Effects of Diaphragm Compliance on Spring-Diaphragm Pressure Regulator Dynamics

Abstract

A dynamical model is derived for a spring-diaphragm type automotive pressure regulator containing an annular membrane. Previous studies have generally assumed that the diaphragm was of constant area and that it remained flat. Central features of the model presented are the calculation of the deformed shape of the annular diaphragm and the effects of its resulting fluid compliance and force on the drain orifice cover plate. Elasticity theory is used to derive the diaphragm two-port compliance relation that is integrated into an overall regulator dynamic model. Effects of diaphragm elastic modulus on system dynamic response are studied. The model and its results may be used in other design parameter studies and as a component of a fueling system dynamic model.