Hydraulic source ripple and source impedance in 3D acoustic FEM model

Pressure ripple, fluid-borne acoustic pressure wave, can be critical in hydraulic system design. Hydraulic pumps can be considered as an acoustic source causing pressure ripple. And thus, acoustic modeling approaches are appropriate to simulate pressure ripple in the system. Acoustic source characteristics include source strength and source impedance below the plane wave cutoff frequency. They can not only be used to analytical model straightforwardly, but also be applied in a 3D acoustic model with proper setup. This paper demonstrates how source characteristics of hydraulic pumps be applied in finite element models. The proposed method is validated by comparing to a 1-D analytical model, and then a case study demonstrates how the source characteristics can assist on pressure ripple design of the system. The method can also be translated to applications other than hydraulic systems, like engine intakes, exhaust systems, and HVAC systems.