硅藻典型壳壁结构的摩擦学特性及其在水润滑轴承上的应用

发布时间：2018-11-06 19:24

【摘要】：圆筛藻是一种典型的海生硅藻，生存在恶劣的海洋环境中。研究发现，圆筛藻壳壁精细的多级孔状结构优良的弹性、韧性等相关力学性能，但对该结构下的摩擦学性能研究尚少。本论文研究了该多级孔状结构的摩擦学性能，并将该结构应用到水润滑轴承的摩擦学性能改性上，这对有效控制水润滑轴承润滑失效，提高其工作效率，具有重要意义。本文立足国家自然科学基金面上项目“仿生硅藻典型壳壁结构的水润滑轴承摩擦学性能研究”(项目编号51375509),主要研究内容如下：本文首先介绍了硅藻的培养方法，发明设计并自行制造了硅藻培养装置，结合ZEISSAURIGA双束系统设备(扫描电子显微镜)，以圆筛藻为研究对象，对其进行了图像采集，观察了圆筛藻的形貌结构，发现圆筛藻壳壁具有精细的多级孔状结构。然后，选取圆筛藻壳的一个基本单元作为研究对象，应用ANSYS14.5中的CFX模块对其进行了流固耦合分析，研究了不同孔状结构尺寸对其承载力（抗水压能力）、摩擦力和摩擦系数等摩擦学性能的影响，并与无孔结构对比。数值结果表明：圆筛藻壳的单层孔状结构能够增大圆筛藻在水中游动时的承载力，减小摩擦力和摩擦系数。并通过近似的实验进行了验证，为硅藻壳体摩擦学研究提供了一定的参考。进一步，在上述研究的基础上，分析计算了具有双层孔状结构的圆筛藻壳在不同孔状结构尺寸下的摩擦学性能，并将双层结构与对应的单层结构以及无孔结构下的性能进行了对比。计算结果表明：具有双层孔状结构的圆筛藻壳在海水中运动时，其承载力大于单层孔状结构的对应值，大于无孔结构的对应值；摩擦系数小于单层孔状结构的对应值，小于无孔结构的对应值。此外，本文将与圆筛藻壳孔状结构相似的微造型应用于水润滑轴承的内表面，应用ANSYS14.5中的Fluent模块对其进行了声功率级以及相关摩擦学性能分析。研究发现：与圆筛藻孔状结构相类似的微造型具有减小滑动轴承声功率级噪音的作用，在一定尺寸范围内，，滑动轴承对应的噪音随着微造型深度的增大而减小，且微造型置于不同位置时，减小噪音的能力不同；适当尺寸和位置的微造型具有提高滑动轴承承载力，减小摩擦力的作用。
[Abstract]:Chlorophyta rotundii is a typical marine diatom, living in a bad marine environment. It is found that the fine multistage pore structure with fine shell wall has excellent mechanical properties such as elasticity, toughness and so on, but the tribological properties of the structure are not studied. In this paper, the tribological properties of the multistage porous structure are studied, and the structure is applied to the modification of the tribological properties of the water-lubricated bearing, which is of great significance for effectively controlling the lubrication failure of the water-lubricated bearing and improving its working efficiency. Based on the project of National Natural Science Foundation of China, "study on tribological properties of water lubricated bearing with typical shell wall structure of bionic diatoms" (Project No. 51375509), the main contents of this paper are as follows: firstly, the cultivation method of diatom is introduced in this paper. A diatom culture device was designed and manufactured by ourselves. With ZEISSAURIGA double beam system equipment (scanning electron microscope), the image was collected and the morphology and structure of filamentous algae were observed. It was found that the shell wall had fine multilevel pore structure. Then, a basic unit of the algae shell was selected as the research object. The fluid-solid coupling analysis was carried out by using the CFX module in ANSYS14.5, and the bearing capacity (water pressure resistance) of different pore structure sizes was studied. The effects of friction force and friction coefficient on tribological properties are compared with the structure without pores. The numerical results show that the single-layer pore structure of the algae shell can increase the bearing capacity of the algae and reduce the friction force and friction coefficient. The results are verified by approximate experiments, which provides a certain reference for tribological study of diatom shell. Furthermore, on the basis of the above research, the tribological properties of the algal shell with double pore structure under different pore sizes are analyzed and calculated. The performance of the double layer structure is compared with that of the corresponding single layer structure and the non-porous structure. The results show that the bearing capacity of the shell with double pore structure is larger than the corresponding value of the single-layer pore structure and the corresponding value of the non-porous structure when it moves in the sea water. The friction coefficient is smaller than the corresponding value of the single-layer porous structure and the corresponding value of the non-porous structure. In addition, the micro-modeling similar to the pore structure of the shell of the algae is applied to the inner surface of the water-lubricated bearing. The acoustic power level and the related tribological properties of the bearing are analyzed by using the Fluent module in ANSYS14.5. It is found that the micro modeling similar to the pore structure of the algae has the effect of reducing the noise of the acoustic power level of the sliding bearing. In a certain range of dimensions, the corresponding noise of the sliding bearing decreases with the increase of the depth of the micro molding. The ability to reduce noise is different when the micro-modeling is placed in different positions. The micro-moulding with proper size and position can improve bearing capacity and reduce friction.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TH133.3;TH117

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