MUSICA project - Multi-Site Coupled Simulation for Advanced collaborative design
In the scope of the European Union Horizon2020 CleanSky mission, Cadence (formerly Numeca) is working together with Airbus on the MUlti-SIte Coupled simulation for Advanced collaborative design (MUSICA) project.
Background
The use of multiple CFD solvers to resolve complex engineering simulation tasks, is common practice nowadays. Such an approach is extensively used for multiphysics simulations, where various specialized solvers are combined to be able to analyze the interaction of different physical phenomena and their influence on the global behavior of the design. Typical applications are fluid-structure interaction (FSI) studies, aero-acoustic analysis and optimization frameworks.
A lot less common is the application of a coupling approach for heterogeneous CFD solvers, as this requires a conservative interpolation of flow quantities at the connection interface between the computation domains. To set up such simulations, the connecting interface between solvers needs to be properly defined and the meshes need to have the exact same geometrical position. As the different solvers are usually used in completely different environments, this is seldom the case, and engineers often need to spend a considerable amount of time trying to make the meshes fit the interface.
- The first objective of the MUSICA project is to extend the Omnis™ collaborative platform with a conservative coupling library and to open this to the community. Scientists and industrials will be able to couple their solvers to the platform, enabling in-situ code-to-code coupling with other solvers, while leveraging all the benefits of the integrated platform.
- The second objective is to allow secure site-to-site coupling through the public internet, without sharing intellectual property. By design, sensitive data are kept private within each organization's perimeters, while only the required coupling data are shared through the interfaces.
Project information:
Grant agreement ID: 887148
Funded under H2020-EU.3.4.5.1.
Overall budget €872,500
An integrated platform
The Omnis platform comes with a variety of CAD tools, automatic meshing software systems Hexpress™ and Autogrid™ and integrated co- & post-processing features, and it links directly to all Cadence and other CFD solvers. The environment allows users to read-in and clean their CAD, prepare domains and meshes and launch simulations in a fast, easy and consistent way. The platform enables handling of multiple geometry designs and parameterizations, multiple domains and meshes and multiple solvers in a multi-users, collaborative way, oriented towards multidisciplinary (CFD, FSI, CAA) applications.
Furthermore, the Omnis platform takes advantage of a full multi-threaded and distributed architecture, running on Linux and Windows, LAN computers, HOC centers or cloud. User collaboration is based on a peer-to-peer model, where tcp connections between processes are established on demand. Within a given project, the system relies on a client-server architecture to distribute tasks to computation processes.
Omnis™
The traditional approach for heterogeneous co-simulations relies on principles where each simulation set-up is performed in totally different environments for each solver. While this approach minimizes the work of the integrators, it leaves all the burden to the users who need to spend a considerable amount of time to set up simulations and make sure that they are consistent. Furthermore, as the project is spread across heterogeneous tools, it is difficult to keep global coherency on the longer run, for example for archiving.
Using the Omnis integrated platform's consistent interface to setup all simulations, greatly reduces set-up time and complexity and provides ready-to-use inspection tools.
Intellectual property protection
Heterogeneous co-simulations set-up and management complexity get exacerbated when the tools and codes are manipulated by different organizations. Each partner needs to regularly exchange data to study the impact of other's simulations on theirs, while protecting confidential data and know-how is of the utmost importance.
The MUSICA project will extend the Omnis platform to allow co-simulation across independent projects. Each domain specialist within a given organization will use Omnis to set up his/her part of the computation within a local project. He/she will then define external coupling boundaries that will be linked to external coupling boundaries of other projects. Specific tools will be developed to share coupling boundary data and to ensure that the matching of coupling boundaries is consistent before co-simulation starts. The simulation set-up data and results of each part of a collaborative simulation, will be stored and remain within the private organizations.
Site-to-site coupling
The MUSICA project will extend the Omnis platform to allow co-simulation with solvers running in different locations across public networks. The platform will be able to establish a secure and encrypted connection between two end-points in order to exchange coupling boundary data at regular intervals. In our demo case, both end-points are compute nodes of distinct HPC centers. They are behind firewalls and NAT devices and do not have direct access to the internet. The project will favor a durable solution, compliant with IT policies of both sites, requiring minimum administrator intervention and based on industry best practices, tools and services.
The Omnis platform will be extended with tools to manage site-to-site co-simulation: involving site configurations, remote matching of coupling boundaries, control of the co-simulation data exchange rate, start, stop and pause of the simulations, possibility to share some extra data with the remote site like convergence of the simulation, etc...
Target use case
A multi-site co-simulation will be realized with an airframe and fan geometry representative of a commercial aircraft. Typically, the entity responsible for the airframe does not have access to the fan geometry and vice versa. Then a sensitivity study will be performed by varying one or two design parameters for both fan and airframe. Results will be analyzed together with Airbus to validate the coupling platform.
Conclusion
MUSICA proposes a collaborative, multi-site environment, where the whole coupled simulation project definition and set-up is realized in the consistent interface of the open platform Omnis, but where proprietary data and the simulation runs are kept in remote organizations.
It is believed that through the challenging developments in MUSICA, a unique open platform will become available that will favor the collaboration between heterogeneous organizations that each have their own expertise and tools, thereby bringing CAE simulations to the next level.