Deciding the System Dynamic Parameters in a Complex Flow Passage through CFD

Laminar flow resistance in a straight pipe is generally used as a representative model for flow resistance because it is convenient to use and often yields reasonable resistance values in a straight pipe under steady state condition. However, the laminar flow resistance model in a straight pipe is not applicable to oil flow passage in a real circuit owing to the complex shape of the flow passage in a real circuit. Furthermore, a mathematical model of the fluid column in a pipe under in an inviscid flow condition is often used as an inertial model while considering dynamic conditions. Under actual operating conditions of an oil-hydraulic circuit, the two abovementioned effects, complex flow passage shape and flow dynamic characteristics, appear in viscous flow condition. Therefore, it is necessary to develop a new model or modeling method for solving these effects reasonably. This study aims to introduce a new modeling method based on the computational fluid dynamics (CFD) theory.