The design of new hydraulic components such as volumetric pumps is becoming more sophisticated over the years, so that pump manufacturers can keep on being competitive on the market. As pump technology evolves, we have to be able to offer within Simcenter Amesim a way to help and support our customers to face these new challenges years after years.
Creating a detailed volumetric pump model can sometimes be time consuming because of the complexity of some designs. Simcenter Amesim responds to this engineering challenge by facilitating the design task and making easier and faster a pump model generation by offering the new tool named CAD Import.
The CAD Import tool can be used for both variable displacement vane pump (sliding and pivoting) and gerotor pump technologies. In order to demonstrate the effectiveness of this new feature we use a variable displacement piston vane pump.
A variable displacement vane pump is an assembly of multiple mechanical pieces that all play a role on the proper working of the pump. In order to create a pump model only few elements need to be kept on the CAD part as shown on the figure above:
The fluid volumes also need to be extracted from the pump body (they correspond to the blue and red parts).
The selected pump elements enable to retrieve the necessary geometric parameters needed to set the pump model once generated in Simcenter Amesim.
You can proceed to the automatic calculation of the geometrical parameters (length, radius, volume, etc) of each components just by selecting them on the 3D view (left part of the window) one after the other.
Most of the time, in order to calculate automatically the geometrical parameters you have to pick the whole body part, while sometime you have to pick a specific face of the component in order to get the right dimension.
If the pump parts have been well defined and named at the beginning of the process, the selection of the faces and bodies takes only a couple of minutes if not seconds.
Once all the parameters have been properly retrieved it is then possible to generate automatically a pump sketch.
The automatic pump sketch generation can be made using either the Hydraulic (HYD) and Hydraulic Components Design (HCD) libraries or the Thermal Hydraulic (THH) and Thermal Hydraulic Components Design (THCD) libraries:
After selecting the library, the pump can be automatically generated as shown below:
The pump sketch is composed of an integrated pump submodel, the inlet and outlet volumes and a constant speed motor.
Regarding the integrated pump submodel, if we take a look at its parameters we can notice that they have been correctly retrieved from the CAD part (cf. parameters tagged with a blue square).
Beyond the fact that those parameters are used for the pump simulation they can also be used into a dedicated application that has been developed just for the purpose of the pumps design as we can see on the next figure.
This application complements the CAD Import feature. It allows the users to first check if the geometry of the pump corresponds properly to the one they have on their CAD and secondly to apply easily some changes on the pump design in order to improve the pump performances.
Variable displacement vane pumps (equipped with a sliding or pivoting stator control ring) are more and more installed into lubrication systems by our customers. The automatic pump sketch generation allows them now to reduce considerably the time needed to create a detailed pump model in the early design stages.
Here below you can see an example of a basic hydraulic circuit using a pressure controlled variable displacement vane pump:
CAD Import tool Simcenter Amesim is aiming to make easier the pump design for our customers by offering them an efficient and easy way to use automatic sketch generation feature for several types of pump technologies.
About the author:
Nicolas Laviolette is product manager in the Thermo-Fluids team for Simcenter Amesim, since the end of 2015. He mainly focuses on fluid applications such as mobile hydraulics and lubrication for automotive systems. He has been working on fluid systems modelling for oil and gas companies and also automotive manufacturer since 2010.