Visualizing Simulation Results from Modelica Fluid Models Using Graph Drawing in Python

Models of large thermo-fluid networks can be useful to better understand the dynamic behavior of complex systems. Yet, numerical outputs and line plots of individual variables may not be sufficient ways of processing the simulation results for the user. Thus, the aim of this paper is to present a visualization approach by means of graph drawing. To demonstrate the approach, we use an example from the Modelica Standard Library and the use case of a district heating system model. We parse the Modelica model code to generate a System graph that represents the model structure and its graphical layout. The graph drawing subsequently visualizes the results for every time-step. In the examples, we vary line thickness to visualize mass flow rates between two nodes and line color to show temperatures of the medium. We argue, that this approach can be a useful tool for modeling and analysis.