Space exploration is one of the boldest quests humanity has ever undertaken. In order to successfully send astronauts to space and return them safely to Earth, aerospace engineers have to simulate the complex aeroheating environment surrounding the vehicles upon reentry into the Earth’s atmosphere. Accurate prediction of the heatflux and aerodynamic forces on the surface of the vehicle are crucial to the success of robotic missions and to the safety of the astronauts on board manned missions. In the AEROSPACEPHYS ERC StG project, the team identified a series of complex coupling mechanisms between the flow, radiation, and material response fields surrounding atmospheric entry vehicles.
One successful outcome of the ERC StG was the development of a new software library called Mutation++: MUlticomponent Thermodynamic And Transport properties for IONized gases in C++. The library packages the state-of-the-art data, physico-chemical models, and algorithms developed into a highly extensible and robust software designed to be coupled to simulation tools used by space agencies and industries. The design of Mutation++ allows for high-performance integration in the aforementioned simulation tools by their respective developers. Since Mutation++ is designed to be an extensible framework, its use is not limited to atmospheric entry problems. Technological transfer to various fields, e.g. plasma physics, biomass energy recovery, and fire safety, was envisaged from the beginning. The code is available to the open source community through a public release under an LGPLv3 license on a dedicated website. Taking community development to the next level required the improvement and enrichment of the software testing framework and database, giving new users development guidelines and technology transfer examples. The MUTX project has allowed us to extend the user base of MUTATION++ to the corporate community.
The overall aim of the MUTX project was to characterize and improve the value proposition of the open-source library Mutation++. The project was divided into three parts. The first part focused on improving the code design and development framework of the library, by creating a new unit and regression testing framework, developing collaborative coding practices and documentation guidelines, as well as setting up a new Gitlab server to host the library, providing support for continuous integration. In the second part, Mutation++ was coupled with the Porous Media Analysis toolbox (PATO) and used to define two numerical test cases - one related to aerospace and the other to biomass valorization - in an effort to demonstrate the versatility and capabilities of the library. Experiments were conducted to derive new quantitative models of the pyrolysis kinetics of two materials: ZURAM, an ablative thermal protection material, and wood from a niaouli tree. Using this data, new input files were created for two test cases in PATO to simulate the 1D pyrolysis of both materials. Finally, the third part of the project was devoted to defining the so-called exploitation plan in order to help direct future development efforts in the library and to study its possible valorization. An extensive competitive analysis and a 5-year business plan, based on the consortium model, have been created.
