Displacement pumps and displacement motors represent several special challenges for a virtual CFD investigation. These challenges are the geometrical definition of the functionality itself and in addition the physical boundary conditions at operation.

The flow volume of each chamber of a displacement machine is not constant at operation. These chambers rotate around a decentralized axis and thus change their volumes during circulation. Displacement pumps are mostly operating above 300bar. Therefore, compressibility and the influence of bounded and non-bounded gases in the fluid must be taken into consideration in order to achieve correct compression losses. The gab heights between the stationary and the rotating parts must be comparably small to reduce leakage losses and increase efficiency. Depending on the size of the machine, these gaps are in the range of microns.

Complex Geometry

• Rotating, time-depending volumes
• Intermeshing components (gerotor, gear pumps)
• Big differences in different length scales

Complex physics

• • Fluid compressibility
  • Bounded and non-bounded gases in the fluid must be taken into consideration
  • Cavitation
  • High pressures above 300bar
  • Transient approach

SIMERICS MP can easily handle and simulatively evaluate any type of displacement machine. By using our pre-defined templates, a displacement machine can be meshed and defined in less than one hour, including all steps of pre-processing.

What kind of fluid-mechanical information will be available after simulation:

• Volume flow; mass flow
• Forces, Torques, Performance
• Cavitation effects
• pressure pulsation
• efficiency

Please take a look at our sample applications or contact our experts for displacement machines – we would be happy to talk to you!