Comprehensive Design Environment for Aeromechanics and Flight Mechanics Analysis

MAECOsim®

To address the ever increasing need for more predictive accuracy in the highly complex field of helicopter simulation, the Institute of Flight Systems of DLR together with the Institute for Software Technology are developing a new framework for low and medium fidelity simulations of rotary wing aircraft.

Codes like this are called comprehensive codes, because they encompass a multitude of disciplines. Single aircraft components or even only certain aspects of those components are described with very specialized numerical models which can be large or only a few lines of code. On the other hand, models might be used that encompass multiple aircraft components in a certain discipline. Moreover, a wide range of fidelity is required to support different simulation goals like conceptual and preliminary design, flight mechanics, real-time flight simulators, coupling with high fidelity methods and detailed aeromechanic simulation.

These unique requirements call for an extremely versatile framework which simultaneously allows for a high degree of specialization in the configuration, calculation, and analysis procedures. To address this need in a modern, future-proof way and to push the boundaries of current comprehensive rotorcraft simulations, MAECOsim® (Multibody – Aeromechanics – Comprehensive - Simulation, formerly "VAST") is being developed.

Among other areas of application MAECOsim® is being developed to act as a computational backbone of an integrated rotorcraft design and optimization chain. This drives the modular and parametric nature of the code.

Development

The development of MAECOsim® started in June 2016 in the framework of the DLR Project VicToria and will continue amongst others in the framework of the LuFo project eVOLve and the DLR project UrbanRescue.  Many of the application areas mentioned in the first paragraph will only be available in the future. Currently, the implemented models cater more to the low-fidelity end of the simulation spectrum, such as flight-mechanics in preliminary design. The main reason for this is that the flexible structural models are still in development.

What makes MAECOsim® a particularly capable comprehensive code is its use of true multi-body-simulations for the mechanical structure. This makes the code suitable for virtually any configuration in any state of operation.

Architecture

MAECOsim® is a multi-physics, multi-model simulation program with a very modular and generic approach. The architecture is strictly divided between simulation framework and the actual implementation of physics. It is being developed for helicopter aeromechanic calculations but the Simulation Core, the User Interface, the Configuration, the IO (Input/Output) - in short, the entire simulation framework is developed in such a way that it could be used for any numerical simulation field requiring multi-model-simulation. Apart from physical models, there are tasks implemented in the framework both completely generically like the transient solution through time and specific to the use-case like the free-flight trim of a helicopter.

The main design idea is to divide a simulation problem into different disciplines and to model their respective sub-problems in separate models, which are then connected and simulated in conjunction with each other.

All sub-models are formulated in a generic state-space-form with input, output and states as well as dynamics and output equations.

MAECOsim® is a new framework but many of its models are sourced from other simulation programs of the DLR’s Institute of Flight Systems, for example S4. However, almost all code has been entirely rewritten to meet the demands of MAECOsim® and current software development standards. The code is being developed with a strong focus on unit and system tests, and its integrity is safeguarded by a continuous integration framework. The validation/verification test-matrix is continuously enhanced and automatically recomputed, making the current level of accuracy always readily available.

Disclaimer

MAECOsim® is a research code. No guarantee for completeness or correctness can be given. Also, it is under heavy development. Every version of MAECOsim® has to be seen as pre-alpha. This means that users will most likely discover inconveniences and errors when using this code. Also, many features expected as a matter of course of aeromechanic codes are still missing. Also, the documentation is far from complete. The upside of this is that bug-reports and (at least smaller) usability feature-requests are very likely to be corrected/implemented with little delay. The MAECOsim®-team endeavors to make the code better every day. So tell us what you need and we will do our best to make it happen!

Use MAECOsim®

If you would like to know how you can use MAECOsim® for your own research or have further questions, please contact us. Please use the contact field below.

Publications

  • Michels, Benedikt und Seelemeyer, Philipp (2024) VAST as a generic, modular aeromechanics code for wind turbine simulation. Journal of Physics: Conference Series, 2767 (5), -052023. Institute of Physics (IOP) Publishing. doi: 10.1088/1742-6596/2767/5/052023. ISSN 1742-6588.

  • F. Weiss, „Drivetrain Influence on the Lead-Lag Motion of Helicopter Rotors“, presented at the 34th Congress of the International Council of the Aeronautical Sciences, Florence, Italy, 9. Sep 2024.

  • F. Weiss, „Prediction of Structural Rotor Loads: When to Consider Drivetrain Dynamics?”, in Vertical Flight Society’s 80th Annual Forum & Technology Display, Montréal, Québec, Canada, Mai 2024.

  • F. Weiss und J. Merlis, „Beam modeling in a floating frame of reference for torsion dynamics of helicopter rotor blades“, Multibody Syst Dyn, Apr. 2024, doi: 10.1007/s11044-024-09986-0.

  • F. Weiß, „Einfluss des Triebstrangs auf die Schwenkbewegung von Hubschrauberrotoren“, DGLR-Magazin „Luft- und Raumfahrt“, Nr. 2/2024, S. 42–45, April 2024.

  • R. K. Majeti, F. Becker, und F. Weiss, „Cross-Sectional Sizing of Rotor Blades with Dynamics and Strength Constraints“, in Vertical Flight Society’s 6th Decennial Aeromechanics Specialists’ Conference, Santa Clara, CA, USA, Feb. 2024.

  • F. Weiss und J. Merlis, „Beam Modeling in a Floating Frame of Reference for Torsion Dynamics of Helicopter Rotor Blades“, in ECCOMAS Thematic Conference on Multibody Dynamics, Lisbon, Portugal, July 2023.

  • F. Weiß, „Einfluss des Triebstrangs auf die Schwenkbewegung von Hubschrauberrotoren“, in Deutscher Luft- und Raumfahrtkongress 2023, Stuttgart, Germany, Sep 2023, doi: 10.25967/610514.

  • F. A. Weiß, „Einfluss des Triebstrangs auf die Schwenkbewegung von Hubschrauberrotoren“, Dissertation, TU Braunschweig, 2022. doi: 10.57676/W1KC-SG83.

  • F. Weiss, J. Merlis, R. Lojewski, J. Hofmann, und M. Roehrig-Zoellner, „Rotor Blade Modeling in a Helicopter Multi Body Simulation Based on the Floating Frame of Reference Formulation“, in 48th European Rotorcraft Forum, Winterthur, Switzerland, Sep. 2022.

  • Hofmann, Johannes und Mindt, Maximilian und Weiß, Felix Armin (2021) AERODYNAMIC AND STRUCTURAL MODELING IN THE ROTORCRAFT MULTI-PHYSICS SIMULATION VAST. International Council of the Aeronautical Sciences. 32nd Congress of the International Council of the Aeronautical Sciences, 06.-11. Sep. 2021, Shanghai, China. ISBN 978-3-932182-91-4.canccc

  • Hofmann, Johannes und Weiß, Felix Armin und Mindt, Maximilian (2021) A New Approach to Comprehensive Rotorcraft Aeromechanics Simulation. 77th Annual Vertical Flight Society Forum and Technology Display: The Future of Vertical Flight, FORUM 11.-13. Mai 2021, Palm Beach, Florida, USA. ISBN 978-171383001-6.

  • Hofmann, Johannes und Kontak, Max und Mindt, Maximilian und Weiß, Felix Armin (2020) VAST - VERSATILE AEROMECHANICS SIMULATION PLATFORM FOR HELICOPTERS. Deutscher Luft- und Raumfahrtkongress 2020, 1.-3.9.2020, Aachen.

  • Kontak, Max und Röhrig-Zöllner, Melven und Hofmann, Johannes und Weiß, Felix Armin (2019) Automatic Differentiation in Multibody Helicopter Simulation. In: Proceedings of the 9th ECCOMAS Thematic Conference on Multibody Dynamics, Multibody Dynamics 15.-18. Juli 2019, Duisburg, Deutschland. 53, Seiten 534-542. Springer International Publishing. doi: 10.1007/978-3-030-23132-3_64. ISBN 978-3-030-23131-6. ISSN 1871-3033.

  • Weiss, Felix; Kessler, Christoph: Drivetrain Influence on the Blade Loads of Hingeless Helicopter Rotors. In: VFS 75th Annual Forum. Philadelphia, Pennsylvania, USA, Mai 2019

  • Weiss, Felix; Kessler, Christoph: Load prediction of hingeless helicopter rotors including drivetrain dynamics. In: CEAS Aeronautical Journal 12 (2021), Nr. 2, S. 215–231

  • Hofmann, Johannes; Roehrig-Zoellner, Melven; Weiss, Felix; Lojewski, Reinhard; Rieser, Jasper; Mindt, Maximilian; Gatter, Alexander; Klitz, Margrit; Schmierer, Lukas; Thangavel, Sakthivel: VAST - Flexible Aeromechanics Simulation Platform for Helicopters. Präsentation auf dem 67. Deutscher Luft- und Raumfahrtkongress. Friedrichshafen, Deutschland, September 2018

Contact

Project team MAECOsim®