Dymola commands

Exporting Dymola model to FMU for calibration

Written by: Xiaoran Han – Project Engineer This blog post demonstrates the concept of using a Functional Mock-up Unit [1] (FMU) for external model calibration. The example used is a combustion model from the Claytex Engines Library [2] with appropriate boundaries to enable its calibration through many engine operating points. Figure 1 shows the combustion read more

Posted on Friday, July 15th, 2016

Customising the Dymola environment

Options to customize the Dymola environment. If you click on Edit -> Options, a number of options are available to customise the working environment. Manual formatting: the user can choose to use their own formatting or an automatic formatting. Automatic formatting can be useful for consistency and to avoid triggering a change in a model read more

Posted on Friday, June 17th, 2016

Saving all your work with two simple shortcuts

Whilst we are developing models in Dymola we might like to be able to save all of our progress using keyboard shortcuts which do not disrupt our work flow. Up to and including Dymola 2015 FD01, the shortcut for “Save All” is Alt + F + A. This will save any unsaved changes in the read more

Posted on Friday, May 27th, 2016

Automatic tracking of stiff calculations in the models for improving simulation performance

Often in modelling, we want to identify which parts of the model are causing the simulation to run slow. For example, we might notice that the simulation is getting stuck at a particular time or points during a simulation. State variables and related variables which fluctuate at a high frequency can cause the simulation to read more

Posted on Tuesday, April 26th, 2016

Preparing models for use in Real-Time

A “Real-Time” function exists in the Claytex Library to ease the simulation of a model in real-time. This function allows to set number flags that are available in Dymola for inline integration and to improve performance for real-time simulation.  Figure 1: Real-time function from the Claytex library Inline integration is a combined symbolic and numeric approach read more

Posted on Friday, April 15th, 2016

Creating a function for loading libraries

There is the ability within Dymola to create a function to load a customised list of libraries, rather than manually loading each library. Using this approach, you can create multiple functions to load the sets of libraries required in different projects.  These functions can then be made easily accessible as a toolbar menu item or read more

Posted on Friday, April 8th, 2016

Handling trajectory files and utilising simulation results within Dymola

Introduction Many engineering problems require the results of one simulation to influence the inputs into a second simulation; in effect, a preliminary simulation is used to calibrate a second simulation. This could be done manually, but it makes more sense to automate the process wherever possible. With a little knowledge of the format of Dymola read more

Posted on Friday, April 1st, 2016

Using Eigenvalue Function – Illustrative Example & Applications

Introduction The intention of this article is to provide additional comment and examples, relating to the article about the eigenvalue function, and above all the meaning of its results. Having provided simple instructions on the function, this article is aimed at undergraduates and those interested in revising the subject with Dymola as a tool for read more

Posted on Tuesday, March 15th, 2016

Using the Onboard Eigenvalue Function

Introduction This article introduces the use of the Dymola function for calculating eigenvalues, with syntax, inputs and interpretation of outputs. It’s also intended to present some examples of diagrams produced in the software that can provide insight into linear systems, and explain a little about what eigenvectors and their eigenvalues are. There is a separate read more

Posted on Tuesday, March 15th, 2016

Using & Creating Directories

The working directory is the location on the computer in which Dymola runs and writes various files and of course the output file containing relevant trajectories of variables. It’s possible to find out, or alter which directory this is at some point during a simulation by using functions in the base library. By doing this, read more

Posted on Monday, February 29th, 2016

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