Development research of reflection-absorption compound type fluid pulsation attenuator
Based on the disadvantages analysis of the existing fluid pulsation attenuator, two reflection-absorption compound type of fluid pulsation attenuators which are both composed of a chamber and a mass-spring-damping system are developed: in-line reflection-absorption compound type of fluid pulsation attenuators (in-line RAFPA) and side-branch reflection-absorption compound type of fluid pulsation attenuators (side-branch RAFPA). The transfer matrix models of the two attenuators are established as well as expansion chamber attenuator and Helmholtz resonator. Based on the transfer matrix model, the transmission loss of the four attenuators is given out to evaluate their attenuation characteristic. The attenuation characteristic comparisons of in-line RAFPA with expansion chamber attenuator and side-branch RAFPA with Helmholtz resonator are carried out respectively. And the effect of the mass-spring-damping system to in-line RAFPA and side-branch RAFPA is investigated. The simulation reveals the two reflection-absorption compound type of fluid pulsation attenuators have better attenuation characteristic and are more compact than expansion chamber attenuator and Helmholtz resonator.
Improving Performance of a Resonant String-Based Pulsation Attenuator in Hydraulic Systems
Hydraulic pulsation attenuators (HPA) are commonly used to suppress the noise and vibration in fluid power systems. However, most existing HPAs lack a reasonable optimization strategy and effective methods to improve the performance of HPAs. This paper proposes an adaptive particle swarm optimization (APSO) algorithm to speed up the geometry optimization process of a resonant string-based compound HPA (RSHPA), which was proposed in our previous work. Then, the study discusses the possibility of improving the performance of RSHPA by varying the configuration and location of the RSHPA. The experiment result validates the feasibility of the proposed optimization method for RSHPA.
ON THE USE OF VARIABLE ORDER INFINITE WAVE ENVELOPE ELEMENTS FOR ACOUSTIC RADIATION AND SCATTERING
The use of the variable order infinite wave envelope element to model acoustic radiation and scattering problems is investigated. Different acoustic modeling aspects are focused upon. These involve the modeling of acoustic wave propagation above infinite homogeneous impedance planes, different methods to prescribe acoustic sources and alternative postprocessing procedures. Special attention is given to limitations encountered for this finite element based modeling of wave propagation in unbounded domains. The limitations are assessed by analyzing the higher‐order multipoles of the axisymmetric pulsating rigid sphere.