- You will have to tune the hard stop spring/damper coefficients so you don't get any oscillations/penetration of the hard stop that you don't want.
- Because the hard stop is a force source, you will also need a Mass block on the Mechanical side to honor our friend Newton ( F = ma ).
How to simulate an empty initial volume in Simulink - Thermal Liquid Library ?
5 views (last 30 days)
I am currently working on a project in which I need to simulate an empty volume at the beginning of the simulation. Here are the specifications:
- The source is a 10 bars pressure source
- I have a restriction which limits the flow rate to 280 mL/min.
I want to fill a volume of 25 mL which is at the atmospheric pressure at the beginning. This volume is closed so the pressure will increase over time. When the volume is completely filled (Flow=0mL/min and Pressure=10bars), I need to wait for a given time (some seconds) and then, a valve after this volume is open so the water will flow and the flow rate will tend to 280 mL/min.
I tried to use a pipe with a volume of 25 mL but I came to the conclusion that there was already water inside the pipe. Indeed, the pressure increases until 10 bars in only 0.04 seconds. In reality, it should take 5.4 seconds (25/280*60).
Do you know how I could solve this problem ? Thank you very much for your help !
Sebastian Castro on 18 Feb 2016
Edited: Sebastian Castro on 18 Feb 2016
It's not easy to model an empty thermal liquid container with the built-in blocks, and would likely require some serious customization.
What I would recommend is using a Translational Mechanical Converter (TL) block, which is essentially an ideal piston-cylinder assembly. You can then hook up a Translational Hard Stop block on the mechanical side so that the travel is limited to a volume of 25 mL (or a displacement of 25 mL / cross-sectional area).
What you'd have to look out for here is: