Orifice Frequency Dispersion Characteristics Effect on Hydraulic System Pressure Pulsation

Pressure pulsations are inevitable in hydraulic transmission systems. Orifices are employed to damp pressure pulsation to improve the system control accuracy. In the present study, a frequency dispersion model based on Biot's theory is implemented to describe phase velocity-frequency and amplitude attenuation-frequency characteristics of pressure pulsation. One contribution of this research is underlined as the quantification of the flow characteristics impacts from parameters, i.e., frequency, beta ratio beta, and orifice length. Consequently, the pressure pulsation is decomposed into two types of dilatational waves propagating within the orifice via hydraulic oil. The numerical results confirm the second dilatational wave type is considerable in this object of research. The results obtained in the present study have been compared with CFD simulation results and they show a good agreement. According to the Reynolds number Re, the flow regime in the slender orifice is laminar. Introduction of an orifice with beta = 0.20 for two distinct frequencies, the flow regime transitions from laminar to turbulence.