EIGENVALUE ANALYSIS OF DIRECT-ACTING POPPET VALVE CIRCUIT

Abstract

This paper deals with a direct-acting poppet valve circuit in which the pipelines are modeled by a lumped parameter approximation of the first order. The dynamic characteristics and stability of thesystem are investigated from the viewpoint of the eigenvalue analysis. The eigenvalues of the system are obtained numerically based on the lumped parameter model. Applicability of this model is investigated by comparing eigenvalues with those for the higher order approximation model and the distributed parameter model. Although the eigenvalues for these lumped parameter models are quantitatively different from those for the accurate distributed parameter model, they give qualitatively distinct explanations to dynamic phenomena in the system. We found the equivalent pipeline volume for giving a quantitatively better approximation for eigenvalues for the lumped parameter model. Furthermore, the transitions of the complex eigenvalues to the real ones with the change of supply pressure and pipeline length can be explained theoretically by the lumped parameter approximation.