STUDY ON THE INSERTION LOSS CHARACTERISTICS OF SIDE BRANCH RESONATOR IN HYDRAULIC LINE

Abstract

A quarter wavelength side branch resonator has been widely used as a reactive type silencer to attenuate pressure pulsation in hydraulic circuit. The structure of this conventional silencer is very simple and therefore it is a useful device in terms of cost efficiency. However, it is also known as a rather narrow frequency banded resonator that only attenuates the odd order harmonics of the pressure pulsation.
In this study, the attenuation performance of side branch resonator in the hydraulic line is examined numerically by changing the parameters such as the insertion location of side branch and the length of connecting pipe between the side branch and termination load of circuits. The level of attenuation is accessed by insertion loss which is defined as the ratio of overall amplitude harmonics of pressure pulsation with and without the side branch. The paper describes the fundamental principle of side branch and the mathematical model of insertion losscharacteristics. Some calculation results for the insertion loss characteristics are carried out to show the influence of even order harmonics and the interaction of pump, termination load and all pulsation propagation characteristics of the circuit including side branch.