三次元流体ー構造連成解析を用いたテクスチャ表面における潤滑油流れの調査

摘要

In previous studies, the tribological properties of textured surfaces under hydrodynamic lubrication have been investigated using numerical analysis and various lubrication theories have been proposed. However, improvement in analytical method must be made in order to further elucidate the lubrication mechanism. Previous studies have employed the steady-state analysis, and the influence of unsteady-state flow was not considered. Also, two-dimensional models were commonly used in the analysis, and the flow in the depth direction had been neglected. In actual phenomenon, the oil film shape is changing from moment to moment and the flow in the depth direction also occurs. Therefore, in this study, the influence of the unsteady-state flow and the flow in the depth direction are investigated utilizing three-dimensional Fluid-Structure Interaction (FSI) analysis. By comparing the results of steady-state and unsteady-state analyses, the influence on the pressure distribution became clear. In addition, the results show that the pressure distributions of the two-dimensional and three-dimensional models were different. From these results, it is demonstrated that a three-dimensional FSI analysis is required to understand the actual flow of oil lubricants and to optimize the textured surface.%表面テクスチャリングとは，摺動表面に微細な幾何形状を施すことで摺動特性を向上させる表面改質技術である.表面テクスチャリングにより発現する効果のーつに，動圧の発生に起因する負荷容量の増加が挙げられる.この動圧発生メカニズムの調査には，数値解析的手法が広く用いられてきた.しかし，これらの数値解析は定常流れを仮定しており，油膜形状が時々刻々と変化する様な非定常流れの影響は考慮されていない.また，先行研究の多くは二次元解析を用いており，奥行き方向には流れが生じないという仮定の下で計算が行われている.