On the Unsteady, Dynamic Response of Phase Changes in Hydraulic Systems

Abstract

This paper is concerned with the unsteady, dynamic behavior of hydraulic systems and, in particular, with the dynamic characteristics of internal flows involving phase-change and two-phase flows. This emphasis is motivated by the large number of different flows of this kind which exhibit "active" dynamic characteristics (see Section 3) and therefore have the potential to cause instability in the whole hydraulic system of which they are a part (see Section 4). We begin, first, with a discussion of the form and properties of dynamic transfer functions for hydraulic systems. Then, following the discussion of a number of examples we present an analysis leading to the transfer function for a simple phase-change and demonstrate its "active" dynamic character.