流れの数値解析によるオイルダンパの動特性計算

（数値解法による剥離渦の影響の見積もり）

抄録

The purpose of the present study is to clarify the fluid flow of an oil damper through numerical analysis in order to estimate the exact damping coefficient of an oil damper. The finite difference method was used to solve the governing equation of the fluid flow generated by a moving piston. Time steps based on the fractional step method and the arbitrary Lagrangian-Eulerian (ALE) method were adopted for the moving boundary. In the moving boundary problem, a masking method with a single block grid system was used to stabilize the computation . In other words, algebraic grid generation using a stretching function was used for the moving piston in the cylinder of the oil damper. The time-dependent coordinate system in the physical domain, which coincides with the contour of the moving boundary, is transformed into a stationary rectangular coordinate system in the computational domain. In order to valiade the caluculated results, they were compared with experimental results and the approximate algebraic solution. As a result, it became possible to estimate exactly the degree of contribution of the conversation term the Navier-Stokes equation on the damping coeffcient of the oil damper.