Resonant characteristics of flow pulsation in pipes due to swept sine constraint

A fast and easy to use method for analysing the amplitude frequency characteristics of pulsating flow in pipes with a sine sweep input function is presented. The key element is the sweeping excitation of the pulse generator frequency which generates fast whole-spectrum resonance (from 20 Hz to 160 Hz). A case study describes tests conducted into the applicability of the method for research into pulsating flows. First, the test rig is briefly described, along with the main assumptions of the research. Next, theamplitude frequency resonance dueto swept oscillations is estimated for increasing, decreasing and changeable input mass flow rates. These characteristics are approximated based on a second-order transfer function. Following such assumptions, the damping coefficients and resonance frequencies are estimated. The influence of the direction of the frequency sweep method (increasing or decreasing) on the resultant resonance frequency is also investigated.