Development of an Active Attenuator for Pressure Pulsation in Liquid Piping Systems 3rd Report, Trial Construction of the Control System and Fundamental Experiments for Wide-Band Random Pressure Pulsation.

Abstract

A new technique for an active attenuator for pressure pulsation in liquid piping systems, which detects the progressive wave component of fluid-borne vibration and then controls the second source feed-forwardly by this detected signal so as to eliminate the progressive wave in its downstream pipe completely by producing cancelling fluid vibration, has been presented, together with experimental results. In this report, emphasis is placed on the design of a signal processing circuit for the controller applicable to the wide-band random fluid vibration. The desired (target) characteristics for the controller could be realized through a newly devised signal processing circuit combining the finite-impulse-response (FIR) digital filter and analog compensating circuit. The pressure pulsation, including many harmonic components over the wide frequency range, was produced by a rotary-type spool valve. It could be confirmed by the test in a model experimental pipeline that, when the present control system was operated, the pressure pulsation in a downstream pipe of the second source was reduced to around 1/10 (-20dB) of that in the case where the control system was off for almost all harmonics of 15 to 400Hz.