Version française
RSS feeds
Home > Expertise > Research divisions > Applied Physical Chemistry and Mechanics > Pushing back the boundaries of parallelization

Applied Physical Chemistry and Mechanics

Pushing back the boundaries of parallelization

The numerical simulation and HPCa professions have benefited significantly from technological advances in the field of processors, particularly multi-core architectures, in recent decades.

The parallelization methods employed to enhance the performance of numerical calculation are useful but their efficiency decreases as the degree increases. To overcome this limitation, IFPEN’s researchers have developed pragmatic approaches.

Two examples, implemented on IFPEN’s Grains3D and PeliGRIFF computational codes respectively, illustrate their approach:

  • The first consisted in developing specific methods (for example, applied to domain decomposition techniquesb) aimed at optimizing the “efficiency” of HPC calculations, thereby avoiding the additional costs associated with inter-processor communications. For the biggest system studiedc, the performance obtained for 768 cores(1) (figure) was around 91% of the ideal case.
  • A second method was based on a multiscale strategy(2), consisting in modeling and solving physical problems on a small scale, before transferring data filtered using statistical approaches to larger scales via cascading.

This approach was successfully used in 2015 within the context of the ANR’s MORE4LESS collaborative project, dedicated to the multiscale modeling of reactive particle flows.


a - High Performance Computing.
b - Separation into coupled sub-problems, defined for smaller domains forming a division of the global domain.
c - Around 230 million fluidized particles.
d - Standardized for a complete knot of 16 cores.


Scientific contact:

Published in Science@ifpen n°33 - June 2018


  1. A. D. Rakotonirina, A. Wachs, Grains3D, a flexible DEM approach for particles of arbitrary convex shape - Part II: Parallel implementation and scalable performance, Powder Technology, 2015, 154-172.
    >> DOI: 10.1016/j.powtec.2017.10.033
  2. A. Esteghamatian, F. Euzenat, A. Hammouti, M. Lance, A. Wachs, A stochastic formulation for the drag force based on multiscale numerical simulation of fluidized beds, International Journal of Multiphase Flow.
    >> DOI: 10.1016/j.ijmultiphaseflow.2017.11.003

links list

  • Print page