢量图及速度云图。定性地分析了液流在典型流道中涡旋产生的位置、大小及耗能机理，得到了块内流道结构形式对液阻性能的影响规律。进而提出流道在几何结构上的改进措施，实现了降低液体流经液压集成块的压力损失、减少能耗的目的。依据仿真的结果对液压集成块进行了进一步的优化，优化后的集成块在实际工程应用中有很好的效果。 关键词：液压集成块，计算流体动力学，液阻，能耗，优化设计 ANALYSIS FOR FlOWING CHARACTERISTIES OF LOCAL FLUID IMPEDANCE IN HYDRAULIC MANIFLOD BLOCK ABSTRACT Hydraulic manifold block(HMB)schemes are used more and more widely in hydraulic driving and controlling fields，reduced connectors，size and complexity, and enhanced flexibility for installation and maintenance．It provides a cleaner，leak-free，less vibrant and more reliable solution to difficult machine control system problems． Hydraulic Manifold Block(HMB)is the key part of the integrated hydraulic system，and energy loss and working performance of the hydraulic system are directly influenced by the flow performance．For engineering application，the design result of HMB need have good structure and the performance in according with the fixed design demand of hydraulic system. A design method for optimizing typical configuration in HMB (hydraulic manifold block) pipeline combined with flow characteristic was introduced，which was based on Computational Fluid Dynamic(CFD)simulation．Through the results of numerical simulation expressed by the figure pressure contour，velocity vector and velocity contour，qualitative analysis of the location and size of the eddy in typical pipeline was confirmed，as well as energy consumption causation. The regulation that the pipeline configuration affected the flow resistance was gained，which was helpful to provide improvements to the pipeline’s geometric structure．The optimal design achieves the aim of pressure loss reduction and ene