Application of Linearized Friction Impedance Models to Complex Fluid Systems

Results of correlating system frequency response test data with analytic data are presented. The test data are from four complex systems, incorporating series and parallel piping configurations and dynamic components, flowing liquid or gas in the turbulent and laminar regime. Distributed parameter transmission line theory is used to develop the system mathematical models. Analytic results from linear and nonlinear laminar flow friction models are compared. It is shown that the correlation between pressure transfer functions determined from test and linear analytical models is satisfactory to predict system frequency response modes, to explain unanticipated test results, and to predict response of systems during design studies.