Advanced Aeronautical Propulsion: Modelling Boundary Layer Ingesting Propulsion Systems in PROOSIS

In the ASME 2020 TURBO-EXPO Virtual conference, the National Technical University of Athens (NTUA) presented a modelling approach of Boundary Layer Ingesting (BLI) propulsion systems for future aircrafts. A distorted compressor model was created first in PROOSIS utilizing the parallel compressor theory in order to estimate the impact of inlet distortion on fan performance. A BLI propulsor component model was then developed in PROOSIS considering both distortion effects and reduced inlet momentum drag caused from boundary layer ingestion.

A Turbo-electric Distributed Propulsion (TeDP) model based on NASA’s N3-X aircraft concept (Hybrid Wing Body) was eventually set up, consisting of the BLI propulsor model, the associated turboshaft engine model and a representation of the relevant electrical system.

All models were validated through comparison with numerical and/or experimental data. A design point calculation was carried out initially to establish propulsor key dimensions for a specified number of propulsors and assuming common inlet conditions. Parametric design point analyses were then carried out to study the influence of propulsors number and location under different inlet conditions, by varying fan design pressure ratio between 1.15 and 1.5. BLI and non BLI configurations were compared at propulsion system level to assess the BLI benefits.

The results show that maximum BLI gains of 9.3% in TSFC and 4.7% in propulsive efficiency can be achieved with 16 propulsors and FPR=1.5, compared to podded propulsors, while further benefits can be achieved by moving the propulsor array backwards in the airframe.

Constructing digital building twins with EcosimPro

A new toolkit for HVAC systems and building energy modelling tools in EcosimPro has been released within the H2020 Sphere European project. It allows the user to make digital twins of buildings for performing energy studies, optimization and real time simulations. These simulations can even include models of humans interacting with the rooms, CO2 control, a ventilation model, thermal impact, etc.

A connection has been created with the BIM and IFC standards to be able to export 3D models to the EcosimPro environment and automate model conversion in EcosimPro. The final simulation model can also be exported as a digital twin of the building. When there are a lot of appliances, walls, volumes and ducts like in our virtual building shown above, you can speed up the pre-processing cycle with a plugin to derive schematics from .ifc, a 3D BIM format. Then, after the simulation, a black-box can be created and integrated with a SCADA system to improve energy savings.

HVAC model

To simulate comfort, the first of these tools, the HVAC library, simulates the physics of fluid networks—heating, AC, tap water—and the air ducts with all their appliances: pumps, chillers, ducts, boilers, rooms, etc. Human ventilation models that can breathe in the room—taking in O2, giving off CO2 and water—and exchange heat can also be included. Meanwhile, the BUILDINGS library can be used to simulate the building itself (walls,doors, windows,etc.), as it contains all the architectural components that store, conduct, transfer and radiate heat.

The systems into which the air conditioning, ventilation and control loops are coupled are physically connected with the HVAC library. What’s more, the HVAC library allows the user to analyze transient aspects due to fluid inertia, wall friction and heat transfer. It also provides an extensive database of properties of real fluids and materials.

HVAC model detail

These libraries aim to fill in gaps about how our buildings work. These digital twins of buildings with humans inside them, so we could observe every physical magnitude and convert them into comfort and real money. They can be used to enhance building design, improve energy efficiency, and control our appliances with hardware-in-the-loop.

EcosimPro/PROOSIS 2020 (6.2) released

EcosimPro/PROOSIS 2020 (6.2) mathematical simulation tools have just been released. Since mid-March the whole development team is working from home, this shows that great things can be done using teleworking. It has been 20 years since the first commercial version came out, mainly for the space sector at that time, now it is already used in many others like aeronautics, energy, cryogenics, fluids, etc.

This new version includes the following improvements:

– New experiment libraries that allow decoupling the partitions of the experiments. Now many users can create their own experiment library and create multiple experiments on some existing partitions in other libraries.
– Port array management tool in the graphical editor that allows dynamic sizing of ports and connection to multiple connections.
– New option to export schematics and all their experiments.
– Compatibility with SVN versions from 1.7 to 1.13.

– The new version allows to pass partition classes as function arguments.
– Creation of a parent class called EPartition for all partition classes that allows any partition to be used generically.
– Use of object pointers.
– New virtual methods for classes.
– Use of the “this” pointer as in C++.
– Methods for copying variables between partitions and identifying a partition.

– New versions of IDAS and CVODE improved to work with thousands of equations.
– New variables of IDAS and CVODE solvers. Now the user can tune for each Jacobian variable by changing maximum step, maximum order of calculation, threshold for parallel calculation, etc.

– Help the user to select variables by categories in the REPORT_TABLE and REPORT_LIST functions (for example to select all the algebraic at once)

– Improved 3D widget in Monitor with scene edition.
– A new variable tree widget in Monitor.
– Permitted moving widgets (eg. plotters) among tabs in Monitor.

– Improvements in the connection with the FMI standard allowing the use of enumerated, equivalent variables, etc.
– The Co-simulation Wizard has been updated with new features (eg. capability to add external OPC-UA servers in a co-simulation scenario, capability to simulate the master program in Linux, new option to use a bus mechanism to speed up deck OPC-UA server communication, asynchronous calls).
– Added the capability to produce HDF5 files in Linux.
– Export models to RT-LAB platform.

– New improved automatic testing tool.

This new version will be available to any user who is up to date on their maintenance contract.

If you would like any information about any of these new features please do not hesitate to contact us

Improved the FMI for co-simulation

The FMI-FMU model connection for co-simulation has been updated and validated in EcosimPro/PROOSIS improving the performance of the external model connection. This new improvement facilitates the co-simulation of models with other simulation tools using the international standard FMI.

EcosimPro/PROOSIS models can be easily exported as FMUs by means of an intuitive wizard where the model configuration can be performed graphically. This does not require any manual programming, everything is generated automatically.

Likewise, the import process of FMU models for co-simulation has been added to the EL language. The FMU models can be imported and executed in EcosimPro/POOSIS through a set of simple and well-defined functions that follow the FMI standard. The modelers can work simulatenously with many FMU instances (running in different processes of the CPU).

New version of FLUIDAPRO 5.2 for modelling fluid systems in EcosimPro

A new version of the FLUIDAPRO 5.2 toolkit is now available for users. This new version includes important improvements in the modelling and simulation of fluid systems (liquid/vapour, two phases) such as: combustors can define the set of chemicals taking part of the combusted gases, volumetric pumps can work with several types of performances maps, new 1D Tank component for the simulation of the temperature stratification inside the liquid and gas parts, new option in Pipe component that permits to simulate draining and blowdown conditions, etc.

New aeronautical simulation toolkit available: ASYST

This new toolkit permits to simulate a wide range of subsystems of the aircraft: gas turbine simulation, environmental control system (ECS), aircraft hydraulic systems, thermal management, organic rankine cycle (ORC), cabin and air distribution subsystem simulation, vapor cycles, etc.

With ASYST you can save time and cost designing your aircraft joining the detailed performance modelling of the gas turbine and the different subsystems of the aircraft. ASYST can be used for the cycle analysis, on-design and off-design studies.

Do not hesitate to contact us for more details.

Tritium International Conference in Busan (South Korea)

Last week the studies performed with TRITIUM toolkit about the isotopic effect on tritium permeation in breeding blankets were presented during the 12th International Conference on Tritium Science & Technology (

Carlos Moreno, from CIEMAT, was in charge of this presentation. CIEMAT and Empresarios Agrupados have been working together in the development of this tritium simulation area.

In this work, the effect of co-permeation and counter-permeation of hydrogen isotopes has been studied. Using the tritium transport simulation library in EcosimPro, the past experimental results have been successfully reproduced and the addition of hydrogen as a mitigating agent for the permeation in the different european blanket designs has been confirmed considering DEMO and ITER operational conditions.

EA launches the new version of EcosimPro/PROOSIS 6.0 for the simulation of systems in the fields of space, aeronautics and energy

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

The following is a list of just some of these improvements:

  • UTF-8 support for storing strings. Now the modeler can introduce comments and variable contents in Chinese, Greek, German, etc.
  • Commuter licenses for moving license tokens to laptops. Users may sometimes want to use a license token when they are away from the office for a time. They can now transfer a commuter license to their laptops and use the tool.
  • New, more flexible software licenses.
  • Monetization of decks using run-time licenses. This new version admits forcing the use of a runtime license token for a deck, which could provide income for the modeler.
  • Supports new Microsoft Visual C++ 2017 and GCC 4.8 compilers.
  • New 3D widget for visualisation of 3D scenarios in the Monitor connected to the simulation models.
  • Playback slider in Monitor that permits moving back and forth in the simulation.
  • New undocked tabs that permit editing multiple models simultaneously on several screens.
  • New experiment settings menu that permit defining error levels, creating post-process files, producing log files, etc.
  • More intelligent wizards for partition validation that detects differences with previous partitions.
  • New options in the partition wizard that allow changing library constants and construction parameters to produce a more sophisticated mathematical model.
  • New option to create new buttons in the GUI that are associated with user scripts. These buttons can be used to automate repetitive tasks, connect to repositories, etc.
  • Methods for variables of type STRING and FILEPATH that permit any type of operation with strings.
  • Improved simulation logs.
  • Advanced generation of residues for producing more optimal C++ code for the calculation of the Jacobian.
  • Complete workspaces can now be packed in one unique file up (.pke) to 10 times faster than in previous version.
  • Direct access to table/map editor from the object editors of the schematic.
  • INIT block of experiment now admits any sequential statement.
  • New global variable INSTANCE_NAME that returns the actual instance name.
  • Save/restore complete simulation state in binary HDF5 format.
  • Improved connection with Excel.
  • Improved manuals with more manuals better formatting.
  • More than 150 SPRs solved.

Optimum Trim of an Experimental Hypersonic Glider with EcosimPro

An interesting paper has been uploaded from Victor F. Villace (ESA) and Sergey A. Takovitskii (TsAGI). The subject is about the calculation of an optimum trim of an experimental hypersonic glider with EcosimPro and a new library based on the EcosimPro FLIGHT_SIM library.

Single point trimming of the hypersonic glider is not sufficient to accomplish the mission requirements The research shows that drifts of +/-4% around the centre of gravity imply large penalties on the aerodynamic efficiency along the intended glider trajectory, unless that the vehicle control is optimised for each particular case.

Papers from the Space Propulsion Conference in Seville (May-2018)

As in previous editions, the 2018 Space Propulsion Conference held in Seville (Spain) last May was once again a meeting place for users of EcosimPro/ESPSS. The customary user workshop was held as usual to present new features and upcoming developments as well as to gather suggestions from users. The technical sessions included several papers based on using ESPSS, showing its usefulness and confirming the users’ ongoing interest in this software. Examples of the papers given include the following: design of a round-trip mission to the moon with a hybrid propulsion rocket (DLR), research into two-phase cryogenic flows and their application to liquid propulsion rockets (Ariane Group), the passivation of helium remaining in orbiting satellite propulsion systems (OHB), implementation of a two-phase pipe in ESPSS (VKI), and the development of an innovative system for regulating xenon for electrical propulsion (Air Liquide). The articles mentioned here along with many other papers on space propulsion are available in the “Papers” section of this website.