Numerical Analysis of the Internal Flow in an Oil Damper (Analysis Based on the Two-Dimensional Cylindrical Coordinates to the Damper with Annular Cross-Sectional Flow Channel)

Abstract

The purpose of this study is to know the fluid flow of an oil damper by a numerical analysis, so as to obtain the exact values of the damping coefficient of an oil damper. The Finite Difference Method (FDM) was used for solving the governing equation of the fluid caused by the moving piston. Each time step proceeded in the Fractional Step method, and the Arbitrary Lagrangian-Eulerian (ALE) method was adopted for the moving boundary. In order to stabilize the computation in the moving boundary problem, we employed the masking method with a single block grid system. That is, the algebraic grid generation using stretching function was used for the moving piston. The time dependent coordinate system in physical domain which coincides with a contour of moving boundary is transformed into a fixed rectangular coordinate system in computational domain. The computational results were compared with the experimental ones and the approximate analytical solution. The results of present analysis show good agreement with the experimental results over a wide range of piston diameter.