State variable representation of modal approximations for fluid transmission line systems
Abstract
This paper presents a method for developing finite dimensional models for distributed fluid transmission lines which form part of a system. The work concentrates on pneumatic lines although similar procedures are valid for hydraulic line cases. Normalized values for poles and residues of the pertinent complex line transfer functions are given yielding reduced order modal approximations. A four mode approximation gives reasonable representation of the first four modes and is superior to the use of a four product expansion. A single mode approximation could be used to capture fundamental mode effects, but residue correction is required. The paper presents an example of the method for a complex network of transmission lines interacting with lumped elements.
 Publication:

Fluid Transmission Line Dynamics
 Pub Date:
 1981
 Bibcode:
 1981ftld.proc...57H
 Keywords:

 Approximation;
 Computational Fluid Dynamics;
 Equations Of State;
 Fluid Transmission Lines;
 Hydraulic Fluids;
 Finite Element Method;
 Flow Distribution;
 Lumped Parameter Systems;
 Pneumatic Circuits;
 Transfer Functions;
 Transient Response;
 Fluid Mechanics and Heat Transfer