supply variable efficiency map to a hydraulic pump

Hi All,

How can I input an efficiency map instead of a fixed value parameter for the fixed-displacement hydraulic pump model in simhydraulics?

Any ideas?

[Junfei Tang]

You can have a look at this. I guess it might be similar to your issue: http://www.mathworks.com/matlabcentral/answers/44515#answer_208604

Answer 1

[Yifeng Tang]

In newer versions of Simscape Fluids, the fixed-displacement pumps allow lookup tables as inputs to specify the efficiency as a function of pressure gain and rpm.

https://www.mathworks.com/help/physmod/hydro/ref/fixeddisplacementpump.html

https://www.mathworks.com/help/physmod/hydro/ref/fixeddisplacementpumpil.html

If those are not available to you, the way to implement this manually is via lookup table outside ideal source blocks. A diagram like below can be a starting point. It only cover the volumetric efficiency part and requires RPM as a signal input.

If you want to couple it with the mechanical domain, as in the fixed-displacement pump block, you may add a torque source and a velocity sensor for that purposes. The input to the torque source will be calculated from the delta_P and mechanical efficiency lookup table. The output from the velocity sensor will be sent to the "pump".