From complex model to intuitive app – Web-based simulation for engineering, sales and marketing

Simulate in the cloud © ra2studio /


TLK Energy Apps for communicating the added value of complex products. For the sale of products in need of explanation in the B2B or B2C area, a TLK Energy simulation app can help to convey complex interrelationships and the added value of a product to potential customers. The TLK Energy Apps can be used in different areas. For example, to illustrate and calculate system behavior in the field of thermodynamics, energy and process technology. Questions can be answered such as, “What costs can be saved if the efficiency of my system increases?” Communicating a technical benefit in the area of complex systems can be greatly simplified with descriptive graphics. The apps can be customized and designed in your corporate design. At the customer’s site, you can access the app online via laptop, tablet or smartphone.

How we get from model development with expert software to an intuitive app with interactive graphics and what else we need the apps for, we will explain in the further course of this article.

Start: Model development with Modelica

For and together with our customers, we at TLK Energy develop simulation models of complex thermodynamic and energy systems using expert software (such as Modelica, Dymola, Python, our own model libraries and software). Using the simulation models, we can better understand the dynamic behavior of these systems, improve their efficiency, and even develop entirely new system topologies.

In order to build the right model, a constant exchange between us and our customers about the current state and simulation results achieved so far is very important. We learn from practical experiences in the company and thus define the requirements for the simulation model.

Problem: Simulation only with expert software

In the communication with our customers, we used to be missing an important component: Our customers could not simply run simulations themselves with the current state of the model! But this is exactly what makes sense for feedback on model development and internal discussion. The development and maintenance of simulation models takes a lot of time and expert knowledge, since complex software is usually used. The complicated operation leads to the fact that the use is limited to a small circle of experts. Even after completion, the provision of models to other development teams, the sales department or even the company’s own customers is not so easy. But especially for the exchange with our customers and within the company itself, a fast and simple provision of the model in a user-friendly environment is of great benefit and in some cases even necessary.

Solution: Web-based simulation with TLK Energy Apps

With the TLK Energy App called sim.TLK we have developed just such a user-friendly environment! Models based on the FMI standard (e.g. created with Modelica) can be quickly made available in customized web apps for all stakeholders. Exchange is now child’s play. Just log in and simulate! Whether tablet or laptop does not matter here. No installation of software and no problems with updates!

Based on our experience we are convinced of the potential of dynamic web apps for simulation applications! The TLK Energy Apps can be created by us in each customer project and subsequently managed and customized by the customer himself. They are designed to provide meaningful visual feedback during parameter input so that even complicated and non-intuitive physical parameters can be understood. Following a successful simulation, interactive graphics clearly present the data, making the results easy to interpret. In this way, the app can also be used for products requiring explanation in technical sales.

Workflow: From complex model via FMI to graphical evaluation

The TLK Energy App sim.TLK takes you from complex model to intuitive app in 3 steps:

  1. create and upload an FMU of the model.
  2. configuration of a user interface for the parameterization of the simulation
  3. configuration of a user interface for the result evaluation

1.) Creating and uploading an FMU of the model:
Output for the app is a model capable of simulation. The model is exported as a FMU (Functional Mock-Up Unit) uploaded to sim.TLK. The FMU is based on the FMI standard and consists of an XML file describing the model structure, among other things, and the model equations as C code. The export as FMU makes it possible to use once created simulation models in other programs. By providing the model structure including all information about available parameters, inputs and outputs, an intuitive user interface can be created directly by drag and drop.

2.) Configuration of a user interface for the parameterization of the simulation:
First, the relevant parameters are defined with which settings can be made on the model. In addition, the display mode of the parameters is implemented in the app so that even physical parameters that are difficult to understand are displayed clearly and their valid value range is restricted. For example, interactive graphics can be integrated. Here at the example of annual weather data of different cities and years.

3.) Configuration of a user interface for the evaluation of results:
In the third step the visualisation of the simulation results can also be adapted to the respective requirements. For this purpose, a selection of interactive graphics is available, which display the simulation results in a temporally resolved or categorised manner. Phase diagrams are also available in which thermodynamic cycles can be dynamically visualised. Now nothing stands in the way of a first simulation! The data is then prepared and made available in a clear and concise manner. Simulation results can even be compared directly and exported in full. The results of the annual simulation of a heat pump are shown here. Using the time-resolved COP, all points in time can be controlled and phase diagrams or temperature curves in heat exchangers can be analysed.

Interactive graphics - Apps as an alternative to Excel

All programmes have their strengths and weaknesses. When providing models via clearly defined apps, in contrast to complex desktop simulation software, not all setting options are available and the direct insight into the model structure is lost. Analysis tools such as Excel are not directly available in our apps. With the export of results in pdf-reports or as Excel-file we therefore enable an individual further processing of the data. For many, however, a quick classification of simulation results in predefined interactive graphics is of central importance. Here we offer an alternative to Excel. A web tool can also be used to process large amounts of data in the background.

Examples: Heat pump simulation and air quality

Our demonstrators for heat pump design show what such a simulation app can do. This also includes the model for icing of evaporators in heat pumps that we presented in our first blogpost! Anyone can easily test our free simulation apps at:

More free simulation apps and info about our specialized webtools can also be found at:
For example, the online tool Aerosim can be used to simulate air quality.

If you want to provide your own model via sim.TLK and turn it into your personal user-friendly TLK Energy App, feel free to contact us.

author image

M. Sc.

Pascal Padberg

Software and Project Engineer at TLK Energy

Pascal Padberg studied process engineering at the RWTH Aachen University. He has been working at TLK Energy since 2017 and has built up the model library PSL for the simulation of process engineering processes. He is also involved in the development and implementation of web tools for the simple simulation of technical systems via web browser.

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