How to control pressure gain and mass flow with Fixed Displacement Pump

Hi,

I am currently learning Simscape by building a simple system with pumps and pipelines.

For my system i use a Fixed Displacement Pump with parameters that calculate pressure gain and mass flow with the torque or the angular velocity source. If i understand well the documentation, torque that drive the pump and pressure gain from inlet to outlet can be linked with that equation:

However, mysensors my measurement never match the calculus whatever parametes i decide to set in the pump window .

I kept the pump parameters by default, i apply a 50N*m torque and i measure a ΔP of almost 14MPa whearas with the formula i predicted 2 Mpa

Is the formula wrong ? How do i preddict my pressure gain and my mass flow at the outlet thanks to the parameters of the pump?

Here is my Simscape system

:

Thanks by advance

[Yifeng Tang]

Is it possible to share the model here? That'll make it easier to reproduce and diagnose.

Answer 1

[Nadir]

Hi, here is my simlcape model.

Answer 2

[Yifeng Tang]

Hi Nadir,

From you model, I measured of 9.2MPa. This is consistent with the formula you showed. I believe when you put in the displacement parameter (D), you were using cm^3/rev or m^3/rev. Convert rev to in radian and you'll calculate 9.215MPa of pressure difference for 50 N*m torque and 0.88 mechanical efficiency.

In short: unit of displacement.

Answer 3

[Nadir]

Thank you !

Indeed i forgot converting the rev and now it give the good result.