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Code Coupling and User Interface


CERFACS has a strong expertise in the development and use of generic code coupling libraries.The couplers developed at CERFACS are daily used to address complex scientific problems such as:

Chemistry-Atmosphere coupling with OASIS

Chemistry-Atmosphere coupling with OASIS

  • earth system modelisation for climate science
  • multiphysics coupling (heat transfer, fluid/structure interaction …)
  • multi-composant coupling
  • data assimilation
  • multidisciplinary optimization

All these applications rely on the integration of different solvers that interact at different levels between each others following coupling algorithms.


OASIS and OpenPALM couplers are used to make modular and evolutive coupled applications in a user friendly way. The domains of applications go from many types of research fields to industrial uses.

Any type of code can be coupled with different languages (Fortran, C, C++, Python, Perl, R, …) and type of parallelization (from mono-processor to massively parallel). Coupling of commercial solvers is performed thanks to TCP/IP protocols through user defined functions.

Both coupling libraries provide interpolation functionalities when quantities to exchanges are discretized on different meshes. In OASIS, the interpolation is dedicated to geophysical applications while OpenPALM provide a more generic interpolation framework based on an unstructured mesh formalism thanks to the CWIPI library developed by ONERA.

Both OASIS and OpenPALM runs on high performance computers where computation times as well as parallel data exchanges are optimized in order to not penalize the speed up of massively parallel codes.

ESCAPADE project with OpenPALM

ESCAPADE project with OpenPALM

Associated with the Graphical User Interface generator OpenTea, OASIS and OpenPALM are daily used by Cerfacs and its partners involving academic laboratories as well as industrial companies. OASIS and OpenPALM are distributed under the OpenSource license LGPL.

About two training per year are proposed for Oasis and OpenPalm. OASIS and OpenPALM are still under development following users’ requests as well as optimizations and bug corrections. The funding of these actions rely on different collaborations through industrial, national or european projects.


First 360-degrees Large-Eddy Simulation of a full engine

Jérôme DOMBARD |  17 June 2020

Within the PRACE project FULLEST (First fUlL engine computation with Large Eddy SimulaTion), a joint collaboration between CERFACS, SAFRAN and AKIRA technologies, Dr. C. Pérez Arroyo (post doctoral fellow at CERFACS) has carried out under the supervision of Dr. J. Dombard the first high-fidelity simulation of a part of the real engine DGEN380 (for now, from the fan to the combustion chamber). This 360-degrees integrated large-eddy simulation contains around two billion cells on the three instances, carried out with the AVBP code of CERFACS.  The CPU cost is obviously large but still within reach, performing around one turn of fan during 5 days over 14400 skylake cores. Post-treatments are in progress and already show, among other complex phenomena, a strong interaction between the high pressure compressor and the combustion chamber (see forthcoming paper GT2020-16288 C. Pérez Arroyo et al). Below a video showing: in the fan an isosurface at mid-height of the vein colored by the Mach number, in the high pressure compressor a gradient of density, in the bypass of the combustion chamber the static pressure and in the flame tube a temperature field. One of the goals of the project is to create a high-fidelity unsteady database to study interactions between modules and may help other teams to develop new lower order models and/or validate existing ones. Beyond the feasibility and the maturity of the AVBP code, this kind of calculation is an important milestone for the aeronautical industry and would allow to apprehend earlier in the design the effect of integration and installation and thus, to reduce the cycle and therefore the cost of the future aircraft engines. We acknowledge PRACE for awarding us access to Joliot-Curie (Genci) hosted at CEA/TGCC, FRANCE, Safran Tech and DGAC fundings within the project ATOM, along with the invaluable technical support at...Read more

B. Cuenot distinguished as Program Chair of international Symposium on Combustion

superadmin |  29 May 2020

B. Cuenot has been distinguished as Program Chair for the 39th International Symposium on Combustion, to be held in Vancouver (Canada) in 2022. The International Symposium on Combustion is a major event for the combustion community, where the current best research is presented.Read more