I want to model and simulate a hydraulic system in Modelica. In this system I have a nozzle. I want to include the nozzle in Modelica. But I cant find a suitable component in Modelica which represents the nozzle. Do you have an idea if there is a nozzle component in Modelica library ?
Try the package Modelica.Fluid.Valves. In particular, the model Modelica.Fluid.Valves.ValveVaporizing could be what you are looking for.
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I want to do local senstivity analysis in Dymola to evaluate different parameters affecting the energy consumption in a building (for multi-familyhouse).
Can anyone give me some suggestions, how to do it in Dymola (Modelica) software?
You could export you model as FMU and then follow one of many the different paths for sensitivity analysis with FMUs:
PyFMI + SAlib Sensitivity Analysis using PyFMI - FMU in for-loop
FMI Toolbox for Excel by Modelon http://www.modelon.com/products/modelon-deployment-suite/fmi-add-in-for-excel/
openTURNS + FMI https://www.researchgate.net/publication/321624302_A_Probabilistic_take_on_system_modeling_with_Modelica_and_Python, https://github.com/openturns/otfmi, http://www.openturns.org/
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Did you take a look at the "Design" library that comes with Dymola? It contains functions to sweep and perturb parameters.
You can load it in File -> Libraries -> Design. Some examples on how to apply the library can be found in the first chapers of the Dymola Manual 2. From the question I guess the Calibration package should be most useful for you.
One approach could be to do the modelling in Dymola (or OpenModelica, Simulation X, whatever), and then do the parameter sweep, pre- and post-processing, plotting, optimization and so on from Python. Dymola has a Python interface, so you can start simulation, read results, change parameters and so on from Python. Everything that can be done from the GUI is in theory also possible from the Python interface.
A Matlab interface and a Javascript interface are also available.
The description of the Simulink MATLAB package for Simscape Multibody says it can formulate the equations of motion for a mechanical system. I searched everywhere in the documentation and examples and I can't find a single example of how to do this, is there a specific block or does it actually mean the software calculates the equations as a black box and can't be extracted? Additionally, I'm also looking to calculate and simulate the natural frequencies of a planetary gearbox, can this packages also do this?
I'd appreciate any comments and suggestions, thank you!
https://uk.mathworks.com/help/physmod/sm/
"You can model multibody systems using blocks representing bodies, joints, constraints, force elements, and sensors. Simscape Multibody formulates and solves the equations of motion for the complete mechanical system. You can import complete CAD assemblies, including all masses, inertias, joints, constraints, and 3D geometry, into your model. An automatically generated 3D animation lets you visualize the system dynamics."
Simscape Multibody solves the equations of motions under the hood, it does not make them available to the user. It is in effect, a black box.
With regards to vibration analysis, this can be done in the Simscape Driveline package. Though the level of detail might not be high enough to do this for a single planetary gearbox.
There's a tool called simscape2casadi that, though in alpha stage, claims to be able to do what you want. A description can be found in this paper and the code can be found in this git repository. Please note that it requires Simulink Coder to generate C code from your model.
I have simmechanics model in simscape, I have imported it from solidworks design
I'm able to get linearized model using linmod and it is okay as any system in simulink
The problem here that I want to get the differential equations for that system, Is there any way to extract them?
The short answer: no, there is no built-in functionality.
The long answer: you'd have to parse the Simscape network, query the source equations (if the source code is visible). And stack these together. That's a pretty involved workflow.
I was wondering how a mechanical stop can be modeled most efficiently.
I do a hydraulic simulation with a controlled hydraulic cylinder in OpenModelica. For the hydraulic cylinder I use the sweptVolume model from the Modelica Standard Library.
What bugs me about this model is that there is no mechanical stop if the piston reaches the bottom of the cylinder.
I tried several ideas with no good result. I tried to reset the displacement of the piston to zero, if it hits the bottom, via an if-expression. But this is not really a good option due to the fact that the volume is calculated using the piston's displacement.
I then tried to introduce a force that equals the force applied to the piston, if the piston hits the stop. This option didn't work either, because in this case the pressure inside the cylinder can not be calculated.
The third try was to use the MSL model of MassWithStopAndFriction linked to the translational flange of the sweptVolume model, but this model seems to be broken for me.
Now I count on you as a competent community to bring in some more ideas for me to test.
Depending on your application, you may deploy the Hydraulics library? The library aims to model (compressible) fluid power systems and contains cylinders with end-stops. Its scope is different than the Fluid package you are using.
Using when and/or if statements for this task, I'd strongly discourage from experience. You may get one cylinder to work, but using that in a larger system will definitely get you into numerical problems. Have a look at the Mechanics package and analyse if the ElastoGap can be of any use to you.
Does anybody know what components in Simulink (MATLAB package) are analogs for AnyLogic components? (e.g: source, buffer, delay, sink).
Or how can I easily simulate behavior of AnyLogic model in MATLAB?
Maybe there are some cool magic tools?
If you're asking whether or not there is an easy way to convert from an AnyLogic model to a Simulink model, I doubt it. I haven't seen any conversion tools like that.
I have a feeling you're just going to have to rebuild your AnyLogic model in Simulink if you want to simulate your models in MATLAB. I would start by looking through the Block List and Function List links on this Simulink documentation page. You should be able to find analogous components to those in your AnyLogic model.
AnyLogic is one of the best tools for business simulation and Matlab is the best engineering tool. But they have different notations.So in the most cases conversion is just impossible! E.g. to convert DE model of airport into Matlab.
My suggestion: use Matlab for engineering tasks and AnyLogic for business simulation.