Why don't pipe and orifice blocs in Simscape Fluids cause a pressure change ?

Question

Antoine Dugauquier 2021-5-30

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/843760-why-don-t-pipe-and-orifice-blocs-in-simscape-fluids-cause-a-pressure-change

编辑： Antoine Dugauquier 2021-5-30

waterjet_nozzle.slx

I want to modelize a water flow going in a nozzle, especially the value of the pressure at the end of the nozzle orifice. However, no matter what the value of the pressure input or of the parameters of the blocks, the pressure differential of the several blocs are zero. My model has no pressure loss, the input and ouput pressures of the fluid are the same, which is problematic and unrealistic.

What could I do in order to change this ?

Thank you in advance.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Yifeng Tang 2021-5-30

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/843760-why-don-t-pipe-and-orifice-blocs-in-simscape-fluids-cause-a-pressure-change#answer_712970

The model does not have an outlet right now. The system is all pressurized to the value set by the constant pressure source, but there is no flow as I don't see an outlet reservoir. Zero flow, zero pressure drop. Add a reservoir to the right of the Orifice, you should see both flow and pressure drop. Add a flow rate sensor in line with the flow to show that on a scope, or use Simscape Result Explorer or Simulink Data Inspector.

Also, consider use Isothermal Liquid domain (blue color) instead of Hydraulics (yellow). Read about the difference and advantage of using the IL domain: https://www.mathworks.com/help/physmod/simscape/ug/upgrading-hydraulic-models-to-use-isothermal-liquid-blocks.html#mw_6db868a4-020d-402e-9cc4-aed14307a38f