基于自主开发的血泵样机性能分析

发布时间：2018-04-11 06:30

本文选题：植入式血泵 + 水力性能　；参考：《浙江大学》2013年硕士论文

【摘要】：人工心脏作为一种治疗终末期心力衰竭的有效手段,是活体心脏移植的替代方案,可有效缓解自然心脏供体严重不足的现状。作为人工心脏的核心部件血泵,则要求其具有较好的水力性能、溶血性能、水动力性能。对于植入式血泵还需要具有结构体积小、重量轻、旋转部件少的特点。本课题针对植入式人工心脏,对其血泵样机进行结构设计,并应用理论计算、数值模拟、性能试验等途径对其水力性能、水动力性能、溶血性能进行分析,评价血泵整体设计指标。论文主要开展了以下四个方面的研究： 1)血泵样机设计。对血泵样机进行结构设计,确定其内部结构布局、总体形状尺寸。根据血泵流量、扬程等水力特性要求,应用离心泵一元设计理论,对叶轮、压水室等过流部件主要参数进行计算,得到水力模型。在此基础上完成对血泵上下盖板、支承结构、转轴等结构部件的设计,并对各部件进行加工制作,完成其总体装配。 2)血泵内部流动特性分析及外特性试验验证。运用计算流体力学基本原理,对血泵循环系统实现全流场数值模拟,得到血泵内各节点流动参数；改变节流阀开口实现管路系统阻尼调节,得到血泵不同工况下流动性能。搭建血泵循环测试试验台,对加工设计的血泵样机进行外特性试验,得到其特性曲线,验证水力性能是否满足设计要求及数值模拟结果的精确性。 3)血泵血液相容性分析及体外溶血试验验证。针对传统血液损伤模型存在的局限性,提出一种新的溶血估算模型,并将新模型用于血泵样机的溶血计算,得到不同红细胞颗粒流经血泵过程中的溶血估算值及血泵整体溶血指标。搭建体外溶血测试试验台,对血泵样机进行溶血试验,并将试验结果与新模型计算结果相对比,验证新溶血模型的准确性。 4)血泵叶轮结构动力学性能分析。血泵内部流场的复杂性及瞬变性使得叶轮表面所受到的作用力为交变应力。对叶轮进行结构分析时,应考虑流体场、固体场之间的相互耦合作用,得到叶轮在交变应力作用下的动力学特性。应用流固耦合瞬态联合仿真,计算在流体力作用下高速旋转叶轮内部应力、应变分布以及叶轮变形对流场分布的反作用,验证叶轮结构特性是否满足结构动力学要求。
[Abstract]:As an effective method to treat end-stage heart failure, artificial heart is an alternative to live heart transplantation, which can effectively alleviate the serious shortage of natural heart donors.As the core component of artificial heart, blood pump is required to have better hydraulic performance, hemolytic energy and hydrodynamic performance.For implantable blood pump, it also needs small structure, light weight and less rotating parts.In this paper, the structure of the blood pump prototype is designed for the implanted artificial heart, and its hydraulic performance, hydrodynamic performance and hemolytic energy are analyzed by theoretical calculation, numerical simulation and performance test.To evaluate the whole design index of blood pump.The thesis mainly carries out the following four aspects of research:1) prototype design of blood pump.The blood pump prototype was designed to determine its internal structure layout and overall shape and size.According to the requirements of hydraulic characteristics such as blood pump flow, head and so on, the hydraulic model is obtained by calculating the main parameters of the impeller and water pressure chamber by using the monolithic design theory of centrifugal pump.On this basis, the design of the upper and lower cover plate, supporting structure, rotating shaft and other structural parts of the blood pump is completed, and the components are processed and manufactured to complete the overall assembly.2) Analysis of internal flow characteristics of blood pump and verification of external characteristic test.Using the basic principle of computational fluid dynamics, the whole flow field of blood pump circulatory system is simulated, and the flow parameters of each node in the blood pump are obtained. The throttle opening is changed to realize the damping regulation of the pipeline system, and the flow performance of the blood pump under different working conditions is obtained.The external characteristic test of the blood pump prototype was carried out to verify whether the hydraulic performance satisfied the design requirements and the accuracy of the numerical simulation results.3) Blood compatibility analysis and in vitro hemolysis test verification of blood pump.In view of the limitation of the traditional blood injury model, a new hemolysis estimation model is proposed, and the new model is applied to the hemolysis calculation of the blood pump prototype.The estimated values of hemolysis and the whole hemolysis index of the blood pump were obtained in the course of different erythrocyte granules flowing through the blood pump.In order to verify the accuracy of the new hemolysis model, an in vitro hemolysis test rig was set up, and the hemolysis test was carried out on the prototype of the blood pump, and the results were compared with the results of the new model.4) dynamic analysis of impeller structure of blood pump.Because of the complexity and transient variation of the flow field in the blood pump, the acting force on the impeller surface is alternating stress.In the analysis of impeller structure, the interaction between fluid field and solid field should be considered, and the dynamic characteristics of impeller under alternating stress should be obtained.By using fluid-solid coupling transient simulation, the internal stress, strain distribution and flow field distribution of high-speed rotating impeller are calculated, and the structural characteristics of impeller are verified to meet the requirements of structural dynamics.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R318.11

【参考文献】