Abstract
In studying hydraulic control systems, blood circulation systems and so on, it is well known that the dynamic characteristics of pipe lines transmitting the liquid are very important and should be accurately known. While the dynamic characteristics of liquid lines have been known to a great extent when the pipe wall can be assumed to be elastic, almost nothing is known about the dynamic characteristics when the pipe wall is viscoelastic as with rubber hoses and arteries.
Then it is the object of this paper to derive the transfermatrix of the liquid lines with the viscoelastic pipe wall so that their dynamic responses may be easily obtained with a reasonable accuracy for actual applications.
The viscoelastic pipe wall is simulated by the Voigt models which are distributed along the pipe line in the analysis. In the experiment the so-called high pressure rubber hoses reinforced by the one wire braid are used. The frequency responses are taken, and the results agree well with the theoretical results. It is said in this analysis that the damping constant in the propagation constant of the liquid lines in case of the viscoelastic pipe becomes larger and the wave length constant becomes smaller than the one in the case of the elastic pipe lines. The results obtained in this paper may make it possible to predict correctly the dynamic characteristics of a variety of liquid lines.
