螺旋形贝壳承压减阻机理及离心式压缩机蜗壳的仿生研究

The volute performance has become the important influence factors for improving the efficiency and performance of centrifugal compressor. Many measures of the volute are taken to improve the efficiency and performance of centrifugal compressor, including reducing the flow resistance, decreasing the loss of energy, improving the circumferential pressure distribution and so on. Many studies have showed that spiral marine shells have the performance of reducing fluid resistance and the energy consumption. So, we intend to use the ways of laboratory experiments, numerical simulation and theoretical analysis comprehensively in this project to acquire the relation between the shells geometric structure and the performance of bearing strength and drag reduction. We explore the effects and mechanisms both shells geometry and the bearing strength and drag reduction based on the studies on three aspects of the shell performance, which include the shell geometric structure and the mechanical parameters, the bearing strength test results and shell cavity fluid drag reduction performance analysis. The bionic optimization design for volute shape of centrifugal compressor is machined by being used comprehensively the shell performance of the geometric structure, the mechanical properties, the fluid properties and the biological micro structure. The research results will enrich the content of engineering bionics. It has the important significance for the further development of mechanical bionic theory and technology.

蜗壳性能是提高离心压缩机效率和性能的重要影响因素。降低蜗壳内腔流动阻力、减少蜗壳能量损失、改善其周向压力分布对提高离心式压缩机效率和性能具有重要意义。大量研究表明，深海螺旋形贝壳（以下简称螺壳）具有减少流体阻力、降低流体能量损耗的性能。因此本项目拟从仿生学的角度，综合应用室内实验、数值模拟与理论分析等多种手段，研究螺壳外型几何形状结构与承压减阻降耗性能间的关系，揭示螺壳承压减阻作用机理，并进行离心式压缩机蜗壳仿生优化设计。本项目从螺壳外型几何结构特征和力学参数研究、螺壳承压性能测试研究、螺壳内腔流体减阻性能分析三方面进行螺壳外型几何形状结构与承压减阻性能间的作用机理研究，基于螺壳外形结构参数与螺壳减阻机理进行离心式压缩机蜗壳仿生优化设计与样件试制。其研究成果将丰富工程仿生学的内容，对进一步发展机械仿生理论与技术具有重要意义。

涡轮蜗壳性能对提高涡轮增压器的效率和性能具有重要影响。大量研究表明，深海螺旋形贝壳具有减少流体阻力、降低流体能量损耗的性能。本项目以三种海洋螺旋形贝壳为仿生原型，系统研究螺壳几何外型结构与承压性能和流体减阻性能，揭示螺壳几何外型形状和结构与承压、减阻性能间的作用机理，采用仿生设计手段实现仿香螺壳内腔结构的增压器涡轮蜗壳仿生设计。.1）采用逆向工程技术实现三种螺旋贝壳的外型和内腔的数字化扫描，并完成3D数字建模，在三维数模的基础上实现特征数据测量研究；借助ZEISS EVO 18扫描电镜和XRD衍射仪设备实现三种贝壳截面特征结构和贝壳成分测定，为螺壳力学性能分析提供理论依据。2）基于fluent流体力学仿真分析软件采用空气和水两种不同介质完成螺壳内腔流体力学的仿真模拟，实现螺壳外型几何结构与流场变化的内在联系研究，总结螺壳内腔形状对水和空气不同流体间的相似性和不同。3）借助万能力学试验机完成三种螺壳的力学参数测量和整体承压性能试验，获取螺壳的应力-应变曲线，结合裂纹破坏方式进行破坏规律研究；采用ls-dyna软件实现螺壳内腔承压性能仿真研究，获取螺壳的破裂位置、破坏形式；搭建基于高压气体的螺壳爆裂试验台，实现螺壳高压气体状态下破裂试验研究，实现螺旋贝壳破裂特征研究。4）基于壳体外型几何特征尺寸进行增压器涡轮蜗壳仿生优化设计，采用fluent软件实现仿生蜗壳流体力学分析；采用3D打印技术实现仿生蜗壳的样件试制，流体测试对比研究发现，仿生蜗壳内腔流态平稳，节能降耗。仿生设计方法使增压器涡轮性能提升显著，为汽车和机械涡轮增压系统设计和优化提供重要参考和借鉴。