Unsteady flow modeling of an electrorheological valve system with experimentalvalidation

Abstract

This paper presents an unsteady flow modeling of an electrorheological (ER) valve systemand verifies its effectiveness through experimental investigation. After designing acylindrical ER valve, a dynamic model for unsteady flow of ER fluid is derived byconsidering the fluid inertia. The field-dependent pressure drop of the unsteady flow isthen calculated and validated with the experimental result. In order to clearlyobserve the difference between the unsteady flow model and the steady model, theflow rate of the ER valve is analyzed under low frequency and high frequencysinusoidal inputs. In addition, in order to demonstrate the effectiveness of theproposed unsteady flow model, a position control system activated by ER valves isconstructed. The dynamic model of the control system is formulated on the basis of theunsteady flow analysis, and control responses such as flow rate, pressure dropand displacement are compared between the unsteady flow and the steady flowmodels.