Modernization and optimization of a legacy open-source CFD code for high-performance computing architectures

Aytekin Gel, Jonathan Hu, El Moustapha Ould-Ahmed-Vall, Alexander A. Kalinkin

Research output: Contribution to journalArticlepeer-review

5 Scopus citations


Legacy codes remain a crucial element of today's simulation-based engineering ecosystem due to the extensive validation process and investment in such software. The rapid evolution of high-performance computing architectures necessitates the modernization of these codes. One approach to modernization is a complete overhaul of the code. However, this could require extensive investments, such as rewriting in modern languages, new data constructs, etc., which will necessitate systematic verification and validation to re-establish the credibility of the computational models. The current study advocates using a more incremental approach and is a culmination of several modernization efforts of the legacy code MFIX, which is an open-source computational fluid dynamics code that has evolved over several decades, widely used in multiphase flows and still being developed by the National Energy Technology Laboratory. Two different modernization approaches,‘bottom-up’ and ‘top-down’, are illustrated. Preliminary results show up to 8.5x improvement at the selected kernel level with the first approach, and up to 50% improvement in total simulated time with the latter were achieved for the demonstration cases and target HPC systems employed.

Original languageEnglish (US)
Pages (from-to)122-133
Number of pages12
JournalInternational Journal of Computational Fluid Dynamics
Issue number2
StatePublished - Feb 7 2017


  • Computational fluid dynamics (CFD)
  • MFIX
  • Trilinos project
  • Xeon Phi
  • code modernization
  • code refactoring
  • high-performance computing
  • legacy software
  • many cores
  • reacting multiphase flow simulations

ASJC Scopus subject areas

  • Computational Mechanics
  • Aerospace Engineering
  • Condensed Matter Physics
  • Energy Engineering and Power Technology
  • Mechanics of Materials
  • Mechanical Engineering


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