Effects of inclined cylinder ports on gaseous cavitation of high-speed electro-hydrostatic actuator pumps: a numerical study

Abstract

Raising the rotational speed of electro-hydrostatic actuator (EHA) pumps is a useful way to improve their power density. However, gaseous cavitation tends to occur in the displacement chambers at high speed, reducing the effective delivery flow rate of EHA pumps. It is a common approach to reduce the gaseous cavitation by increasing the inlet pressure. However, this conventional approach requires additional devices to boost the inlet line, which decreases the EHA pump's power density. The contribution of this study is to reduce the gaseous cavitation by introducing inclined cylinder block ports for EHA pumps, which only modifies the cylinder ports and needs no additional devices. A computational fluid dynamics (CFD) model was developed to investigate the effects of the inclined direction of cylinder ports on the gaseous cavitation. The simulation results showed that the inwardinclined design of cylinder ports could effectively decrease the gaseous cavitation using centrifugal effects of rotating fluid. Compared with a standard cylinder block, the cylinder block with inwardinclined ports could increase the effective delivery flow rate by 4% at an inlet pressure of 1 MPa and a rotational speed of 20,000 r/min. ARTICLE HISTORY

Nonlinear Control Method of Electromechanical Actuator Using Genetic Algorithm

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Study on cavitation phenomenon of twin-tube hydraulic shock absorber based on CFD

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Investigation of the Churning Loss Reduction in 2D Motion-Converting Mechanisms

“…After Jang introduced the churning loss to a study of axial piston pumps in 1997 [26], Håkan stated that the churning loss is significant when the pressure is low and estimated it to be up to 20% of the total loss in axial piston pumps [27]. In the next decade, the reports of churning losses in hydraulic pumps have been rare until many researchers have started focusing on the energy losses of pumps when operated at high rotational speeds [28,29]. Ivantysynova and her group established a mathematical model with the assumption of laminar flow to predict the churning losses in the cylinder block, pistons, and slippers of axial piston pumps, and they validated their model with a series of experiments [30].…”