Case study

CFD simulation of an axial piston pump with Ansys CFX

A comprehensive study on axial piston pump dynamics, comparing CFD and 0D models, analyzing flow, chamber dynamics, and erosion triggers

Author: Sara Bonati, CASAPPA

Thanks to their compactness and efficiency, swashplate axial piston pumps are widely used as fluid power sources in fixed and mobile applications that require high pressure and variable flow rates. In order to guarantee high performances, reliability, and reduced time-to-market, their development process requires more and more the use of advanced simulation tools. With specific reference to fluid dynamic simulation, different approaches are available; nowadays, the most common one is still represented by the lumped parameter method (0D-1D models). 

The advantages of this approach are the fast computation time and the ease of obtaining convergence, but some physical phenomena are inevitably simplified or even neglected at all. In this sense a three-dimensional approach is the most advanced and accurate method; however, there are still considerable challenges to be overcome before reaching a comparable level of usability: CPU time and convergence issues, in order to solve complex transient analyses characterized by small clearances and high pressure drops.

This work presents the CFD model of an axial piston pump and compares it to a validated 0D model. The main objective of this study was to analyze the flow field inside the pump, focusing on the aspects that involved the main inner volumes, such as the filling and emptying dynamics in the piston chambers and the flow field inside the ducts. Finally, particular attention was paid to the pressure transition phases, investigating their potential role in triggering erosion.

Source: Newsletter EnginSoft Year 18 n°4