Empresarios Agrupados has just released version 6.0 of EcosimPro/PROOSIS, a tool specialising in the simulation of dynamic systems in the fields of space, aeronautics and energy. This new version 6.0 is a very important milestone in the new generation of simulation tools requested by the market. The product of years of work, it creates a 0D-1D simulation environment that covers the most demanding requirements of users from front-running companies in the Space, Aeronautics and Energy sector at the international level as well as some of the most relevant Research Centers worldwide and some of the best universities in Spain and abroad. Today, many prestigious companies such as the European Space Agency, Airbus, Safran, Thales Alenia, CERN, ITER, etc. are using EcosimPro/PROOSIS to model space propulsion systems, aeronautical gas turbines, process plants, cryogenic systems, electrical machines, etc. EcosimPro/PROOSIS is currently one of the top references in the modeling of space propulsion systems, aeronautical gas turbines, process plants, cryogenic systems, electrical machines, etc. The new version extends its integration capabilities to cover every international standard, such as OPC UA and FMI in order to be able to import and export models between different environments (e.g. scadas, PLCs, etc.). Likewise, version 6.0 has a new co-simulation tool that lets several simulations run in parallel and on multiple machines, controlling all the results from the graphic interface of EcosimPro/PROOSIS in an intuitive way. In addition, improvements have been added to handle highly complex models and run the simulation faster thanks to new algorithms to speed up the calculations. This turns EcosimPro/PROOSIS not only into a 0D-1D simulation platform, but also into an integration platform for complex simulations. The goal is to make that market need possible in terms of creating Digital Twins by making it simpler. The models can be exported in various formats for monitoring complex systems (an engine, a power plant, an airplane’s environmental control system, etc.) and detecting malfunctions, system prognoses, etc. What’s more, for the first time, it includes a 3D viewer to make it easier to design simulation scenes in 3 dimensions connected to the variables of the model in real time. This helps users make more realistic simulations of certain scenarios such as orbital calculation, robotics, thermal control, etc. The tool has a scene generator that lets the modeler create his own scenario by adding three-dimensional shapes, 3D objects and photographs connected with mathematical variables. During simulation, these 3D models make it possible to intuitively visualize the evolution in space, for example, of a satellite with respect to solar radiation. The core of the tool has also been improved by adding support for the international standard UTF-8 to represent character strings. From this version of the tool on, users can write comments, string values and file names in any language. New algebraic-differential equation solvers have been optimized for real time and new sentences have been included to run blocks of equations in parallel and to generate post-process files in the international standard HDF5. All of these new features have improved the capabilities of the mathematical nucleus, turning EcosimPro/PROOSIS into a high-capacity calculation tool, even in real time. Another major feature worth mentioning is the user interface, which has been enhanced so that users can edit simulation models on multiple screens simultaneously, thereby substantially increasing the usability of the tool. All current users with active maintenance contract will receive a notification in the following weeks to obtain the new version. If you have any question related to this new version please contact us at info@ecosimpro.com The following is a list of just some of these improvements:

EcosimPro/PROOSIS can generate automatic library documentation, so in this blog we’ll show the various different views we can have of the components. The library we’ll use is TURBOJET from the STANDARD workspace. We can generate automatic documentation from this library if we choose the library and the option: “Documentation->Generate Documentation”, which opens a browser with the following header: From here we can browse through the different components, ports, classes, functions, enumeratives and global variables in the TURBOJET library. Let’s take a closer look at what’s under the Components heading. If we click on Components, it takes us to another page with this header: It gives us three different views to see the components: one in alphabetical order, another with a inheritance tree in text mode and the last with the inheritance tree in graph mode. In the first we see a table with each component, its icon and a description: If we click on the [+] sign it takes us directly to the source code for this component (only if available). If we choose the “Inheritance Tree” option, we see: in which we see the inheritance hierarchy among components. For example, GasChannel is inherited from GasInGasOut and Afterburner is in turn inherited from GasChannel. If we want to see this information in graph mode, we can choose the “Inheritance Graph” view, which displays a graph like this: Each bubble represents a component. When a bubble has an arrow pointing to another bubble, it means it is Inherited from that component. For example, we see that GasChannel points to GasInGasOut, indicating that the former is inherited from the latter, and so on  for the rest of the components. It’s a useful view because it shows us all the inheritance relationships of all the components in the library at a glance. Moreover, the user can interact with the graph by moving the bubbles around with the mouse into new arrangements; when one bubble is moved, the others move automatically to make way for it. We recommend users to reach this view and “play” with this high-level overview of the library.

EcosimPro and PROOSIS have joined file comparing options to make it easier to spot differences between results from simulations, experiments, partitions, etc. This change shows the comparison options in the context menu of the different elements in the “Files” tab and the “Items” tab: When comparing files, EcosimPro and PROOSIS try to make the best comparison they know in terms of the file type. In other words, they compare files as if they were text, unless they are post-process files with an h5 extension (HDF5 format) in which they make a detailed binary comparison: The binary comparison of post-process files is useful for analyzing the differences between the results from two simulations by comparing each communication interval (CINT) or each step in integration (STEP). It is a powerful, flexible comparison that shows exactly what happened. Moreover, instead of detecting the best comparison, file comparing can be done to make a graphic comparison of the post-process files or to force a text comparison of the chosen files. The next dialog shows the files that hang from the elements to be compared to choose which files to compare by selecting on from the left side, another from the right, and how to compare them by dropping down the options from the “Compare” button: If two post-process files are compared on the monitor, it makes a graphic comparison of any variables that exist in both files and both have the same type, such as shown in the screen shot below:

EcosimPro and PROOSIS are in constant development and take special care that their numerical solvers work as efficiently and robustly as possible. The latest versions of EcosimPro and PROOSIS include several performance enhancements, one of which is the linear equations solver. The graph  below shows that the new linear box solver is up to 50% faster than in previous versions while maintaining the same numerical results. Of course, not all the model has linear boxes, and depending on the number and size of linear boxes, the influence of this improvement will be more noticeable in some cases than others in cutting down on simulation time. Electrical models usually benefit the most from this improvement. Figure 1 Linear box solver performance (higher is better): In addition to the improved linear box solver, there are improvements to how memory is managed in the CVODE and IDAS solvers included in EcosimPro and PROOSIS as well as optimizing the Jacobian calculation during the solving process, leading to substantial improvements in some simulations. Figure 2 Performance of the Priming_complex ESPSS experiment using IDAS and CVODE. EcosimPro 5.6.1 vs EcosimPro 5.10.0 (Lower relative values are better): EcosimPro and PROOSIS have not only improved the existing solvers, but have also added the following to give the user even more flexibility when simulating:

One of the main new features in the new version of EcosimPro 5.10 and PROOSIS 3.10 is the new Attribute Editor included in the schematic diagrams. This new tool replaces the old attribute editor and gives the end user much more flexibility and speed in handling data on the components, since it now works much like the standards followed by modern spreadsheets. Fig. A view of the new editor: Listing all the features of the new editor is a task that involves detail, so here we’ll focus on the three main ones: So, with the new EcosimPro/PROOSIS, you can work with several editors open at once, including in different schematic diagrams. The end user can easily compare data, copy them from one editor to another, export them, and all while performing operations such as compiling a schematic diagram, editing a symbol, or launching the monitor to simulate an experiment. Fig. Multiple editors in the same schematic diagram: However, the main feature of the new editor is the ability to manage different components of the same schematic diagram all in one single table. In other words, users can choose whatever components they want and edit all of them at the same time. The system automatically manages the information and groups the data by name, type and unit. The end result is a spreadsheet that makes it easy to find, compare, and edit the values of dozens of components. Fig. Multiple components in one single editor: And all with multiple aids in editing and filtering the data to make it easier and quicker to find variables based on their category, value, component type, name, etc. In short, the new Attribute Editor is a completely new tool, extraordinarily versatile and powerful, designed and built in answer to our users’ requests. And we will keep enhancing it.

Functional Mockup Interface (FMI) is a standard for exchanging dynamic models between simulation tools. In this standard, an FMU or Functional Mockup Unit is the unit of exchange, i.e., the model that implements the FMI interface, its binaries or source code and a file that describes the capabilities of the FMI standard as well as information on the model such as the input and output variables. Version 2.0 of the standard defines two ways of exporting models to be used by tools that can understand the FMI interface: EcosimPro 5.6 and PROOSIS 3.8 introduced the ability to export models following the “FMI 2.0 for Co-simulation” standard, which lets any use model in EcosimPro and send it for use by third-party tools such as Matlab-Symulink, Dymola, ANSYS, Simulation X, AMESim, etc. What’s new to EcosimPro 5.10 and PROOSIS 3.10 is the ability to use FMI 2.0 models for co-simulation that are already generated using EcosimPro 5.6 or greater, PROOSIS 3.8 or greater or any other tool able to export models with the FMI 2.0 interface for co-simulation (AMESim, ANSYS, Dymola, Simulation X, etc.). This new feature can be used to complete a co-simulation diagram much like the one below using PROOSIS or EcosimPro as master simulators: Generating an FMU in EcosimPro or PROOSIS entails creating a model, generating a simple experiment in which to integrate until the next communication interval (CINT), and then generating a deck with the FMI 2.0 co-simulation interface, as shown in the screen shot below: The deck creation wizard also lets you choose the variables that will be FMU inputs and outputs. Once the wizard is done, it will have created an FMU ready to send to a third party: To control an FMU from EcosimPro and PROOSIS, they both include the COMM_FMI library to create components that interact with the FMU and to use them subsequently in other, more complex models or create power co-simulation experiments written in EL, such as the following experiment that load four FMUs containing a turbojet model and are simulated in parallel: For more details on how to generate FMUs or use FMUs with EcosimPro or PROOSIS, we encourage you to read the chapter on FMI in the EcosimPro and PROOSIS manual.

The simulation team here at Empresarios Agrupados has been doing more work for the ITER experimental fusion reactor. Over this period of time, a prototype of the cryogenic distribution system in ITER (FEDCS) was developed. It includes the auxiliary cold box (ACB) of the cryogenic pumps, the distribution lines that carry the coolant from the ACB to the cold valve box (CVB), the CVB, including its control, and one of the cryogenic pumps of the torus. The final model, which will include all the cryogenic pumps, and has a twofold purpose: The cryogenic pumps are used in high-vacuum applications and consist of an internal surface (cryogenic panels) cooled to low temperatures where the gases and vapors condense. The gas molecules are immobilized on these surfaces, thus reducing the pressure within the system. In the specific case of ITER, the cryogenic pumps serve two purposes: firstly, they are used downstream from the mechanical pumps to reduce the pressure in the vacuum vessel down to adequate pressure conditions and, secondly, they adsorb the gases from the plasma during reactor operation. Because of the intrinsic difficulty involved in trapping helium particles, the surfaces need to be cooled to a very low temperature (4.5 K). In addition, every so often deuterium and tritium particles are adsorbed with the helium particles. Those particles will subsequently be recovered and treated in the tritium plant so they can be put back into the system. Therefore, the pumps operate in a constant cooling-pumping-heating cycle and are within a temperature range of between 4.5K during the pumping, and 470K during one of the regeneration scenarios. The FEDCS control system has to operate the clients dynamically in such a way that they comply with the operating requirements of the plasma, taking the correct regeneration of the pumps into account at the same time. Having a dynamic model available has two main advantages: first, it can be used to verify the behavior of the FECDS elements that operate together and second, it can be used to design and verify the complex control system required for correct operation.

One of ITER Organization’s goals is to develop an integrated simulator of the different systems making up the ITER experimental reactor under construction in Cadarache (France). The simulator is meant to bring together the individual simulators developed in the different systems and integrate them. The final purpose of the integrated simulator is to support the commissioning of ITER and the training of operators. The ITER team responsible for the cryogenics system has been working for some time on developing models that can verify the design, design advanced control algorithms and test the control with hardware simulations in the loop. With this aim, the simulation department at EAI has developed dynamic models of the circuits that cool the ITER magnets and initial models for the cryogenic pumps and their distribution. Because of the complexity of the system, IO has proposed creating a distributed simulation platform that can integrate models from the different subsystems and simulate them jointly. To achieve this goal, EAI developed some particular features in EcosimPro in 2017 to allow distributed simulation of these highly complex models. In the framework of this project, EAI endowed EcosimPro with the capability of generating OPC UA servers from the tool itself. This lets models developed in EcosimPro connect to other tools that have an OPC UA interface and create a powerful distributed simulation platform. Similarly, a mechanism for synchronizing models has been developed that links up many different systems so that they can be simulated all together as a whole, with the results displayed in EcosimPro in a unified way.

A beta version of the Aircraft Systems Simulation Toolkit for PROOSIS is ready, and will soon be commercially available to simulate the thermo-fluid systems of aircraft, such as: the pneumatic system (environmental control ECS), hydraulics (fuel, oil) and steam cycles (cooling, bottoming cycles, etc.). The libraries included in the toolkit are compatible  with the TURBO library for simulating gas turbines, therefor making it possible to simulate the engine along with the systems it interacts with: fuel feed systems, oil coolant loop, air bleeding system and the ECS, etc. and of course, the thermal interactions between them. The toolkit shares the TURBO library’s philosophy in terms of modelling and scope. That makes it a useful tool for analyzing the thermodynamic cycle by making it possible to run design point studies (including all the normal calculations in these analysis: parametric, optimization, Monte Carlo, etc.) as well as off-design simulations of a particular system (static calculations and dynamic simulations). For dynamic simulations, the libraries include the most significant transient effects (slow dynamics). The modelling flexibility (any thermal-fluid system) along with the variety of possible calculations make PROOSIS-Aircraft Systems a very useful design tool to integrate the different aircraft systems (thermal management). Although useful for any fluid system of the aircraft, the toolkit is especially useful for simulating the ECS. It can be used to simulate any conventional or innovative configuration (more electric aircraft) based on air cycles (ACM) or vapor cycles (VCM). Not only can the toolkit be used to simulate the cooling cycle, but also the air bleeding subsystem and the cabin air distribution subsystem as well. Do not hesitate to contact us for more information (info@ecosimpro.com)

Elena Gómez Sayalero & César de Prada, Valladolid Univ. (UVA) Hydrogen is an expensive utility used in several processes in oil refineries, mainly in desulphurization and hydrocracking plants, and which is gaining increasing importance in the global refinery economic balance. Within the framework of a project aimed at the optimal operation in real-time of the Petronor refinery H2 network, an EcosimPro library H2NET has been developed. The H2NET library comprises first-principles models of the main equipments and operations involved in the network management: gas streams, reactors, high-pressure separators, low-pressure separation processes, tanks, membranes, compressors, meters, valves, and mixers and splitters supporting also pipes with unknown direction for flow. The network model built with the H2NET library has been used for different purposes. For What-If analysis in simulation; in a cooperative project with the Repsol Technology Center in Móstoles (Madrid) aiming at the revamping of the Petronor H2 network, where new connections and alternatives were considered and assessed; as case study for the formulation of real-time resource efficiency indicators REIs in the European project MORE; as well as for the network optimal operation in real-time. Regarding this last target of on-line decision support, firstly a data reconciliation problem is solved by optimization techniques, formulated as the minimization of the measurement-model deviations taking advantage of all the redundant flowmeters available; model parameters are calibrated at this stage and measured and unknown variables estimated. The optimal operation has been addressed with a real-time optimization RTO approach as the minimization of the H2 production cost based on the network model once calibrated in the data reconciliation stage, and including all process constraints and specifications. Reasonable results, ready to be implemented as decision-support for the operation, has been achieved and analysed regarding the production rates in producer plants, the make-up flow rates to consumer plants from the different headers, as well as the high-pressure purges and membranes flow rates. Snopt, based on a SQP algorithm, is used as NLP solver for both optimization problems. The H2NET library includes several additional features: i) configuration structure to enable an easy link with the SCADA for process data acquisition; ii) functions to perform the corresponding data treatment and initialization of variables; iii) functions for the automatic generation of the code needed to implement both optimization problems; iv) management of the linear constraints to conveniently bound the search region in both optimization problems, exploiting model structure. Financial support from the MICINN and the cooperation and involment of the Petronor-Repsol group are gratefully acknowledged.